JP2000144454A - Equipment and method for wet etching - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of precipitates after wet etching. SOLUTION: This equipment is provided with an etching chamber 4 having a shower nozzle 4N for feeding the surface of a glass substrate 1 with an etching solution 4S for a chromium or chromium-alloy film formed on the surface of the glass substrate 1, a first cleaning chamber 5 having a shower nozzle 5N for feeding the surface of the glass substrate 1 with a first cleaning solution 5S composed of an acidic aqueous solution of hydrochloric acid of pH 0-1.3, a second cleaning chamber 6 having a shower nozzle 6N for feeding the surface of the glass substrate 1 with a second cleaning solution 6S composed of pure water, and a drying chamber 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for wet etching, and more particularly to a technique for suppressing the generation of precipitates on a substrate surface after etching.

[0002]

2. Description of the Related Art In wet etching, for example, a metal layer is formed on a substrate surface, a resist film having a predetermined pattern serving as an etching mask is formed on the metal layer, and then a metal layer is formed on the substrate surface. An etching solution for etching is supplied to process the metal layer into a predetermined pattern. afterwards,
In order to remove the etching solution containing the etched metal layer, a cleaning solution (also referred to as a rinsing solution) such as pure water is supplied onto the substrate surface to wash the substrate, and then draining is performed.
dry.

Further, the wet etching apparatus removes, for example, an etching chamber provided with a nozzle for discharging an etching solution for a metal layer from a direction substantially perpendicular to the substrate surface on which the metal layer is formed, by replacing the etching solution. A first cleaning chamber having a nozzle for discharging a first cleaning liquid from a direction substantially perpendicular to the substrate surface, a second cleaning chamber having a nozzle for discharging a second cleaning liquid for finish cleaning from a direction substantially perpendicular to the substrate, and a substrate. And a drying chamber for drying.

[0004]

In a conventional wet etching apparatus in which the first cleaning liquid in the first cleaning chamber immediately after the etching of the metal layer is made of pure water, a large amount of the etching liquid on the substrate is removed in the first cleaning chamber. Replace with water at once and wash.

However, before cleaning the etching solution on the substrate with a large amount of pure water, a small amount of pure water retained in the cleaning solution nozzle may drop onto the substrate, generate mist, or cause a problem during cleaning. (1) There is a problem that a precipitate is deposited on the substrate surface due to a decrease in the flow rate of pure water as a cleaning liquid or the like. In other words, if a small amount of pure water falls on the substrate after the etching is completed, for example, before cleaning, the pH of the etching solution in that part locally increases due to the pure water. For this reason, a precipitate is generated on the substrate, and the precipitate may have an adverse effect.

Hereinafter, as one example, a description will be given of wet etching in a manufacturing process of a TFT (thin film transistor) -liquid crystal display panel (ie, liquid crystal display element, LCD).

For example, in a manufacturing process of a TFT-liquid crystal display panel, when wet etching of a chromium (Cr) film or a chromium alloy film for forming a gate wiring as a metal layer on a substrate, the nitric acid is used as an etchant. An aqueous solution of cerium ammonium 2 is used. Pure water is used as the first and second cleaning liquids in the first and second cleaning chambers.

In the conventional wet etching apparatus in which the first cleaning liquid in the first cleaning chamber immediately after the etching of the chromium film (or the chromium alloy film) is made of pure water,
A large amount of pure water replaces the etching solution on the substrate at once. However, for example, before the etchant on the substrate is removed at once, the pH of the etchant in that portion locally increases due to the pure water due to a small amount of pure water falling from the nozzle onto the substrate, and the weakness is weakened. It becomes an acidic region. Cerium (Ce ⁴⁺ ) ions in the chromium etching solution had a pH of 1.3.
It precipitates in the above weakly acidic region. Therefore, before the pH of the etching solution on the substrate is completely replaced with pure water, the cerium compound remains in a weakly acidic region where the cerium compound is easily precipitated. May occur. This deposit adheres to the substrate,
A-Si (amorphous-Si) forming a TFT is not removed even after a subsequent washing and a resist film removing process.
In the process of forming the (silicon) film / SiN (silicon nitride) film, this has an adverse effect, and the characteristics such as the threshold voltage of the TFT are reduced.

