JP2010087525A - Surface processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface processing method that prevents dust from being produced by improving the adherence of a film attached on a susceptor. <P>SOLUTION: The surface processing method includes a step (H) of blasting a surface of the susceptor consisting principally of SiO<SB>2</SB>using SiO<SB>2</SB>or SiC, and a step (I) of etching the susceptor surface. The susceptor includes a susceptor body and a level difference portion provided on the susceptor body to support the substrate from the bottom, the level difference portion being formed of a size smaller than the substrate. In a step of masking, the level difference portion is masked preferably to avoid conduction between an end of the substrate and the susceptor body. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention generally relates to a surface treatment method for an object to be processed such as a susceptor, and more specifically, a substrate pedestal in a chamber of a substrate manufacturing process, particularly a sputtering apparatus and a vacuum apparatus for forming a thin film. The present invention relates to a surface treatment method for an object to be treated such as a susceptor.

  In general, the susceptor is not cleaned every time the substrate is formed, but is cleaned every time a set of several substrates is formed. For this reason, the film | membrane adhering to a susceptor is laminated | stacked at the time of board | substrate film-forming.

  Conventionally, a susceptor cleaning method generally performed after completion of a film forming process is performed in accordance with the process flow of FIG. First, an etching process is performed until the laminated film deposited on the susceptor is completely removed during film formation of the substrate (A in FIG. 7). Thereafter, pure water cleaning step (B in FIG. 7), ultrapure water cleaning step (C in FIG. 7), drying step (D in FIG. 7), inspection step (E in FIG. 7), packaging (F in FIG. 7). The cycle of re-use is followed through the above processes.

  By the way, with the recent spread of the Internet, the sales of personal computers are growing rapidly, and the new and old changes are intense, and the specifications of the liquid crystal panel mounted on it are also higher brightness, higher definition, higher aperture ratio, faster response However, since the period of price collapse is also fast, there is an urgent need to improve the yield.

  In particular, in order to cope with higher definition and higher aperture ratio, it is necessary to make the gate and source lines thinner than before. In the thin film transistor (TFT) process, reduction of particles during film formation in a metal wiring forming apparatus such as a sputtering apparatus is an essential item because it suppresses the line disconnection rate.

  As a dust generation source, in most cases, a film adheres to a wall surface, a member or the like in the chamber and is peeled off at the time of film formation. As for the adhesion preventing plate used in the chamber as shown in FIG. 8, the base material such as Al or SUS is currently blasted, or the surface is subjected to Al spraying to reduce peeling. It is common.

Japanese Patent Laid-Open No. 10-070099

However, as shown in FIG. 8, there is a susceptor portion in the chamber that cannot be handled by the above-described deposition plate. A susceptor is a pedestal part of a substrate that does not allow conduction to the substrate, and has excellent surface flatness and heat resistance. Usually, SiO ₂ is the main component in order not to damage the substrate. Generally, it is made of glass. For this reason, the present situation is that no particular ingenuity has been given to the surface treatment due to the risk of cracks and the like.

  That is, the susceptor is not cleaned every time the substrate is formed, and several substrates are generally formed after forming several sets of films. Therefore, the deposited film deposited on the susceptor is formed on the substrate. It was a source of dust that sometimes fell off the substrate.

  Therefore, in order to promote the demand for quality improvement in the future and the reduction of the material cost, it has become necessary to prevent dust generation due to peeling of the film attached to the susceptor.

  Japanese Patent Application Laid-Open No. 10-070099 discloses a method for cleaning a semiconductor wafer subjected to sandblasting and a semiconductor wafer cleaned by this method. There is disclosed a method for reliably removing contamination caused by sandblasting by defining an etching treatment temperature of hydrofluoric acid to be washed after the sandblasting treatment. It also discloses blasting and etching the semiconductor itself.

However, the sandblasted semiconductor cleaning method disclosed in Japanese Patent Application Laid-Open No. 10-070099 cannot be used as it is when the susceptor is made of glass having SiO ₂ as a main component and is easily broken.

  In addition, there is a problem that the deposited film deposited on the susceptor is electrically connected to the film formed on the end face of the substrate to cause abnormal discharge.

  The present invention has been made to solve the above-described problems, and provides a surface treatment method (including a cleaning method and the like) for preventing dust generation by increasing the adhesion of a film attached to a susceptor. There is.

