JP4809715B2 - Photoelectric conversion device, manufacturing method thereof, and semiconductor device - Google Patents

Description

  The present invention relates to a photoelectric conversion device, and more particularly to a photoelectric conversion device including a thin film semiconductor element and a manufacturing method thereof. In addition, the present invention relates to an electronic device using a photoelectric conversion device.

  Many photoelectric conversion devices generally used for electromagnetic wave detection are known. For example, devices having sensitivity from ultraviolet rays to infrared rays are collectively called optical sensors. Among them, those having sensitivity in the visible light region with a wavelength of 400 nm to 700 nm are particularly called visible light sensors, and are used in many devices that require illuminance adjustment and on / off control according to the human living environment. .

  Particularly in a display device, the brightness around the display device is detected and the display luminance is adjusted. This is because it is possible to reduce wasteful power and improve visibility by detecting ambient brightness and obtaining appropriate display brightness. For example, such an optical sensor for adjusting luminance is used in a mobile phone or a personal computer (see, for example, Patent Document 1).

  Further, not only the brightness of the surroundings but also the brightness of the backlight of a display device, particularly a liquid crystal display device, is detected by an optical sensor to adjust the brightness of the display screen (for example, Patent Document 2 and Patent Document 3). reference).

  In a display device using a projector, the convergence is adjusted using an optical sensor. Convergence adjustment is adjustment of an image so that the image of each color of RGB does not shift. The position of the image of each color is detected using an optical sensor, and the image is arranged at the correct position (see, for example, Patent Document 4).

  A conventional photoelectric conversion device is shown in FIG. In FIG. 2, an electrode 1002 is formed over a substrate 1001, and a p-type semiconductor layer 1003, an intrinsic semiconductor layer (also referred to as an i-type semiconductor layer) 1004, and an n-type semiconductor layer 1005 that serve as a photoelectric conversion layer are formed over the electrode 1002. Has been. An electrode 1006 is formed on the n-type semiconductor layer 1005. Further, an insulating film 1007 covering the electrodes 1002 and 1006 is formed. Further, a first extraction electrode 1012 connected to the electrode 1002 and a second extraction electrode 1013 connected to the electrode 1006 are formed over the insulating film 1007.

  However, it has been found that the photoelectric conversion device having the structure of FIG. 2 may generate a leakage current when operated for a long time. The occurrence of this leakage current is due to the fact that cracks 1021 are formed in corner portions (stepped portions) of the photoelectric conversion layer, particularly i-type semiconductor layer 1004, and that portion becomes a leak path.

FIG. 22 shows an electron micrograph of the conventional structure. In FIG. 22, it can be seen that cracks are generated at corner portions (stepped portions) of the i-type semiconductor layer. If the electric field concentrates on the crack, it may cause defects such as generation of leakage current.
JP 2003-60744 A Japanese Patent No. 3171808 Japanese Patent No. 3193315 JP 2003-47017 A

  It is an object of the present invention to manufacture a photoelectric conversion device that prevents electric field concentration at the corner portion of the photoelectric conversion layer and suppresses generation of leakage current.

  In the photoelectric conversion device of the present invention, by removing a part of the upper layer and the middle layer of the photoelectric conversion layer, it is possible to prevent concentration of an electric field in a corner portion and suppress a leakage current.

  The present invention provides a first electrode on a substrate, a first semiconductor layer of one conductivity type on the first electrode, a second semiconductor layer, and a conductivity type opposite to the one conductivity type. A photoelectric conversion layer having a third semiconductor layer, wherein a part of an end portion of the first electrode is covered with the first semiconductor layer. It is.

  In the present invention, the first semiconductor layer covers an end portion of the first electrode, an insulating film is formed on the third semiconductor layer, and an insulating film is formed on the insulating film via the insulating film. And a second electrode electrically connected to the third semiconductor layer, and the region of the photoelectric conversion layer that is not covered with the insulating film is the second semiconductor layer and the third semiconductor layer. A part of has been removed.

  The present invention also includes a first electrode on a substrate, a first semiconductor layer of one conductivity type on the first electrode, and a second semiconductor layer on the first semiconductor layer. 1 structure, the first semiconductor layer on the substrate, the second semiconductor layer on the first semiconductor layer, and the first semiconductor layer on the second semiconductor layer. A second structure having a third semiconductor layer of opposite conductivity type and a second electrode on the third semiconductor layer, wherein the first electrode and the first semiconductor layer The contact portion and the contact portion between the third semiconductor layer and the second electrode are separated from each other.

  According to the present invention, a first electrode is formed on a substrate, and the first semiconductor film of one conductivity type, the second semiconductor film, and the one conductivity type are opposite to each other on the first electrode. A method of manufacturing a photoelectric conversion device, wherein a third semiconductor film of a conductive type is formed, and a part of an end portion of the first electrode is covered with the first semiconductor layer. is there.

  According to the present invention, a first electrode is formed on a substrate, and the first semiconductor film of one conductivity type, the second semiconductor film, and the one conductivity type are opposite to each other on the first electrode. A third semiconductor film of the conductivity type is formed, a second electrode is formed on the third semiconductor film, and the substrate, the first semiconductor film, the second semiconductor film, and the third semiconductor film are formed. The semiconductor film and the second electrode include the first electrode on the substrate, the first semiconductor layer of one conductivity type on the first electrode, and the second electrode on the first semiconductor layer. A first structure having a semiconductor layer, the first semiconductor layer on the substrate, the second semiconductor layer on the first semiconductor layer, and the second semiconductor layer, A second structure having a third semiconductor layer having a conductivity type opposite to that of the first semiconductor layer, and a second electrode on the third semiconductor layer, the first electrode comprising: Serial contact portion of the first semiconductor layer, the contact portion of the third semiconductor layer and the second electrode is related to a method for manufacturing a photoelectric conversion device, characterized in that apart.

  According to the present invention, a first electrode is formed on a substrate, and the first semiconductor film of one conductivity type, the second semiconductor film, and the one conductivity type are opposite to each other on the first electrode. A third semiconductor film of the conductivity type is formed, a first conductive film is formed on the third semiconductor film, and the first semiconductor film, the second semiconductor film, and the third semiconductor film are formed. Forming a first island-shaped semiconductor film, a second island-shaped semiconductor film, a third island-shaped semiconductor film, and a first island-shaped conductive film using the semiconductor film and the first conductive film; and A part of the first electrode is exposed, a second conductive film is formed using the first island-shaped conductive film, and the second island-shaped film is formed using the second island-shaped conductive film as a mask. A part of the semiconductor film and a part of the third island-like semiconductor film are removed, and the first island-like semiconductor film is used as a first semiconductor layer of a photoelectric conversion layer, and the part of the semiconductor film is removed. The island-shaped semiconductor film is the second semiconductor layer of the photoelectric conversion layer, and the third island-shaped semiconductor film from which the part has been removed is the third semiconductor layer of the photoelectric conversion layer, and the exposed first Covering the electrode, the first semiconductor layer of the photoelectric conversion layer, the second semiconductor layer of the photoelectric conversion layer, and the third semiconductor layer of the photoelectric conversion layer, and forming an insulating film in the insulating film Are formed with a first groove and a second groove reaching the exposed first electrode and the second conductive film, respectively, and the first groove and the second groove are formed on the insulating film, respectively. And forming a second electrode and a third electrode which are electrically connected to the first electrode and the second conductive film, respectively, through a method for manufacturing a photoelectric conversion layer.

  Further, the present invention includes a photoelectric conversion element and an amplifier circuit that amplifies the output value of the photoelectric conversion element on a substrate, and the photoelectric conversion element is on the first electrode and the first electrode. A photoelectric conversion layer having a first semiconductor layer of one conductivity type, a second semiconductor layer, and a third semiconductor layer of a conductivity type opposite to the one conductivity type; and on the third semiconductor layer , An insulating film, and a second electrode electrically connected to the third semiconductor layer via the insulating film on the insulating film, and the first semiconductor layer includes the first semiconductor layer In the region of the photoelectric conversion layer that is not covered with the insulating film, a part of the second semiconductor layer and the third semiconductor layer are removed, and the amplification layer is covered. The circuit includes a plurality of thin film transistors, and each of the plurality of thin film transistors includes a source region, a drain region, and a chip. An island-shaped semiconductor region including a channel formation region, a gate insulating film, a gate electrode, a source electrode electrically connected to the source region, and a drain electrode electrically connected to the drain region. The present invention relates to a semiconductor device characterized by the above.

  In the present invention, the substrate is a flexible substrate.

  In the present invention, the flexible substrate is any one of a polyethylene naphthalate (PEN) film, a polyethylene terephthalate (PET) film, a polybutylene naphthalate (PBN) film, a polyimide (PI) film, and a polyamide (PA) film. One.

  In the present invention, the substrate is a glass substrate.

  In the present invention, a color filter is provided between the substrate and the first semiconductor layer.

  In the present invention, each of the source electrode and the drain electrode has a laminated film structure.

  In the present invention, the laminated film is a film in which a titanium (Ti) film, an aluminum (Al) film containing a small amount of silicon (Si), and a titanium (Ti) film are laminated.