FIGS. 3 and 4 are views for explaining the problems of the wet etching apparatus according to the present invention. FIG. 3 is a sectional view of a normal a-Si / SiN film formed on a substrate. Indicates that a-Si / abnormally grown on the substrate due to precipitates
It is sectional drawing of a SiN film.

3 and 4, 1A is a glass substrate,
Reference numeral 9 denotes a gate wiring made of a chromium film (or a chromium alloy film), 10 denotes an a-Si / SiN film, an upper a-Si film is a channel forming film, and a lower SiN film is a gate insulating film. In FIG. 4, 11 is a precipitate (cerium hydroxide),
10A is an a-Si / SiN film abnormal growth portion.

As shown in FIG. 3, normal a-Si / Si
Although the N film 10 has a flat film surface, as shown in FIG.
When a precipitate 11 made of cerium hydroxide or the like exists on the substrate 1A, the a-Si / SiN film 10 on the precipitate 11 is formed.
Abnormally grows (10A), and the surface of the a-Si / SiN film becomes uneven. The abnormality of the a-Si / SiN film causes the film to be clouded, which causes a decrease in TFT characteristics, and causes a problem of causing display failure of the liquid crystal display device.

An object of the present invention is to provide a wet etching apparatus and method capable of preventing generation of precipitates after etching.

[0013]

In order to solve the above problems, the present invention is characterized in that the first cleaning liquid immediately after etching is an acidic aqueous solution. That is, the wet etching apparatus of the present invention comprises a substrate supporting means, a means for supplying an etching liquid on the substrate surface, a first cleaning liquid comprising an acidic aqueous solution on the substrate surface, and a second cleaning liquid comprising pure water. And means for supplying

Further, in an apparatus for wet-etching a metal layer formed on a substrate surface, an etching chamber having means for supplying an etching solution for the metal layer onto the substrate surface, A first cleaning chamber having a means for supplying the first cleaning liquid to the substrate surface; a second cleaning chamber having a means for supplying the second cleaning liquid onto the substrate surface; and a drying chamber, wherein the first cleaning liquid in the first cleaning chamber is provided. Preferably, an acidic aqueous solution is supplied, and pure water is supplied as the second cleaning liquid in the second cleaning chamber.

Further, all or at least one of the etching liquid, the first cleaning liquid and the second cleaning liquid is discharged and supplied from a direction substantially perpendicular to the substrate surface.

Further, at least two of the means for supplying the etching liquid, the first cleaning liquid, and the second cleaning liquid may be used.
One is shared, or the etching chamber, the first
At least two of the cleaning chamber, the second cleaning chamber, and the drying chamber are shared.

Further, in the wet etching method of the present invention, a metal layer is formed on a substrate surface, and an etching mask film having a predetermined pattern is formed on the metal layer. Supplying a liquid, processing the metal layer into a predetermined pattern, and then performing a cleaning step of supplying a cleaning liquid onto the substrate surface and performing cleaning at least twice, wherein the cleaning step includes a first cleaning step and a second cleaning step. In the first cleaning step, an acidic aqueous solution is used as the cleaning liquid, and in the subsequent second cleaning step, pure water is used as the cleaning liquid.

The acidic aqueous solution has a pH of from 0 to 1.
3 range.

Further, the acidic aqueous solution is at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and acetic acid.

Further, the metal layer is a chromium film or a chromium alloy film.

According to the above-mentioned means, even if the acidic aqueous solution comes into contact with the substrate surface by dropping from a nozzle or the like before the cleaning of the etching solution on the substrate, the pH of the etching solution in that portion is reduced.
Does not fluctuate in the pH range where the components of the etching solution are deposited by the contacted acidic aqueous solution. For this reason, immediately after etching, generation of a precipitate on the substrate surface can be prevented, and adverse effects due to the precipitate can be prevented.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings described below, those having the same functions are denoted by the same reference numerals, and the repeated description thereof will be omitted.

Embodiment 1 FIG. 1 is a schematic configuration diagram of a wet etching apparatus according to Embodiment 1 of the present invention.

