JP3077810B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a method for forming transparent electrodes arranged in a matrix corresponding to picture elements.

[Summary of the Invention]

The present invention relates to a liquid crystal display device comprising a plurality of transparent electrodes arranged in a matrix corresponding to picture elements, and a switching thin film transistor connected to each of these transparent electrodes. Is formed, and the passivation film containing hydrogen is patterned in the film to leave a passivation film containing hydrogen in the film on the thin film transistor, and thereafter, a transparent conductive film is formed at a temperature lower than a transition temperature. After forming the film, patterning is performed by etching, and then the transparent conductive film is annealed at a temperature equal to or higher than the transition temperature to form a transparent electrode, thereby improving the characteristics of the thin film transistor, improving the patterning property of the transparent conductive film, To improve the light transmittance of the transparent electrode and reduce the sheet resistance, the liquid It is obtained by allowing high quality of the display device.

[Conventional technology]

Conventionally, PSG (phospho-silicon) has been used as a passivation film for switching elements (TFTs) used in liquid crystal display devices.
icate glass) or a plasma nitride film (P-SiN film). In particular, when a P-SiN film is used as a passivation film, its mechanical strength is high, so that the switching element can be protected from scratches and moisture can be prevented from entering the switching element. Also,
Since a large amount of hydrogen (H ₂ ) is contained, hydrogen (H ₂ ) is supplied to the channel region of the switching element, which has the advantage of improving characteristics.

Next, a method of manufacturing a conventional liquid crystal display device using a P-SiN film as a passivation film will be described with reference to FIG.

First, as shown in FIG. 14A, a gate cell-aligned TFT is placed at a required position on an insulating substrate (41) made of glass or the like.
To form a switching element (Q). here,
(42) is an active layer, (43) is a gate insulating film, and (44) is a gate electrode (selection line). After that, an interlayer insulating film (for example, PSG) (45) is formed on the entire surface including the switching element (Q).

Next, as shown in FIG. 14B, windows (46s) and (46d) are formed at positions corresponding to the source region (42s) and the drain region (42d) of the active layer (42) in the interlayer insulating film (45). Form.

Next, as shown in FIG. 14C, after forming an Al layer on the entire surface, patterning is performed to form a signal line (47). This signal line (47) is connected to the drain region (42) through the window (46d).
electrically connected to d).

Next, as shown in FIG. 14D, after forming an interlayer insulating film (for example, PSG) (48) for buffer on the entire surface, a plasma nitride film (P) for passivation is formed on the upper surface of the interlayer insulating film (48). -SiN film) (49) is formed.

Next, as shown in FIG. 14E, a P-SiN film (49) and an interlayer insulating film (48) are formed at positions corresponding to the source region (42s).
After forming a window (50) penetrating through each of (45) and (45), a transparent conductive film (51) is formed on the entire surface. Thereafter, the transparent conductive film (51) is patterned to form a transparent electrode (52). At this time, the transparent electrode (52) has a shape separated for each picture element by patterning.

Next, as shown in FIG. 14F, when the substrate (53) and the substrate (41) are opposed to each other on the other insulating substrate (53), wiring portions (selection lines (44), A light shielding layer (54) is formed at a position corresponding to the portion where the signal line (47) and the like are present) and the switching element (Q). Then, the light shielding layer (5
A counter electrode (55) is formed on the entire surface including 4). The transparent electrode (52) on the substrate (41) and the counter electrode (55) on the substrate (53) are subjected to a molecular orientation treatment.

Next, as shown in FIG. 14G, the substrate (41) and the substrate (5
3) with the transparent electrode (52) and the counter electrode (55) facing each other and sealing via a spacer (not shown), and then injecting a liquid crystal layer (56) between the substrate (41) and the substrate (53). After that, the injection port is sealed and the liquid crystal display device (B) according to the conventional example is sealed.
Get.

