JPH11253893A - Washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent chemicals from being deposited on a nozzle to cause foreign matter and also to simplify constitution irrespectively of the number of kinds of chemicals to be used. SOLUTION: This washer for washing an insulating substrate 10 by using chemicals and water in this order during the process in which a photosensitive photoresist film is formed on the surface of the substrate 10 to form a desired pattern by photolithography is equipped with a turntable 9 on which the substrate 10 is mounted to rotate it, one nozzle 7 arranged above the substrate 10, and at least two systems of liquid supply paths consisting of a chemical check valve 5 and a water check valve 6 connected in common to the nozzle 7 on the outlet side thereof and a chemical supply valve 3 and a pure water supply valve 4 connected to the check valves 5, 6 on the inlet sides thereof respectively. In this way, to the substrate 10 mounted on the turntable 9, the chemicals and the water are fed with a time-lag by alternately opening/closing the chemical supply valve 3 and the pure water supply valve 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a cleaning device,
In particular, the present invention relates to a cleaning apparatus in which a chemical solution and pure water are supplied to an object to be cleaned with a time difference using one nozzle, thereby preventing contamination of the object to be cleaned by the chemical solution deposited on the nozzle.

[0002]

2. Description of the Related Art An insulating substrate (hereinafter, referred to as a liquid crystal panel) constituting a liquid crystal panel.
In the manufacture of a substrate (also referred to as a unit substrate) or the manufacture of a substrate (wafer) for a semiconductor element, cleaning using a chemical solution or pure water is performed in a process of forming various thin film patterns formed on the substrate.

In general, a chemical solution in which a powdery chemical is dissolved in pure water is used in many cases. In the substrate cleaning step, a series of processes for removing chemical components using pure water after the cleaning with the chemical solution is used. Be executed.

For example, in the manufacture of a thin film transistor type liquid crystal panel, various signal electrodes, thin film transistors (TFTs), pixel electrodes, color filters, and other thin film patterns are formed on a substrate by using a photolithography technique. Prior to the photolithography process, there is always a process of cleaning the substrate.

To clean a substrate of a liquid crystal panel, a substrate to be cleaned is placed on a rotating machine called a spinner, and the above-mentioned chemical solution is supplied to the surface of the substrate by a nozzle and shaken off.
After that, it is usual that pure water is supplied from another nozzle, and cleaning is performed by the same shake-off. Note that this type of cleaning process is not limited to a process using a spinner, and a process for performing cleaning by spraying a chemical solution or pure water on a stationary substrate is also known.

FIG. 8 is a schematic diagram illustrating an example of a conventional cleaning apparatus using a spinner. In the figure, a substrate 10 is placed on a turntable 9 of a spinner 8. The rotary disk 9 rotates at a high speed in one direction to rotate the substrate, as indicated by an arrow.

First, the chemical solution stored in the chemical solution storage tank 1 is supplied onto the substrate 10 by the chemical solution nozzle 7A via the chemical solution valve 3, and the substrate 10 is shaken off by the rotation of the spinner 8.
Is washed with chemicals. After performing this chemical cleaning for a predetermined time, the chemical liquid valve 3 is closed, and then the pure water stored in the pure water storage tank 2 is supplied from the chemical liquid nozzle 7B onto the substrate 10 via the pure water valve 4. In the same manner, the spinner 8 is cleaned while being shaken off by rotation. The chemical solution and pure water used for cleaning are treated by the purification treatment system 11, and the pure water is collected and goes to the reuse system through the collection path shown by the arrow 12, and the chemical solution is discarded through the waste path shown by the arrow 13. .

[0008] In the above configuration, there is only one kind of chemical solution,
Although one chemical liquid nozzle and one pure water nozzle are arranged, in a cleaning apparatus using a plurality of chemical liquids, it is necessary to install the number of chemical liquid nozzles as many as the number of used chemical liquids.

FIG. 9 is a flow chart for explaining an example of the operation cycle of the cleaning apparatus shown in FIG. The operation of FIG. 8 will be further described with reference to FIG. 9. When the substrate 10 is placed on the spinner 8 and the cleaning process is started, first, the chemical solution valve 3 is opened to supply the chemical solution onto the substrate 10 from the chemical solution nozzle 7A. (S-11). This chemical cleaning is performed for a predetermined time T = t.
Subjected during the ₁ (S-12), closes the chemical valve to stop the supply of the chemical liquid (S-13), followed by pure water from the pure water nozzle 7B opens the deionized water valve 4 on the substrate 10 Is supplied (S-14), and cleaning (rinsing) with pure water is performed for a predetermined time to remove the chemical component from the substrate. Cleaning with pure water is subjected for a predetermined time _{T = t 2 (S-15} ), closes the deionized water valve 4 to stop the supply of the pure water (S-16). Thereafter, the substrate 10 is unloaded from the spinner 8, a new substrate is loaded, and the same cleaning cycle as described above is repeated.

