JP4845592B2 - Method for manufacturing semiconductor device - Google Patents

Description

The present invention relates to a method for manufacturing a groove in a substrate and a method for cutting the substrate. The present invention also relates to a method for manufacturing a semiconductor device. A semiconductor device corresponds to a transistor including a transistor.

In recent years, development of semiconductor devices including transistors has been promoted. A semiconductor device is manufactured by forming a transistor on a substrate and then cutting the substrate.

In many cases of cutting a substrate, first, a groove (also referred to as a scribe line) is formed on the surface of the substrate using a scribing device. Next, the substrate is forcibly cut along the groove by using a cutting device. In the cutting of a substrate using a laser beam (laser beam is included in laser light; the same applies hereinafter), first, the substrate is selectively irradiated with the laser beam to locally heat the substrate. Next, the surface of the heated substrate is locally cooled with a coolant. Then, a board | substrate is cut | disconnected by forming a crack using the thermal stress which generate | occur | produces in a board | substrate (for example, refer patent document 1).
JP 2001-64029 A

When the substrate is cut using a scribe device, the groove may not be formed in a desired shape due to the layer provided on the surface of the substrate. As a result, the substrate cannot be cut into a desired shape, which can be a factor for reducing the yield. In addition, since the substrate is cut using a pressing force, a crack easily runs from the groove, which adversely affects the cut surface (see the photograph of the cut surface of the glass substrate in FIG. 6D). Further, when the substrate is plastic, burrs can occur. A burr means a state where corners are not smoothly processed, and is often a whisker. As described above, when the substrate is cut using the scribing apparatus, an appearance problem of the cut surface occurs, which causes a reduction in yield. In addition, it has been difficult to form a scribe line having a polygonal or rounded shape by cutting a substrate using a scribe device.

Moreover, the cutter is used for the scribe device. Cutters wear out when used multiple times and need to be replaced. Since such a cutter is expensive, it is difficult to reduce the production cost when the cutter is used.

In cutting a substrate using a laser beam, the substrate may be deformed to heat the substrate, or a crack may be generated in the substrate because stress remains in the substrate.

In view of the above circumstances, the present invention provides a method for manufacturing a groove in a substrate, a method for cutting a substrate, and a method for manufacturing a semiconductor device, which can improve yield.

The substrate groove manufacturing method of the present invention includes a step of selectively irradiating a laser beam to form a groove in the substrate. The present invention is characterized in that ablation processing is used. Ablation processing is a method in which a molecular bond in a portion irradiated with a laser beam, that is, a portion that has absorbed a laser beam is cut and photodecomposed, vaporized and evaporated. This is a process that uses the phenomenon. That is, in the substrate groove manufacturing method of the present invention, the substrate is irradiated with a laser beam, the molecular bond of the portion irradiated with the laser beam is cut, photolyzed, vaporized and evaporated to the substrate. Grooves are formed.

The substrate cutting method of the present invention includes a step of selectively irradiating a laser beam to form a groove in the substrate, and a step of selectively irradiating the groove with a laser beam to cut the substrate. In the present invention, ablation processing is used, and the substrate is cut by irradiating the substrate with a laser beam, cutting the molecular bond of the portion irradiated with the laser beam, photolyzing, vaporizing and evaporating. .

Alternatively, the substrate may be thinned by performing one or both of grinding and polishing on the substrate using one or both of a grinding device and a polishing device. More specifically, the substrate is thinned to 100 μm or less using one or both of a grinding device and a polishing device. By making the substrate thin, grooves can be formed in the substrate and the substrate can be cut easily and in a short time.

One embodiment of a method for manufacturing a semiconductor device according to the present invention is characterized by using the above-described substrate groove manufacturing method and substrate cutting method. A method for manufacturing a semiconductor device of the present invention includes a step of forming a layer including a transistor over a substrate, a step of forming a first insulating layer over the layer including a transistor, and an opening provided in the first insulating layer. A step of forming a conductive layer connected to a source region or a drain region of the transistor through the portion, a step of forming a second insulating layer covering the conductive layer, and ablation processing by selectively irradiating a laser beam The step of cutting the first insulating layer, the insulating layer provided in the layer including the transistor, the second insulating layer, and the substrate is performed.

Another embodiment of a method for manufacturing a semiconductor device of the present invention includes a step of forming a layer including a transistor over a substrate, a step of forming a first insulating layer over the layer including a transistor, and a step of providing the first insulating layer A step of forming a conductive layer connected to a source region or a drain region of the transistor, a step of forming a second insulating layer covering the conductive layer, and a laser beam are selectively irradiated through the formed opening. Forming a groove in one or a plurality selected from the first insulating layer, the insulating layer provided in the layer including the transistor, the second insulating layer, and the substrate by performing ablation processing The groove includes the step of cutting the first insulating layer, the insulating layer provided in the layer including the transistor, the second insulating layer, and the substrate.