In this embodiment, the wet etching apparatus includes an etching chamber, a first cleaning chamber, a second cleaning chamber, and a drying chamber, and each chamber includes a shower nozzle for discharging an etching liquid or a cleaning liquid. An example of an etching apparatus is shown.

In FIG. 1, reference numeral 1 denotes a glass substrate. This glass substrate is formed by forming a chromium film (or chromium alloy film; the same applies hereinafter) on the chromium film, and then performing photographic processing (that is, selective exposure using a mask from the application of a resist film) as an etching mask thereon. After that, a series of operations up to the development of the resist film is shown) to form a resist film in a predetermined pattern (that is, selectively).
Reference numeral 2 denotes a substrate transfer roller which also serves as a substrate support means and a substrate transfer means, 3 denotes a substrate loading chamber, 4 denotes an etching chamber, 4N denotes a shower nozzle for discharging a chromium etching solution, and 4S denotes chromium etching made of a ceric ammonium nitrate aqueous solution. The liquid 5 is a first cleaning chamber, 5N is a shower nozzle for discharging the first cleaning liquid, 5S is a first cleaning liquid made of an acidic aqueous solution such as hydrochloric acid having a pH in a range of 0 to 1.3, and 6 is a second cleaning liquid.
A cleaning chamber, 6N is a shower nozzle for discharging a second cleaning liquid,
6S is a second cleaning liquid made of pure water, 7 is a drying chamber, and 8 is a substrate unloading chamber.

Hereinafter, a description will be given of a wet etching process of a metal layer formed on a substrate, which is performed in the wet etching apparatus having the above configuration.

First, a chromium (or chromium alloy; hereinafter the same) film-formed glass substrate 1 with a resist film as an etching mask formed in a predetermined pattern is transported from a substrate loading chamber 3 to an etching chamber 4 by a substrate transport roller 2. ,
After being stopped and supported in the etching chamber 4, the chromium film is etched by the chromium etching solution 4S discharged from the shower nozzle 4N.

The chromium-deposited glass substrate 1 with the resist film after the etching is transported from the etching chamber 4 to the first cleaning chamber 5 by the substrate transport roller 2 and is resisted by the acidic aqueous solution 5S discharged from the shower nozzle 5N. The chromium etching solution on the chromium-coated glass substrate 1 with a film is removed while replacing it with an acidic aqueous solution 5S.

Next, the chromium-coated glass substrate 1 with the resist film is transported from the first cleaning chamber 5 to the second cleaning chamber 6 by the substrate transport roller 2 and is purified by pure water 6S discharged from the shower nozzle 6N. Cleaning is performed while replacing the acidic aqueous solution on the chromium-coated glass substrate 1 with the resist film with pure water 6S.

Next, the chromium-coated glass substrate 1 with the resist film is transported from the second cleaning chamber 6 to the drying chamber 7 by the substrate transport roller 2, and after draining pure water, using a hot plate or the like. Completely dry and remove the water.

Next, the chromium-coated glass substrate 1 with the resist film is transported from the drying chamber 7 to the substrate unloading chamber 8 by the substrate transport roller 2, and a series of wet etching steps is completed. After that, a resist film peeling step is performed.

In order to realize highly uniform etching, control and adjustment of the temperature of the etching solution, the first and second cleaning solutions, the composition of the solution, the shape of the shower nozzle, the spray pressure, the amount of the solution, and the like are appropriately performed. .

As described above, in the wet etching apparatus of the present embodiment, an acidic aqueous solution 5S made of hydrochloric acid having a pH in the range of 0 to 1.3 is supplied as the first cleaning liquid 5S in the first cleaning chamber 5. As a result, before the chromium etching solution 4S composed of the ceric ammonium nitrate aqueous solution on the substrate 1 is replaced with the acidic aqueous solution 5S discharged from the shower nozzle 5N and removed, the acidic aqueous solution 5S is removed.
Even if S comes in contact with the surface of the substrate 1 by dropping from the shower nozzle 5N or the like, the p of the chromium etching solution 4S at that portion
H does not enter a weakly acidic region where cerium, which is a component of the aqueous ceric ammonium nitrate solution, precipitates as cerium hydroxide. Thereafter, when the second cleaning is performed in the second cleaning chamber 6 with the second cleaning liquid 6S made of pure water, the chromium etching liquid is washed away by the first cleaning liquid 5S and does not exist, so that a problem such as deposition does not occur. For this reason, immediately after the chromium etching, precipitation of cerium hydroxide on the surface of the substrate 1 can be prevented. Therefore, a-Si which is a constituent film of a TFT to be formed later is
Since the a-Si / SiN film is formed normally without causing abnormal growth of the / SiN film (see FIGS. 3 and 4 described above), the display of the liquid crystal display device can be performed without deteriorating the TFT characteristics. The occurrence of defects can be prevented. Therefore, product quality and production yield are improved.