[Problems to be solved by the invention]

Generally, a transparent conductive film formed on a substrate is formed by sputter deposition. At this time, the film quality of the transparent conductive film changes greatly depending on the substrate temperature at the time of vapor deposition. That is, when a transparent conductive film is deposited by raising the substrate temperature, a film having a high light transmittance and a low sheet resistance can be obtained, but the subsequent patterning process, that is, the etching process using an HCl solution or the like becomes difficult. There are drawbacks. On the other hand, when the transparent conductive film is deposited at a lower substrate temperature, the subsequent patterning process is facilitated, but the light transmittance is deteriorated and the sheet resistance is increased. As a result, in the related art, the latter method is emphasized with emphasis on the patterning property, that is, the transparent conductive film (51) is deposited by lowering the substrate temperature, and thereafter, the transparent electrode (52) is formed by patterning. Therefore, as described above, at present, it is inevitable to use a material having poor film quality as the transparent electrode (52).

When the transparent conductive film (51) is formed by increasing the substrate temperature with emphasis on the film quality, the patterning process becomes difficult. Therefore, patterning using a strong acid may be considered. , Passivation film (P-Si
If a crack is generated in the N film (49), there is a disadvantage that a strong acid infiltrates and the Al wiring (the signal line (47) or the like) is etched, so that it cannot be used.

The present invention has been made in view of such a point, and aims at improving the patterning property of a transparent conductive film, improving the light transmittance of a transparent electrode, and reducing the sheet resistance thereof. It is an object of the present invention to provide a method of manufacturing a liquid crystal display device which can realize high quality of the liquid crystal display device.

[Means for solving the problem]

In the method for manufacturing a liquid crystal display device according to the present invention, a plurality of transparent electrodes (12) arranged in a matrix corresponding to picture elements, and a switching thin film transistor (Q) is connected to each of the transparent electrodes (12). Forming a passivation film (5) containing hydrogen in the entire surface including the thin film transistor (Q), and a passivation film (5) containing hydrogen in the film. 5) patterning to leave a passivation film (5) containing hydrogen in the film on the thin film transistor (Q), and thereafter forming a transparent conductive film (11) at a temperature lower than the transition temperature; Patterning is performed by etching, and then the patterned transparent conductive film (11) is annealed at a temperature equal to or higher than the transition temperature to form a transparent electrode (12). With the process.

[Action]

According to the above-described manufacturing method of the present invention, the transparent conductive film (11) is formed at a temperature equal to or lower than the transition temperature and then patterned by etching.
Patterning to 1) becomes easy and man-hours can be reduced. After that, since the annealing process is performed so that the transparent conductive film (11) has a temperature equal to or higher than the transition temperature, the light transmittance of the transparent conductive film (11) is improved, and the sheet resistance is also reduced to improve the film quality. Therefore, the liquid crystal display device (A)
Quality can be improved. Furthermore, a passivation film (5) containing hydrogen is formed in the film on the entire surface including the thin film transistor (Q), and the passivation film (5) containing hydrogen is patterned in the film to form a film on the thin film transistor (Q). Passivation film containing hydrogen (5)
Since the mechanical strength of the passivation film (5) is high, the thin film transistor (Q) can be protected from scratches and moisture can be prevented from entering the thin film transistor (Q). Since a large amount of hydrogen is contained, hydrogen is supplied to the channel region of the thin film transistor (Q), which leads to improvement in characteristics of the thin film transistor (Q).

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a process chart showing a method for manufacturing a liquid crystal display device in an active matrix drive system according to the present embodiment. Hereinafter, the steps will be described in order.

First, as shown in FIG. 1A, a switching element (Q) using a gate cell aligned type TFT is formed at a required position on a transparent insulating substrate (1) made of glass or the like. Here, (2) is an active layer made of a polycrystalline silicon thin film,
(3) is a gate insulating film made of SiO ₂ or the like, and (4) is a gate electrode (selection line) made of a polycrystalline silicon layer doped with an N-type impurity. Thereafter, an interlayer insulating film (for example, PSG) (5) is formed on the entire surface including the switching element (Q).