Another embodiment of a method for manufacturing a semiconductor device of the present invention includes a step of forming a layer including a transistor over one surface of a substrate, a step of forming a first insulating layer over the layer including a transistor, A step of forming a conductive layer connected to a source region or a drain region of the transistor through an opening provided in the insulating layer; a step of forming a second insulating layer covering the conductive layer; The first insulating layer, the insulating layer provided in the layer including the transistor, the second insulating layer, and the substrate are cut by polishing the surface and selectively ablating by laser beam irradiation. The process of carrying out.

Another embodiment of a method for manufacturing a semiconductor device of the present invention includes a step of forming a layer including a transistor over a substrate, a step of forming a first insulating layer over the layer including a transistor, and a step of providing the first insulating layer A step of forming a conductive layer connected to a source region or a drain region of the transistor through the formed opening, a step of forming a second insulating layer covering the conductive layer, and polishing the other surface of the substrate A process and ablation processing by selectively irradiating with a laser beam, whereby one selected from the first insulating layer, the insulating layer provided in the layer including the transistor, the second insulating layer, and the substrate; A step of forming a plurality of grooves, and a step of cutting the first insulating layer, the insulating layer provided in the layer including the transistor, the second insulating layer, and the substrate using the formed grooves.

Note that a solid-state laser that can oscillate a laser beam with a wavelength of 1 nm to 380 nm in the ultraviolet region is preferably used as the laser. This is because the Nd: YVO ₄ laser beam having a wavelength in the ultraviolet region is more easily absorbed by the substrate than other laser beams on the long wavelength side and can be ablated.

A glass substrate may be used as the substrate. This is because the glass substrate easily absorbs the laser beam in the ultraviolet light region and is therefore easily ablated.

Further, a plastic substrate may be used as the substrate. In the case of using a plastic substrate, a laser beam with a wavelength of 1 nm to 350 nm is preferably used. The plastic substrate is preferably made of polyethylene terephthalate.

As the laser beam, a laser beam oscillated from an Nd: YVO ₄ laser having a wavelength in the ultraviolet region may be used.

In the present invention, it is preferable that the corner of the cut surface of the substrate is rounded.

The method for dividing a substrate or forming a groove according to the present invention can also be applied to a method for manufacturing a liquid crystal display device, an EL (OLED) display device, or the like that requires a substrate dividing method. In addition, the method of dividing a substrate or the groove of the present invention can be applied not only to an active matrix display device but also to a passive matrix display device. These devices also include an insulating layer.

In the present invention, by using ablation processing, the formation of grooves in the insulating layer provided on the substrate and the substrate and the cutting of the insulating layer provided on the substrate and the substrate can be easily performed in a short time. And the yield can be improved. In addition, since the present invention uses a laser beam, not only simple rectangular processing but also processing into a desired shape such as a polygonal shape or a rounded shape can be easily performed.

Embodiments of the present invention will be described in detail with reference to the drawings. 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. Note that in the structures of the present invention described below, the same reference numerals are used in common in different drawings.

A method for manufacturing a semiconductor device of the present invention will be described with reference to FIGS. Hereinafter, a case where six thin film integrated circuits are formed over the substrate 11 will be described. 1A, 2A, and 3A, a region where one thin film integrated circuit is provided corresponds to a region 26 surrounded by a dotted line. 1B, 2B, and 3B are cross-sectional views from point A to point B in FIGS. 1A, 2A, and 3A, respectively. It corresponds to.

First, the insulating layer 12 is formed over one surface of the substrate 11 (see FIG. 1B). Next, a layer including a plurality of transistors 13 is formed over the insulating layer 12. Subsequently, an insulating layer 15 and an insulating layer 16 are formed over the layer including the plurality of transistors 13. Next, conductive layers 17 to 24 connected to the source region or the drain region of each of the plurality of transistors 13 are formed through openings provided in the insulating layer 15 and the insulating layer 16. Next, the insulating layer 25 is formed so as to cover the conductive layers 17 to 24.

The substrate 11 corresponds to a glass substrate, a plastic substrate, a silicon substrate, a quartz substrate, or the like. Preferably, a glass substrate or a plastic substrate is used as the substrate 11. A glass substrate or a plastic substrate can be easily manufactured with a side of 1 meter or more, and a substrate with a desired shape can be easily manufactured. Therefore, for example, if a large glass substrate or plastic substrate having a quadrangular shape and one side of 1 meter or more is used, productivity can be greatly improved. Such an advantage is a great advantage compared to the case of using a circular silicon substrate.