One aspect of the present invention is a surface treatment method including a step of blasting the surface of a susceptor containing SiO ₂ as a main component and a step of etching the surface of the susceptor using SiO ₂ or SiC.

  Prior to the blasting step, the method may further comprise a step of masking a part of the susceptor where the susceptor and the substrate to be placed on the susceptor come into contact.

  The susceptor is provided on the susceptor main body and is formed on the susceptor main body so as to be slightly smaller in size than the substrate, and includes a stepped portion that supports the substrate from below as a part of the susceptor. It may be masked to prevent conduction between the edge of the substrate and the susceptor body.

  Prior to the step of blasting, a step of washing the surface of the susceptor with high-pressure water may be further provided.

  A step of washing the surface of the susceptor with high-pressure water may be further provided after the etching step.

Another aspect of the present invention is a glass jig mainly composed of SiO ₂ used in the periphery of a substrate and a wafer in a semiconductor forming process, a plasma display panel forming process, a plasma address liquid crystal forming process, and a flat panel display forming process. A surface treatment method comprising: a first step of blasting a surface of an object to be treated; a second step of etching the surface of an object to be treated; and the following (i) or (ii): And a third step of cleaning.

(I) Wash with high pressure water.
(Ii) Wash with pure water and high pressure water.

  In still another aspect of the present invention, there is provided a surface treatment method for a substrate of a thin film transistor of a reflective liquid crystal panel, the first step of blasting the surface of the substrate of the thin film transistor, and a second step of etching the surface of the substrate of the thin film transistor. A surface treatment method comprising: a step; and a third step of cleaning a substrate of a thin film transistor as a target object by means of the following (i) or (ii).

(I) Wash with high pressure water.
(Ii) Wash with pure water and high pressure water.

  Prior to the blasting step, the method may further comprise a step of masking a part of the susceptor where the substrate contacts the susceptor that supports the substrate from below.

  The susceptor is provided on the susceptor main body and is formed on the susceptor main body so as to be slightly smaller in size than the substrate, and includes a stepped portion that supports the substrate from below as a part of the susceptor. It may be masked to prevent conduction between the edge of the substrate and the susceptor body.

  Prior to the first step of blasting, a step of washing the surface of the susceptor with high-pressure water may be provided.

  The second step of etching and the step of washing with high pressure water may be repeated.

It is a perspective view explaining the relationship between the dimension of the board | substrate of this invention, and a susceptor. (A) is a top view of a susceptor, (B) is an AA cross-sectional view of (A), and (C) is a partially enlarged view of (B). It is a figure which shows the process of the washing | cleaning method of this invention. It is a figure which shows the cross-sectional state and surface state of a susceptor before a blast process. It is a figure which shows the cross-sectional state and surface state after a blast process. It is a figure which shows the cross-sectional state and surface state after a blast process + an etching process. It is a figure which shows the process of the conventional cleaning method. It is an apparatus structure figure explaining the shift of the substrate at the time of film formation by the side deposition method.

Embodiment 1
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 is a perspective view showing the shape of a susceptor 1 that serves as a base for a substrate according to an embodiment. 2A is a top view of the susceptor 1 serving as a base for the substrate, FIG. 2B is a cross-sectional view of the susceptor 1 of FIG. 2A cut along an AA cutting line, and FIG. It is an enlarged view of the part surrounded by the circle of 2 (B).

  As shown in FIG. 1, the susceptor 1 includes a main body portion 2 and a step portion 3. On the main body 2, the step 3 is provided with a size m × n that is slightly smaller than the size M × N of the substrate 4.

  When the size is slightly smaller, the size m and n of the stepped portion are such that the film does not adhere to the back surface of the susceptor during film formation of the substrate, and the substrate warps due to stress during film formation, and the surface of the substrate and the susceptor is The size is such that it does not touch.

  For example, when the substrate size is 400 × 500 mm, the difference between M and m (M−m) and the difference between N and n (N−n) are preferably 8 mm to 12 mm, and more preferably about 10 mm. This is not preferable because the value of (M−m) and (N−n) is too large because the substrate warps due to stress during film formation, the substrate and the susceptor surface come into contact with each other, and abnormal discharge occurs. If the values of (M−m) and (N−n) are too small, the substrate adheres not only to the susceptor surface but also to the back surface when the substrate is formed, so that the substrate and the susceptor conduct, and abnormal discharge occurs. Therefore, it is not preferable. In addition, for example, when the substrate size is 400 × 500 mm, the height of the stepped portion 3 is preferably 2 mm to 4 mm, but is preferably matched to the warpage of the substrate due to stress during film formation.