When the number of cleaning cycles becomes N = n (S-17), chemical nozzle cleaning for removing the chemical deposited on the chemical nozzle 7A is executed (S-18). The chemical nozzle may be cleaned by executing the chemical nozzle cleaning before or after the first cleaning step.

[0011]

In the above-mentioned conventional cleaning apparatus, the chemical liquid nozzle and the pure water nozzle are separately provided, so that the chemical is deposited on the chemical liquid nozzle with time, and this becomes foreign matter and adheres to the substrate surface. However, there has been a problem that foreign matter is not removed even by washing with pure water and remains as foreign matter, thereby deteriorating product quality.

Further, in a cleaning device such as a spinner, there is also a problem that the number of chemicals to be used is limited because the installation space of the nozzle is limited.

An object of the present invention is to solve the above-mentioned problems of the prior art, to prevent the deposition of chemicals on the nozzle and to cause foreign matter, and to simplify the structure irrespective of the number of chemicals used. A cleaning device is provided.

[0014]

In order to achieve the above object, the present invention provides a chemical solution nozzle and a pure water nozzle, and a valve and a check valve provided in each of a chemical solution supply passage and a pure water supply passage. The liquid and pure water supply paths were sequentially switched and connected to the nozzle. In addition, the nozzle was washed with pure water before the supply of the chemical solution, thereby preventing mixing and precipitation of the chemical solution at the nozzle.

That is, the present invention provides the following (1) and (2)
Is characterized in that it is configured as described above.

(1) One nozzle has a valve and a check valve connected in series, a liquid supply path for supplying at least one chemical solution to the object to be cleaned, and a liquid supply for supplying pure water. A plurality of liquid supply paths including a path are connected in parallel, and the chemical solution and pure water are supplied from the one valve to the object to be cleaned with a time lag in this order.

(2) During the process of forming a photosensitive resist film on the surface of the insulating substrate and forming a required pattern by photolithography, the insulating substrate is cleaned using a chemical solution and pure water in this order. In the apparatus, a turntable on which the insulating substrate is mounted and rotated, a single nozzle disposed above the insulating substrate, a check valve for chemical liquid having an outlet connected to the nozzle in common, and a pure water check valve At least two of a check valve and at least one system of a chemical liquid supply valve and a pure water supply valve connected to the inlet side of each of the check valves.
A liquid supply path of a system is provided, and the chemical substrate and the pure water are supplied to the insulating substrate mounted on the turntable with a time lag by alternately opening and closing the chemical supply valve and the pure water supply valve. The cleaning of the substrate is performed.

In the constitutions (1) and (2), the pure water valve is opened for a short time to clean the nozzle immediately before the chemical liquid valve is opened, thereby completely removing the chemical adhering to the nozzle. In this way, the nozzle can be kept in a highly clean state.

Further, according to the above configuration, the piping of the nozzle and the liquid supply path near the nozzle can be simplified.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic view for explaining the configuration of one embodiment of the cleaning apparatus of the present invention, wherein 1 is a chemical storage tank, 2 is a pure water storage tank, 3 is a chemical liquid valve, 4 is a pure water valve, 5 is a chemical check valve, 6 is a pure water check valve, 7 is a nozzle, 8 is a spinner, 9
Is a rotary plate, 10 is a substrate, 11 is a purification system, 12
Denotes a pure water recovery path, and 13 denotes a waste path.

The substrate 10 is a TFT substrate constituting a liquid crystal panel. This substrate 10 is mounted on the rotating disk 9 of the spinner 8 and is rotated at high speed in the direction of the arrow. The chemical in this embodiment is an ammonium carbonate solution, which is stored in the chemical storage tank 1. The chemical solution supply path including the chemical solution storage tank 1, the chemical solution valve 3, and the chemical solution check valve 5, and the pure water supply path including the pure water storage tank 2, the pure water valve 4, and the pure water check valve 6 are arranged in parallel with the nozzle 7. It is connected.

First, the chemical solution valve 3 is opened, and the chemical solution from the chemical solution storage tank 1 passes through the check valve 5 from the nozzle 7 to the substrate 1.
0, and cleaning with a chemical solution is performed. After the chemical solution valve 3 is closed, the pure water valve 4 is opened, and the chemical solution from the chemical solution storage tank 2 passes through the check valve 6 from the nozzle 7 to the substrate 10.
And cleaning with a chemical solution is performed.