  In the present invention, each of the source electrode and the drain electrode is a single layer film.

  In the present invention, the single layer film includes titanium (Ti), tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co), zirconium (Zr), zinc (Zn), An element selected from ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), or an alloy material or a compound material containing the element as a main component A single-layer film or a single-layer film made of these nitrides, for example, titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride.

  The photoelectric conversion device of the present invention can suppress leakage current. Therefore, according to the present invention, a photoelectric conversion device with high reliability and low power consumption can be obtained. In addition, an electric device incorporating such a photoelectric conversion device can have high reliability.

  The photoelectric conversion device of the present invention will be described with reference to FIGS. 1, 4A to 4C, 5A to 5B, and 6A to 6B. To do. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

  A manufacturing process of the photoelectric conversion device of the present invention is described below. First, the first conductive film 151 is formed over the substrate 101 (see FIG. 4A).

  A flexible substrate is used as the substrate 101, and specifically, a polyethylene naphthalate (PEN) film is used. Besides polyethylene naphthalate, films of polyethylene terephthalate (PET), polybutylene naphthalate (PBN), polyimide (PI), polyamide (PA), etc. may be used. Further, a glass substrate may be used as the substrate 101.

  As the first conductive film 151, titanium (Ti), tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), aluminum (Al), gold (Au), silver (Ag), copper (Cu) Or a single layer film made of an alloy material or a compound material containing the element as a main component, or a single layer film made of a nitride thereof, for example, titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride. be able to.

As the first conductive film 151, a transparent conductive film material may be used. As such a transparent conductive film material, an indium tin oxide alloy containing silicon (Si) (also referred to as indium tin oxide containing Si) may be used. In addition to the indium tin oxide alloy containing Si, a target in which zinc oxide (ZnO), tin oxide (SnO ₂ ), indium oxide, and indium oxide are further mixed with 2 to ₂₀ wt% zinc oxide (ZnO) is used. An indium oxide-zinc oxide alloy formed in this manner may be used. Alternatively, ZnO (GZO) doped with Ga ₂ O ₃ , ZnO (AZO) doped with Al ₂ O ₃ , or ZnO (SZO) doped with SiO ₂ may be used. GZO, AZO, and SZO are useful in that they do not oxidize silicon.

  Next, the electrode 102 is formed using the first conductive film 151 (see FIG. 4B).

  After the electrode 102 is formed, a p-type semiconductor film 152 is formed. In this embodiment, for example, a p-type amorphous semiconductor film is formed as the p-type semiconductor film 152. As the p-type amorphous semiconductor film, an amorphous silicon film containing an impurity element belonging to Group 13 such as boron (B) is formed by a plasma CVD method.

  After the p-type semiconductor film 152 is formed, a semiconductor film (intrinsic semiconductor film or i-type semiconductor film) 153 that does not contain an impurity imparting conductivity type and an n-type semiconductor film 154 are sequentially formed. In this embodiment mode, the p-type semiconductor film 152 is formed to a thickness of 10 to 50 nm, the i-type semiconductor film 153 is formed to a thickness of 200 to 1000 nm, and the n-type semiconductor film 154 is formed to a thickness of 20 to 200 nm.

  As the i-type semiconductor film 153, an amorphous silicon film may be formed by a plasma CVD method, for example. As the n-type semiconductor film 154, an amorphous silicon film containing a 15 group impurity element such as phosphorus (P) may be formed, or an amorphous silicon film may be formed and then an 15 group impurity element may be introduced. Good.

  Note that the p-type semiconductor film 152, the i-type semiconductor film 153, and the n-type semiconductor film 154 may be stacked in the reverse order, that is, the n-type semiconductor film, the i-type semiconductor film, and the p-type semiconductor film are stacked in this order. May be.

  Further, as the p-type semiconductor film 152, the i-type semiconductor film 153, and the n-type semiconductor film 154, not only an amorphous semiconductor film but also a semi-amorphous semiconductor film may be used.

Note that a semi-amorphous semiconductor film is a film including a semiconductor having a structure intermediate between an amorphous semiconductor and a semiconductor (including single crystal and polycrystal) films having a crystal structure. This semi-amorphous semiconductor film is a semiconductor film having a third state that is stable in terms of free energy, and is a crystalline film having short-range order and lattice distortion, and has a grain size of 0.5 to 20 nm. And can be dispersed in the non-single-crystal semiconductor film. The semi-amorphous semiconductor film has its Raman spectrum shifted to a lower wavenumber than 520 cm ⁻¹ , and diffraction peaks of (111) and (220) that are derived from the Si crystal lattice are observed in X-ray diffraction. The Further, in order to terminate dangling bonds (dangling bonds), at least 1 atomic% or more of hydrogen or halogen is contained. In this specification, for convenience, such a semiconductor film is referred to as a semi-amorphous semiconductor (SAS) film. Further, by adding a rare gas element such as helium, argon, krypton, or neon to further promote lattice distortion, stability is improved and a good semi-amorphous semiconductor film can be obtained. Note that a microcrystalline semiconductor film is also included in the semi-amorphous semiconductor film.

The SAS film can be obtained by glow discharge decomposition of a gas containing silicon. A typical gas containing silicon is SiH ₄ , and Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , SiF _{4, and the} like can also be used. In addition, it is easy to form a SAS film by diluting the gas containing silicon with hydrogen or a gas obtained by adding one or more kinds of rare gas elements selected from helium, argon, krypton, and neon to hydrogen. Can be. It is preferable to dilute the gas containing silicon in a range of a dilution rate of 2 to 1000 times. Furthermore, a gas containing silicon, a carbide gas such as CH ₄ or C ₂ H ₆ , a germanium gas such as GeH ₄ or GeF ₄ , F _2, or the like is mixed, so that the energy bandwidth is 1.5-2. It may be adjusted to .4 eV, or 0.9 to 1.1 eV.

  Next, a second conductive film 155 is formed over the n-type semiconductor film 154 by a sputtering method or the like (see FIG. 4C). Note that the second conductive film 155 may be formed using a material similar to that of the first conductive film 151.

  Next, using the p-type semiconductor film 152, the i-type semiconductor film 153, the n-type semiconductor film 154, and the second conductive film 155 as masks, island-shaped semiconductor films, that is, the p-type semiconductor layer 103 and the i-type semiconductor layer, respectively. 161, an n-type semiconductor layer 162, and a third conductive film 156 which is an island-shaped conductive film are obtained (see FIG. 5A).

  Next, the electrode 106 is formed using the third conductive film 156 (see FIG. 5B).

  Using the electrode 106 as a mask, part of the n-type semiconductor layer 162 and part of the i-type semiconductor layer 161 are etched to form the i-type semiconductor layer 104 and the n-type semiconductor layer 105 (see FIG. 6A). At this time, the etching time is adjusted so that the p-type semiconductor layer 103 is not etched. Since the i-type semiconductor film 153 is formed thick when the semiconductor film is formed, the etching stops in the middle of the i-type semiconductor layer 161. In other words, since the i-type semiconductor layer 161 serves as a mask for the p-type semiconductor layer 103 during etching, the n-type semiconductor layer 162 can be etched without etching the p-type semiconductor layer 103. By this etching, the n-type semiconductor layer 162 and the i-type semiconductor layer 161 which are not covered with the electrode 106 are partially removed. Thus, the photoelectric conversion layer 171 including the p-type semiconductor layer 103, the i-type semiconductor layer 104, and the n-type semiconductor layer 105 is formed.

  Next, an insulating film 107 having grooves 165 and 166 is formed over the electrode 106, the photoelectric conversion layer 171 and the electrode 102 by a screen printing method or the like. Alternatively, after forming an insulating film over the entire surface, the grooves 165 and 166 may be formed by a laser scribing method or the like (see FIG. 6B).

  Further, extraction electrodes 112 and 113 are formed in the grooves 165 and 166 (FIG. 1). The extraction electrodes 112 and 113 are formed by screen printing using a conductive paste. As the conductive paste, a conductive paste containing a metal material such as silver (Ag), gold (Au), copper (Cu), nickel (Ni), or a conductive carbon paste can be used. The extraction electrodes 112 and 113 may be formed by an ink jet method.

  A photoelectric conversion device illustrated in FIG. 1 includes a first portion in which an electrode 102, a p-type semiconductor layer 103, and an i-type semiconductor layer 104 are formed over a substrate 101, and a p-type semiconductor layer 103 and an i-type over the substrate 101. It can be considered that the semiconductor layer 104, the n-type semiconductor layer 105, and the second portion where the electrode 106 is formed are included. As described above, the order of stacking the p-type semiconductor film and the n-type semiconductor film may be reversed. When the contact portion between the electrode 102 and the p-type semiconductor layer 103 and the contact portion between the n-type semiconductor layer 105 and the electrode 106 are separated from each other, a stepped portion (a corner of the photoelectric conversion layer 171, particularly the i-type semiconductor layer 104). Even if a crack occurs in (part), the influence can be removed. Accordingly, generation of a leak current can be suppressed, and a highly reliable photoelectric conversion device can be obtained.

