JP4693439B2 - Method for manufacturing active matrix substrate - Google Patents

Description

The present invention relates to an active matrix substrate, and more particularly to a method for manufacturing an active matrix substrate .

In active matrix liquid crystal display devices that are currently widely used, a support substrate that can withstand the formation of active matrix elements, such as an alkali-free glass substrate, is used when forming an active element group. For example, when a thin film transistor using polysilicon is formed in a semiconductor layer for forming a channel, it is manufactured by the following procedure in consideration of a processing temperature at the time of forming each functional film:
(A) First, an organic film such as an aluminum oxide, a tantalum oxide, a silicon nitride film, or a fluororesin is formed as an etching stopper layer on an alkali-free glass substrate as a first support substrate. Then, a barrier layer is formed on the etching stopper layer, and an amorphous silicon film is further formed thereon.

  (B) After that, in order to polycrystallize the amorphous silicon layer, local short-time heating using an excimer laser is performed, and after crystallization by solid phase or liquid phase growth, shape processing of the polycrystalline silicon layer is performed. I do.

  (C) A thin film to be a gate insulating film is deposited thereon, and then a metal film for forming a gate electrode and a gate wiring is formed and processed. Further, in order to form a bonding surface in the semiconductor layer, ions are implanted using an ion doping method (ion implantation method) using the gate electrode as a mask, and then heat treatment for activation is performed. Then, after forming an interlayer insulating film to take the interlayer between the signal line and the gate line, a contact hole to the semiconductor layer is formed, and after the metal film is formed, shape processing to become the source and drain electrodes To form a thin film transistor, a wiring, and the like, thereby forming an active matrix element.

  (D) Thereafter, the first support substrate is removed while protecting the active matrix element with the etching stopper layer.

  (E) After that, the active matrix element is transferred to a second support substrate that is lightweight and thin and has excellent shape flexibility, such as a plastic substrate.

The alkali-free glass substrate as the first support substrate can be an effective support substrate when forming an active matrix element group using thin film transistors made of polysilicon. However, since the specific gravity and rigidity as a material are relatively high, for example, A display device such as a TFT-LCD is a factor that imposes a heavy load on applications, such as an increase in weight and thickness, and a limitation on the degree of freedom of shape. For this reason, the functional separation of the support substrate is performed, and when forming the active matrix element group, the active matrix element is formed on the first support substrate excellent in high-temperature process resistance, and then the first support substrate is removed. It is transferred to a second support substrate that is lightweight and thin and has excellent shape flexibility. As a method for removing the first support substrate, a method using a liquid phase etchant has been proposed (see Patent Documents 1 and 2).
JP 2001-7340 A JP 2004-119936 A

  The total thickness of the layer group including the active matrix element group is about 1 μm, whereas the first support substrate is about several hundred times. When the first support substrate is present, local stresses due to the laminated film stress and the electrodes for forming the active element group can be held by the support function of the first support substrate. However, if the first support substrate is removed, the local stress due to the shape becomes obvious. Therefore, the first support substrate is removed without affecting the active matrix element group due to local structural destruction or functional degradation. This is an issue.

  In addition, when an organic film such as aluminum oxide, tantalum oxide, silicon nitride film, or fluororesin is used as an etching stopper layer, several problems arise when the first glass substrate is removed by etching. Aluminum oxide, tantalum oxide, silicon nitride film, etc. have some etching stopper function, but when the second film-forming layer is exposed to the etching solution for a long time, the etching stopper layer is gradually eroded by the etching solution. Go. This can be dealt with if the active matrix substrate has a relatively small area because the exposure time of the second film-forming layer in the etching solution is short. However, the active matrix substrate having a relatively large area covers the entire surface. Before the first support substrate is removed, the second film formation layer exposed in the etching solution is eroded.

  On the other hand, when an organic film such as a fluororesin is used for the second film formation layer, the function as the second film formation layer can be applied to an active matrix substrate having a relatively large area. At the time of formation, it is difficult to form an active element group having a sufficient function due to the low heat resistance of the second film-forming layer and expansion and contraction due to thermal history.

In view of the above problems, the present invention can manufacture a highly reliable active matrix substrate without destroying the structure and function of the active matrix element group when transferring from the first support substrate to the second support substrate. An object of the present invention is to provide a method for manufacturing an active matrix substrate .

In order to achieve the above object, the first feature of the present invention is as follows. (A) On the first support substrate, at least one of the material and the composition is different from the first support substrate, and the internal stress is a tensile stress. A first film-forming layer, at least one of the material and the composition is different from the first film-forming layer, and the second film-forming layer whose internal stress is a compressive stress and the second film-forming layer are at least of the material and composition (B) laminating an alignment film, a protective layer, and a temporary adhesion layer in this order on the third film-forming layer in this order; And (c) a step of adhering the temporary support substrate onto the temporary attachment layer, and (d) a first etching solution having an angle of contact with the first support substrate that is smaller than the contact angle with the first film-forming layer. Etching of the support substrate was started, and bubbles were bubbled from the bubbler immediately after the surface of the first film formation layer was partially exposed. By introducing the etching solution, while protecting the exposed surface at the bubble selectively collected bubbles to the exposed surface of the first film forming layer surface, a step of removing the first supporting substrate, a first (e) And (f) adhering a second support substrate to the exposed surface of the second film-forming layer through a resin layer. The gist of the present invention is a method for manufacturing an active matrix substrate.
The second feature of the present invention is: (a) a first film-forming layer having a material and a composition different from those of the first support substrate and having an internal stress of tensile stress on the first support substrate; At least one of material and composition differs from the first film formation layer, and the second film formation layer whose internal stress becomes compressive stress and at least one of the material and composition differs from the second film formation layer, and the internal stress is tensile. (B) a step of laminating an alignment film, a protective layer, and a temporary attachment layer in this order on the third film formation layer; In the step of adhering the temporary support substrate onto the temporary attachment layer, and (d) in a state where the first support substrate remains in the shape of an island on the surface of the first film-forming layer, the contact angle with the first support substrate is the first formation angle. An etching solution selected to be smaller than the contact angle with the film layer is selectively applied to the surface of the island-shaped first support substrate. Collecting the first supporting substrate; (e) removing the first film-forming layer and exposing the second film-forming layer; and (f) a resin on the exposed surface of the second film-forming layer. And a step of adhering the second support substrate through the layer. The present invention provides a method for manufacturing an active matrix substrate.