FIG. 2 is a flow chart for explaining an example of an operation cycle of the cleaning apparatus shown in FIG. The operation of FIG. 1 will be further described with reference to FIG. 2. When the substrate 10 is placed on the spinner 8 and the cleaning process is started, first, the chemical solution valve 3 is opened and the chemical solution is supplied from the nozzle 7 onto the substrate 10. (S-
1). Subjected during the washing with a chemical solution for a predetermined time _{T = t 1 (S-2} ), closes the chemical valve 3 to stop the supply of the chemical liquid (S-3), then it opens the deionized water valve 4 Then, pure water is supplied from the nozzle 7 onto the substrate 10 (S-4), and cleaning (rinsing) with pure water is performed for a predetermined time to remove the chemical component from the substrate. After cleaning with pure water was applied for a predetermined time _{T = t 2 (S-5} ), closes the deionized water valve 4 to stop the supply of the pure water (S-6). Thereafter, the substrate 10 is unloaded from the spinner 8, a new substrate is loaded, and the same cleaning cycle as described above is repeated.

Before the first start of the cleaning cycle, a step of opening the pure water valve 4 for a short time to clean the nozzle 7 may be added.

FIG. 3 is an explanatory view of the result of verifying the relationship between the concentration of ammonium carbonate in the chemical solution and the number of deposits having a diameter of 1 μm or more, which greatly affects the quality of the liquid crystal panel, when ammonium carbonate is used as the chemical for the chemical solution. The horizontal axis indicates the concentration of ammonium carbonate (ppm), and the vertical axis indicates the number of precipitated foreign substances having a diameter (φ) of 1 μm or more (q / substrate).

A chemical solution obtained by dissolving ammonium carbonate in pure water is used as a chemical solution for cleaning the TFT substrate constituting the liquid crystal panel. Ammonium carbonate lowers the specific resistance of pure water, and is used for cleaning the substrate after TFT formation. In addition, there is an effect that the TFT is protected from electrostatic destruction due to the application of the cleaning liquid.

As shown in FIG. 3, when the concentration of the ammonium carbonate exceeds 50 ppm, the precipitate is remarkably attached to the substrate immediately.

FIG. 4 is a plan view of the substrate for explaining the result of measuring the actual number of deposited foreign matters remaining on the substrate.
(A) is obtained by cleaning using the cleaning apparatus of the present embodiment,
(B) shows the result of cleaning using the conventional cleaning apparatus shown in FIG. The substrate size is 650 mm × 83
0 mm.

As a result of cleaning by the cleaning apparatus of this embodiment shown in FIG. 3A, 46 foreign substances having a diameter of 1 μm or more were obtained by cleaning by the conventional cleaning apparatus shown in FIG. Was.

As described above, according to the cleaning apparatus of the present embodiment, it is possible to prevent the chemicals from being deposited on the nozzles and to cause foreign matter, and to simplify the cleaning regardless of the number of chemicals used. An apparatus can be provided.

In the above embodiment, one kind of chemical solution is used.
The present invention is not limited to this. The same effect can be obtained by using a plurality of types of chemical liquids and connecting the supply paths for the respective chemical liquids to one nozzle in parallel with the pure water supply path.

Next, as an example of a manufacturing process to which the present invention is applied, a manufacturing process of a TFT substrate of a TFT type liquid crystal panel will be described with reference to FIGS.

In the following steps, the above-mentioned cleaning step is performed at least before the photolithography step.

In each of the figures, the letters at the center are abbreviations of the process names, the left side shows the pixel portion, and the right side shows the processing flow as seen in the cross-sectional shape near the gate terminal.

Also, except for steps B and D, steps A to G
Is a process corresponding to each photographic process (photolithography process, hereinafter, also simply referred to as photo process). In each cross-sectional view of each process, the process after the photo process is completed, the stage where the photoresist is removed Is shown.

In the following description, the above-mentioned photographic processing refers to a series of operations from application of a photosensitive organic material (photoresist), through selective exposure using a mask to development thereof, and is repeated. Avoid explanation.

The following is an explanation according to the divided steps.

Step A, FIG. 5 First substrate 1 (TF) made of 7059 glass (trade name)
After a silicon oxide film SIO is provided on both surfaces of a T substrate (hereinafter, referred to as SUB1) by dipping, 500 ° C.
Bake for 60 minutes. The SIO film is formed to alleviate the irregularities on the surface of the transparent glass substrate SUB1, but can be omitted when the irregularities are small.