  In this embodiment, the photoelectric conversion device of the present invention and a conventional photoelectric conversion device are compared with each other with reference to FIGS.

  In this example, the photoelectric conversion device was evaluated by performing a THB test under conditions of high temperature (temperature 60 ° C.) and humidity (humidity 90 to 95%) bias −5V.

23A shows the THB test of the conventional photoelectric conversion device shown in FIG. 2, and FIG. 23B shows the THB test result of the photoelectric conversion device of the present invention shown in FIG. In FIGS. 23A and 23B, the horizontal axis represents V _L (V), and the vertical axis represents the frequency at each voltage. V _L indicates a voltage at which a leak current is generated.

  At a test time of 240 hours, a shift of Vr leakage was observed in the results of both the conventional photoelectric conversion device shown in FIG. 2 and the photoelectric conversion device of the present invention shown in FIG. However, there was a difference in the frequency of occurrence of Vr leakage between the conventional photoelectric conversion device shown in FIG. 2 and the photoelectric conversion device of the present invention shown in FIG. When the shift to −15 V or more is regarded as defective (area surrounded by a dotted line in FIG. 23), the conventional photoelectric conversion device showed 11/24 defects in the 240-hour test, whereas the photoelectric conversion according to the present invention. The conversion device had 2/24 defects.

  According to this example, the photoelectric conversion device of the present invention has a result that the frequency of occurrence of leakage current is lower than that of the conventional photoelectric conversion device. That is, according to the present invention, a highly reliable photoelectric conversion device can be obtained.

  In this example, an example in which an electrode that overlaps a photoelectric conversion layer is formed as a stacked film will be described with reference to FIGS. 3A to 3B and FIGS. 16A to 16B. In addition, the same code | symbol is used for the same thing as what was demonstrated in embodiment.

In this embodiment, an example in which the electrode 102 in FIG. 1 is formed of a three-layered film is shown in FIGS. 3 (A) to 3 (B) and FIGS. 16 (A) to 16 (B). First, in FIG. 3A, the wiring 131 is titanium (Ti), the wiring 132 is aluminum (Al), and the wiring 133 is titanium (Ti). In the case where the wiring 131 is a transparent electrode, for example, an indium tin oxide alloy (also referred to as indium tin oxide) or an indium tin oxide alloy containing silicon (Si) (also referred to as indium tin oxide including Si) is used. May be. Further, as a transparent electrode, indium zinc oxide formed by using a target in which zinc oxide (ZnO), tin oxide (SnO ₂ ), indium oxide, indium oxide and 2 to ₂₀ wt% zinc oxide (ZnO) are further mixed. An alloy may be used. Alternatively, ZnO (GZO) doped with Ga ₂ O ₃ , ZnO (AZO) doped with Al ₂ O ₃ , or ZnO (SZO) doped with SiO ₂ may be used. GZO, AZO, and SZO are useful in that they do not oxidize silicon.

  In order to obtain the wiring structure shown in FIG. 3A, a titanium film is formed as a lower conductive film and an aluminum film is formed as an intermediate conductive film. A mask is formed over the middle-layer conductive film, and the lower layer conductive film and the middle-layer conductive film are etched using this mask to obtain the wirings 131 and 132. After that, a titanium film is formed as an upper conductive film and etched to form the wiring 133. After the wiring 133 is formed, the photoelectric conversion layer 171 is formed so as to overlap with the wiring 133.

  In the structure shown in FIG. 3A, since the wiring 133 covers the side surface of the wiring 132 made of aluminum, diffusion of aluminum atoms into the photoelectric conversion layer 171 can be prevented.

  In the structure of FIG. 3B, a wiring 134 is formed by first forming and etching a titanium film as a lower conductive film. After that, an intermediate conductive film is formed using aluminum and an upper conductive film is formed using titanium on the wiring 134, and etching is performed using the same mask to obtain the wiring 135 and the wiring 136. Further, a photoelectric conversion layer 171 is formed so as to overlap with the wiring 134. Note that the wirings 135 and 136 and the photoelectric conversion layer 171 may be formed first after the wiring 134 is formed. In the case where the wirings 135 and 136 are formed after the photoelectric conversion layer 171 is formed, the wirings 135 and 136 may be formed while forming a mask so as to cover the photoelectric conversion layer 171 and protecting the photoelectric conversion layer 171.

  In the structure of FIG. 3B, since the insulating film 107 exists between the wiring 135 and the photoelectric conversion layer 171, aluminum atoms do not diffuse into the semiconductor layer of the photoelectric conversion layer 171.

  In FIG. 16A, a wiring 141 is formed using a titanium film which is a lower conductive film, aluminum is formed as an intermediate conductive film, and the intermediate conductive film is etched to form a wiring 142. Next, after the photoelectric conversion layer 171 is formed, a titanium film is formed as an upper conductive film so as to cover the wiring 142, and the wiring 143 is formed using the titanium film.

  In FIG. 16A, the wiring 143 may be in contact with the i-type semiconductor layer 104 or may not be in contact with the n-type semiconductor layer 105. However, since the wiring 143 is formed so as to cover the side surface of the wiring 142, diffusion of aluminum atoms into the photoelectric conversion layer 171 can be prevented.

  FIG. 16B illustrates an example in which the lower conductive film in FIGS. 3A and 16A is removed, and a wiring is formed using an intermediate conductive film and an upper conductive film.

  In FIG. 16B, the wiring 144 is formed using an aluminum film, and the wiring 145 is formed using a titanium film so as to cover a side surface of the wiring 144. Thereby, aluminum atoms can be prevented from diffusing into the photoelectric conversion layer 171.

  In particular, when FIG. 16B is compared with FIG. 3A, in FIG. 3A, the uppermost layer 133 is formed over the ends of the wires 131 and 132, so that the step becomes large. In FIG. 16B, since the uppermost wiring 145 can only get over the end of the wiring 144, the step is reduced, and the disconnection can be further suppressed.

  The structure of the laminated film is not limited to three layers or two layers, and may be formed of four or more layers. However, if it comes into contact with the uppermost layer of the photoelectric conversion layer (in this embodiment, the n-type semiconductor layer), the p-type semiconductor layer and the n-type semiconductor layer are short-circuited and cannot function as a photoelectric conversion layer. It is formed so as not to contact the top layer. In the case of forming a wiring containing aluminum, the wiring is formed so that aluminum atoms do not diffuse into the photoelectric conversion layer 171.

  The wirings 131 to 136 and 141 to 145 may be extended from the source wiring or drain wiring of the TFT. For example, when a circuit for amplifying the output of a photoelectric conversion element having a photoelectric conversion layer is formed by a TFT as in an embodiment described later, the source wiring or drain wiring of the TFT can be used as the wirings 131 to 133.

  In addition, this embodiment can be applied to any description in Embodiment Mode and Embodiment 1.

  In this embodiment, a photoelectric conversion device having a structure different from that in FIG. 1 will be described with reference to FIGS.

  In the photoelectric conversion device illustrated in FIG. 7A, an insulating film 175 is formed instead of the electrode 106 in FIG. In the step of etching part of the n-type semiconductor layer 162 and part of the i-type semiconductor layer 161 illustrated in FIG. 6A in Embodiment, the insulating film 175 functions as a mask in the same manner as the electrode 106. In this way, a part of the n-type semiconductor layer 162 and the i-type semiconductor layer 161 that are not covered with the insulating film 175 is removed, and the photoelectric semiconductor including the p-type semiconductor layer 103, the i-type semiconductor layer 104, and the n-type semiconductor layer 105 is removed. A conversion layer 171 is formed.

  Next, a groove is formed in the insulating layer 175, and an electrode 177 in contact with the n-type semiconductor layer 105 is formed by a screen printing method. Next, the whole is covered with an insulating film 107. Alternatively, the insulating film 107 having a groove is formed over the insulating film 175, the photoelectric conversion layer 171 and the electrode 102 by a screen printing method or the like, and the extraction electrodes 112 and 113 are formed by a screen printing method using a conductive paste. Alternatively, after forming an insulating film on the entire surface, grooves may be formed by a laser scribing method or the like, and then the extraction electrodes 112 and 113 may be formed.

  The photoelectric conversion device illustrated in FIG. 7B is formed based on the description of the embodiment up to FIG. 6A, and then an insulating film 191 having a groove is formed by a screen printing method or the like. The electrode 192 is formed by screen printing using Alternatively, after the insulating film 191 is formed over the entire surface, a groove may be formed by a laser scribing method or the like, and then the electrode 192 may be formed.

  Next, as described in the embodiment mode, the insulating film 107 is formed, and the extraction electrodes 112 and 113 are formed.

  Note that this embodiment can be applied to any description of the embodiment mode and Embodiments 1 to 2.

  In this embodiment, an example in which a color filter is formed in the photoelectric conversion device of the present invention will be described with reference to FIGS.

  8A and 8B illustrate an example in which a color filter is formed in the photoelectric conversion device illustrated in FIG. In the photoelectric conversion device in FIG. 8A, the color filter 181 is formed on the surface of the substrate 101 on the side where the photoelectric conversion layer 171 is not formed.

  By providing the color filter 181, light of red (R), green (G), and blue (B) can be selectively absorbed.