The second feature of the present invention is that (b) a second support substrate, (b) a resin layer provided on the second support substrate, and (c) an adhesive to the second support substrate via the resin layer. It is a second film forming layer internal stress is a material which is a compressive stress, (d) the al is provided on the second film forming layer is, and the second film forming layer is at least one of the materials and composition Unlike the third film-forming layer, the third film-forming layer includes a third film-forming layer whose internal stress is a tensile stress, includes the entire tensile stress of the lower structure including the second support substrate and the resin layer, and the third film-forming layer. The gist of the present invention is that the active matrix substrate is balanced with the internal stress in the sum of the total tensile stress of the upper superstructure.

According to the present invention, at the time of transferring from the first support substrate to the second supporting substrate, without destroying the structure and function of the active matrix element group, an active matrix capable of producing a highly reliable active matrix substrate A method for manufacturing a substrate can be provided.

  Next, first and second embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  The first and second embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is The material, shape, structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

(First embodiment)
As shown in FIG. 1A, the active matrix substrate according to the first embodiment of the present invention has a plurality of scanning lines W ₁ , W ₂ , W ₃ ,. W _i, ·····, in a W _m, the plurality of signal lines B _1, B _2, B ₃ extending in the column direction, ·····, B _j, ·····, and B _m A thin film transistor (TFT) T _ij (i = 1 to m; j = 1 to n), where m and n are positive integers, and pixels connected to the thin film transistor T _ij , respectively, constituting a two-dimensional matrix The electrode Q _ij is arranged by constituting a pixel (T _ij ; Q _ij ).

FIG. 1B illustrates a portion of one pixel (T _ij ; Q _ij ) of the active matrix substrate according to the first embodiment, and the intersection of the scanning line W _i and the signal line B _j . A thin film transistor T _ij is arranged in the vicinity of. The gate electrode 17 of the thin film transistor T _ij is connected to the scanning line W _i, the source electrode 19 is connected to the signal line B _j. The drain electrode 20 of the thin film transistor is connected to the pixel electrode Q _ij occupying most of the pixel. Under the pixel electrode _Qij , a storage capacitor electrode (not shown) is disposed substantially opposite to the pixel electrode _Qij and is connected to a storage capacitor line (not shown).

<Stress in active matrix substrate>
FIG. 2 is a schematic diagram showing a cross-sectional structure of the main part of the active matrix substrate viewed from the AA direction of the pixel (T _ij ; Q _ij ) shown in FIG. The semiconductor layer (15S, 15C, 15D) forms an active region on the laminated substrate (11, 12, 13, 14) in which the resin layer 12, the second film forming layer 13, and the third film forming layer 14 are sequentially laminated. It is patterned so that it does. The semiconductor layer (15S, 15C, 15D) includes a p-type channel region 15C, an n-type source region 15S on both sides of the p-type channel region 15C, and an n-type drain region 15D. The semiconductor composing the channel region 15C is desirably crystalline in order to allow carriers to travel smoothly, and is desirably composed of polycrystals or single crystal grains. On the other hand, the source region 15S and the drain region 15D may be crystalline or non-crystalline. Specifically, the semiconductor layers (15S, 15C, 15D) are made of silicon or other various semiconductors, and can be formed of, for example, polysilicon (polycrystalline silicon). A gate insulating film 16 is formed on the semiconductor layers (15S, 15C, 15D), and a gate electrode 17 is disposed on the gate insulating film 16. Furthermore, the interlayer insulating film 18 covers the gate electrode 17, penetrates the interlayer insulating film 18, and contacts the source region 15S and the drain region 15D through contact holes that expose portions of the source region 15S and the drain region 15D. A source electrode 19 and a drain electrode 20 are connected to each.
Further, in the active matrix substrate in which the active element group is transferred onto the second support substrate 11 having desired characteristics as shown in FIG. 2, the stress state greatly affects the performance as the active matrix substrate. . For example, when a flexible substrate is used as the second support substrate 11, deformation due to uneven stress is likely to occur. Therefore, as shown in FIG. 2, the stress state (σ ₁ ) on the bonding surface side of the second support substrate 11 and the stress on the active element group formation side with respect to the second film-forming layer 13 that is compressive stress (σ ₂ ). State where state (σ ₃ ) is compensated:
σ ₂ = σ ₁ + σ ₃ (1)
Or it is desirable that it is a state close to it.

  Similar attention should be paid to the intermediate product for the active matrix substrate in the manufacturing method of the active matrix substrate according to the first embodiment of the present invention. Sufficient consideration is required for stress control so as not to bring about this. This greatly affects the process margin and the reliability of the structure not only when the active matrix element group is formed but also when the first support substrate 21 is removed or transferred to the second support substrate 11. Because.

First, in the manufacturing method of the active matrix substrate according to the first embodiment, when the active element group is formed on the first support substrate 21, the intermediate product for the active matrix substrate formed up to the second film formation layer 13a is formed. FIG. 3A schematically shows the stress state. In the manufacturing method of the active matrix substrate, the second film-forming layer 13a includes the first film-forming layer 22a below the second film-forming layer 13a and the third film-forming layer formed on the second film-forming layer 13a. It is important that the compressive stress σ _c2 is larger than 14 (see FIG. 4).

For example, as shown in FIG. 3A, the first film-forming layer 22a and the second film-forming layer 13a are in opposite stress states, that is, the first film-forming layer 22 has a tensile stress σ _t1 , and the second film-forming is performed. Assuming that the layer 13 has a compressive stress σ _c2 , the first film formation layer 22a and the second film formation layer 13a give different stresses to the first support substrate 21, respectively. 1 It becomes possible to reduce the stress applied to the support substrate 21.

On the other hand, for example, as shown in FIG. 3B, when both the first film formation layer 22b and the second film formation layer 13b have compressive stresses σ _c1 and σ _c2 , the first support substrate 21 has the first film formation layer. Since the sum of the stresses of 22b and the second film formation layer 13b is applied, it causes the warp of the first support substrate 21 and the like during the formation of the third film formation layer 14 and the formation of the active element group. It will cause troubles.

Conversely, as shown in FIG. 3C, when both the first film formation layer 22c and the second film formation layer 13c have compressive stresses σ _t1 and σ _t2 , the first film formation on the first support substrate 21 is performed. Since the sum of the stresses of the layer 22a and the second film formation layer 13a is applied, it causes a warp of the first support substrate 21 and the formation of the third film formation layer 14 and the formation of the active element group. It will interfere with the situation.