Next, Al-Ta, A having a thickness of 2800.degree.
First conductive film g1 made of l-Ti-Ta, Al-Pd, or the like
Is provided by sputtering. After the photo-treatment, the first conductive film g1 is selectively etched with a mixed acid solution of phosphoric acid, nitric acid and glacial acetic acid.

Step B, FIG. 5 After the resist is directly drawn (after the above-described anodic oxidation pattern is formed),
PH 6.25 ± 0.05 3% tartaric acid by ammonia
The substrate SUB1 is immersed in an anodizing solution consisting of a solution prepared by diluting the solution adjusted to 1: 9 with an ethylene glycol solution,
The formation current density is adjusted to 0.5 mA / cm ² (constant current formation). Next, anodic oxidation (anodic formation) 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 maintain this state for several tens of minutes (constant voltage formation).

This is important for obtaining a uniform Al ₂ O ₃ film. As a result, the conductive film g1 is anodized, and the scanning signal line (gate line) GL (1 of the above embodiment) is formed.
4) An anodic oxide film AOF having a thickness of 1800 ° is formed on the upper and side surfaces in a self-aligned manner, and becomes a part of the gate insulating film of the thin film transistor TFT.

Step C, FIG. 5 A conductive film d1 made of an ITO film having a thickness of 1400 ° is provided by sputtering. After the photo-treatment, the conductive film d1 is selectively etched with a mixed acid solution of hydrochloric acid and nitric acid as an etchant, thereby forming the gate terminal GTM, the uppermost layer of the drain terminal DTM, and the transparent pixel electrode ITO1.

Step D, FIG. 6 Ammonia gas, silane gas, and nitrogen gas are introduced into the plasma CVD apparatus to provide a 2000-nm thick Si nitride film, and silane gas and hydrogen gas are introduced into the plasma CVD apparatus to reduce the film thickness. After providing a 2000 ° i-type amorphous Si film, hydrogen gas and phosphine gas are introduced into a plasma CVD apparatus to form a 300 ° -thick N ⁺ -type amorphous Si film d0. This film formation is performed continuously by changing the reaction chamber in the same CVD apparatus.

Step E, FIG. 6 After photo processing, SF ₆ , BC is used as a dry etching gas.
n + type amorphous Si film d0, i-type amorphous Si
The film AS is etched. Subsequently, the Si nitride film GI is etched using SF ₆ . Of course, the N ⁺ -type amorphous Si film d0, the i-type amorphous Si film AS and the Si nitride film GI may be successively etched with SF ₆ gas.

The feature of the manufacturing process of the present embodiment is that the three-layer CVD film is continuously etched with a gas containing SF ₆ as a main component. That is, the etching rate with respect to the SF ₆ gas increases in the order of the N ⁺ type amorphous Si film d0, the i type amorphous Si film AS, and the Si nitride film GI. Accordingly, N ⁺ -type amorphous Si film d0 is completed etched, the i-type amorphous Si film AS begins to be etched upper portion of the N ⁺
The type amorphous Si film d0 is side-etched, and as a result, the i-type amorphous Si film AS is processed into a tape of about 70 degrees.

When the etching of the i-type amorphous Si film AS is completed and the etching of the Si nitride film GI starts,
Upper N ⁺ -type amorphous Si film d0, i-type amorphous Si film AS
In this order, resulting in i-type amorphous Si film A
S is taped to about 50 degrees, and the silicon nitride film GI is taped to 20 degrees. Due to the taper shape, the probability of disconnection is significantly reduced even when the source electrode SD1 is formed thereon. Although the taper angle of the N ⁺ -type amorphous Si film d0 is close to 90 degrees, since the thickness is as thin as 300 °, the probability of disconnection at this step is very small. Therefore, N + type amorphous S
Since the plane patterns of the i film d0, the i-type amorphous Si film AS, and the Si nitride film GI are not exactly the same pattern but have a tapered cross section, the N ⁺ type amorphous The larger the pattern in the order of the Si film d0, the i-type amorphous Si film AS, and the Si nitride film GI.
It becomes.

Step F, FIG. 7 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.
A third conductive film d3 made of Pd, Al-Si, Al-Ta, Al-Ti-Ta, or the like is provided by sputtering.
After the photo-treatment, the third conductive film d3 is etched with the same liquid as in the step A, the second conductive film d2 is etched with a ceric ammonium nitrate solution, and the video signal line DL, the source electrode SD1, and the drain electrode SD2 are formed. To form

In this embodiment, as shown in step E, the N ⁺ type amorphous Si film d0, the i type amorphous Si film AS,
Since the Si nitride film GI has a forward taper, in a liquid crystal display device having a large tolerance of the resistance of the video signal line DL, it is possible to form only the second conductive film d2.