  FIG. 8B illustrates an example in which a color filter is formed between the substrate 101 and the photoelectric conversion layer 171.

  In FIG. 8B, a color filter 183 is formed over the substrate 101, and a passivation film 184 is formed between the color filter 183, the photoelectric conversion layer 171, the color filter, and the electrode 102.

  In the structure as shown in FIG. 8B, even if light entering from the substrate 101 side passes through the color filter even if it is oblique, incident light can be used effectively.

  In addition, this embodiment can be applied to any description of the embodiment mode and Embodiments 1 to 3.

  In this embodiment, examples of a semiconductor device using the photoelectric conversion device of the present invention are shown in FIGS. 9 (A) to 9 (B), FIGS. 10 (A) to 10 (B), FIG. 11, and FIG. ) To FIG. 12 (D), FIG. 13 (A) to FIG. 13 (D), and FIG. 14 (A) to FIG. 14 (C).

  9A and 9B illustrate an example of a semiconductor device using the photoelectric conversion device of the present invention, for example, a two-terminal visible light sensor chip. The visible light sensor chip illustrated in FIGS. 9A and 9B includes a substrate 210, a base insulating film 212, and a gate insulating film 213. Since the light to be received passes through the substrate 210, the base insulating film 212, and the gate insulating film 213, it is preferable to use materials having high light-transmitting properties for these materials.

  The PIN photoelectric conversion element 225 may be formed based on the description of the embodiment, and an outline thereof is shown in this example. A photoelectric conversion element 225 illustrated in FIG. 9A includes a wiring 204 and a p-type semiconductor layer 221p, an n-type semiconductor layer 221n, which are photoelectric conversion layers 221, and a p-type semiconductor layer 221p and an n-type semiconductor layer 221n. An intrinsic (i-type) semiconductor layer 221i and a terminal electrode 226 are sandwiched.

  The wiring 204 has a stacked structure of a refractory metal film and a low resistance metal film (such as an aluminum alloy or pure aluminum). Here, the wiring 204 has a three-layer structure in which a titanium film (Ti film), an aluminum film (Al film), and a Ti film are sequentially stacked. When the end portion of the wiring 204 is tapered, the distance between the wiring 204 and the uppermost layer of the photoelectric conversion layer 221, in this embodiment, the n-type semiconductor layer 221 n is increased, and the effect of preventing leakage current is increased.

  The wiring 204 may be formed using a single-layer conductive film, and a titanium film (Ti film) is preferable as such a single-layer conductive film. Further, in place of the titanium film, tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh) ), Palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), or a single layer film made of an alloy material or a compound material containing the element as a main component, or these A single layer film made of a nitride such as titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride can be used.

  Further, the photoelectric conversion element 225 illustrated in FIG. 9B includes a protective electrode 218 over the wiring 204. Further, a protective electrode 272 is formed on the source or drain electrode 202 of the TFT 231, a protective electrode 273 is formed on the source or drain electrode 203 of the TFT 230, a protective electrode 271 is formed on the terminal electrode 201, and a protective electrode 220 is formed on the connection electrode 205. ing.

  In the photoelectric conversion element 225 illustrated in FIG. 9B, the wiring 204 is protected by the protective electrode 218 that covers the wiring 204 when the photoelectric conversion layer 221 is etched. The material of the protective electrode 218 is preferably a conductive material whose etching rate is lower than that of the photoelectric conversion layer with respect to the gas (or etchant) for etching the photoelectric conversion layer 221. In addition, the material of the protective electrode 218 is preferably a conductive material that does not react with the photoelectric conversion layer 221 to form an alloy. Further, the protective electrodes 271, 272, 273, and 220 may be formed using the same material as that of the protective electrode 218.

  Further, the positional relationship between the photoelectric conversion layer 221 and the wiring 204, and the photoelectric conversion layer 221, the wiring 204, and the protective electrode 218 is described with reference to the description of Embodiment 2 with reference to FIGS. 16 (A) to FIG. 16 (B) may be used.

  An amplifier circuit provided on the same substrate for amplifying the output value of the PIN photoelectric conversion element 225 includes a current mirror circuit 232 including n-channel thin film transistors (Thin Film Transistors) 230 and 231. Has been.

  10A and 10B are equivalent circuit diagrams of a two-terminal visible light sensor. FIG. 10A is an equivalent circuit diagram in which an n-channel TFT is used for the current mirror circuit which is an amplifier circuit, and is an equivalent circuit diagram of FIGS. 9A and 9B.

  When the amplifier circuit is formed of a p-channel TFT, an equivalent circuit diagram shown in FIG. 10B is obtained. When the amplifier circuit is formed using p-channel TFTs as described above, the n-channel TFTs 230 and 231 shown in FIGS. 9A and 9B may be formed using p-channel TFTs 302 and 303.

  10B, terminal electrodes 226 and 253 are the same as those in FIG. 10A, but are connected to p-channel TFTs 302 and 303 and the photoelectric conversion element 301 as shown in FIG. 10B, respectively. That's fine. The p-channel TFT 302 is electrically connected to the anode side electrode of the photoelectric conversion element 301. In the photoelectric conversion element 301, an n-type semiconductor layer, an intrinsic semiconductor layer (i-type semiconductor layer), and a p-type semiconductor layer are sequentially stacked on an anode-side electrode connected to the p-channel TFT 302, and then the first electrode (cathode). Side electrode) may be formed. Alternatively, a photoelectric conversion element in which the stacking order is reversed may be used. A p-type TFT 302 is formed by sequentially stacking a p-type semiconductor layer, an intrinsic semiconductor layer (i-type semiconductor layer), and an n-type semiconductor layer on the cathode-side electrode. An anode-side electrode connected to the first electrode may be formed, and a cathode-side terminal electrode connected to the first electrode may be formed.

  10A and 10B show two TFTs. In order to actually increase the output value by a factor of 5, for example, in the structure of FIG. Two TFTs 230 (channel length (L) and channel width (W) of 8 μm and 50 μm, respectively) and ten n-channel TFTs 231 (channel length (L) and channel width (W) of 8 μm and 50 μm, respectively) are provided. That's fine.

  Further, FIG. 11 shows an example in which one n-channel TFT 230 and 100 n-channel TFTs 231 are provided to increase the output value by 100 times. In FIG. 11, the same components as those in FIGS. 9A to 9B and 10A are denoted by the same reference numerals. In FIG. 11, the n-channel TFT 231 is composed of 100 n-channel TFTs 231a, 231b, 231c, 231d,. As a result, the photocurrent generated in the photoelectric conversion element 225 is amplified 100 times and output.

  Further, in order to amplify the output value, the amplifier circuit may be composed of an operational amplifier (op-amp) in which n-channel TFTs or p-channel TFTs are appropriately combined, but has five terminals. In addition, an operational amplifier can be configured by an operational amplifier and a level shifter can be used to reduce the number of power supplies to four terminals.

  9A and 9B, n-channel TFTs 230 and 231 are examples of top-gate TFTs having a structure including one channel formation region (referred to as a “single gate structure” in this specification). Although illustrated, a structure having a plurality of channel formation regions (referred to as “multi-gate structure” in this specification) may reduce variation in on-state current value. Further, in order to reduce the off-current value, lightly doped drain (LDD) regions may be provided in the n-channel TFTs 230 and 231. An LDD region is a region in which an impurity element is added at a low concentration between a channel formation region and a source region or a drain region formed by adding an impurity element at a high concentration. When the LDD region is provided, This has the effect of relaxing the electric field in the vicinity of the drain region and preventing deterioration due to hot carrier injection. In order to prevent deterioration of the on-current value due to hot carriers, a structure in which n-channel TFTs 230 and 231 are arranged with an LDD region overlapped with a gate electrode through a gate insulating film (in this specification, “GOLD (Gate− (Drain Overlapped LDD) structure ”).

  When the GOLD structure is used, the electric field in the vicinity of the drain region is further relaxed and the deterioration due to hot carrier injection is prevented, compared with the case where the LDD region is not formed overlapping the gate electrode. By adopting such a GOLD structure, the electric field strength in the vicinity of the drain region is relaxed and hot carrier injection is prevented, which is effective in preventing a deterioration phenomenon.

  Also, the p-channel TFTs 302 and 303 in FIG. 10B may have a structure similar to that of the n-channel TFTs 230 and 231, that is, a single gate structure or a multi-gate structure, and an LDD region may be provided if necessary. Good.

  A wiring 214 is connected to the wiring 204 and extends above the channel formation region of the TFT 230 of the amplifier circuit and serves as a gate electrode.

  The wiring 215 is a wiring connected to the n-type semiconductor layer 221n and is connected to a drain wiring (also referred to as a drain electrode) or a source wiring (also referred to as a source electrode) of the TFT 231. Reference numerals 216 and 217 denote insulating films, and 205 denotes a connection electrode. Since the light to be received passes through the insulating films 216 and 217, it is desirable to use materials having high light-transmitting properties. Note that the insulating film 217 is preferably a silicon oxide film (SiOx) formed by a CVD method. When the insulating film 217 is a silicon oxide film formed by a CVD method, the fixing strength is improved.