As shown in FIG. 3D, the first film-forming layer 22d and the second film-forming layer 13d are in opposite stress states, that is, the first film-forming layer 22 has a compressive stress σ _c1 , and the second film-forming layer 13 Is the tensile stress σ _t2 , the first film-forming layer 22a and the second film-forming layer 13a give different stresses to the first support substrate 21, respectively, as shown in FIG. Similarly, in this state, the stress applied to the first support substrate 21 is reduced. However, as will be described later with reference to FIG. 23, when the second film formation layer 13d is in a tensile stress state as shown in FIG. 3D, the first support substrate is used in the manufacturing process of the active matrix substrate. At the stage of removing 21 and the first film-forming layer 22a, defects (scratches) 35a and 35b on the surface of the second film-forming layer 13d are in a growing direction, which easily causes structural destruction, which is not preferable. On the other hand, in the stress relationship shown in FIG. 3A, the second film-forming layer 13a that becomes the bonding surface to the second support substrate 11 in a state where the first support substrate 21 and the first film-forming layer 22 are removed. 23 is in a compressed state, and even when minute defects (scratches) 35a and 35b as shown in FIG. 23 are present, the development of minute defects (scratches) 35a and 35b is suppressed. It becomes possible to suppress the appearance of defects.

Thus, as is clear from the comparison and examination of the four stress-related modes in the intermediate product for the active matrix substrate shown in FIGS. 3A to 3D, the first as shown in FIG. The second film formation layer 13a is made of a material having a compressive stress σ _c2 or a film quality having a composition ratio higher than that of the first support substrate 21 or the first film formation layer 22a, and the first film formation layer 22a has a tensile stress. It can be concluded that it is preferable to use a material system having σ _t1 .

For the examination of the stress state, it is necessary to examine various intermediate products for the active matrix substrate throughout the manufacturing process of the active matrix substrate. For example, the manufacturing of the active matrix substrate according to the first embodiment described below is performed. When the third film formation layer 14 is formed as in the intermediate product for the active matrix substrate in FIG. 4 described in the method, the second film formation layer 13 includes the first film formation layer 22 and the third film formation layer 14. A material having a large compressive stress σ _c2 and a film quality with a composition ratio compared to the film layer 14 is used, and the first film-forming layer 22 and the third film-forming layer 14 have a material system having tensile stresses σ _t1 and σ _t3. Is preferably used.

Further, in the manufacturing process of the active matrix substrate, if the same examination is performed until the active element group is formed like an active matrix substrate intermediate product in the stage of FIG. When the film quality of tensile stress is selected for the third film formation layer 14 and the film quality of compressive stress σ _c2 is selected for the second film formation layer 13, deformation due to stress on the first support substrate 21 can be reduced, When the active elements (15S, 15C, 15D, 16, 17, 18, 19, 20) are formed, they can be formed with a small amount of deformation.

  Then, as shown in the intermediate product for the active matrix substrate in the stage of FIG. 22, when the first support substrate 21 is removed, the first support substrate 21 and the active elements (15S, 15C, 15D, 16, 17, 18, 19, 20), it is understood that it is preferable to have a three-layered film structure (first film-forming layer 22, second film-forming layer 13, and third film-forming layer 14). At this time, the first film-forming layer 22, the second film-forming layer 13, and the third film-forming layer 14 have different materials and composition ratios (see FIG. 34), and the first film-forming layer 22 and the second film-forming layer 22 are different from each other. The film forming layer 13 only needs to have an etching resistance higher than that of the first support substrate 21 with respect to the etching solution used when the first support substrate 21 is removed, and an infinite or close resistance is not essential.

<Selection of each layer material of the three-layer laminated film>
From such a study, materials that can be used for the laminated film (22, 13, 14) of the intermediate product for the active matrix substrate can be widely selected with a selection width as shown in Table 1, and further, active When the elements (15S, 15C, 15D, 16, 17, 18, 19, 20) are formed, the conventional manufacturing method can be handled without greatly changing.

(A) As a material constituting the first film formation layer 22,
The etching resistance of the first support substrate 21 is higher than that of the first support substrate 21;
The contact angle (wetting) is different from the etching solution of the first support substrate 21;
Etc. are the required material conditions. From such material conditions, a metal film typified by molybdenum (Mo), a semiconductor film typified by amorphous silicon (a-Si), a metal nitride film typified by silicon nitride film (SiN _x ), a fluorine film. Examples include materials such as metal fluorides typified by calcium fluoride (CaF _x ) and metal oxide films typified by silicon nitride films. Here, the first film-forming layer 22 is preferably amorphous or microcrystalline (μC) film quality in consideration of the etching stopper function. This is because in the crystalline film quality, the crystal grain boundary portion is selectively attacked and easily affects the active elements (15S, 15C, 15D, 16, 17, 18, 19, 20) and the like. That is, when the contact angle between the first support substrate 21 and the etchant of the first support substrate 21 is θsub, and the contact angle between the first film formation layer 22 and the etchant is θsac,
θsub <θsac (2)
A material or a composition ratio that causes a difference in surface energy ΔU that can be used may be used. By selecting a combination of materials or composition ratios of the first support substrate 21 and the first film formation layer 22, selective etching using a difference in contact angle (wetting property) with an etchant as described later The method becomes possible. Increasing the difference ΔU between the surface energy Usub of the first support substrate 21 and the surface energy Usac of the first film formation layer 22 can also be handled by changing the film quality of the first film formation layer 22. For example, when amorphous silicon (a-Si) is employed as the first film-forming layer 22, normal amorphous silicon contains hydrogen (a-Si: H), and this hydrogen content is adjusted. It becomes possible to change the contact angle (wetting property) with respect to the etching solution.

  In particular, by selecting a contact angle (wetting property) with respect to the etchant 31 on the surfaces of the first support substrate 21 and the first film formation layer 22 so as to satisfy the formula (2), it will be described later with reference to FIGS. With respect to the distribution of the etching rate at the time of removing the first support substrate 21 as described above, self-alignment protection portions 32a that protect the etching solution in a self-aligned manner on the portions where the first film-forming layer 22 is exposed unevenly. 32b can be formed. The self-alignment protection parts 32a and 32b can be formed by a gas phase or liquid phase layer. For example, when an alkali-free glass substrate is used as the first support substrate 21, amorphous silicon is used as the first film formation layer 22, and a hydrofluoric acid aqueous solution is used as the etchant, the contact angle θsub between the first support substrate 21 and the etchant is used. Is small (good wettability), but the contact angle θsac between the first film-forming layer 22 and the etching solution is very large (wetability is very poor). For this reason, as shown in FIGS. 16 to 19, the self-alignment protection portions 32a and 32b made of a gas phase or a liquid phase are selectively aggregated and adhered to the surface of the first film formation layer 22, thereby Since the exposed surface of the film formation layer 22 is covered with the self-alignment protection parts 32a and 32b, and the self-alignment protection parts 32a and 32b move the first film formation layer 22 away from the etching solution, the self-alignment protection parts 32a and 32b. Will function as a self-aligned etching stopper layer.