Next, SF ₆ , B
By introducing Cl and etching the N ⁺ -type amorphous Si film d0, the N ⁺ -type semiconductor layer d0 between the source and the drain is selectively removed.

Step G, FIG. 7 An ammonia gas, a silane gas and a nitrogen gas are introduced into a plasma CVD apparatus to form a 0.6 μm-thick Si nitride film. After photo processing, SF _{6 is used} as a dry etching gas.
The protective film PSV1 is etched by using
To form As the protective film, not only a SiN film formed by CVD but also a film using an organic material can be used.

The TFT substrate thus formed and a color filter substrate formed by a separate process are bonded together via a liquid crystal layer to form a liquid crystal panel.

It should be noted that the present invention is not limited to the manufacturing process of the TFT substrate of the TFT type liquid crystal panel described above, and the cleaning in the manufacturing process of the color filter substrate of the liquid crystal panel, other types of liquid crystal panel substrates, or semiconductor wafers. Needless to say, it can be applied to.

[0054]

As described above, according to the present invention,
The problem that chemicals are deposited on the nozzle and adhere to the substrate surface as foreign matter, and remain as foreign matter without being removed even by washing with pure water, thereby deteriorating the quality of the product, is solved. The problem that the number of chemicals used is limited by the limitation of the installation space is also solved, and a high-quality substrate cleaning effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an embodiment of a cleaning device of the present invention.

FIG. 2 is a flowchart illustrating an example of an operation cycle of the cleaning device illustrated in FIG. 1;

FIG. 3 is an explanatory diagram of the result of verifying the relationship between the concentration of ammonium carbonate in a chemical solution and the number of deposits having a diameter of 1 μm or more that greatly affects the quality of a liquid crystal panel when ammonium carbonate is used as the chemical for the chemical solution.

FIG. 4 is a plan view of the substrate for explaining the result of measuring the actual number of deposited foreign matters remaining on the substrate.

FIG. 5 is an explanatory diagram of a manufacturing process of a TFT substrate to which the cleaning device according to the present invention is applied.

FIG. 6 is an explanatory view following FIG. 5 of a manufacturing process of a TFT substrate to which the cleaning device according to the present invention is applied;

FIG. 7 is an explanatory view following FIG. 6 of a manufacturing process of a TFT substrate to which the cleaning device according to the present invention is applied.

FIG. 8 is a schematic diagram illustrating an example of a conventional cleaning device using a spinner.

9 is a flowchart illustrating an example of an operation cycle of the cleaning apparatus illustrated in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chemical liquid storage tank 2 Pure water storage tank 3 Chemical liquid valve 4 Pure water valve 5 Chemical liquid check valve 6 Pure water check valve 7 Nozzle 8 Spinner 9 Turntable 10 Substrate (insulating substrate) 11 Purification processing system 12 Pure water recovery path 13 Waste road.

Continued on the front page (72) Inventor Morio Uchida 3300 Hayano, Mobara-shi, Chiba Prefecture Electronic Device Division, Hitachi, Ltd. (72) Inventor Yasushi Yasushi 3300-Hayano, Mobara-shi, Chiba Prefecture Electronic Device Division, Hitachi, Ltd. (72 Inventor Toshiki Kaneko 3300 Hayano, Mobara City, Chiba Pref.Hitachi, Ltd.Electronic Device Division

Claims (2)

[Claims] 1. A liquid supply path for supplying at least one chemical liquid to an object to be cleaned having a valve and a check valve connected in series to one nozzle, and a liquid supply path for supplying pure water. And a plurality of liquid supply paths including a plurality of liquid supply paths connected in parallel, and the chemical liquid and pure water are supplied from the one valve to the object to be cleaned with a time lag in this order. 2. A cleaning apparatus for forming a photosensitive resist film on a surface of an insulating substrate and cleaning the insulating substrate by using a chemical solution and pure water in this order during a step of forming a required pattern by photolithography. In the above, a rotating disk on which the insulating substrate is mounted and rotated, a single nozzle disposed above the insulating substrate, a check valve for chemical solution and a check valve for pure water, the outlet side of which is commonly connected to the nozzle. A stop valve and at least two liquid supply passages each including at least one chemical liquid supply valve and pure water supply valve connected to the inlet side of each check valve, and mounted on the turntable; A cleaning device for cleaning the insulating substrate by supplying the chemical solution and the pure water with a time difference by alternately opening and closing the chemical solution supply valve and the pure water supply valve to the insulating substrate.