  The terminal electrode 250 is formed in the same process as the wirings 214 and 215, and the terminal electrode 201 is formed in the same process as the wiring 204 and the connection electrode 205.

  The terminal electrode 226 is connected to the n-type semiconductor layer 221n, and is mounted on the electrode 261 of the printed wiring board 260 with solder 264. The terminal electrode 253 is formed in the same process as the terminal electrode 226, and is mounted on the electrode 262 of the printed wiring board 260 with solder 263.

  12A to 12D, FIGS. 13A to 13D, and FIGS. 14A to 14C are used in the following manufacturing steps. Shown in

  First, an element is formed over a substrate (first substrate 210). Here, AN100 which is one of glass substrates is used as the substrate 210.

  Next, a silicon oxide film containing nitrogen (with a thickness of 100 nm) that serves as the base insulating film 212 is formed by a plasma CVD method. Further, the semiconductor film 281 such as an amorphous silicon film containing hydrogen (film thickness) is formed without exposure to the air. 54 nm) are stacked (FIG. 12A). Alternatively, the base insulating film 212 may be a stack of a silicon oxide film, a silicon nitride film, and a silicon oxide film containing nitrogen. For example, a film in which a silicon nitride film containing oxygen is stacked with a thickness of 50 nm and a silicon oxide film containing nitrogen is stacked with a thickness of 100 nm may be formed as the base insulating film 212. Note that the silicon oxide film or silicon nitride film containing nitrogen functions as a blocking layer for preventing diffusion of impurities such as alkali metal from the glass substrate.

  Next, the amorphous silicon film is crystallized by a known technique (solid phase growth method, laser crystallization method, crystallization method using a catalytic metal, etc.), and a semiconductor film having a crystal structure (crystalline semiconductor film) For example, a polycrystalline silicon film is formed. Here, a polycrystalline silicon film is obtained by a crystallization method using a catalytic element. A nickel acetate aqueous solution containing 10 ppm of nickel by weight is applied by a spinner. Note that a nickel element may be dispersed over the entire surface by sputtering instead of coating. Next, heat treatment is performed for crystallization to form a semiconductor film having a crystal structure (here, a polycrystalline silicon film). Here, after heat treatment (500 ° C., 1 hour), heat treatment for crystallization (550 ° C., 4 hours) is performed to obtain a polycrystalline silicon film.

  Next, the oxide film on the surface of the polycrystalline silicon film is removed with dilute hydrofluoric acid or the like. After that, irradiation with laser light (XeCl: wavelength 308 nm) for increasing the crystallization rate and repairing defects left in the crystal grains is performed in the air or an oxygen atmosphere.

As the laser light, excimer laser light having a wavelength of 400 nm or less or the second harmonic or the third harmonic of a YAG laser is used. Here, a pulsed laser beam having a repetition frequency of about 10 to 1000 Hz is used, the laser beam is condensed to 100 to 500 mJ / cm ² by an optical system, and irradiated with an overlap rate of 90 to 95%. May be scanned. In this embodiment, laser light irradiation is performed in the atmosphere at a repetition frequency of 30 Hz and an energy density of 470 mJ / cm ² .

Note that an oxide film is formed on the surface by irradiation with a laser beam because it is performed in the air or in an oxygen atmosphere. Although an example using a pulse laser is shown in this embodiment, a continuous wave laser may be used. In order to obtain a crystal with a large grain size when crystallizing a semiconductor film, continuous oscillation is possible. It is preferable to apply a second to fourth harmonic of the fundamental wave using a solid-state laser. Typically, a second harmonic (532 nm) or a third harmonic (355 nm) of an Nd: YVO ₄ laser (fundamental wave 1064 nm) may be applied.

In the case of using a continuous wave laser, laser light emitted from a continuous wave YVO ₄ laser having an output of 10 W is converted into a harmonic by a non-linear optical element. There is also a method of emitting harmonics by putting a YVO ₄ crystal and a nonlinear optical element in a resonator. Then, it is preferably formed into a rectangular or elliptical laser beam on the irradiation surface by an optical system, and irradiated to the object to be processed. At this time, the energy density of approximately 0.01 to 100 MW / cm ² (preferably 0.1 to 10 MW / cm ²⁾ is required. Then, irradiation may be performed by moving the semiconductor film relative to the laser light at a speed of about 10 to 2000 cm / s.

  Next, in addition to the oxide film formed by the laser light irradiation, the surface is treated with ozone water for 120 seconds to form a barrier layer made of an oxide film having a total thickness of 1 to 5 nm. This barrier layer is formed to remove a catalyst element added for crystallization, for example, nickel (Ni) from the film. Here, the barrier layer is formed using ozone water, but the surface of the semiconductor film having a crystal structure is oxidized by a method of oxidizing the surface of the semiconductor film having a crystal structure by irradiation with ultraviolet light in an oxygen atmosphere or the oxygen plasma treatment. The barrier layer may be formed by depositing an oxide film of about 1 to 10 nm by a method, plasma CVD method, sputtering method or vapor deposition method. Further, the oxide film formed by laser light irradiation may be removed before forming the barrier layer.

Next, an amorphous silicon film containing an argon element serving as a gettering site is formed with a thickness of 10 to 400 nm, here 100 nm, over the barrier layer by a sputtering method. Here, the amorphous silicon film containing an argon element is formed using a silicon target in an atmosphere containing argon. In the case where an amorphous silicon film containing an argon element is formed using a plasma CVD method, the film formation conditions are as follows: the flow ratio of monosilane to argon (SiH ₄ : Ar) is 1:99, and the film formation pressure is 6.665 Pa. The RF power density is 0.087 W / cm ² and the film formation temperature is 350 ° C.

  Thereafter, the catalyst element is removed (gettering) by performing a heat treatment for 3 minutes in a furnace heated to 650 ° C. As a result, the concentration of the catalytic element in the semiconductor film having a crystal structure is reduced. A lamp annealing apparatus may be used instead of the furnace.

  Next, the amorphous silicon film containing an argon element which is a gettering site is selectively removed using the barrier layer as an etching stopper, and then the barrier layer is selectively removed with dilute hydrofluoric acid. Note that during gettering, nickel tends to move to a region with a high oxygen concentration, and thus it is desirable to remove the barrier layer made of an oxide film after gettering.

  Note that in the case where the semiconductor film is not crystallized using a catalytic element, the above-described barrier layer formation, gettering site formation, heat treatment for gettering, gettering site removal, barrier layer removal, etc. This step is unnecessary.

  Next, after forming a thin oxide film with ozone water on the surface of the obtained semiconductor film having a crystalline structure (for example, a crystalline silicon film), a mask made of resist is formed using a first photomask, and a desired film is formed. Semiconductor films (referred to as “island semiconductor regions” in this specification) 283 and 284 separated into island shapes are formed by etching treatment into a shape (see FIG. 12B). After the island-shaped semiconductor regions 283 and 284 are formed, the resist mask is removed.

Next, if necessary, a small amount of impurity element (boron or phosphorus) is doped in order to control the threshold value of the TFT. Here, an ion doping method in which diborane (B ₂ H ₆ ) is plasma-excited without mass separation is used.

  Next, the oxide film is removed with an etchant containing hydrofluoric acid, and at the same time, the surface of the island-like semiconductor film is washed, and then an insulating film containing silicon as a main component to be the gate insulating film 213 is formed. Here, a silicon oxide film containing nitrogen (composition ratio: Si = 32%, O = 59%, N = 7%, H = 2%) with a thickness of 115 nm is formed by a plasma CVD method.

  Next, after a metal film is formed over the gate insulating film 213, gate electrodes 285 and 286, wirings 215 and 214, and a terminal electrode 250 are formed using a second photomask (see FIG. 12C). As this metal film, for example, a film in which tantalum nitride (TaN) and tungsten (W) are stacked in a thickness of 30 nm and 370 nm, respectively, is used.

  Further, as the gate electrodes 285 and 286, the wirings 215 and 214, and the terminal electrode 250, in addition to the above, titanium (Ti), tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co ), Zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), aluminum (Al), gold (Au) ), Silver (Ag), copper (Cu), or a single layer film made of an alloy material or a compound material containing the element as a main component, or a nitride thereof, for example, titanium nitride, tungsten nitride A single layer film made of tantalum nitride or molybdenum nitride can be used.

  Next, the island-shaped semiconductor regions 283 and 284 are doped to form a source region or drain region 291 of the TFT 230 and a source region or drain region 293 of the TFT 231 (see FIG. 12D). Further, a channel formation region 292 is formed between the source region and the drain region in the TFT 231, and a channel formation region 294 is formed between the source region and the drain region in the TFT 232.

  Next, after forming a first interlayer insulating film (not shown) including a silicon oxide film by CVD with a thickness of 50 nm, a step of activating the impurity element added to each of the island-like semiconductor regions 283 and 284 is performed. This activation process is performed by a rapid thermal annealing method (RTA method) using a lamp light source, a method of irradiating a YAG laser or an excimer laser from the back surface, a heat treatment using a furnace, or a combination thereof. By different methods.

  Next, a second interlayer insulating film 216 including a silicon nitride film containing hydrogen and oxygen is formed with a thickness of 10 nm, for example.