As a method for forming the active layer (2), there is a CVD (Chemical Vapor Deposition) method, but in this method, there is a disadvantage that the grain size is not uniform and the surface is uneven. Therefore, in this example, first, the film thickness on the substrate (1) is about 800 mm.
Heat treatment (for example, at 700 ° C. for 5 to 10 minutes) on the amorphous silicon thin film (formed after forming a polycrystalline silicon thin film and then implanting Si ions into the amorphous silicon thin film) to obtain 10 ⁸ / cm ^3. After generating nuclei (nuclei for growing polycrystalline silicon, so-called seed crystals, micrograin) with a density of sec or more, 10 ⁶ / cm
Heat treatment (for example, 600 ° C., 5 to 10 hours) at a temperature corresponding to the speed at which nuclei are generated at a density of ³ · sec or less, and solid-phase grown to make a polycrystalline silicon thin film having a uniform grain size (2)
To Normally, the amorphous silicon thin film is subjected to a single heat treatment (for example, at 600 ° C. for 30 hours) to grow grains in the amorphous silicon thin film and to form a polycrystalline silicon thin film (2).
However, in this case, as shown in FIG. 2, the generation of nuclei is time-dependent, and only a few nuclei are generated at first, but increase rapidly with time. For this reason, the grain growth of the nucleus generated first grows larger by the time difference than the nucleus generated later, and as shown by the curve I in FIG. Large variations in grain size occur. When this thin film (2) is used as an active layer of the switching element (Q), a channel is formed by one grain,
Channels are formed by several grains, causing variations in characteristics. Therefore, in this example, the heat treatment is performed in two stages as described above, the nuclei are uniformly generated by the first relatively high-temperature heat treatment, and the grains are gradually grown by the next low-temperature heat treatment, whereby the structure shown in FIG. curve
As shown in II, the grains having approximately medium size become uniform throughout the thin film (2). Therefore, in this example, the characteristics of the switching element (Q) do not vary. In addition, as can be seen from the heat treatment time, it is usually 30 hours, but in this example, it can be completed in about 10 hours at most. If the thickness of the amorphous silicon thin film is more than 800 °, the generation rate of nuclei increases, so that the time of the first heat treatment can be reduced. Further, laser annealing may be used in this heat treatment. In this case, the heat treatment time can be further reduced. The final grain size may be smaller than the channel length, for example, 5 μm or less. After the second heat treatment, in order to reduce the trap density at the grain boundaries, a laser (for example, an excimer laser) that emits light having a short wavelength with energy that does not melt the polycrystalline silicon thin film (2) may be used. It may be. In this case, the heat treatment is performed at a temperature equal to or higher than 1000 ° C. and equal to or lower than the melting point of silicon. In this laser annealing, only the trap density at the grain boundary is reduced, and the grain size is maintained without change.

Next, as shown in FIG. 1B, windows (6s) and (6d) are formed at positions corresponding to the source region (2s) and the drain region (2d) of the active layer (2) in the interlayer insulating film (5). Form.

Next, as shown in FIG. 1C, a signal line (7) is formed by depositing an Al layer on the entire surface and then patterning. This signal line (7) is connected to the drain region (2d) through the window (6d).
Is electrically connected to

Next, as shown in FIG. 1D, an interlayer insulating film (for example, PSG) (8) for buffer is formed on the entire surface by, for example, a CVD method or the like, and a plasma for passivation is formed on the interlayer insulating film (8). A nitride film (P-SiN film) (9) is formed by, for example, a CVD method.

Next, as shown in FIG. 1E, a photoresist (1) is usually placed on a portion where a transparent electrode (12) to be formed later is to be separated.
After forming (0), as shown in FIG. 1F, the P-SiN film (9) and the interlayer insulating film (8) are removed by etching using the photoresist (10) as a mask. That, after P-SiN film (9) is etched away by plasma etching (CF ₄ gas), is etched away by wet etching using the interlayer insulating film (8) to dilute hydrofluoric acid. At this time,
Since the P-SiN film (9) is not removed by etching with diluted hydrofluoric acid and the interlayer insulating film (8) is removed by isotropic etching peculiar to wet etching, the remaining P-SiN film (9) is removed. The interlayer insulating film (8) existing below the side end of the P-SiN film (9) is removed.
Has a so-called overhang shape.

Next, as shown in FIG. 1G, a transparent conductive film (in this example, an ITO film is used) (11) is formed on the entire surface by sputtering deposition. At this time, the transparent conductive film (11) is electrically connected to the source region (2s) via the window (6s). In addition, the transparent conductive film (11) has an overhang portion (9) of the P-SiN film (9).
Since it is cut in a), it is separated into individual picture elements at the same time as the vapor deposition, and the portion of the film (11) connected to the source region (2s) becomes the transparent electrode (12). At this time, the substrate temperature is set to be lower than or equal to the transition temperature of the transparent conductive film (11). Transition temperature of transparent conductive film (ITO film) (11) is 190 ℃ ～ 20
Since the temperature is 0 ° C., in this example, the above-mentioned substrate temperature is set to 190 ° C. or lower (annealing treatment), and the transparent conductive film (11) is deposited.