In the present embodiment, hydrochloric acid having a pH in the range of 0 to 1.3 is preferably used as the acidic aqueous solution 5S of the first cleaning solution. Even if one or more of sulfuric acid, nitric acid, phosphoric acid, and acetic acid in the range of 0.3 and a strong acid having a pH of 0 or less are used, the same effect can be obtained by the same action.

Embodiment 2 FIG. 2 is a schematic configuration diagram of a wet etching apparatus according to a second embodiment of the present invention.

In the present embodiment, the wet etching apparatus has both an etching and first cleaning chamber and a second cleaning and drying chamber, and each chamber is provided with a shower nozzle for discharging an etching liquid or a cleaning liquid and a substrate rotating mechanism. An example of a wet etching apparatus is shown.

In FIG. 2, 1 is a glass substrate (similar to FIG. 1), 3 is a substrate loading chamber, 2A is a substrate support, 4A is an etching and first cleaning chamber, 2B is a substrate rotation support, 4N
W is a shower nozzle for discharging a chromium etching liquid and a first cleaning liquid, 4SW is a chromium etching liquid or an acidic aqueous solution, 6A is a second cleaning and drying chamber, 6N is a shower nozzle for discharging a second cleaning liquid, and 6S is pure water. The second cleaning liquid 8 is a substrate unloading chamber.

As shown in FIG. 2, a chromium (or chromium alloy; hereinafter the same) film-formed glass substrate 1 with a resist film formed in a predetermined pattern as an etching mask.
Is transferred from the substrate carrying-in chamber 3 to the substrate rotating support 2B in the first cleaning chamber 4A by the substrate transfer arm 3 by a chromium etching solution 4SW discharged from the shower nozzle 4NW. The chromium film is etched.

Subsequently, the chromium etchant on the chromium-coated glass substrate 1 with the resist film is removed by the acidic aqueous solution 4SW discharged from the shower nozzle 4NW while replacing it with the acidic aqueous solution 4SW. In the present embodiment,
The chromium etching solution or the acidic aqueous solution 4SW is supplied from different supply sources, but is shared by the shower nozzle 4NW. It goes without saying that the chromium etching solution or the acidic aqueous solution may be supplied from separate shower nozzles.

A chromium-coated glass substrate 1 with a resist film
Is the second cleaning and drying chamber 6A by the substrate transfer arm.
Transported onto the substrate rotation support 2B inside the shower nozzle 6
Cleaning is performed while replacing the acidic aqueous solution on the chromium-coated glass substrate 1 with the resist film with the pure water 6S using pure water 6S supplied from N.

Next, the chromium-coated glass substrate 1 with the resist film is completely drained in the second cleaning and drying chamber 6A by spin rotation with the substrate rotation support 2B and injection of dry air. , Dried and removed.

Next, the substrate 1 is moved by the substrate transfer arm.
Transported from the second cleaning and drying chamber 6A to the substrate unloading chamber 8,
A series of wet etching steps is completed.

In order to realize highly uniform etching, control of the liquid temperature, liquid composition of the etching liquid and the first and second cleaning liquids, the shape of the shower nozzle, the spray pressure, the liquid amount, the number of spin rotations, and the like are performed. Adjustments are made appropriately.

As described above, also in the wet etching apparatus of the present embodiment, the etching and the first cleaning chamber 4
By supplying an acidic aqueous solution consisting of hydrochloric acid having a pH in the range of 0 to 1.3 as the first washing liquid in A,
Before the chromium etching solution composed of the ceric ammonium nitrate aqueous solution on the substrate 1 is removed by replacing it with the acidic aqueous solution 4SW discharged from the shower nozzle 4NW, the acidic aqueous solution is dropped from the shower nozzle 4NW or the like. , The pH of the chromium etchant in that part is such that cerium, which is a component of the ceric ammonium nitrate aqueous solution, precipitates as cerium hydroxide.
It will not be in the H range. For this reason, precipitation of cerium hydroxide on the surface of the substrate 1 immediately after the chromium etching can be prevented. Therefore, the a-Si / SiN film, which is a constituent film of the TFT to be formed later, is formed normally without causing abnormal growth, and the display characteristics of the liquid crystal display device are not deteriorated without deteriorating the TFT characteristics. Can be eliminated.

In this embodiment, it is preferable to use hydrochloric acid having a pH in the range of 0 to 1.3 as the acidic aqueous solution of the first cleaning solution.
Even if one or more of sulfuric acid, nitric acid, phosphoric acid, and acetic acid in the above range and a strong acid having a pH of 0 or less are used, the same effect can be obtained by the same action.

Next, the reason why precipitates do not occur when the pH is low will be described.

For example, the chromium (Cr) etching reaction is carried out when Ce ⁴⁺ ions in the Cr etching solution are reduced to Ce ³⁺ ions as shown in the following chemical reaction formula.
This is a reaction for oxidizing r (0), and the Cr (0) film is formed of Cr ³⁺
Dissolves as ions.

3Ce ⁴⁺ + Cr (0) → 3Ce ³⁺ + Cr ³⁺ (1) In the Cr etching solution, C involved in the etching reaction
There are ^{e4 +} , Ce3 ⁺ , and Cr3 ⁺ ions. FIG.
In addition, the ease of existence of these ions as ions,
It is shown by the relationship between pH and ion concentration. The lower part of each line dissolves as ions and the upper part of each line precipitates as hydroxide. When the pH of the Cr etching solution changes from acidic to neutral, Ce ⁴⁺ , Cr ³⁺ , and Ce ³⁺ are obtained as shown in the following chemical reaction formula.
It is known that the ions are likely to precipitate as hydroxides in the order of ions.

Ce ⁴⁺ + 4OH ⁻ → Ce (OH) ₄ (2) Cr ³⁺ + 3OH ⁻ → Cr (OH) ₃ (3) Ce ³⁺ + 3OH ⁻ → Ce (OH) ₃ (4) From FIG. 5, it can be seen that when the ion concentration in the etching solution is increased, precipitation is likely to occur even at a lower pH.

Since the ease of precipitation of the Ce compound greatly varies depending on the pH at the time of washing the substrate, the precipitation behavior of the Ce compound when diluted with an acidic aqueous solution capable of keeping the pH low was examined.

FIG. 6 shows that the Cr etching solution is made of hydrochloric acid (HC).
l) The concentration of hydrochloric acid when diluted according to
The relationship with the precipitation dilution rate at which the compound e starts to precipitate is shown.

When the pH value decreases by increasing the amount of hydrochloric acid added, the precipitation dilution ratio increases, and the hydrochloric acid concentration becomes 0.7 ×
In an acidic aqueous solution having a pH of 10 ^-1 mol / l or more and a pH of 1.3 or less, precipitation of a Ce compound does not occur even if the Cr etching solution is diluted 35 times. This is because even if the Cr etching solution is diluted with an acidic aqueous solution having a pH of 1.3 or less, the pH does not reach 1.3 or more, which is the pH range in which the Ce compound is precipitated. Therefore, the cleaning solution immediately after the Cr etching is not pure water but an acidic aqueous solution, for example, pH 1.
By using hydrochloric acid of 3 or less, precipitation of the Ce compound can be prevented. Although the case where the metal layer is made of Cr has been described as an example, the same phenomenon occurs when a Cr alloy film such as Cr-Mo (chromium-molybdenum) or another metal layer is used. The present invention is not limited to the case where the metal layer is made of Cr or a Cr alloy, and it is needless to say that the present invention can be applied to a case where another metal layer is wet-etched.

<< Outline of Liquid Crystal Display Panel >> FIG. 7 is a plan view showing one pixel of an active matrix type color liquid crystal display panel as an example to which the present invention is applied and its periphery.
FIG. 8 shows an image in which the pixel portion of the matrix is located at the center (b) (cross section taken along the line 8-8 in FIG. 7), the left side (a) is near the panel angle, and the right side (c) is connected to the video signal drive circuit. FIG. 3 is a diagram illustrating a cross section near a signal terminal DTM.

As shown in FIG. 7, each pixel has two adjacent scanning signal lines (gate signal lines or horizontal signal lines) GL.
And two adjacent video signal lines (drain signal lines or vertical signal lines) DL (in a region surrounded by four signal lines). Each pixel includes a thin film transistor TFT, a transparent pixel electrode ITO1, and a storage capacitor Cadd. The scanning signal lines GL extend in the left-right direction in FIG. Video signal line DL
Extend in the up-down direction and are arranged in a plurality in the left-right direction.

As shown in FIG. 8, a thin film transistor TFT and a transparent pixel electrode ITO1 are formed on the lower transparent glass substrate SUB1 side with respect to the liquid crystal layer LC, and a color filter FIL and a light-shielding element are formed on the upper transparent glass substrate SUB2 side. A black matrix pattern BM is formed. A silicon oxide film SIO formed by dipping or the like is provided on both surfaces of the transparent glass substrates SUB1 and SUB2.

The light shielding film BM and the color filter FI are provided on the inner surface (the liquid crystal LC side) of the upper transparent glass substrate SUB2.
L, protective film PSV2, common transparent pixel electrode ITO2 (CO
M) and an upper alignment film ORI2 are sequentially laminated.

<< Manufacturing Method >> Next, a method of manufacturing the above-described liquid crystal display device on the substrate SUB1 side will be described with reference to FIGS. In the same figure, the characters in the center are the abbreviations of the process names, and the left side is the pixel portion shown in FIG.
The right side shows the flow of processing viewed from the cross-sectional shape near the gate terminal. Except for the process D, the processes A to I are classified according to the respective photographic processes, and any cross-sectional view of each process shows a stage where the processing after the photographic process is completed and the photoresist is removed. In the present description, photographic processing refers to a series of operations from application of a photoresist to selective exposure using a mask to development thereof, and a repeated description will be omitted. A description will be given below according to the divided steps.

Step A, FIG. 9 After a silicon oxide film SIO is provided on both surfaces of a lower transparent glass substrate SUB1 made of 7059 glass (trade name) by dipping, baking is performed at 500 ° C. for 60 minutes. The film thickness is 1100Å on the lower transparent glass substrate SUB1.
The first conductive film g1 made of chromium is provided by sputtering, and after the photographic processing, the first conductive film g1 is selectively etched with a ceric ammonium nitrate solution as an etchant. Thereby, the gate terminal GTM, the drain terminal DTM, the anodized bus line SHg for connecting the gate terminal GTM, the bus line SHd for short-circuiting the drain terminal DTM, and the anodized pad connected to the anodized bus line SHg (not shown) To form

Step B, FIG. 9 Al-Pd, Al-Si, Al-S having a thickness of 2800 °
Second conductive film g2 made of i-Ti, Al-Si-Cu, or the like
Is provided by sputtering. After the photographic processing, the second conductive film g2 is selectively etched with a mixed acid solution of phosphoric acid, nitric acid, and glacial acetic acid.

Step C, FIG. 9 After photographic processing (after the formation of the anodic oxidation mask AO described above), 3
% Tartaric acid was adjusted to pH 6.25 ± 0.05 with ammonia, and the substrate SUB1 was immersed in an anodic oxidizing solution consisting of a solution obtained by diluting 1: 9 with an ethylene glycol solution, and the formation current density was 0.5 mA / cm. ² so as to adjust (constant current Kasei). Next, anodic oxidation is performed until the formation voltage 125 V necessary for obtaining a predetermined Al ₂ O ₃ film thickness is reached. Thereafter, it is desirable to hold this state for several tens of minutes (constant voltage formation). This is important for obtaining a uniform Al ₂ O ₃ film. Thereby, the conductive film g2 is anodized,
An anodic oxide film AOF having a thickness of 1800 ° is formed on scanning signal line GL, gate electrode GT and electrode PL1.

Step D, FIG. 10 Ammonia gas, silane gas, and nitrogen gas are introduced into the plasma CVD apparatus to form a 2000-nm thick Si nitride film, and silane gas and hydrogen gas are introduced into the plasma CVD apparatus. Is provided with a 2000 ° i-type amorphous Si film, and then a hydrogen gas and a phosphine gas are introduced into a plasma CVD apparatus to form an N (+)-type amorphous Si film having a thickness of 300 °.

Step E, FIG. 10 After the photographic processing, SF ₆ or CC is used as a dry etching gas.
Using l ₄ , N (+) type amorphous Si film, i type amorphous Si
By selectively etching the film, islands of the i-type semiconductor layer AS are formed.

Step F, FIG. 10 After the photo processing, the Si nitride film is selectively etched using SF ₆ as a dry etching gas.

Step G, FIG. 11 A first conductive film d1 made of an ITO film having a thickness of 1400 ° is provided by sputtering. After the photographic processing, the first conductive film d1 is selectively etched with a mixed acid solution of hydrochloric acid and nitric acid as an etchant, thereby forming the uppermost layer of the gate terminal GTM and the drain terminal DTM and the transparent pixel electrode ITO1.
To form

Step H, FIG. 11 A second conductive film d2 made of Cr having a thickness of 600 .ANG. Is provided by sputtering, and a second conductive film d2 having a thickness of 4000 .ANG.
Pd, Al-Si, Al-Si-Ti, Al-Si-C
A third conductive film d3 made of u or the like is provided by sputtering. After the photographic processing, the third conductive film d3 is etched with the same liquid as in the step B, and the second conductive film d2 is etched with the same liquid as in the step A to form the video signal line DL, the source electrode SD1, and the drain electrode SD2. I do. Next, CCl ₄ and SF ₆ are introduced into a dry etching apparatus to form an N (+) type amorphous S
By etching the i film, the N (+) type semiconductor layer d0 between the source and the drain is selectively removed.

Step I, FIG. 11 An ammonia gas, a silane gas, and a nitrogen gas are introduced into a plasma CVD apparatus to form a 1 μm-thick Si nitride film. After the photo processing, the protective film PSV1 is formed by selectively etching the Si nitride film by a photo etching technique using SF ₆ as a dry etching gas.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and it is needless to say that various modifications can be made without departing from the gist of the present invention. It is.

[0068]

As described above, according to the present invention,
Even if the cleaning solution contacts the substrate before cleaning the etching solution on the substrate, the pH range of the etching solution in that portion does not become the pH range in which the components of the etching solution are deposited. For this reason, generation of a precipitate on the substrate after the etching can be prevented, so that an adverse effect of the precipitate can be prevented, and there is an effect that a product quality and a manufacturing yield can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a wet etching apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a wet etching apparatus according to a second embodiment of the present invention.

FIG. 3 is a diagram for explaining a problem of the wet etching apparatus according to the present invention.

FIG. 4 is a diagram for explaining a problem of the wet etching apparatus according to the present invention.

FIG. 5 is a diagram showing a relationship between pH and ion concentration of Ce ⁴⁺ , Cr ³⁺ , and Ce ³⁺ ions involved in an etching reaction in a Cr etching solution.

FIG. 6 is a graph showing the relationship between the concentration of hydrochloric acid when the Cr etching solution is diluted with hydrochloric acid, and the pH and the precipitation dilution ratio at which a Ce compound starts to precipitate.

FIG. 7 is a plan view of a principal part showing one pixel of an active matrix type color liquid crystal display panel and its periphery.

8A and 8B are cross-sectional views of a pixel portion of the matrix of FIG. 7 in the center (b), a left side (a) near a panel angle, and a right side (c) near a video signal terminal to which a video signal drive circuit is connected. It is.

FIG. 9 is a flowchart of a cross-sectional view of a pixel portion and a gate terminal portion showing a manufacturing process of processes A to C on the substrate SUB1 side.

FIG. 10 is a flowchart of a cross-sectional view of a pixel portion and a gate terminal portion showing manufacturing processes of processes D to F on the substrate SUB1 side.

FIG. 11 is a flowchart of a cross-sectional view of a pixel portion and a gate terminal portion showing a manufacturing process of processes G to I on the substrate SUB1 side.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Substrate conveyance roller, 3 ... Substrate carry-in room, 4 ... Etching room, 4N ... Chrome etching liquid shower nozzle, 4S ... Chrome etching liquid, 5 ... First cleaning chamber, 5N ... First cleaning liquid shower nozzle 5S: first cleaning liquid, 6: second cleaning chamber, 6N: second cleaning liquid shower nozzle, 6S: second cleaning liquid, 7: drying chamber, 8: substrate unloading chamber,
2A: substrate support, 2B: substrate rotation support, 4A: etching and first cleaning chamber, 4NW: chromium etching solution and first cleaning solution shower nozzle, 4SW: chromium etching solution or acidic aqueous solution, 6A: second cleaning and drying Chamber, 1A: glass substrate, 9: gate wiring, 10: a-S
i / SiN film, 11: precipitate, 10A: a-Si / Si
N film abnormal growth part.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K057 WA01 WB08 WC10 WE02 WE03 WE04 WE12 WK10 WM06 WN02 5F043 AA02 AA11 AA22 BB15 BB27 CC16 DD13 EE02 EE07 EE08 FF07 GG02

Claims (11)

[Claims] 1. A wet etching apparatus, comprising: means for supporting a substrate; means for supplying an etchant onto the substrate surface; a first cleaning solution comprising an acidic aqueous solution on the substrate surface; and a second cleaning solution comprising pure water. A wet etching apparatus comprising: 2. An apparatus for wet-etching a metal layer formed on a substrate surface, comprising: an etching chamber having means for supplying an etching solution for the metal layer onto the substrate surface; A first cleaning chamber having a means for supplying the cleaning liquid to the top, a second cleaning chamber having a means for supplying the second cleaning liquid onto the substrate surface, and a drying chamber, wherein the first cleaning liquid in the first cleaning chamber is provided. An acidic aqueous solution is supplied, and pure water is supplied as the second cleaning liquid in the second cleaning chamber. 3. The wet etching apparatus according to claim 1, wherein the acidic aqueous solution has a pH in a range of 0 to 1.3. 4. The wet etching apparatus according to claim 1, wherein the acidic aqueous solution is at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and acetic acid. 5. The wet etching apparatus according to claim 1, wherein the metal layer is a chromium film or a chromium alloy film. 6. The method according to claim 1, wherein all or at least one of the etching solution, the first cleaning solution, and the second cleaning solution is discharged and supplied from a direction substantially perpendicular to the substrate surface. Wet etching equipment. 7. At least two of the means for supplying the etching liquid, the first cleaning liquid, and the second cleaning liquid are shared, or the etching chamber, the first cleaning chamber,
The wet etching apparatus according to claim 2, wherein at least two of the second cleaning chamber and the drying chamber are shared. 8. An etching solution for the metal layer is supplied on the substrate surface on which a metal layer is formed on a substrate surface and an etching mask film having a predetermined pattern is formed on the metal layer;
After processing the metal layer into a predetermined pattern, a cleaning step of supplying a cleaning liquid onto the substrate surface and performing cleaning is performed at least twice, and the cleaning step includes a first cleaning step and a second cleaning step. A wet etching method, wherein an acidic aqueous solution is used as the cleaning liquid in the first cleaning step, and pure water is used as the cleaning liquid in the subsequent second cleaning step. 9. The wet etching method according to claim 8, wherein said acidic aqueous solution has a pH in a range of 0 to 1.3. 10. The acidic aqueous solution according to claim 1, wherein the acidic aqueous solution is hydrochloric acid, sulfuric acid, nitric acid,
The wet etching method according to claim 8, wherein at least one of phosphoric acid and acetic acid is used. 11. The wet etching method according to claim 8, wherein said metal layer is a chromium film or a chromium alloy film.