  Next, a third interlayer insulating film 217 made of an insulating material is formed over the second interlayer insulating film 216 (see FIG. 13A). As the third interlayer insulating film 217, an insulating film obtained by a CVD method can be used. In this embodiment, in order to improve adhesion, a silicon oxide film containing nitrogen formed with a thickness of 900 nm is formed as the third interlayer insulating film 217.

  Next, heat treatment (300 to 550 ° C. for 1 to 12 hours, for example, in a nitrogen atmosphere at 410 ° C. for 1 hour) is performed to hydrogenate the island-shaped semiconductor regions 283 and 284. This step is performed to terminate dangling bonds in the island-shaped semiconductor regions 283 and 284 with hydrogen contained in the second interlayer insulating film 216. The island-shaped semiconductor region can be hydrogenated regardless of the presence of the gate insulating film 213.

  Further, as the third interlayer insulating film 217, an insulating film using siloxane and a stacked structure thereof can be used. Siloxane has a skeleton structure with a bond of silicon (Si) and oxygen (O). As a substituent, a compound containing at least hydrogen (for example, an alkyl group or aromatic hydrocarbon) is used. Fluorine may be used as a substituent. Alternatively, as a substituent, a compound containing at least hydrogen and fluorine may be used.

  In the case where an insulating film using siloxane or a laminated structure thereof is used as the third interlayer insulating film 217, a heat treatment for hydrogenating the island-shaped semiconductor regions 283 and 284 after the second interlayer insulating film 216 is formed. Then, the third interlayer insulating film 217 can be formed.

  Next, a resist mask is formed using a third photomask, and the first interlayer insulating film, the second interlayer insulating film 216, the third interlayer insulating film 217, or the gate insulating film 213 is selectively etched. A contact hole is formed. Then, the resist mask is removed.

  Note that the third interlayer insulating film 217 may be formed as necessary. When the third interlayer insulating film 217 is not formed, the first interlayer insulating film and the second interlayer insulating film 216 are formed after the second interlayer insulating film 216 is formed. The second interlayer insulating film 216 and the gate insulating film 213 are selectively etched to form contact holes.

  Next, after a metal laminated film is formed by a sputtering method, a mask made of a resist is formed using a fourth photomask, and the metal film is selectively etched, so that a wiring 204, a connection electrode 205, and a terminal electrode 201 are formed. Then, the source or drain electrode 203 of the TFT 230 and the source or drain electrode 202 of the TFT 231 are formed. Then, the resist mask is removed. Note that the metal laminated film of this example is formed by laminating three layers of a Ti film with a thickness of 100 nm, an Al film containing a trace amount of Si with a thickness of 350 nm, and a Ti film with a thickness of 100 nm.

  Further, the wiring 204, the connection electrode 205, the terminal electrode 201, the source or drain electrode 203 of the TFT 230, and the source or drain electrode 202 of the TFT 231 may be formed using a single conductive film. As such a conductive film, a titanium film (Ti film) is preferable. Further, in place of the titanium film, tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh) ), Palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), or a single layer film made of an alloy material or a compound material containing the element as a main component, or these A single layer film made of a nitride such as titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride can be used. By forming the wiring 204, the connection electrode 205, the terminal electrode 201, the source or drain electrode 203 of the TFT 230, and the source or drain electrode 202 of the TFT 231 as a single layer film, the number of depositions can be reduced in the manufacturing process. It becomes.

  Further, protective electrodes 218, 220, 271, 273, and 272 were formed on the wiring 204, the connection electrode 205, the terminal electrode 201, the source electrode or drain electrode 203 of the TFT 230, and the source electrode or drain electrode 202 of the TFT 231, respectively. An example is shown in FIG.

  The protective electrode 218 can protect the wiring 204 when the photoelectric conversion layer is etched in a later step. Therefore, the material of the protective electrode 218 is preferably a conductive material whose etching rate is lower than that of the photoelectric conversion layer with respect to the gas (or etchant) for etching the photoelectric conversion layer. In addition, the material of the protective electrode 218 is preferably a conductive material (such as titanium (Ti) or molybdenum (Mo)) that does not react with the photoelectric conversion layer to form an alloy.

  When the protective electrodes 218, 220, 271, 273, and 272 are used, the wiring 204, the connection electrode 205, the terminal electrode 201, the source or drain electrode 203 of the TFT 230, and the source or drain electrode 202 of the TFT 231 are stacked films, For example, when the film is formed by laminating three layers of a titanium (Ti) film, an aluminum (Al) film, and a titanium (Ti) film, the side surface on which the second Al film is exposed is also covered, and the photoelectric conversion layer There is an advantage that diffusion of aluminum atoms into the metal can be prevented.

  Through the above steps, top-gate TFTs 230 and 231 using a polycrystalline silicon film can be manufactured. A current mirror circuit 232 is formed by the TFTs 230 and 231.

  Next, the photoelectric conversion layer 241 is formed. The photoelectric conversion layer 241 may be formed based on the description of Embodiment Mode and Examples 1 to 3.

  The photoelectric conversion layer 241 includes a p-type semiconductor layer 241p, an i-type semiconductor layer 241i, and an n-type semiconductor layer 241n. Each of the p-type semiconductor layer 241p, the i-type semiconductor layer 241i, and the n-type semiconductor layer 241n may be formed of an amorphous silicon film, for example. In this embodiment, the p-type semiconductor layer 241p is formed to a thickness of 10 to 50 nm, the i-type semiconductor layer 241i is formed to a thickness of 200 to 1000 nm, and the n-type semiconductor layer 241n is formed to a thickness of 20 to 200 nm.

  An insulating film 242 is formed over the photoelectric conversion layer 241. The insulating film 242 may be formed in the same manner as the insulating film 175 described in Embodiment 3.

  Next, the photoelectric conversion layer 241 is etched using the insulating film 242 as a mask. At this time, the upper n-type semiconductor layer is etched, but the etching time is adjusted so as not to etch the lower p-type semiconductor layer 241p. The i-type semiconductor layer 241i is formed thick so that etching stops at the middle i-type semiconductor layer. When the etching of the photoelectric conversion layer 241 is finished, the insulating film 242 is removed.

  By this etching step, part of the n-type semiconductor layer 241n and the i-type semiconductor layer 241i is removed to have shapes illustrated in 221n and 221i, respectively (see FIG. 14A). Since the p-type semiconductor layer 241p is not etched, it remains in the same shape (221p). As described above, the photoelectric conversion layer 221 including the p-type semiconductor layer 221p, the i-type semiconductor layer 221i, and the n-type semiconductor layer 221n is formed.

  Next, a sealing layer 224 made of an insulating material (for example, an inorganic insulating film containing silicon) is formed over the entire surface with a thickness (1 μm to 30 μm) to obtain the state shown in FIG. Here, a silicon oxide film containing nitrogen having a thickness of 1 μm is formed as the insulating material film by a CVD method. Adhesion is improved by using an insulating film formed by CVD.

  Next, after the sealing layer 224 is etched to provide openings, terminal electrodes 226 and 253 are formed by sputtering. The terminal electrodes 226 and 253 are laminated films of a titanium film (Ti film) (100 nm), a nickel film (Ni) film (300 nm), and a gold film (Au film) (50 nm). The terminal electrode 226 and the terminal electrode 253 thus obtained have a fixing strength exceeding 5N, which is sufficient as a terminal electrode.

  Through the above steps, the terminal electrode 226 and the terminal electrode 253 that can be soldered are formed, and the structure shown in FIG. 14C is obtained.

  Next, a plurality of optical sensor chips are cut out individually. A large amount of optical sensor chips (2 mm × 1.5 mm) can be manufactured from one large-area substrate (for example, 600 cm × 720 cm).

  A cross-sectional view of one cut out optical sensor chip (2 mm × 1.5 mm in the top view) is shown in FIG. 15A, a bottom view thereof is shown in FIG. 15B, and a top view thereof is shown in FIG. In FIG. 15, the same reference numerals are used for portions that are the same as those in FIGS. 13 and 14. 15A, the total film thickness including the substrate 210, the element formation region 311 where the photoelectric conversion elements are formed, the terminal electrode 226, and the terminal electrode 253 is 0.8 ± 0.05 mm. is there.

  In order to reduce the total film thickness of the optical sensor chip, the substrate 210 may be thinned by CMP processing or the like, and then individually cut with a dicer to cut out a plurality of optical sensor chips.

In FIG. 15B, one electrode size of the terminal electrodes 226 and 253 is 0.6 mm × 1.1 mm, and the electrode interval is 0.4 mm. In FIG. 15C, the area of the light receiving portion 312 is 1.57 mm ² . In addition, about 100 TFTs are provided in the amplifier circuit portion.