Next, as shown in FIG. 1H, the transparent conductive film (11) is subjected to a patterning process to achieve complete separation for each picture element. That is, in the transparent conductive film (11), a part formed on the signal line (7) is removed by wet etching using an HCl solution or the like. At this time, as described above, since the substrate temperature is set to be equal to or lower than the transition temperature of the transparent conductive film (11) and the transparent conductive film (11) is deposited, the transparent conductive film (11) becomes the fourth conductive film (11). As can be seen from the X-ray diffraction intensity characteristics in FIG. A, since there is no peak indicating crystallinity, the film (11) itself is amorphous, and the etching characteristics in this state are as shown in the table below. High etching rate (using 25% HCl aqueous solution as an etching solution).

Therefore, patterning of the transparent conductive film (11) can be easily performed.

However, as can be seen from the spectral transmission characteristics curves I and II in FIG. 5, the light transmittance of the transparent conductive film (11) is deteriorated as compared with that obtained by annealing at a transition temperature or higher (curves III and IV). At the same time, the sheet resistance also deteriorates (increases) as can be seen from the sheet resistance characteristics in FIG. Therefore, in this example, after the patterning of the transparent conductive film (11), annealing is performed until the temperature of the transparent conductive film (11) becomes higher than its transition temperature (that is, 200 ° C. or higher). By this annealing process,
The light transmittance of the transparent conductive film (11) is shown by curves III and I in FIG.
V, the sheet resistance is reduced as shown in FIG. 6, and the film quality is improved. This is shown in FIG.
As can be seen from the X-ray diffraction intensity characteristics, the transparent conductive film (11)
There are peaks (P ₁ ), (P ₂ ) and (P ₃ ) indicating crystallization of the transparent conductive film (11) by setting the substrate temperature to a transition temperature or more (here, 200 ° C.) from the beginning. ) Shows the same crystallization state as the characteristics when vapor deposition (see FIG. 4C). However, when the transparent conductive film (11) is formed by setting the substrate temperature to the transition temperature or higher from the beginning, the film quality certainly improves, but the patterning characteristics thereafter deteriorate.
The annealing temperature after patterning is 20
0 ° C to 450 ° C is preferred. This is because if the temperature is 450 ° C. or higher, the switching element (Q) may be affected.

Next, as shown in FIG. 1I, a light shielding layer (14) is formed at a required position on the other insulating substrate (13). When the substrate (13) and the substrate (1) are opposed to each other, the light shielding layer (14) forms a wiring portion (a portion such as a selection line (4) and a signal line (7)) and a switching element (Q). ) Is formed at a location corresponding to the portion (see FIG. 1J). afterwards,
A counter electrode (15) is formed on the entire surface including the light shielding layer (14). The transparent electrode (12) on the substrate (1) and the substrate (13)
The upper counter electrode (15) is subjected to a molecular orientation treatment.

Next, as shown in FIG. 1J, the substrate (1) and the substrate (13)
With the transparent electrode (12) and the counter electrode (15) facing each other,
In addition, the substrate (1) and the substrate (1) are
3) The liquid crystal layer (16) is sealed in between to obtain the liquid crystal display device (A) according to this example.

As described above, according to this example, in forming the transparent conductive film (11), the substrate temperature is first set to be lower than or equal to the transition temperature of the transparent conductive film (11) which will later become the transparent electrode (12). Since (11) is deposited, its patterning characteristics are improved, and the subsequent patterning process is facilitated.
Man-hours can be reduced. In addition, transparent conductive film (11)
After the patterning process, the transparent conductive film (11) is subjected to a heat treatment so as to have a temperature equal to or higher than the transition temperature, so that the light transmittance of the transparent conductive film (11), that is, the transparent electrode (12) is improved. Further, the sheet resistance is also improved (reduced), the film quality is improved, and the quality of the liquid crystal display device (A) can be improved. In this example, in the normal case, that is, as shown in FIG. 14E, a window (FIG. 14E) penetrating the P-SiN film (49), the interlayer insulating films (48) and (45) on the source region (42s). After the formation of the transparent conductive film (51) after the formation of the transparent conductive film (51), the present invention can be applied to the process of patterning.