The insulating layer 12 serves to prevent impurities from entering from the substrate 11. The insulating layer 12 is formed by a single layer or a stack of layers containing silicon oxide or silicon nitride by a sputtering method, a plasma CVD method, or the like. The silicon oxide material is a substance containing silicon (Si) and oxygen (O), and corresponds to silicon oxide, silicon oxide containing nitrogen, and the like. The silicon nitride material is a substance containing silicon and nitrogen (N) as main components, and corresponds to silicon nitride, silicon nitride containing oxygen, and the like. Note that the insulating layer 12 is not necessarily provided when not necessary.

Each of the plurality of transistors 13 includes a semiconductor layer 27, an insulating layer 14, and a conductive layer 29 that is a gate electrode. The semiconductor layer 27 includes an impurity region 30 that functions as a source region or a drain region and a channel formation region 31. An impurity element imparting N-type or P-type is added to the impurity region 30. Specifically, an impurity element imparting N-type (elements belonging to Group 15 such as phosphorus (P) or arsenic (As)) and an impurity element imparting P-type (for example, boron (B)) are added. . The insulating layer 14 corresponds to a gate insulating layer.

In the illustrated configuration, only the plurality of transistors 13 are formed, but the present invention is not limited to this configuration. Elements provided over the substrate 11 may be appropriately adjusted depending on the use of the semiconductor device. For example, when a semiconductor device having a function of transmitting and receiving electromagnetic waves is formed, only a plurality of transistors may be formed over the substrate 11 or a plurality of transistors and a conductive layer functioning as an antenna may be formed over the substrate 11. Note that the conductive layer functioning as an antenna may have a plurality of layers instead of a single layer. In the case of forming a semiconductor device having a function of storing data, a plurality of transistors and storage elements (eg, transistors and memory transistors) may be formed over the substrate 11. In the case of forming a semiconductor device having a function of controlling a circuit, a function of generating a signal, or the like (eg, a CPU, a signal generation circuit, or the like), a transistor may be formed over the substrate 11. In addition to the above, other elements such as a resistance element and a capacitor element may be formed as necessary. Note that when a semiconductor device having a function of transmitting and receiving electromagnetic waves is formed, a plurality of transistors may be formed only over the substrate 11.

The insulating layers 15 and 16 are formed as a single layer or stacked layers of an inorganic material or an organic material using an SOG (spin-on-glass) method, a droplet discharge method, a screen printing method, or the like. For example, a silicon nitride containing oxygen may be formed as the insulating layer 15, and a silicon oxide containing nitrogen may be formed as the insulating layer 16.

Next, a laser beam is selectively applied to a predetermined position, that is, an insulating layer 14, an insulating layer 15, an insulating layer 16, an insulating layer provided in a layer including the substrate 11, the insulating layer 12, and the plurality of transistors 13 A groove 32 is formed in one or a plurality selected from the layer 25 (see FIGS. 2A and 2B). In the configuration shown in the figure, the insulating layer 12, the insulating layer 14, the insulating layer 15, and the insulating layer 16 are cut by a laser beam, and a groove 32 is formed in the substrate 11.

The laser is composed of a laser medium, an excitation source, and a resonator. Lasers can be classified into gas lasers, liquid lasers, and solid-state lasers according to the medium. Free lasers, semiconductor lasers, and X-ray lasers are classified according to the characteristics of oscillation. In the present invention, any laser is used. Also good. Note that a gas laser or a solid laser is preferably used, and a solid laser is more preferably used.

Gas lasers include helium neon laser, carbon dioxide laser, excimer laser, and argon ion laser. The excimer laser includes a rare gas excimer laser and a rare gas halide excimer laser. A rare gas excimer laser has oscillation by three types of excited molecules, argon, krypton, and xenon. Argon ion lasers include rare gas ion lasers and metal vapor ion lasers.

Liquid lasers include inorganic liquid lasers, organic chelate lasers, and dye lasers. Inorganic liquid lasers and organic chelate lasers use rare earth ions such as neodymium, which are used in solid-state lasers, as laser media.

A laser medium used by a solid-state laser is obtained by doping a solid matrix with an active species that acts as a laser. The solid matrix is a crystal or glass. The crystal is YAG (yttrium / aluminum / garnet crystal), YLF, YVO ₄ , YAlO ₃ , sapphire, ruby, or alexandride. In addition, the active species having a laser action are, for example, trivalent ions (Cr ³⁺ , Nd ³⁺ , Yb ³⁺ , Tm ³⁺ , Ho ³⁺ , Er ³⁺ , Ti ³⁺ ).

Note that a continuous wave laser or a pulsed laser can be used as the laser used in the present invention. The laser beam irradiation conditions (for example, frequency, power density, energy density, beam profile, etc.) take into consideration the thickness of the substrate 11, the insulating layer 12, the insulating layer 14, the insulating layers 15 and 16, the insulating layer 25, their materials, and the like. And control as appropriate.