  Finally, the obtained optical sensor chip is mounted on the mounting surface of the printed wiring board 260. The terminal electrode 226 and the electrode 261, and the terminal electrode 253 and the electrode 262 are connected by using solders 264 and 263, respectively, which are previously formed on the electrodes 261 and 262 of the printed wiring board 260 by a screen printing method or the like. Then, after the solder and the terminal electrode are in contact with each other, the solder reflow process is performed for mounting. The solder reflow process is performed, for example, in an inert gas atmosphere at a temperature of about 255 ° C. to 265 ° C. for about 10 seconds. In addition to solder, bumps formed of metal (gold, silver, etc.) or bumps formed of conductive resin can be used. Moreover, you may mount using lead-free solder in consideration of an environmental problem.

  9A and 9B show the optical sensor chip mounted through the above steps. The photosensor of the present invention (a circuit-integrated photosensor having an amplifier circuit that increases the output value by 100) can obtain a photocurrent of about 10 μA at an illuminance of 100 lux. The sensitivity wavelength range of the optical sensor of the present invention is 350 to 750 nm, and the peak sensitivity wavelength is 580 nm. The dark current (Vr = 5V) is 1000 pA.

  Note that this embodiment can be combined with any description of the embodiment mode and Embodiments 1 to 4.

  In this embodiment, examples in which the photoelectric conversion device obtained by the present invention is incorporated into various electronic devices will be described. Examples of electronic devices to which the present invention is applied include computers, displays, mobile phones, and televisions. Specific examples of these electronic devices are shown in FIGS. 17, 18A to 18B, 19A to 19B, 20 and 21A to 21B. Show.

  FIG. 17 shows a mobile phone, which includes a main body (A) 601, a main body (B) 602, a housing 603, operation keys 604, an audio input unit 605, an audio output unit 606, a circuit board 607, a display panel (A) 608, a display. A panel (B) 609, a hinge 610, a light-transmitting material portion 611, and an optical sensor 612 are provided. The present invention can be applied to the optical sensor 612.

  The optical sensor 612 detects light transmitted through the translucent material portion 611 and controls the luminance of the display panel (A) 608 and the display panel (B) 609 in accordance with the detected illuminance of external light, or the optical sensor 612. Illumination control of the operation key 604 is performed in accordance with the illuminance obtained in. Thereby, current consumption of the mobile phone can be suppressed.

  18A and 18B show another example of a mobile phone. 18A and 18B, 621 is a main body, 622 is a housing, 623 is a display panel, 624 is an operation key, 625 is an audio output unit, 626 is an audio input unit, and 627 and 628 are optical sensors. Part.

  In the mobile phone illustrated in FIG. 18A, the luminance of the display panel 623 and the operation keys 624 can be controlled by detecting external light using the optical sensor portion 627 provided in the main body 621.

  In addition, in the mobile phone illustrated in FIG. 18B, an optical sensor portion 628 is provided inside the main body 621 in addition to the structure in FIG. The light sensor portion 628 can also detect the luminance of the backlight provided in the display panel 623.

  FIG. 19A illustrates a computer, which includes a main body 631, a housing 632, a display portion 633, a keyboard 634, an external connection port 635, a pointing mouse 636, and the like.

  FIG. 19B shows a display device which corresponds to a television receiver or the like. This display device includes a housing 641, a support base 642, a display portion 643, and the like.

  FIG. 20 shows a detailed structure in the case where a liquid crystal panel is used as the display portion 633 provided in the computer in FIG. 19A and the display portion 643 of the display device in FIG.

  A liquid crystal panel 662 illustrated in FIG. 20 is incorporated in a housing 661 and includes substrates 651a and 651b, a liquid crystal layer 655 sandwiched between the substrates 651a and 651b, polarization filters 652a and 652b, a backlight 653, and the like. Yes. An optical sensor portion 654 is formed in the housing 661.

  The optical sensor unit 654 manufactured using the present invention senses the amount of light from the backlight 653, and the information is fed back to adjust the luminance of the liquid crystal panel 662.

  21A and 21B are diagrams illustrating an example in which the photoelectric conversion device of the present invention is incorporated in a camera, for example, a digital camera. FIG. 21A is a perspective view seen from the front side of the digital camera, and FIG. 21B is a perspective view seen from the rear side. In FIG. 21A, the digital camera includes a release button 701, a main switch 702, a finder window 703, a flash 704, a lens 705, a lens barrel 706, and a housing 707.

  In FIG. 21B, a viewfinder eyepiece window 711, a monitor 712, and operation buttons 713a and 713b are provided.

  When the release button 701 is pressed down to a half position, the focus adjustment mechanism and the exposure adjustment mechanism are operated, and when the release button 701 is pressed down to the lowest position, the shutter is opened.

  A main switch 702 switches the power of the digital camera ON / OFF when pressed or rotated.

  A viewfinder window 703 is disposed on the front of the lens 705 on the front surface of the digital camera, and is a device for confirming the shooting range and focus position from the viewfinder eyepiece window 711 shown in FIG.

  The flash 704 is arranged at the upper front of the digital camera, and emits auxiliary light simultaneously with the release button being pressed to open the shutter when the subject brightness is low.

  The lens 705 is disposed in front of the digital camera. The lens is composed of a focusing lens, a zoom lens, and the like, and constitutes a photographing optical system together with a shutter and a diaphragm (not shown). In addition, an imaging element such as a CCD (Charge Coupled Device) is provided behind the lens.

  The lens barrel 706 moves the lens position in order to focus the focusing lens, the zoom lens, and the like. During photographing, the lens barrel 705 is extended to move the lens 705 forward. In addition, when carrying the camera, the lens 705 is moved down to be compact. In the present embodiment, the structure is such that the subject can be zoomed by extending the lens barrel. However, the present invention is not limited to this structure, and the lens barrel is configured by the configuration of the imaging optical system in the housing 707. It is also possible to use a digital camera that can perform zoom shooting without extending the camera.

  The viewfinder eyepiece window 711 is provided in the upper part of the rear surface of the digital camera, and is a window provided for eye contact when confirming a photographing range and a focus position.

  The operation buttons 713a and 713b are various function buttons provided on the rear surface of the digital camera, and include a setup button, a menu button, a display button, a function button, a selection button, and the like.

  When the photoelectric conversion device of the present invention is incorporated in the camera shown in FIGS. 21A and 21B, the photoelectric conversion device can sense the presence and intensity of light, thereby adjusting the exposure of the camera. It can be carried out.

  The photoelectric conversion device of the present invention can be applied to other electronic devices such as a projection television and a navigation system. In other words, it can be used for any object that needs to detect light.

  Note that this embodiment can be combined with any description of the embodiment mode and Embodiments 1 to 5.

  According to the present invention, a photoelectric conversion device capable of preventing concentration of an electric field in a stepped portion and suppressing leakage current can be manufactured. In addition, by incorporating the photoelectric conversion device of the present invention, a highly reliable electric device can be obtained.

Sectional drawing of the photoelectric conversion apparatus of this invention. Sectional drawing of the conventional photoelectric conversion apparatus. Sectional drawing of the photoelectric conversion apparatus of this invention. Sectional drawing which shows the manufacturing process of the photoelectric conversion apparatus of this invention. Sectional drawing which shows the manufacturing process of the photoelectric conversion apparatus of this invention. Sectional drawing which shows the manufacturing process of the photoelectric conversion apparatus of this invention. Sectional drawing of the photoelectric conversion apparatus of this invention. Sectional drawing of the photoelectric conversion apparatus of this invention. Sectional drawing of the apparatus which mounted the photoelectric conversion apparatus of this invention. The equivalent circuit diagram of the apparatus incorporating the photoelectric conversion apparatus of this invention. The equivalent circuit diagram of the apparatus incorporating the photoelectric conversion apparatus of this invention. Sectional drawing which shows the manufacturing process of the apparatus which mounted the photoelectric conversion apparatus of this invention. Sectional drawing which shows the manufacturing process of the apparatus which mounted the photoelectric conversion apparatus of this invention. Sectional drawing which shows the manufacturing process of the apparatus which mounted the photoelectric conversion apparatus of this invention. The side view and top view of the apparatus which mounted the photoelectric conversion apparatus of this invention. Sectional drawing of the photoelectric conversion apparatus of this invention. The figure which shows the example of the electric equipment incorporating the photoelectric conversion apparatus of this invention. The figure which shows the example of the electric equipment incorporating the photoelectric conversion apparatus of this invention. The figure which shows the example of the electric equipment incorporating the photoelectric conversion apparatus of this invention. The figure which shows the example of the electric equipment incorporating the photoelectric conversion apparatus of this invention. The figure which shows the example of the electric equipment incorporating the photoelectric conversion apparatus of this invention. Electron micrograph of the conventional structure. The figure which shows the comparison of the photoelectric conversion apparatus of this invention, and the conventional photoelectric conversion apparatus.

Explanation of symbols

101 substrate 102 electrode 103 p-type semiconductor layer 104 i-type semiconductor layer 105 n-type semiconductor layer 106 electrode 107 insulating film 112 extraction electrode 113 extraction electrode 131 wiring 132 wiring 133 wiring 134 wiring 135 wiring 136 wiring 141 wiring 142 wiring 143 wiring 144 wiring 145 wiring 151 first conductive film 152 p-type semiconductor film 153 i-type semiconductor film 154 n-type semiconductor film 155 conductive film 156 conductive film 161 i-type semiconductor layer 162 n-type semiconductor layer 165 groove 166 groove 171 photoelectric conversion layer 175 insulating film 177 Electrode 181 Color filter 183 Color filter 184 Passivation film 191 Insulation film 192 Electrode 201 Terminal electrode 202 Drain electrode 203 Drain electrode 204 Wiring 205 Connection electrode 210 Substrate 212 Base insulation film 213 Gate insulation film 214 Wiring 215 wiring 216 insulating film 217 insulating film 218 protective electrode 220 protective electrode 221 photoelectric conversion layer 221p p-type semiconductor layer 221i i-type semiconductor layer 221n n-type semiconductor layer 224 sealing layer 225 photoelectric conversion element 226 terminal electrode 230 n-channel TFT
231 n-channel TFT
231a n-channel TFT
231b n-channel TFT
231c n-channel TFT
231d n-channel TFT
232 Current mirror circuit 241 Photoelectric conversion layer 241p p-type semiconductor layer 241i i-type semiconductor layer 241n n-type semiconductor layer 242 Insulating film 250 Terminal electrode 253 Terminal electrode 260 Printed wiring board 261 Electrode 262 Electrode 263 Solder 264 Solder 271 Protective electrode 272 Protective electrode 273 Protective electrode 281 Semiconductor film 283 Island semiconductor region 284 Island semiconductor region 285 Gate electrode 286 Gate electrode 291 Source region or drain region 292 Channel formation region 293 Source region or drain region 294 Channel formation region 301 Photoelectric conversion element 302 p channel type TFT
303 p-channel TFT
311 Element formation region 312 Light-receiving part 601 Main body (A)
602 Body (B)
603 Case 604 Operation key 605 Audio input unit 606 Audio output unit 607 Circuit board 608 Display panel (A)
609 Display panel (B)
610 Hinge 611 Translucent material portion 612 Optical sensor 621 Main body 622 Case 623 Display panel 624 Operation key 625 Audio output portion 626 Audio input portion 627 Optical sensor portion 628 Optical sensor portion 631 Main body 632 Housing portion 633 Display portion 634 Keyboard 635 External Connection port 636 Pointing mouse 641 Housing 642 Support base 643 Display unit 651a Substrate 652a Polarizing filter 652b Polarizing filter 653 Backlight 654 Optical sensor unit 655 Liquid crystal layer 661 Housing 662 Liquid crystal panel 701 Release button 702 Main switch 703 Finder window 704 Flash 705 Lens 706 Lens barrel 707 Case 711 Viewfinder eyepiece window 712 Monitor 713a Operation button 713b Operation button 1001 Substrate 1002 Electrode 1003 P-type semiconductor layer 1004 i-type semiconductor layer 1005 n-type semiconductor layer 1006 electrode 1007 insulating film 1012 extraction electrode 1013 extraction electrode 1021 crack

Claims (16)

A photoelectric conversion device having a first region and a second region,
A first electrode provided on a substrate;
A first semiconductor layer of one conductivity type provided on the first electrode;
A second semiconductor layer provided on the first semiconductor layer;
A third semiconductor layer having a conductivity type opposite to the one conductivity type provided on the second semiconductor layer;
A second electrode provided on the third semiconductor layer,
The first semiconductor layer and the second semiconductor layer each have a first portion and a second portion,
The first region comprises the first electrode, a first portion of the first semiconductor layer, and a first portion of the second semiconductor layer,
The second region includes a second portion of the first semiconductor layer, a second portion of the second semiconductor layer, the third semiconductor layer, and the second electrode. A photoelectric conversion device characterized by that. A photoelectric conversion device having a first region and a second region,
A first electrode provided on a substrate;
A first semiconductor layer of one conductivity type provided on the first electrode;
A second semiconductor layer provided on the first semiconductor layer;
A third semiconductor layer having a conductivity type opposite to the one conductivity type provided on the second semiconductor layer;
An insulating film provided on the third semiconductor layer;
A second electrode electrically connected to the third semiconductor layer through the insulating film,
The first semiconductor layer and the second semiconductor layer each have a first portion and a second portion,
The first region comprises the first electrode, a first portion of the first semiconductor layer, and a first portion of the second semiconductor layer,
The second region includes a second part of the first semiconductor layer, a second part of the second semiconductor layer, the third semiconductor layer, the insulating film, and the second part. And a photoelectric conversion device comprising: an electrode; In claim 1 or claim 2,
The photoelectric conversion device according to claim 1, wherein the first portion of the second semiconductor layer is thinner than the second portion of the second semiconductor layer. In any one of Claims 1 thru | or 3,
The first electrode includes a first conductive film made of aluminum, a stacked structure of the second conductive film in order,
The photoelectric conversion device, wherein the second conductive film is provided so as to cover the first conductive film and is in contact with the first semiconductor layer. In any one of Claims 1 thru | or 3,
The first electrode has a structure in which a first conductive film and a second conductive film made of aluminum are sequentially stacked,
The photoelectric conversion device, wherein the first conductive film is in contact with the first semiconductor layer. In any one of Claims 1 thru | or 5,
The photoelectric conversion device, wherein the substrate is a flexible substrate. In any one of Claims 1 thru | or 6,
A photoelectric conversion device comprising a color filter between the substrate and the first semiconductor layer and the first electrode. Forming a first electrode on the substrate;
A first semiconductor film of one conductivity type, a second semiconductor film, and a third semiconductor film of a conductivity type opposite to the one conductivity type are sequentially formed on the first electrode,
Forming a conductive film on the third semiconductor film;
The first semiconductor film, the second semiconductor film, the third semiconductor film, and the conductive film cover an end portion of the first electrode, and a part of the first semiconductor film is the first semiconductor film. A part of the first electrode is exposed so as to be in contact with one electrode, and a first island-shaped semiconductor film, a second island-shaped semiconductor film, a third island-shaped semiconductor film, and an island-shaped conductive film are respectively formed. Forming,
A portion of the island-like conductive film overlapping the said first electrode first semiconductor film to form a second electrode and at least removed,
A method for manufacturing a photoelectric conversion device, wherein a part of the second island-shaped semiconductor film and a part of the third island-shaped semiconductor film are removed using the second electrode as a mask. In Claim 8, it covers and insulates the exposed first electrode, the first island-like semiconductor film, the second island-like semiconductor film, the third island-like semiconductor film, and the second electrode. A first groove and a second groove reaching the exposed first electrode and the second electrode, respectively, are formed in the insulating film;
A third electrode and a fourth electrode that are electrically connected to the first electrode and the second electrode through the first groove and the second groove, respectively, are formed on the insulating film. A method for manufacturing a photoelectric conversion device. Forming a first electrode on the substrate;
A first semiconductor film of one conductivity type, a second semiconductor film, and a third semiconductor film of a conductivity type opposite to the one conductivity type are sequentially formed on the first electrode,
Forming a first insulating film on the third semiconductor film;
The first semiconductor film, the second semiconductor film, the third semiconductor film, and the first insulating film cover an end portion of the first electrode, and are part of the first semiconductor film Are exposed so that the first electrode is in contact with the first electrode, and the first island-shaped semiconductor film, the second island-shaped semiconductor film, the third island-shaped semiconductor film, and the first Formed an island-like insulating film,
A portion of the first island-shaped insulating film overlapping the said first electrode first semiconductor film to form a second island-shaped insulating film is at least removed,
A method for manufacturing a photoelectric conversion device, characterized in that a part of the second island-shaped semiconductor film and a part of the third island-shaped semiconductor film are removed using the second island-shaped insulating film as a mask. In claim 10,
Forming a first groove in the second island-shaped insulating film;
Forming a second electrode electrically connected to the third island-shaped semiconductor film via the first groove on the second island-shaped insulating film;
The exposed first electrode, the first island-shaped semiconductor film, the second island-shaped semiconductor film, the third island-shaped semiconductor film, the second island-shaped insulating film, and the second electrode A third insulating film is formed, and a second groove and a third groove reaching the exposed first electrode and the second electrode, respectively, are formed in the third insulating film. ,
A third electrode and a fourth electrode electrically connected to the first electrode and the second electrode, respectively, on the third insulating film through the second groove and the third groove, respectively. A method for manufacturing a photoelectric conversion device, comprising forming an electrode. In any one of Claims 8 thru | or 11,
The first electrode is formed by sequentially laminating a first conductive film made of aluminum and a second conductive film,
The method for manufacturing a photoelectric conversion device, wherein the second conductive film is provided so as to cover the first conductive film and to be in contact with the first island-shaped semiconductor film. In any one of Claims 8 thru | or 11,
The first electrode is formed by sequentially laminating a first conductive film and a second conductive film made of aluminum,
The method for manufacturing a photoelectric conversion device, wherein the first conductive film is provided so as to be in contact with the first island-shaped semiconductor film. In any one of Claims 8 thru | or 13,
The method for manufacturing a photoelectric conversion device, wherein the substrate is a flexible substrate. In any one of Claims 8 thru | or 14,
A method for manufacturing a photoelectric conversion device, comprising: providing a color filter between the substrate, the first island-shaped semiconductor film, and the first electrode.   A semiconductor device comprising the photoelectric conversion device according to claim 1.