In the formation of the switching element (Q), particularly the active layer (2), the amorphous silicon thin film is subjected to a two-step heat treatment, that is, the first heat treatment is performed at a relatively high temperature and the second heat treatment is performed at a lower temperature. As a result, the polycrystalline silicon thin film (2) has a grain size substantially equalized, so that variations in characteristics due to variations in grain size can be prevented and the heat treatment time can be significantly reduced.

Further, the P-SiN film (9) for passivation and the interlayer insulating film (8) for buffer are removed by etching while leaving the wiring portion, so that the side edge (9a) of the P-SiN film (9) is overlaid. The transparent conductive film (11) is formed on the hang shape, and the transparent conductive film (11) is separated at the overhang portion (9a). P-SiN film (9) can leave, can be fed hydrogen in P-SiN film (9) to (H ₂₎ to the switching element (Q). Therefore, the switching characteristics of the switching element (Q) can be improved, and the quality of the liquid crystal display device (A) can be improved. Further, in this example, since the interlayer insulating layer (8) and the P-SiN film (9) are removed from the source region (2s) to the region where the transparent electrode (12) is formed, a step on the source region (2s) is formed. And the step coverage becomes good.
Therefore, when the transparent conductive film (11) is formed, disconnection on the source region (2s) does not occur, and high reliability of the liquid crystal display device (A) can be achieved. In addition, since the side end of the remaining P-SiN film (9) in FIG. 1F has an overhang shape, when the subsequent transparent conductive film (11) is deposited, the transparent conductive film (11) is simultaneously formed with the deposition. It can be separated for each picture element.

In the above embodiment, a large number of picture elements are arranged in a matrix,
Each picture element is controlled by an external signal, that is, the transparent electrode (12) formed separately for each picture element and the transparent electrode (12)
ON / OFF the liquid crystal with the counter electrode (15) formed opposite to
To display the image. As described above, the transparent electrode (12) is divided for each picture element, and there is always a portion without the transparent electrode (12). This portion always transmits light, causing a decrease in contrast. Therefore, in this example, the substrate (13) corresponding to the part without the transparent electrode (12)
A light shielding layer (14) is formed on the inner surface (see FIG. 1J). In particular, since the present embodiment employs an active matrix driving method, a switching element (Q) is formed for each picture element. Therefore, the light shielding layer (14) is formed also at a position corresponding to the switching element (Q). However, since the light shielding layer (14) does not transmit light, the amount of light reaching the transparent electrode (12) decreases. In particular, since the area ratio (opening ratio) of the portion without the light shielding layer (14) is only about 50%, the light utilization factor is deteriorated. Therefore, in this example, the light utilization rate is improved by the following means.

That is, as shown in FIG. 7, a transparent material (for example, a photoresist or the like) (21) is formed on the substrate (13) on the light incident side, and a groove (22) is formed in a required portion of the transparent material (21). Form.
The groove (22) is formed of two opposed tapered portions (including a curved surface) (22a), and is continuously formed at a position corresponding to the light shielding layer (14) formed on the inner surface of the substrate (13). It becomes. By providing the groove (22), light incident on a portion of the substrate (13) corresponding to the light shielding layer (14) is
The transparent electrode (1) is refracted by the tapered portion (22a) of 2).
2) It will be incident on the side. Therefore, the groove (22) functions as a so-called lens for refracting light, and the substrate (13)
To supply all the light incident on the transparent electrode (12) side,
Light utilization is improved.

As a specific example, for example, as shown in FIG. 8, when a light shielding layer (14) having a width d = 10 μm is formed on the inner surface of a glass substrate (13) having a thickness T = 1.1 mm, the substrate ( After a transparent material (21) having a thickness t = 1 to 5 μm is formed on the upper surface of 13), a groove (22) is formed in the transparent material (21) at a position corresponding to the light shielding layer (14). Here, considering the case where perfect parallel light is incident from above the substrate (13), the angle θ at which the light should be refracted at the tapered portion (22a) of the groove (22) is sufficient to be 0.26 °. Light scattering caused by the provision of (22) can be considered negligible. Therefore, by the above-mentioned means (providing the groove (22)), the loss of the amount of light reaching the transparent electrode (12) side can be reduced, and the aperture ratio can be apparently improved. Moreover, in the liquid crystal display device (A) according to the present embodiment, by always directing the surface on which the groove (22) is formed to the light source side, no image blur occurs at all. Also, higher resolution can be achieved.