  That is, when forming the substrate, the substrate 4 is formed using the susceptor 1 provided with the step portion 3 having a size slightly smaller than the size of the substrate 4 as shown in FIG. As shown in FIG. 2C, a step is provided between the film 5 on the end face of the substrate 4 and the film 6 attached not only on the substrate 4 but also on the surface of the susceptor body when the substrate is formed. The conduction (abnormal discharge) between the film surface 5 on the end face of the substrate 4 and the film 6 attached to the main body 2 (on the surface on the side where the stepped portion is present) can be avoided.

Embodiment 2
FIG. 3 shows the cleaning flow of the present invention.

  The first improvement is to reduce the film thickness to be etched, thereby shortening the time taken to complete the etching. After the etching process (A in FIG. 3), a pressure-down water cleaning (G in FIG. 3) is introduced. I decided to repeat this cycle.

  In the high-pressure water washing process, the film that has been peeled off by the etching process is removed by physical force. For this reason, the film that has been peeled off in the etching step (A in FIG. 3) is removed by physical force in the high-pressure water washing (G in FIG. 3) step, and then returned to the etching step (A in FIG. 3). By performing the film treatment, the film thickness to be etched is further reduced. Thus, by introducing high-pressure water cleaning (G in FIG. 3) during the etching process (A in FIG. 3) and repeating this cycle, the etching time of the film formed on the susceptor is half that of the conventional method. It became possible to suppress to the following.

  In addition, by introducing high-pressure water cleaning (G in FIG. 3), the residual film can be removed effectively, so that the amount of mask thinning during etching can be reduced, and the material cost for etching can be reduced. Is also a very effective process.

As a second improvement, blasting (H in FIG. 3) was introduced for the purpose of increasing the adhesion of the film attached to the susceptor surface to prevent film peeling. Since there is a concern about damage to the susceptor (such as cracking), it is preferable to use a material close to the material of the susceptor, and SiC or SiO ₂ is used for the blast material.

  However, since the susceptor is a member that comes into contact with the substrate, it is preferable to mask the contact portion with the substrate during blasting. This is due to the following reasons.

  As a film forming chamber, an apparatus that stands on the side and stands on the side so that particles from the target do not fall on the substrate is currently mainstream, and as shown in FIG. 8, the susceptor rises from horizontal to near vertical, Some have a side position.

  In the case of this structure, the substrate moves to a position supported by the susceptor pin by its own weight when it stands. For this reason, if the contact portion of the susceptor with the substrate such as the stepped portion 3 in FIG. 1 is similarly blasted, the friction coefficient of the contact portion of the susceptor with the substrate increases, so that the substrate falls on the susceptor by its own weight. And the timing of contact with the susceptor pin is shifted, and there is a risk that the substrate is displaced from side to side. Further, when viewed from the apparatus side, since the robot uses the teaching point as the position when the substrate falls evenly on the left and right, there is a risk of abnormal conveyance and substrate cracking.

  Therefore, at the time of blasting the susceptor, by masking the contact area with the substrate and avoiding an increase in the coefficient of friction, it is possible to simultaneously have a function to prevent scratches on the back surface of the substrate and misalignment during transportation. become.

  As a third improvement, an etching process (I in FIG. 3) and a cleaning process were introduced before and after that for the purpose of removing glass particles in the latent scratch portion generated during blasting. That is, after blasting (H in FIG. 3), pure water cleaning (B in FIG. 3) is performed to remove foreign matters generated during blasting, and then an etching process (I in FIG. 3) and pure water cleaning (in FIG. 3). J) By introducing high-pressure water cleaning (L in FIG. 3) and ultrapure water cleaning (C in FIG. 3), the glass particles at the latent scratch portion generated during blasting can be removed.

  Hereinafter, examples of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

In the cleaning method according to the present embodiment, as shown in FIG. 3, a step of high-pressure water cleaning (G in FIG. 3) is introduced after the etching step (A in FIG. 3), and (A in FIG. 3) and ( Step G) in FIG. 3 is repeated. At this time, the pressure of the high-pressure water is desirably 50 to 80 kgf / cm ² .

  By introducing this process, the conventional etching time (about 8 hours) was successfully halved from 3 hours to 4 hours.

  In addition, by introducing high-pressure water cleaning, the remaining film can be removed effectively, so that the amount of mask thinning during etching can be reduced, leading to a reduction in etching material costs. Therefore, this method is a very effective process.

Next, for the purpose of improving the adhesion of the film adhering portion (for example, the main body 2 in FIG. 2A), blasting (H in FIG. 3) is performed using a blasting material such as SiO ₂ and SiC. Do. There are drive blasting and wet blasting methods. However, since the object to be blasted is a susceptor made of glass mainly composed of SiO ₂ such as quartz or Pyrex (registered trademark), it is preferable to use wet blasting in consideration of the risk of cracking. In this example, the diameter of the blasting material used in wet blasting was 50 to 90 μm, and blasting (H in FIG. 1) was performed at a pressure of ³ to 5 kgf / cm ² .

  Further, when performing the blasting process (H in FIG. 3), it is preferable to mask the surface in contact with the substrate to avoid an increase in the friction coefficient. In particular, when the susceptor 1 is blasted as shown in FIG.

  By doing so, a part of one susceptor acts to strengthen the adhesion to prevent the film from peeling off (for example, the main body 2 in FIG. 2), and the other part scratches the glass. It is possible to produce a device having two functions such as a surface for preventing an increase in the coefficient of friction (for example, the step portion 3 in FIG. 2) at the same time. Therefore, this method is a very effective process.

  Thereafter, cleaning with pure water (B in FIG. 3) is performed once to remove foreign matters generated by blasting, and then the etching process (I in FIG. 3) is performed.

  In the subsequent etching process, hydrofluoric acid is used and etching is performed at room temperature for 30 minutes. As a study, we have also evaluated what was etched for 15 minutes and confirmed that there was no problem. However, the 30-minute product is used in consideration of the margin. Actually, it can be easily predicted that if the liquid temperature is increased and the concentration is increased, the etching time can be shortened. However, in this embodiment, the pursuit of this part is omitted.

  After the etching is completed, pure water cleaning (J in FIG. 3) and ultrapure water cleaning (C in FIG. 3) are performed. However, since it does not sufficiently remove foreign matters remaining after etching, High-pressure water cleaning (L in FIG. 3) was introduced between the above two types of cleaning.

The pressure of the high-pressure water is 50 to 80 kgf / cm ² and the object is to effectively remove foreign matters by applying a physical force. Thereafter, ultrapure water cleaning (C in FIG. 3) (specific resistance: 15.0 MΩ / cm or more, TOC (total organic matter): 50 ppb or less) as final cleaning is performed, followed by drying (D in FIG. 3) and inspection (FIG. 3). E) is followed through the process of packing (F in FIG. 3).

  Thus, by introducing the cleaning flow of the present invention, the etching time is shortened, and by blasting, the adhesion of the film adhering to the susceptor is increased to prevent dust generation, and further etching after blasting By introducing the process and the cleaning process, it is possible to prevent the generation of glass particles in the latent scratch portion. In addition, the yield rate of produced products could be improved.

  Actually, a comparative example of the susceptor subjected to the surface treatment according to the present invention and a conventional type is given.

  First, evaluation was performed based on the defect occurrence rate in the liquid crystal panel product when the susceptor into which only blast was introduced and the current type were used.

  The target machine for evaluation is the gate line formation processing machine (since it has multiple chambers, the sample of the comparative example and the countermeasure product are installed in each chamber), and the product line processed in each chamber of that machine The rate of occurrence of wire breakage rate and short-circuit rate was evaluated. This time, let us touch on the ratio of countermeasure products when the incidence of the comparative sample is 1.

  Actually, in the susceptor in which only blasting was performed, the disconnection rate and the short circuit rate were 0.5 times and 1.88 times when the disconnection rate and the short circuit failure rate of the comparative example sample were 1, respectively. Observing the surface after use, it was clear that there was no film peeling, but it was found to have an adverse effect at the micro level.

  4 shows a cross-sectional state and a surface state of the susceptor before blasting, FIG. 5 shows a cross-sectional state and a surface state after blasting, and FIG. 6 shows a cross-sectional state and a surface state after blasting + etching.

  As a result of observing the surface with an optical microscope with reference to FIG. 5, when blasting is performed, the surface state is apparently changed to fine irregularities. However, it was confirmed that the entrance of the part considered to be a latent scar faced a part of the surface and became a groove.

  As a second evaluation, after the blasting process (H in FIG. 3), a comparative evaluation of the defective rate in the product was performed using a susceptor that had been etched (I in FIG. 3) and a comparative sample.

  This time, the failure rate was higher than that of the gate line processing machine used in the first study, and it was installed in the source line forming machine and the pixel electrode forming machine, and the disconnection rates were compared. This is because the number of disconnections in the first gate line formation processing machine is 1 point in the countermeasure product and only 2 points in the comparative sample with respect to a certain parameter. This is because, as a result of analyzing the short-circuit failure, it is difficult to discriminate whether it is caused by the susceptor.

  Actually, the disconnection rate in the source line forming process machine is 0.56 times for the blasting process + etching processed product, assuming that the comparative example sample is 1. For the pixel electrode forming process machine, the comparative example sample is It was halved to 0.53 with respect to 1, and it was clearly found that there was an effect in reducing the disconnection rate.

  Further, when the surface was observed with an optical microscope, the blast treatment of FIG. 5 changed the latent scratch portion that had been visible to the surface so that the groove portion could be clearly observed as shown in FIG. .

  The surface condition after blasting and etching in FIG. 6 is that the average thinning amount per one time by repeated blasting is about 0.4 μm, so the normal use range (repeated cleaning cycle after use) However, it was confirmed that the value was sufficiently tolerable.

In addition, this invention is not limited to the said Example.
For example, in the above embodiment, the case of the shape of the susceptor, which is a jig in the vacuum apparatus used for forming a thin film in the liquid crystal panel production process, and the case of the surface treatment method are described as examples. However, the shape and surface treatment method of the present invention can be applied to a jig used around a substrate or wafer (work) in other semiconductor formation processes, PDP, PALC, FPD processes, etc. Needless to say, is applicable.

  There are also some processes that can be applied to ground processing of glass itself. It is a substrate for a reflective display. When this surface treatment is used in an ordinary transmissive display, the transmittance of the glass itself is lowered and the luminance is lowered. Further, since the substrate surface is uneven, there is a problem that light is scattered and light leakage occurs during black display.

  However, since the reflective display does not use the transmitted light from the backlight, by using this surface treatment for the surface treatment of the glass surface, the adhesion of the thin film in each film-forming process is improved, and the yield rate is improved. Needless to say, improvements are realized.

  As described above, by providing a step on the susceptor surface as in the present invention, abnormal discharge can be avoided (function 1), and the laminated film can be effectively withstood by performing blasting and etching. It is possible to secure adhesion (function 2) and simultaneously reduce particles such as glass particles from latent scratches (function 3).

  Furthermore, the masking process at the time of blasting makes it possible to reduce scratches on the back surface of the substrate by preventing an increase in the coefficient of friction of the substrate contact surface and the conveyance abnormality (function 4). It is possible to achieve a reduction in the thickness reduction (function 5) by shortening the length.

  By using the susceptor utilizing the present invention, the O / H cycle, where film peeling was rate-determined (Function 6), the non-defective product rate (Function 7), and the cost reduction by improving the equipment operating rate ( Function 8) is also achievable and has a great effect.

  The present invention relates to a susceptor provided as a base for a substrate in a vacuum chamber of a thin film production apparatus. The susceptor includes a susceptor body. On the susceptor body, there is provided a step portion that is slightly smaller than the substrate and supports the substrate from below.

  In the surface treatment method of the present invention, first, the surface of the susceptor containing SiO2 as a component is blasted. The surface of the susceptor is etched.

  In the surface treatment method of the present invention, the susceptor portion where the susceptor and the substrate are in contact with each other is masked before the blast treatment.

  In the surface treatment method of the present invention, the surface of the susceptor is washed with high pressure water before the blast treatment.

  In the surface treatment method of the present invention, the blast treatment is performed using SiO2 or SiC.

  In the surface treatment method of the present invention, the surface of the susceptor is washed with high-pressure water after the etching.

  The surface treatment method of the present invention is mainly composed of SiO2 used around the substrate and wafer in the semiconductor formation process, plasma display panel (PDP) formation process, plasma address liquid crystal (PALC) formation process and flat panel display (FPD) formation process. It concerns on the surface treatment method of the glass jig used as a component.

  First, the surface of the object to be processed is blasted (first step). The surface of the object to be processed is etched (second step). The object to be processed is cleaned by the following means (i) or (ii) (third step).

(I) Wash with high pressure water.
(Ii) Wash with pure water and high pressure water.

  The surface treatment method of the present invention is related to a surface treatment method of a thin film transistor substrate (TFT substrate) of a reflective liquid crystal panel.

  First, the surface of the TFT substrate is blasted (first step). The surface of the TFT substrate is etched (second step). The object to be processed is cleaned by the following means (i) or (ii) (third step).

(I) Wash with high pressure water.
(Ii) Wash with pure water and high pressure water.

  The surface treatment method of the present invention further includes a step of masking a susceptor portion where the susceptor and the substrate are in contact with each other prior to the blasting step.

  The surface treatment method of the present invention further includes a step of washing the surface of the susceptor with high-pressure water prior to the step of blasting.

  In the surface treatment method according to another aspect or still another aspect of the present invention, it is desirable to further include a step of masking a susceptor portion where the susceptor and the substrate are in contact with each other prior to the blasting step.

  In the surface treatment method according to another aspect or still another aspect of the present invention, it is desirable to further include a step of washing the surface of the susceptor with high-pressure water prior to the step of blasting.

  A susceptor used in the present invention, for example, is provided as a base for a substrate in a vacuum chamber of a thin film production apparatus. The susceptor includes a susceptor body. On the susceptor body, it is desirable to provide a stepped portion that is slightly smaller than the substrate and supports the substrate from below. Accordingly, it is desirable that the susceptor can withstand the stress of the laminated film at the time of film formation, and the film adhered and laminated on the susceptor is electrically connected to the film formed on the substrate end face and does not cause abnormal discharge.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 susceptor, 2 susceptor main-body part, 3 level | step difference part, 4 board | substrate, 5 film surface of end surface, 6 film | membrane adhering on the surface of a susceptor main-body part.

Claims (11)

Blasting the surface of the susceptor mainly composed of SiO ₂ using SiO ₂ or SiC;
Etching the surface of the susceptor.   The surface treatment method according to claim 1, further comprising a step of masking a part of a susceptor where the susceptor and a substrate to be placed on the susceptor are in contact with each other prior to the blasting step. The susceptor includes a susceptor body and a step portion provided on the susceptor body and having a size slightly smaller than the substrate, and as a part of the susceptor, a step portion that supports the substrate from below.
In the masking step, the stepped portion is masked,
The surface treatment method according to claim 2, wherein conduction between an end of the substrate and the susceptor body can be prevented.   The surface treatment method according to claim 1, further comprising a step of washing the surface of the susceptor with high pressure water prior to the step of blasting.   The surface treatment method according to claim 1, further comprising a step of washing the surface of the susceptor with high-pressure water after the etching step. A surface treatment method for a glass jig mainly composed of SiO ₂ used around a substrate and a wafer in a semiconductor formation step, a plasma display panel formation step, a plasma address liquid crystal formation step, and a flat panel display formation step,
A first step of blasting the surface of the object to be processed;
A second step of etching the surface of the object to be processed;
A surface treatment method comprising: a third step of washing the object to be treated by the following means (i) or (ii).
(I) Wash with high pressure water.
(Ii) Wash with pure water and high pressure water. A surface treatment method for a substrate of a thin film transistor of a reflective liquid crystal panel,
A first step of blasting the surface of the thin film transistor substrate;
A second step of etching the surface of the substrate of the thin film transistor;
And a third step of cleaning the substrate of the thin film transistor as the object to be processed by means of the following (i) or (ii).
(I) Wash with high pressure water.
(Ii) Wash with pure water and high pressure water.   8. The surface treatment method according to claim 6, further comprising a step of masking a part of the susceptor where the substrate contacts the susceptor supporting the substrate from below before the blasting step. The susceptor includes a susceptor body and a step portion provided on the susceptor body and having a size slightly smaller than the substrate, and as a part of the susceptor, a step portion that supports the substrate from below.
In the masking step, the stepped portion is masked,
The surface treatment method according to claim 8, wherein conduction between an end portion of the substrate and the susceptor body can be prevented.   The surface treatment method according to any one of claims 6 to 9, further comprising a step of washing the surface of the susceptor with high-pressure water prior to the first step of blasting.   The surface treatment method according to claim 10, wherein the second step of etching and the step of washing with high-pressure water are repeated.

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