(B) As a material constituting the second film formation layer 13,
The etching resistance of the first support substrate 21 is higher than that of the first support substrate 21;
・ Transmit approximately 80% or more at a wavelength in the visible light region;
・ It must be compressive stress;
・ Excellent insulation
Etc. are the required material conditions. From such material conditions, a metal nitride film represented by silicon nitride film (SiN _x ), a metal fluoride represented by calcium fluoride (CaF _x ),
Examples include materials such as a metal oxide film typified by a silicon nitride film.

(C) As a material constituting the third film formation layer 14,
-It has an effect of preventing impurity diffusion into the active element group;
・ Transmit approximately 80% or more at a wavelength in the visible light region;
・Tensile stress ;
・ Excellent insulation
Etc. are the required material conditions. From such material conditions, similar to the second film formation layer 13, a metal nitride film typified by a silicon nitride film (SiNx), a metal fluoride typified by calcium fluoride (CaFx), and a silicon nitride film A material such as a metal oxide film represented by

<Method for manufacturing active matrix substrate>
As described above, the stress state needs to be examined in detail for the intermediate product for the active matrix substrate at various stages throughout the manufacturing process of the active matrix substrate. A method for manufacturing an active matrix substrate according to a first embodiment of the invention will be described. Note that the manufacturing method of the active matrix substrate described below is an example, and it is needless to say that the present invention can be realized by various manufacturing methods including this modification. The active matrix substrate according to the first embodiment is a case where a thin film transistor T _ij using low-temperature polysilicon is employed as an active element.

  (A) First, an amorphous silicon layer serving as the first film-forming layer 22 is formed on the first support substrate 21 by using, for example, a plasma-enhanced vapor deposition method (PECVD method) using silane gas or the like as a raw material. About a film is formed. As the first support substrate 21, for example, an alkali-free glass substrate typified by an aluminoborosilicate having a thickness of about 0.7 mm can be used. The alkali-free glass substrate is the first support substrate 21 that is widely used when manufacturing an amorphous thin film transistor or a polycrystalline silicon thin film transistor. It is important that the first film-forming layer 22 at this time has high amorphousness.

(B) After forming the first film-forming layer 22, in order to remove dust on the surface of the first film-forming layer 22, sufficient cleaning is performed using a brush and a surfactant. Further, dilute hydrofluoric acid treatment is performed to remove the natural silicon oxide film formed on the surface of the first film formation layer 22. This dilute hydrofluoric acid treatment is performed immediately before the film formation of the second film formation layer 13 formed on the first film formation layer 22. Thereafter, as the second film formation layer 13, a silicon nitride film is formed to a thickness of 50 nm by using a PECVD method using silane (SiH ₄ ) gas, nitrogen (N ₂ ) gas, or the like as a raw material. At this time, as the film quality of the silicon nitride film, a film quality having a composition ratio close to stoichiometry of Si / N = 3/4 was selected. This is because the silicon nitride film can be formed in a relatively wide range of Si / N ratio, but the composition ratio of Si / N ratio closer to stoichiometry is higher in hydrofluoric acid-based aqueous solution used as an etching solution. On the other hand, since the resistance is high and the film stress is on the compressive stress side (see FIG. 34), the function as the second film formation layer 13 is easily developed.

(C) Thereafter, as shown in FIG. 4, a silicon oxide film (SiO ₂ film) is formed as the third film-forming layer 14 by PECVD using silane gas or oxygen (O ₂ ) gas as a raw material. A 350 nm film is formed. Since the function of the third film formation layer 14 is a function of supporting the active matrix element group and an overall stress adjustment function, there is no problem with the material and film quality that can satisfy these conditions as long as the film is an insulating film. Further, since the degree of freedom of the film thickness of the third film formation layer 14 is high, it can be arbitrarily changed depending on the film quality. In the method of manufacturing the active matrix substrate according to the first embodiment, as shown in FIG. 4, a large compressive stress σ _c2 is applied to the second film formation layer 13 to form the first film formation layer 22 and the third film formation. For the layer 14, the film quality and film forming conditions for the tensile stresses σ _t1 and σ _t3 are selected.

  (D) Next, a p-type amorphous silicon (a-Si) film 23 is grown on the third film formation layer 14 by PECVD as shown in FIG. Thereafter, as shown in FIG. 6, irradiation with light hν such as KrF excimer laser light is performed, and the amorphous silicon film 23 is instantaneously melted and crystallized to generate a p-type polycrystalline silicon layer 24. Then, after applying a photoresist on the entire surface of the polycrystalline silicon layer 24, the photoresist is patterned by a photolithography technique, and using this photoresist as a mask, for example, a reactive ion etching method (RIE method) using a fluorine-based gas is performed. The element isolation of the p-type polycrystalline silicon layer 24 is performed by the anisotropic etching method used, and the p-type active region 25 having an island structure is formed as shown in FIG.

  (E) Next, a silicon oxide film or a silicon nitride film to be the gate insulating film 16 is formed by using, for example, PECVD. Then, a metal film such as molybdenum (Mo), tungsten (W), tantalum (Ta), or an alloy thereof is deposited on the gate insulating film 16 by using, for example, a sputtering method. Then, a photoresist is applied on the metal film, a resist pattern is formed using a photolithography method, and, for example, a method in which the metal film is selectively removed by impregnating with a solvent is used. Thus, the shapes of the gate electrode 17 and the gate line group are formed as shown in FIG.

(F) Next, an impurity of the thin film transistor T _ij is selectively introduced into the p-type active region 25 in order to form a junction surface in the active region 25. In the intermediate product for an active matrix substrate according to the first embodiment, phosphorus ions ( ³¹ P ⁺ ) are used as n-type impurity ions. At this time, the gate electrode 17 is used as a mask as shown in FIG. 9 to introduce the ion concentration to about 10 ²² cm ⁻³ by ion doping (ion implantation). Thereafter, heat treatment is performed so that the introduced phosphorus ions ( ³¹ P ⁺ ) are electrically activated. As shown in FIG. 10, n-type source regions 15S and n are formed on both sides of the p-type channel region 15C. A type drain region 15D is formed.