Next, an example of a method of forming the groove (22) will be described with reference to FIGS.

First, as an example, as shown in FIG.
After a photoresist (21A) transmitting visible light is formed thereon, as shown in FIG. 9B, a portion corresponding to a portion where a light shielding layer is to be formed later is removed by patterning using a photomask or the like ( Exposure and development). At this time, the distance m between the opening-side end portions (21Aa) is equal to the light shielding layer (1
Patterning is performed so as to be smaller than the width of 4) (indicated by a two-dot chain line). Then, as shown in FIG.
Heat treatment at ℃ ~ 200 ℃. At this time, the opening side end (21Aa) of the resist (21A) becomes substantially tapered or curved as shown in FIG. When the distance between the tapered portions (22a) is increased, as shown in FIG. 10, an additional SiO ₂ film (23) is formed.
If formed by the CVD method or the sputtering method, the distance between the tapered portions (24a) of the grooves (24) formed on the SiO ₂ film (23) can be sandwiched.

Next, as another example of the method of forming the groove (22), as shown in FIG. 11A, a substrate (1) having a light shielding layer (14) formed on the inner surface in advance.
After forming a negative resist (21B) on the upper surface of 3), the inner surface side of the substrate (13) (the surface on which the light shielding layer (14) is formed)
To expose the negative resist (21B).
At this time, the portion corresponding to the light shielding layer (14) is also irradiated with weak light by the light diffraction phenomenon, and as a result, FIG.
As shown in (1), a portion of the resist (21B) corresponding to the light shielding layer (14) is developed into a tapered or curved concave shape to form a groove (22). In this case, a very narrow groove (22) can be obtained because the diffraction effect of light is used.

In the above two methods, the resist (21A) or (21
If the etching rate of the substrate (13) is the same as that of the substrate (13), the resist (21A) or (2
If the etch back is performed until 1B) disappears, the groove (22) can be formed in the substrate (13) itself because the upper surface of the substrate (13) follows the shape of the resist (21A) or (21B). As the resist (21A) or (21B), for example, a transparent Deep UV resist that transmits a visible light region is preferable. In the first method shown in FIG. 9, a low melting point softening material is used in place of the resist (21A), and the low melting point softening material is patterned by a photoresist method. And the groove (22) may be formed by further softening the low melting point softening material.

In the above example, the groove (22) was formed on the substrate (13) to improve the light utilization efficiency. However, as shown in FIG. A projection (31) having a portion (31a) may be provided. In this case, the drawing, light l ₁ incident on the tapered portion (31aL) existing in the left side is refracted to the right and enters the transparent electrode (12r) side of the right side spaced light-shielding layer (14), light l ₂ incident on the tapered portion (31aR) residing whereas right, in order to enter the left side of the transparent electrode (12l), examples as well as the light utilization of the groove (22) indicated by the seventh figure improves.

As an example of a method of forming the projection (31),
As shown in FIG. A, for example, a P-SiN film (3) having a different etching rate from the etching rate of the substrate (13) is formed on the substrate (13).
After forming 2), light shielding layer (14) of P-SiN film (32)
A photoresist (33) is formed at a location corresponding to (not shown in FIG. 13). Thereafter, plasma etching is performed on the P-SiN film (32) using the photoresist (33) as a mask. At this time, the P-SiN film (32) is
Since the etching rate is higher than that of 3), the etching is performed earlier. At the same time as the etching of the substrate (13) is started, the etching proceeds to the portion under the photoresist (33), and finally, as shown in FIG. 13B. As the substrate (13)
A projection (31) having both sides tapered is formed thereon. The size of the projection (31) is very small, for example, the height h is about 0.3 μm and the width D is about 10 μm.