When the substrate 11 is a glass substrate, a solid laser having a wavelength of 1 nm or more and 380 nm or less in the ultraviolet region is preferably used as the laser. More preferably, an Nd: YVO ₄ laser having a wavelength of 1 nm or more and 380 nm or less in the ultraviolet region may be used. This is because, in a laser having a wavelength in the ultraviolet region, light is more easily absorbed by a substrate (particularly a glass substrate) than other long-wavelength lasers, and ablation processing is easy. In addition, the Nd: YVO ₄ laser is particularly easy to ablate. When the substrate 11 is a plastic substrate, a solid laser having a wavelength of 1 nm to 350 nm may be used. Also in this case, it is preferable to use an Nd: YVO ₄ laser.

Note that the laser irradiation apparatus for irradiating the laser beam includes a moving table, a substrate, a head unit, and a control unit. The moving table is provided with suction holes. The substrate is held in a suction hole on the moving table. The head unit irradiates the laser beam emitted from the laser oscillation device through the laser head. The control unit moves one or both of the moving table and the head unit, thereby positioning the laser head at an arbitrary position on the surface of the substrate and irradiating the laser beam. The control unit recognizes and determines a processing location from a relative position based on a positioning mark on the substrate imaged by the CCD camera.

Next, laser beam is selectively irradiated to cut the substrate 11, the insulating layer 12, the insulating layer 14, the insulating layer 15, the insulating layer 16, and the insulating layer 25 (see FIGS. 3A and 3B). Or you may cut | disconnect dynamically using the formed groove | channel. Through the above steps, a stacked body 33 including the substrate 11 and a plurality of transistors can be obtained.

Next, as necessary, the stacked body 33 including the substrate 11 and the plurality of transistors 13 is sealed using the film 34 and the film 35 (see FIG. 4A). The film 34 and the film 35 are made of a material such as polyethylene, polycarbonate, polypropylene, polyester, vinyl, polyvinyl fluoride, vinyl chloride, ethylene vinyl acetate, urethane, polyethylene terephthalate, or a fibrous material (for example, paper). The film may be a single layer, or a plurality of films may be laminated. Further, an adhesive layer may be provided on the surface. Adhesive layer is polyester, polyolefin-based thermoplastic resin, thermosetting resin, UV curable resin, vinyl acetate resin adhesive, vinyl copolymer resin adhesive, epoxy resin adhesive, urethane resin adhesive, rubber system It corresponds to a layer containing an adhesive such as an adhesive or an acrylic resin adhesive.

The surface of each of the film 34 and the film 35 may be coated with silicon dioxide (silica) powder. The coating can maintain waterproofness even in a high temperature or high humidity environment. That is, it can have a moisture resistance function. Further, the surface thereof may be coated with a conductive material such as indium tin oxide. The coated material is charged with static electricity, and the plurality of transistors 13 can be protected from the static electricity. That is, an antistatic function can be provided. Further, the surface thereof may be coated with a material containing carbon as a main component (for example, diamond-like carbon or carbon containing nitrogen). The coating increases the strength and can suppress deterioration and destruction of the semiconductor device. The film 34 and the film 35 may be formed of a material obtained by mixing a base material (for example, resin) with silicon dioxide, a conductive material, or a material containing carbon as a main component. Further, an antistatic function can be imparted by applying a surfactant to the surface of the film 34 or film 35 or by directly kneading the surfactant.

The plurality of transistors 13 are sealed by the film 34 and the film 35 by melting the surface layer of the film 34 and the film 35 or the adhesive layer of each surface of the film 34 and the film 35 by heat treatment. Further, if necessary, pressure treatment is performed for adhesion.

The semiconductor device of the present invention is characterized in that a stacked body including a substrate 11 and a plurality of transistors 13 is provided between a film 34 and a film 35. With the above characteristics, entry of harmful gas, water, and impurity elements can be suppressed. Therefore, deterioration and destruction of the plurality of transistors 13 can be suppressed and reliability can be improved.

Note that a conductive layer functioning as an antenna may be provided on one or both of the film 34 and the film 35. When the laminated body 33 including the plurality of transistors 13 is sealed with the film 34 and the film 35, the conductive layers on the film 34 and the film 35 may be electrically connected to the plurality of transistors 13. . At this time, an exposed connection conductive layer may be provided in the stacked body including the plurality of transistors 13. And when sealing, the said conductive layer for connection and the conductive layer on the film 34 and the film 35 are made to contact | connect. Then, a semiconductor device capable of transmitting and receiving electromagnetic waves can be provided.

In addition, the other surface of the substrate 11 is subjected to one or both of grinding and polishing using one or both of a grinding device (for example, a grinding machine) and a polishing device (for example, a grindstone), so that the substrate 11 is thinned. May be used. After that, the laser beam is selectively irradiated to cut the insulating layer 12, the insulating layer 14, the insulating layer 15, the insulating layer 16, and the thinned substrate 11. Subsequently, the stacked body 33 including the substrate 11 and the plurality of transistors 13 is sealed using the films 34 and 35 (see FIG. 4B). Note that one or both of grinding and polishing may be performed so that the thickness of the substrate 11 is 100 μm, preferably 50 μm or less, and more preferably 5 μm or less.

When one or both of grinding and polishing are performed, a film for protection is preferably provided on the insulating layer 25 and fixed. Then, one or both of grinding and polishing of the other surface of the substrate 11 are preferably performed. The film provided on the insulating layer 25 may be a film having a UV curable adhesive on the surface. Further, after one or both of grinding and polishing, the film provided on the insulating layer 25 may be left as it is or may be removed.

Thus, by thinning the substrate 11, the insulating layer 12, the insulating layer 14, the insulating layer 15, the insulating layer 16, and the substrate 11 can be easily and quickly cut using a laser beam. . In addition, a flexible semiconductor device can be provided by thinning the substrate. By providing flexibility, the design can be improved, and mounting on an article having a flexible shape can be easily performed, which can be utilized in various fields.

Further, in the above process, the shape obtained by cutting the substrate 11 is a simple square shape, but the present invention is not limited to this. For example, a hexagonal groove 32 is formed in the stacked body including the substrate 11 by scanning and irradiation with a laser beam (see FIG. 5A), and subsequently, the stacked body including the substrate 11 is irradiated with a laser beam. May be cut (see FIG. 5B). Then, a hexagonal laminate including the substrate 11 can be formed. Further, a laser beam is irradiated to form a circular groove 32 in the stacked body including the substrate 11 (see FIG. 5C), and the laser beam is irradiated to cut the stacked body including the substrate 11. It is also possible (see FIG. 5D). Thereby, a circular laminated body including the substrate 11 can be formed.

By devising the shape in this way, the inner angle of the top surface shape of the laminate including the substrate 11 is set to 90 degrees or more (for example, a polygonal shape such as a hexagon), or the corner of the laminate including the substrate 11 is eliminated ( For example, it can be easily handled during transportation by making it circular or elliptical. In addition, it is possible to prevent chipping, cracking, and burring when mounting on a product.

The result of the experiment using the present invention will be described with reference to FIG. 6A to 6C show cut surfaces of the glass substrate.

As a first experiment, a glass substrate was selectively irradiated with a laser beam to form a groove in the glass substrate, and the glass substrate was dynamically cut. The size of the glass substrate used was 126.6 mm × 126.6 mm × thickness 0.7 mm. As the laser, an Nd: YVO ₄ laser having a wavelength of 266 nm was used. The laser beam irradiation conditions were an output power of 2.0 W, a frequency of 15 kHz, and a feed rate of 20 mm / sec.

As a result of selectively irradiating the glass substrate with the laser beam, a V-shaped groove was formed in the glass substrate (see FIG. 6A). Subsequently, as a result of irradiating the glass substrate again with the laser beam, a larger groove was formed in the depth direction (see FIG. 6B). Next, as a result of changing the feed rate from 20 mm / sec to 5 mm / sec and irradiating the glass substrate again with the laser beam, a larger groove was formed in the depth direction (see FIG. 6C). Then, when it tried to cut | disconnect the glass substrate in which said groove | channel was formed dynamically, it was able to cut | disconnect easily. At this time, the position of the groove irradiated with the laser beam became the cut surface.

As a second experiment, the glass substrate was cut only by selective irradiation of the laser beam to the glass substrate. The laser beam was irradiated 6 times. The size of the glass substrate used was 126.6 mm × 126.6 mm × thickness 0.7 mm. As the laser, an Nd: YVO ₄ laser having a wavelength of 266 nm was used. The laser irradiation conditions were an output power of 2.0 W, a frequency of 15 kHz, and a feed rate of 5 mm / sec. As a result of the experiment, it was possible to easily cut the glass substrate without causing cracks.

As a third experiment, the glass substrate was polished to 100 μm or less using a polishing apparatus. Subsequently, the glass substrate was cut only by selectively irradiating the polished glass substrate with a laser beam. The size of the glass substrate used was 126.6 mm × 126.6 mm × thickness 0.7 mm. As the laser, an Nd: YVO ₄ laser having a wavelength of 266 nm was used. The laser irradiation conditions were an output power of 2.0 W, a frequency of 15 kHz, and a feed rate of 30 mm / sec. As a result of the experiment, it was possible to easily cut the glass substrate without causing cracks.

From these results, when the glass substrate is irradiated with a laser beam to form a groove in the glass substrate, or when the glass substrate is irradiated with the laser beam to cut the glass substrate, the thickness of the glass substrate is controlled. It can be seen that it is necessary to appropriately adjust the laser irradiation conditions such as output power, feed rate and number of irradiations.

In addition, when a glass substrate is irradiated with a laser beam to form a groove in the glass substrate, the cut surface of the groove is rounded (see FIGS. 6B and 6C). Compared with the case where the cut surface has corners, as described above, when the cut surface is rounded, it is possible to prevent the corners of the cut surface from being chipped and the occurrence of cracks. Due to such advantages, it is possible to easily handle the glass substrate when it is transported mainly using a robot or the like. Moreover, when mounting on a product, generation | occurrence | production of a chip and a crack can be suppressed and the damage and destruction of a board | substrate can be suppressed.

The structure of the semiconductor device of the present invention will be described with reference to FIG. The semiconductor device 100 of the present invention includes an arithmetic processing circuit 101, a memory circuit 103, an antenna 104, a power supply circuit 109, a demodulation circuit 110, and a modulation circuit 111. The semiconductor device 100 includes the antenna 104 and the power supply circuit 109 as essential components, and other components are provided as appropriate according to the use of the semiconductor device 100.

The arithmetic processing circuit 101 performs instruction analysis, control of the storage circuit 103, output of data to be transmitted to the modulation circuit 111, and the like based on a signal input from the demodulation circuit 110.

The memory circuit 103 includes a circuit including a memory element and a control circuit that performs data writing and data reading. The memory circuit 103 stores at least an identification number of the semiconductor device itself. The identification number is used to distinguish from other semiconductor devices. The memory circuit 103 includes an organic memory, a DRAM (Dynamic Random Access Memory), an SRAM (Static Random Access Memory), an FeRAM (Ferroelectric Random Access Memory), a mask ROM (Read Only Memory ROM). It has one or more types selected from EPROM (Electrically Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory) and flash memory. An organic memory has a structure in which a layer containing an organic compound is sandwiched between a pair of conductive layers. Since the structure is simple, the organic memory has at least the following two advantages. One is that the manufacturing process can be simplified and the cost can be reduced. The other is that the area of the laminated body can be easily reduced, and a large capacity can be easily realized. Further, since it is a non-volatile memory, a battery may or may not be incorporated. Therefore, it is preferable to use an organic memory as the memory circuit 103.

The antenna 104 converts the carrier wave supplied from the reader / writer 112 into an AC electrical signal. Further, load modulation is applied by the modulation circuit 111. The power supply circuit 109 generates a power supply voltage using the AC electrical signal converted by the antenna 104 and supplies the power supply voltage to each circuit.

The demodulation circuit 110 demodulates the AC electrical signal converted by the antenna 104 and supplies the demodulated signal to the arithmetic processing circuit 101. The modulation circuit 111 applies load modulation to the antenna 104 based on the signal supplied from the arithmetic processing circuit 101.

The reader / writer 112 receives the load modulation applied to the antenna 104 as a carrier wave. Further, the reader / writer 112 transmits a carrier wave to the semiconductor device 100. Note that the carrier wave is an electromagnetic wave transmitted and received by the reader / writer 112, and the reader / writer 112 receives the carrier wave modulated by the modulation circuit 111.

As described above, the semiconductor device of the present invention having a function of transmitting and receiving electromagnetic waves wirelessly includes an RFID (Radio Frequency IDentification), an RF chip, an RF tag, an IC chip, an IC tag, an IC label, a wireless chip, a wireless tag, and an electronic chip. Called electronic tag, wireless processor, wireless memory. This embodiment can be freely combined with any of the other embodiments.

The semiconductor device 100 to which the present invention is applied can be used for various articles and systems by utilizing the function of transmitting and receiving electromagnetic waves. Articles include, for example, keys (see FIG. 8A), banknotes, coins, securities, bearer bonds, certificates (driver's license, resident's card, etc., see FIG. 8B), books, Containers (such as petri dishes, see FIG. 8C), packaging containers (such as wrapping paper and bottles, see FIGS. 8E and 8F), recording media (discs, video tapes, etc.), vehicles (bicycles) Etc.), accessories (such as bags and glasses, see FIG. 8D), foods, clothing, daily necessities, electronic devices (liquid crystal display devices, EL display devices, television devices, portable terminals, etc.) and the like. The semiconductor device of the present invention is fixed by being attached or embedded on the surface of an article having various shapes as described above. The system is an article management system, an authentication function system, a distribution system, or the like. By using the semiconductor device of the present invention, the system can be enhanced in function, multifunctional, and added value. This embodiment can be freely combined with other embodiment modes and other embodiments.

In this example, a method for manufacturing a transistor is described with reference to FIGS.

First, the insulating layer 552 is formed over the substrate 551 (see FIG. 9A). Next, the insulating layer 553 is formed over the insulating layer 552. Next, the semiconductor layer 554 is formed over the insulating layer 553. Next, a gate insulating layer 555 is formed over the semiconductor layer 554.

The insulating layer 552, the insulating layer 553, the semiconductor layer 554, the gate insulating layer 555, and the like are preferably formed using plasma treatment. The plasma treatment performed here is preferably performed at an electron density of 1 × 10 ¹¹ cm ⁻³ or more and an electron temperature of plasma of 1.5 eV or less. More specifically, it is preferable that the electron density is 1 × 10 ¹¹ cm ⁻³ or more and 1 × 10 ¹³ cm ⁻³ or less and the plasma electron temperature is 0.5 eV or more and 1.5 eV or less.

When the electron density of plasma is high and the electron temperature in the vicinity of an object to be processed (eg, the insulating layers 552, 553, the semiconductor layer 554, the gate insulating layer 555, or the like) is low, damage to the object to be processed due to plasma can be prevented. it can. In addition, since the electron density of plasma is as high as 1 × 10 ¹¹ cm ⁻³ or more, an oxide or a nitride formed by oxidizing or nitriding an object to be irradiated using plasma treatment is a CVD method or a sputtering method. Compared with the thin film formed by the above, etc., it is excellent in uniformity of the film thickness and the like, and can be formed as a dense film. In addition, since the electron temperature of plasma is as low as 1.5 eV or less, oxidation or nitridation can be performed at a lower temperature than conventional plasma treatment or thermal oxidation. For example, even if the plasma treatment is performed at a temperature lower by 100 degrees or more than the strain point of the glass substrate, the oxidation or nitridation treatment can be sufficiently performed.

Next, a conductive layer 501 and a conductive layer 503 are stacked over the gate insulating layer 555. Each of the conductive layers 501 and 503 is formed using a metal such as tungsten, chromium, tantalum, tantalum nitride, or molybdenum, or an alloy or compound containing the metal as a main component. Note that the conductive layer 501 and the conductive layer 503 are formed using different materials. Specifically, a material that causes a difference in etching rate is used in an etching process performed later.

Next, a resist mask 506 is formed over the conductive layer 503. The mask 506 is formed using an exposure mask including a light shielding film and a semi-transmissive film. The specific configuration of this mask will be described later.

Next, the conductive layer 503 is etched using the mask 506 to form a mask 507 and a conductive layer 504 (see FIG. 9B). The mask 507 is sputtered by ions accelerated by an electric field, divided into two patterns, and arranged separately. Next, the conductive layer 501 is etched using the mask 507 and the conductive layer 504 to form the conductive layer 502 (see FIG. 9C).

Next, the mask 507 and the conductive layer 504 are selectively etched to form the mask 508 and the conductive layer 505 (see FIG. 9D). The mask 508 is sputtered by ions accelerated by an electric field to reduce its size. In this step, the conductive layer 502 is prevented from being etched by adjusting the bias voltage applied to the substrate side.

Next, an impurity element imparting one conductivity type is added to the semiconductor layer 554 to form a first concentration impurity region 509, a first concentration impurity region 516, and a first concentration impurity region 517. (See FIG. 10A). At this time, an impurity element is added to the semiconductor layer 554 in a self-aligning manner using the conductive layers 502 and 505.

Next, an impurity element imparting one conductivity type is added to the semiconductor layer 554 to form a second concentration impurity region 510 and a second concentration impurity region 511 (see FIG. 10B). The second concentration is higher than the first concentration. Note that an impurity element imparting one conductivity type is not added to the semiconductor layer 554 which overlaps with the conductive layer 505. Therefore, the semiconductor layer 554 in a region overlapping with the conductive layer 505 functions as a channel formation region. Through the above steps, the thin film transistor 520 is completed.

Next, an insulating layer 512 and an insulating layer 513 are formed so as to cover the thin film transistor 520 (see FIG. 10C). Next, the second concentration impurity region 510, the conductive layer 514 connected to the second concentration impurity region 511, and the conductive layer 515 are formed through the openings provided in the insulating layer 512 and the insulating layer 513. To do.

The above process is characterized in that the conductive layer 501 and the conductive layer 503 are etched using a mask 506 having a complicated shape with different thicknesses. By using the mask 506, the masks 507 which are arranged separately can be formed. In addition, the interval between the two channel formation regions can be reduced. Specifically, the interval between the two channel formation regions can be less than 2 μm. Accordingly, when a multi-gate thin film transistor having two or more gate electrodes is formed, the occupation area can be reduced, so that high integration can be realized and a high-definition semiconductor device can be provided. .

Next, a method for forming the mask 506 will be described with reference to FIG. FIG. 11A is an enlarged plan view of a part of the exposure mask. FIG. 11B is a partial cross-sectional view of the exposure mask corresponding to FIG. 11A and a cross-sectional view of a stacked body including the substrate 551.

The exposure mask includes a light-transmitting substrate 560, a light-shielding film 561, a light-shielding film 562, and a semi-transmissive film 563. The light shielding film 561 and the light shielding film 562 are made of a metal film such as chromium, tantalum, or CrNx (x is a positive integer). For the semipermeable membrane 563, it is necessary to appropriately select a material with respect to the exposure wavelength. For example, TaSixOy (x and y are positive integers), CrOxNy (x and y are positive integers), CrFxOy (x and y are Positive integers), MoSixNy (x and y are positive integers), and MoSixOy (x and y are positive integers) may be used. The semipermeable membrane 563 functions as an auxiliary pattern.

When the resist mask is exposed using the exposure mask having the above structure, the resist mask is roughly classified into an unexposed area 521 and an exposed area 522. When development processing is performed in this state, the resist in the exposed region 522 is removed, and a part of the resist corresponding to the semi-permeable film 563 in the exposure mask in the unexposed region 521 is removed. A mask 506 having a shape as shown in FIG. 9A is formed.

6A and 6B illustrate a semiconductor device of the present invention. 6A and 6B illustrate a semiconductor device of the present invention. 6A and 6B illustrate a semiconductor device of the present invention. 6A and 6B illustrate a semiconductor device of the present invention. 6A and 6B illustrate a semiconductor device of the present invention. The SEM image which shows the cut surface of a glass substrate. 6A and 6B illustrate a semiconductor device of the present invention. 6A and 6B illustrate a semiconductor device of the present invention. 6A and 6B illustrate a semiconductor device of the present invention. 6A and 6B illustrate a semiconductor device of the present invention. 6A and 6B illustrate a semiconductor device of the present invention.

Explanation of symbols

11 Substrate 12 Insulating layer 13 Transistor 14 Insulating layer 15 Insulating layer 16 Insulating layer 17 Conductive layer 25 Insulating layer 26 Region 27 surrounded by dotted line 27 Semiconductor layer 29 Conductive layer 30 Impurity region 31 Channel formation region 32 Groove 33 Laminate 34 Film 35 Film 100 Semiconductor device 101 Arithmetic processing circuit 103 Memory circuit 104 Antenna 109 Power supply circuit 110 Demodulation circuit 111 Modulation circuit 112 Reader / writer 501 Conductive layer 502 Conductive layer 503 Conductive layer 504 Conductive layer 505 Conductive layer 506 Mask 507 Mask 508 Mask 509 First Impurity region 510 of the second concentration impurity region 511 of the second concentration impurity region 512 of the second concentration 512 insulating layer 513 insulating layer 514 conductive layer 515 conductive layer 516 first concentration impurity region 517 first concentration impurity region 520 Thin film transistor 521 Unexposed region 522 region 551 substrate 552 insulating layer 553 insulating layer 554 semiconductor layer 555 gate insulating layer 560 substrate 561 light shielding film 562 light shielding film 563 semi-transmissive film

Claims (4)

Forming a first insulating layer on the substrate;
Forming a semiconductor layer on the first insulating layer;
Forming a second insulating layer on the semiconductor layer;
Forming a first conductive layer and a second conductive layer on the second insulating layer;
On the second conductive layer, a mask having a different film thickness formed using an exposure mask including a light-shielding film and a light-transmitting film is formed from a resist.
Etching the second conductive layer using the masks having different thicknesses to form a third conductive layer, and simultaneously forming the masks having different thicknesses on the two first masks,
Etching the first conductive layer using the two first masks and the third conductive layer to form a fourth conductive layer;
Selectively etching the third conductive layer to form two fifth conductive layers;
Using the fourth conductive layer and the two fifth conductive layers as a mask, an impurity element imparting a first conductivity type is added to the semiconductor layer, and a first impurity region having a first concentration is added. Forming a second impurity region having a first concentration and a third impurity region having a first concentration;
Using the two fifth conductive layers as masks, an impurity element imparting a second conductivity type is added to the semiconductor layer, so that a second impurity concentration first impurity region and a second concentration first impurity region are added. A method for manufacturing a semiconductor device, comprising forming two impurity regions. In claim 1,
A method for manufacturing a semiconductor device, wherein a semiconductor layer in a region overlapping with each of the two fifth conductive layers functions as a channel formation region. In claim 1 or 2,
The method for manufacturing a semiconductor device, wherein the second concentration is higher than the first concentration. In any one of Claims 1 thru | or 3
Forming a third insulating layer over the semiconductor layer to which the impurity element imparting the second conductivity type is added;
Fabrication of a semiconductor device, wherein the first insulating layer, the second insulating layer, the third insulating layer, and the substrate are cut by selectively irradiating a laser beam using ablation processing Method.