  (G) Then, a silicon oxide film or a silicon nitride film to be the interlayer insulating film 18 is formed by, for example, an atmospheric pressure chemical vapor deposition method (APCVD method). Then, after applying a new photoresist on the entire surface of the interlayer insulating film 18, the new photoresist is patterned by photolithography, and RIE is performed using this new new photoresist as a mask, as shown in FIG. In addition, a source contact hole (through hole) 26S and a drain contact hole (through hole) 26D are formed through the interlayer insulating film 18 and exposing a part of the upper portion of the n-type source region 15S and the n-type drain region 15D. To do.

(H) Then, a metal such as Mo, Ta, W, aluminum (Al), nickel (Ni), or an alloy or a laminated film thereof is deposited using, for example, a sputtering method. Then, after applying a new photoresist on the entire surface of the metal film, the new photoresist is patterned by photolithography, and RIE is performed using the new photoresist as a mask, as shown in FIG. The source electrode 19, the drain electrode 20, and the signal wiring group are formed. In FIG. 11, a part of the signal wiring group connected to the source electrode 19 is shown, but the other signal wiring groups are not shown. Further, a pixel electrode Q _ij is formed so as to be connected to the drain electrode 20 (see FIG. 1B). In this series of thin film transistors T _ij and wiring formation processes, for example, there is local heating or annealing by an excimer laser, but there is no significant effect on the configuration and film quality of the laminated film (22, 13, 14), and the active matrix There is no significant problem in forming the structure.

  (I) Next, the alignment film 27 is formed on the active element group by spin coating using polyimide, for example, with controlling the orientation of the liquid crystal on the active matrix element group side. Further, after the alignment film 27 is formed, a rubbing process, which is an alignment process means, is performed. Usually, the alignment film 27 is formed and the alignment process is performed after the transfer to the second support substrate 11. In this case, however, the structure is destroyed by the heat treatment temperature in the process of the alignment film 27 or the impact during the alignment process. The second support substrate 11 that can be used is limited, so that the rubbing process is performed on the first support substrate 21 in the manufacturing method of the active matrix substrate according to the first embodiment. However, the rubbing process does not need to be performed at this time when the second support substrate 11 or the like that is resistant to such thermal shock and structural destruction is used. Next, for the purpose of protecting the alignment film 27, a coating type resist made of, for example, a novolac resin is formed using a spin coating method to form a protective layer 28 as shown in FIG. At this time, it is desirable that the protective layer 28 has excellent selectivity with the alignment film 27 when the protective layer 28 is removed, and prevents the effect of prior alignment treatment from being reduced.

  (N) Next, as shown in FIG. 13, a temporary support substrate 30 for taking temporary support in order to maintain the structure of the active element group and the like when the first support substrate 21 is removed. It is installed on the opposite side of the substrate 21 via a temporary attachment layer 29. That is, an adhesive capable of changing the tackiness by a method such as UV irradiation is applied on the protective layer 28 as a temporary attachment layer 29 by using, for example, a spin coating method, and, for example, one side is applied thereon. A plastic substrate such as fluororesin-coated quartz glass or polyethersulfone (PES) is used as the temporary support substrate 30 so as to face the first support substrate 21. At this time, if air bubbles are mixed or unevenly applied, the active element group and the film forming layer group are affected when the first support substrate 21 is removed.

By making the structure of (Le) 13 allows the process of removing the first support substrate 21 as shown in FIGS. 14 to 20. In the intermediate product for an active matrix substrate according to the first embodiment, a wet etching method using a hydrofluoric acid aqueous solution as an etching solution is employed as a method for removing the first support substrate 21. This is because the intermediate product for an active matrix substrate according to the first embodiment employs an alkali-free glass substrate as the first support substrate 21 and the glass material is soluble in a hydrofluoric acid aqueous solution. . In the method of manufacturing the active matrix substrate according to the first embodiment, a hydrofluoric acid aqueous solution to which hydrochloric acid is added is used as the hydrofluoric acid etching solution. This is because the resistance to hydrofluoric acid is improved when the material of the first film-forming layer 22 and the second film-forming layer 13 used in the active matrix substrate intermediate product according to the first embodiment is strongly acidic. is there. In order to make it strongly acidic, sulfuric acid and nitric acid are often used. However, since the intermediate product for the active matrix substrate according to the first embodiment uses a lot of organic materials, sulfuric acid and nitric acid are used. This is because when used, there is a concern that they may be oxidized or decomposed. FIG. 14 schematically shows a situation in the middle of removing the first support substrate 21 by etching. As shown in FIG. 14, when the first support substrate 21 is removed, the thickness is not uniformly etched in the surface, and unevenness occurs between a portion where etching progresses quickly and a portion where etching progresses slowly. This is due to the surface state of the first support substrate 21, the composition distribution and stress state inside the substrate, the convection state of the etching solution 31, and the like. Since it is difficult to control all of these, it is inevitable that the distribution will occur. Therefore, when the first support substrate 21 is removed, the portion that is removed in advance, that is, the portion to which the surface of the first film formation layer 22 is exposed, and the first support substrate 21 still remain, that is, the first 1 The part where the support substrate 21 is being etched appears. At this time, there is no problem if the laminated films (22, 13, 14) are not eroded by the etching solution 31, that is, there is an infinite selection ratio. However, in the case of the material system used in the present invention, the hydrofluoric acid aqueous solution is affected to some extent, and therefore, the active element group is destroyed as schematically shown in FIG. In particular, in a device having a large occupied area such as a liquid crystal display device, in order to obtain resistance until etching over the entire area is completed, in anticipation of the erosion of the laminated film (22, 13, 14), It is necessary to take measures to greatly reduce the productivity, such as making each of the laminated films (22, 13, 14) multilayer or increasing the film thickness. Therefore, in the method of manufacturing the active matrix substrate according to the first embodiment, as shown schematically in FIG. 16, the self-alignment protection portions 32a, 32a, A method of forming 32b is used. The portion where the first film formation layer 22 is exposed when the first support substrate 21 is removed and the extent thereof cannot be determined in advance. Examples of the structure of the etching bath having the bubbler 33 having the function of generating the self-alignment protection units 32a and 32b are shown in FIGS. In the etching bath shown in FIGS. 17 to 20, a bubbler 33 capable of introducing air bubbles such as air and nitrogen is installed inside, and immediately after the surface of the first film formation layer 22 appears when the first support substrate 21 is removed. The bubbles 34 are introduced into the etching solution 31 while adjusting the introduction amount. At this time, the structure supported by the temporary support substrate 30 is swung. At this time, since the surface energy difference ΔU is large depending on the material and film forming conditions employed, the first support substrate 21 is excellent in hydrophilicity, and the exposed surface of the first film forming layer 22 can be made water-repellent. . In this case, the bubbles 34 can be selectively collected on the exposed surface of the first film formation layer 22. This is schematically shown in FIGS. At this time, the bubbles 34 selectively gathered on the exposed surface of the first film-forming layer 22 serve as self-alignment protection parts 32a and 32b that protect the first film-forming layer 22 from the hydrofluoric acid-based etching solution. Will be fulfilled. Further, as the removal of the first support substrate 21 proceeds, the area ratio and shape of the exposed portion of the first film-forming layer 22 change, but the bubbles 34 can be deformed into an arbitrary shape by controlling the supply amount. Since the area is changed, the self-alignment protection parts 32a and 32b can be gradually grown in a large area as shown in FIGS. Finally, the first support substrate 21 is completely removed. At this time, as shown in FIG. 20, the separated self-alignment protection portions 32a and 32b are also exposed portions of the first film formation layer 22. It is possible to remove the first support substrate 21 in a state where the first film formation layer 22 is hardly eroded by gathering in the large self-alignment protection unit 32 throughout.

(V) FIG. 21 is an example of a cross-sectional structure after the first support substrate 21 is completely removed from the intermediate product for the active matrix substrate. After the removal of the first support substrate 21, a new intermediate product for an active matrix substrate is obtained with the first film layer 22 exposed. Subsequently, as shown in FIG. 22, the first film formation layer 22 is further removed from the new intermediate product for the active matrix substrate to expose the second film formation layer 13. This is because the liquid crystal display device in the active matrix substrate according to the first embodiment is a transmissive type. That is, the first deposition layer 22 used in the active matrix substrate according to the first embodiment is made of amorphous silicon and has a red coloring, so that transmitted light is colored. The first film layer 22 may be removed using a tetramethylammonium hydroxide aqueous solution. This is because the first film formation layer 22 can be removed and the second film formation layer 13 has a resistance close to infinity. For this reason, the exposed surface of the second film formation layer 13 as shown in FIG. 22 can be formed in a relatively good state. In the intermediate product for an active matrix substrate having a structure in which the second film formation layer 13 is exposed, as shown in FIG. 23, it is important for reducing the defect that the second film formation layer 13 has a compressive stress. That is, as shown in FIG. 23, when there is a defect part such as a defect (scratches) 35a and 35b on the exposed surface side of the second film formation layer 13, or when the first film formation layer 22 is peeled off or second If there is a possibility that fine defects (scratches) 35a, 35b and the like may occur in the process after the exposure of the film forming layer 13, if the compressive stress σ _c is applied to the second film forming layer 13, the defect (Scratches) 35a and 35b receive pressure in a direction to suppress their growth and do not easily progress. On the other hand, when the second film-forming layer 13 is in a tensile stress state, the defects (scratches) 35a and 35b are subjected to stress in the growing direction, so that structural damage is easily caused. .

  (W) Next, as shown in FIG. 24, the resin layer 12 is applied to the exposed second film-forming layer 13, and the second support substrate 11 is attached via the resin layer 12. At this time, an acrylic resin that is cured by mixing two liquids can be used as the resin layer 12, and polyethylene terephthalate (PET) can be used as the second support substrate 11. This is because the active matrix substrate according to the first embodiment has already completed processes that require a relatively high temperature, such as formation of the alignment film 27 and alignment processing. Therefore, a high-performance liquid crystal display device can be manufactured even using a plastic film having poor heat resistance such as PET.

  (F) Next, the adhesiveness or tackiness of the temporary attachment layer 29 is reduced from the temporary support substrate 30 side using a method such as UV light irradiation. Then, as shown in FIGS. 25 and 26, the temporary support substrate 30 and the temporary attachment layer 29 are formed by taking care not to give structural breakdown or stress application to the second support substrate 11 side where the active element group has been transferred. Remove. Thereafter, as shown in FIG. 27, the protective layer 28 on the surface of the active element group is removed using a registry mover. As a result, as shown in FIG. 2, the active element group having the same performance as that on the first support substrate 21 is transferred onto the second support substrate 11, and the manufacturing operation of the active matrix substrate is completed.

  In the manufacturing method of the active matrix substrate according to the first embodiment, when a wet process is frequently used, the influence of the substrate end face cannot be ignored. In particular, an element may be destroyed or a film may be peeled off due to penetration of the etching solution 31 or moisture from the end face. In order to prevent this, as shown in FIG. 28, it is most appropriate to protect the end portion with an end portion protection film 41. In the active matrix substrate according to the first embodiment, the end portions of the four sides are impregnated with a fluorine-based adhesive by about 5 mm and then dried to form the end portion protective film 41. Further, when the end portion is protected by the end portion protective film 41 in this way, the first support substrate 21 over the protection region is not removed by etching, so that a sudden change in the substrate thickness occurs when the first support substrate 21 is removed. Will bring. In order to prevent this, as shown in FIG. 29, the thickness distribution of the first support substrate 21 may be provided stepwise from the protected end. At this time, as a method for providing a step, there is a method in which the removal of the first support substrate 21 is performed in several steps and a protective seal is attached to a portion where the step is to be provided.

  Subsequent manufacturing of the active matrix substrate as a liquid crystal display device will not be described because the manufacturing process using a plastic film can be used as it is.

As described above, according to the manufacturing method of the active matrix substrate according to the first embodiment of the present invention, the array of the low-temperature polysilicon thin film transistors T _ij is arranged on the first support substrate 21 and the active elements (15S , 15C, 15D, 16, 17, 18, 19, 20) to form an active matrix substrate intermediate product, and then active elements (15S, 15C, 15D, 16, 17, 18, 19, 20). It is possible to remove the first support substrate 21 from the intermediate product for the active matrix substrate without causing the structural destruction and the functional degradation.

  Further, after the first support substrate 21 is removed, the first film-forming layer 22 having a large damage when the first support substrate 21 is removed is further removed. Therefore, after the first support substrate 21 is removed, the second support substrate 11 is removed. When the active element (15S, 15C, 15D, 16, 17, 18, 19, 20) is transferred to the second support substrate 11, the surface is excellent in surface smoothness and in an appropriate surface state. A surface of a certain second film formation layer 13 can be realized. As a result, it is possible to improve the performance of the active matrix substrate, further improve the performance and reliability of a liquid crystal display device using the active matrix substrate, and improve the manufacturing yield.

(Second Embodiment)
In the manufacturing method of the active matrix substrate according to the second embodiment, the first support substrate 21 is removed from the intermediate product for the active matrix substrate using a method different from that of the first embodiment. That is, in the second embodiment, the same method as that of the first embodiment is used before the first support substrate 21 is completely removed, that is, until the process step shown in FIG. 14 in the first embodiment. Manufacturing from intermediate products for active matrix substrates.

  Also in the active matrix substrate according to the second embodiment, when the first film formation layer 22 is exposed from the intermediate matrix active product, the structural breakdown of the stacked film group as shown in FIG. This is a method of preventing the destruction of the group and the deterioration of the function.

  FIG. 30 schematically shows an etching method immediately before the removal of the first support substrate 21 in the active matrix substrate intermediate product according to the second embodiment. That is, unlike FIGS. 14 to 20 in the first embodiment, the structure (intermediate product for the active matrix substrate) is not impregnated in the etching solution 31, but just the intermediate product for the active matrix substrate. The etching solution 42 is dropped on the first support substrate 21. At this time, when the first support substrate 21 remains on the entire surface of the first film formation layer 22, the etching solution 42 also exists so as to cover the first support substrate 21. It progresses over.

  On the other hand, as schematically shown in FIG. 31, in a state in which a part of the first support substrate 21 is removed and the first film formation layer 22 is exposed, the first support substrate 21 and the first support substrate 21. Reflecting that the contact angle θsub with the etchant and the contact angle θsac between the first film formation layer 22 and the etchant are selected so as to satisfy Expression (2), While the exposed surface repels the etching solution 42, the etching solution 42 aggregates on the first support substrate 21. At this time, the substrate removal proceeds in the remaining portion of the first support substrate 21, whereas the exposed surface of the first film formation layer 22 is not exposed to the etching solution 42, so that the first film formation layer 22 is removed from the etching solution 42. Will not be attacked. In addition, the remaining portion of the first support substrate 21 is sequentially reduced by the etching solution 42. In response to this change, the etching solution 31 changes its shape and etches from the exposed surface of the new first film formation layer 22. The liquid 42 is removed, and the etching liquid 42 can be aggregated only on the remaining portion of the first support substrate 21. Therefore, it is possible to etch only the first support substrate 21 without touching the exposed surface of the first film formation layer 22 as much as possible with the etchant 42.

  However, in this case, as the etching of the first support substrate 21 proceeds, there is a concern that the etching ability of the first support substrate 21 may be reduced by the etching solution 42. For this reason, the intermediate product for the active matrix substrate is reciprocally swung between the etching solution 42 and the atmosphere just like papermaking, so that a new etching solution 42 is forced on the surface of the first support substrate 21. It is necessary to replace the etching solution 42. Etching in which the vapor phase and the etchant 42 are alternately and repeatedly supplied to the surface of the first support substrate 21 by repeated reciprocating rocking like a paper sheet, and selectively aggregate on the surface of the island-shaped first support substrate 21. The liquid 42 can be replenished with fresh etchant 42. The fresh etchant 42 can be replenished not by the reciprocal oscillation in the air / liquid but by the reciprocal continuous supply of the fresh liquid layer interface by the reciprocal oscillation of the first support substrate 21 only in the etchant 42.

  The contact angle θsub and the contact angle θsac should satisfy the formula (2) also in the step of forcibly supplying the fresh liquid layer interface by the reciprocal oscillation in the air / liquid or the reciprocal oscillation only in the liquid. Since the exposed surface of the first film-forming layer 22 immediately repels the etching solution 42, the etching solution 42 can be selectively aggregated only in the remaining portion of the first support substrate 21, The time for the first film layer 22 to be attacked is very short. Further, the etching solution 42 can selectively follow the remaining portion of the first support substrate 21 at any position in the plane, so that the first support substrate self-aligns. Only the remaining part of 21 can be selectively etched.

  As described above, according to the manufacturing method of the active matrix substrate according to the second embodiment of the present invention, as with the manufacturing method of the active matrix substrate according to the first embodiment, on the first support substrate 21. In addition, it is possible to remove the first support substrate 21 without causing structural destruction or functional degradation of the active elements (15S, 15C, 15D, 16, 17, 18, 19, 20).

  Further, after removing the first support substrate 21, the first film-forming layer 22, which is highly damaged when the first support substrate 21 is removed, is further removed. When moving the active elements (15S, 15C, 15D, 16, 17, 18, 19, 20), the surface is excellent in surface smoothness and is in an appropriate surface state when bonded to the second support substrate 11. The surface of the second film formation layer 13 can be realized. As a result, it is possible to improve the performance of the active matrix substrate, further improve the performance and reliability of a liquid crystal display device using the active matrix substrate, and improve the manufacturing yield.

(Other embodiments)
As described above, the present invention has been described according to the first and second embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

In the description of the first and second embodiments already described, for example, a case where a low-temperature polysilicon thin film transistor is used as an active element has been described. However, as shown in FIGS. 32 and 33, an amorphous silicon thin film transistor is used as an active element. Since the multilayer film structure as shown in the cross-sectional view of FIG. 33 is used in the second embodiment, as in the first and second embodiments, the second component having the compressive stress (σ ₂ ) is used. The relationship expressed by the equation (1) so that the stress state (σ ₁ ) on the bonding surface side of the second support substrate 11 and the stress state (σ ₃ ) on the active element group formation side are compensated for the film layer 13. It is important that

FIG. 32 exemplifies a portion of one pixel (T _ij ; Q _ij ) of the active matrix substrate according to the first embodiment, in the vicinity of the intersection of the scanning line _Wi and the signal line _Bj. A thin film transistor T _ij is arranged. The gate electrode 17 of the thin film transistor T _ij via the scanning lines 53 are connected to the scanning line W _i, the source electrode 19 is connected via a signal line wiring 52 to the signal line B _j. The drain electrode 20 of the thin film transistor is connected to the pixel electrode Q _ij occupying most of the pixel. Under the pixel electrode _Qij , a storage capacitor electrode (not shown) is disposed substantially opposite to the pixel electrode _Qij and is connected to a storage capacitor line (not shown).
FIG. 33 is a schematic diagram showing a cross-sectional structure of the main part when viewed from the AA direction of the pixel (T _ij ; Q _ij ) shown in FIG. 32. The resin layer 12 and the second component are formed on the second support substrate 11. A gate electrode 17 is patterned on a laminated substrate (11, 12, 13, 14) in which a film layer 13 and a third film formation layer 14 are laminated in order. A gate insulating film 16 is formed on the gate electrode 17, and an active region 51 made of amorphous silicon is formed on the gate insulating film 16. The channel protective insulating film 10 is selectively localized on a part of the active region 51, and the source electrode 19 and the drain electrode 20 are provided for the active region 51 exposed from the channel protective insulating film 10. Further, the interlayer insulating film 18 is coated on the source electrode 19 and the drain electrode 20 through contact holes that penetrate the interlayer insulating film 18 and expose portions of the source electrode 19 and the drain electrode 20, respectively. The signal line wiring 52 and the pixel electrode Q _ij are connected.
The amorphous silicon thin film transistors shown in FIGS. 32 and 33 are also used in the active element manufacturing method, as in the active matrix substrate manufacturing method according to the first embodiment of the present invention. Sufficient consideration must be given to stress control so as not to cause structural destruction and functional degradation. This greatly affects the process margin and the reliability of the structure not only when the active matrix element group is formed but also when the first support substrate 21 is removed or transferred to the second support substrate 11. Because.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

FIG. 1A is a schematic plan view for explaining the outline of the array structure of the active matrix substrate according to the first embodiment of the present invention, and FIG. 1B is shown in FIG. 2 is a schematic plan view for explaining an outline of a thin film transistor and a pixel electrode, focusing on one pixel in the array. FIG. 2 is a schematic cross-sectional view illustrating a cross-sectional structure of a main part when viewed from the AA direction of the pixel illustrated in FIG. In the manufacturing method of the active matrix substrate which concerns on 1st Embodiment, it is a figure explaining the four aspects of the stress state in the state which formed the 1st film-forming layer and the 2nd film-forming layer on the 1st support substrate. is there. It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 1). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 2). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 3). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 4). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 5). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 6). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 7). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 8). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 9). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 10). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 11). It is typical sectional drawing explaining the problem in the manufacturing method of an active matrix substrate. It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 12). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 13). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 14). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 15). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 16). FIG. 17 is a schematic process cross-sectional view illustrating the manufacturing method of the active matrix substrate according to the first embodiment (No. 17). FIG. 18 is a schematic process cross-sectional view illustrating the manufacturing method of the active matrix substrate according to the first embodiment (No. 18). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 19). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 20). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 21). FIG. 22 is a schematic process cross-sectional view illustrating the manufacturing method of the active matrix substrate according to the first embodiment (No. 22). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 1st Embodiment (the 23). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on the modification of 1st Embodiment (the 1). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on the modification of 1st Embodiment (the 2). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 2nd Embodiment (the 1). It is typical process sectional drawing explaining the manufacturing method of the active matrix substrate which concerns on 2nd Embodiment (the 2). It is a typical top view explaining the outline of a thin film transistor and a pixel electrode, paying attention to one pixel in an array of an active matrix substrate concerning other embodiments of the present invention. FIG. 33 is a schematic cross-sectional view illustrating a main-portion cross-sectional structure viewed from the AA direction of the pixel illustrated in FIG. It is a figure explaining the relationship between the stress of a silicon nitride film, and N / Si ratio.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Channel protective insulating film 11 ... 2nd support substrate 12 ... Resin layer 13, 13a, 13b, 13c, 13d ... 2nd film-forming layer 14 ... 3rd film-forming layer 15C ... Channel area | region 15D ... Drain area | region 15S ... Source area | region DESCRIPTION OF SYMBOLS 16 ... Gate insulating film 17 ... Gate electrode 18 ... Interlayer insulating film 19 ... Source electrode 20 ... Drain electrode 21 ... 1st support substrate 22, 22a, 22b, 22c, 22d ... 1st film-forming layer 23 ... Amorphous silicon film 24 ... Polycrystalline silicon layer 25 ... Active region 27 ... Alignment film 28 ... Protective layer 29 ... Temporary attachment layer 30 ... Temporary support substrate 31 ... Etching solution 32, 32a, 32b ... Self-alignment protection part 33 ... Bubbler 34 ... Bubble 41 ... End part protective film 42 ... etchant 51 ... active region 52 ... signal line wiring 53 ... scanning lines Q _ij ... pixel electrode T _ij ... TFT W _1, W _{2 , W 3, ·····, W i} , ·····, W m ... scan lines _{B 1, B 2, B 3} , ·····, B j, ·····, B m …Signal line

Claims (3)

On the first support substrate, at least one of the material and the composition is different from that of the first support substrate, and the first film-forming layer whose internal stress is a tensile stress, the first film-forming layer has at least the material and the composition The second film-forming layer in which one is different and the internal stress is a compressive stress, and the third film-forming layer in which at least one of the material and the composition is different from the second film-forming layer and the internal stress is a tensile stress are arranged in this order. Laminating steps;
A step of laminating an alignment film, a protective layer and a temporary adhesion layer in this order on the third film-forming layer;
Adhering a temporary support substrate on the temporary attachment layer;
Immediately after the etching of the first support substrate is started with an etchant whose contact angle with the first support substrate is smaller than the contact angle with the first film formation layer, and the surface of the first film formation layer is partially exposed. Introducing air bubbles from a bubbler into the etching solution, the bubbles are selectively collected on the exposed surface of the first film-forming layer, and the exposed surface is protected by the air bubbles while the first supporting substrate is protected. Removing the
Removing the first film formation layer to expose the second film formation layer;
Adhering the second support substrate to the exposed surface of the second film-forming layer via a resin layer. On the first support substrate, at least one of the material and the composition is different from that of the first support substrate, and the first film-forming layer whose internal stress is a tensile stress, the first film-forming layer has at least the material and the composition The second film-forming layer in which one is different and the internal stress is a compressive stress, and the third film-forming layer in which at least one of the material and the composition is different from the second film-forming layer and the internal stress is a tensile stress are arranged in this order. Laminating steps;
A step of laminating an alignment film, a protective layer and a temporary adhesion layer in this order on the third film-forming layer;
Adhering a temporary support substrate on the temporary attachment layer;
The contact angle with the first support substrate is selected to be smaller than the contact angle with the first film formation layer in a state where the first support substrate remains in an island shape on the surface of the first film formation layer. Removing the first support substrate by selectively aggregating the etched etchant on the surface of the island-shaped first support substrate ;
Removing the first film formation layer to expose the second film formation layer;
Adhering the second support substrate to the exposed surface of the second film-forming layer via a resin layer. The liquid layer interface of the etching solution in contact with the surface of the first support substrate moves relative to the surface of the first support substrate, and selectively aggregates on the surface of the island-shaped first support substrate. The method for manufacturing an active matrix substrate according to claim 2 , wherein the etching solution is replenished.

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