Then, as shown in FIG. 12, if a light reflecting layer (34) having a substantially acute isosceles triangular cross section with a slightly acute angle と is provided on the light shielding layer (14) together with the protrusions (31). , the projections (31) transparent electrode light l ₃ incident in an oblique direction from the vicinity (1
2) The light can be reflected to the side, and the light utilization rate can be further improved.

In the above embodiment, an ITO film is used as the transparent electrode film (11). Alternatively, a SnO ₂ film (Nesa film) or a ZnO film may be used.

〔The invention's effect〕

In the method for manufacturing a liquid crystal display device according to the present invention, a step of forming a passivation film containing hydrogen in the film over the entire surface including the thin film transistor, and patterning the passivation film containing hydrogen in the film to form a hydrogen film on the thin film transistor And a step of leaving a passivation film containing, and after that, after forming a transparent conductive film at a temperature equal to or lower than the transition temperature, patterning is performed by etching, and then the patterned transparent conductive film is annealed at a temperature equal to or higher than the transition temperature. And the step of forming a transparent electrode by performing, the improvement of the thin film transistor characteristics, the improvement of the patterning property of the transparent conductive film, the improvement of the light transmittance of the transparent electrode and the reduction of the sheet resistance thereof can be achieved, High quality of the liquid crystal display device can be realized.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method of manufacturing a liquid crystal display device according to the present embodiment, FIG. 2 is a characteristic chart showing an annealing time dependency of a grain generation speed, and FIG. 3 is a graph showing a grain size per unit area for each size. FIG. 4 is a characteristic diagram showing the crystal state of the transparent conductive film by X-ray diffraction, and FIG. 4A is a characteristic diagram showing the case where the transparent conductive film is deposited by setting the substrate temperature to the transition temperature or lower. FIG. B shows a case where annealing is performed at a transition temperature or higher after vapor deposition, and FIG. C shows a case where a transparent conductive film is vapor deposited with the substrate temperature set at or above the transition temperature. FIG. 5 is a characteristic diagram showing the spectral transmission characteristics of the transparent conductive film, FIG. 6 is a characteristic diagram showing the annealing temperature dependence of the sheet resistance, and FIG. 7 is a configuration showing one example in which the light utilization is improved. FIG. 8, FIG. 8 is an enlarged view showing a main part thereof, FIG. 9 is a process diagram showing a method of forming a groove, FIG.
FIG. 10 is a configuration diagram showing an example of a method of reducing the distance between tapered portions, FIG. 11 is a process diagram showing another example of a method of forming a groove, and FIG.
FIG. 13 is a configuration diagram showing another example in which the light utilization is improved, and FIG.
FIG. 14 is a process diagram showing an example of a method for forming a projection, and FIG. 14 is a process diagram showing a conventional example. (A) is a liquid crystal display device, (1) and (13) are insulating substrates,
(Q) is a switching element, (2) is an active layer, (2s) is a source region, (2d) is a drain region, (3) is a gate insulating film, (4) is a gate electrode, (5) and (8). Is an interlayer insulating film, (7) is a signal line, (9) is a P-SiN film, (11) is a transparent conductive film, (12) is a transparent electrode, (14) is a light shielding layer, (1)
5) is a counter electrode, (16) is a liquid crystal layer, (21) is a transparent material, (2)
2) is a groove, and (31) is a protrusion.

Continued on the front page (72) Inventor Tetsuo Urabe 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Meiji Kawamura 6-35-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Knee Co., Ltd. (56) References JP-A-62-239821 (JP, A) JP-A-61-156025 (JP, A) JP-A-1-223430 (JP, A) JP-A-63-104026 (JP, A) , A)

Claims (1)

(57) [Claims] 1. A method of manufacturing a liquid crystal display device, comprising: a plurality of transparent electrodes arranged in a matrix corresponding to picture elements; and a thin film transistor for switching connected to each of the transparent electrodes. Forming a passivation film containing hydrogen in the film on the entire surface; patterning the passivation film containing hydrogen in the film to leave a passivation film containing hydrogen in the film on the thin film transistor; Forming a transparent conductive film at a temperature equal to or lower than the temperature, performing patterning by etching, and then performing an annealing process on the patterned transparent conductive film at a temperature equal to or higher than a transition temperature to form a transparent electrode. A method for manufacturing a liquid crystal display device, comprising: