JP2000315672A - Method and apparatus for cleaning semiconductor substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning method and apparatus, which reduce residue particles on a substrate face after cleaned and attain synthetic cleaning effects of reduction in a residue organic substance, etc. SOLUTION: A substrate cleaner in a semiconductor manufacture comprises, under the same environment managing a clean level, an optical process part for decomposing a contamination on the surface of a substrate by a chemical reaction, and a water cleaning part and substrate drying part for eliminating a residue substance on the surface of the substrate by a physical external pressure, and after a face of the semiconductor substrate is irradiated with ultraviolet ray lamp in the optical process part for an optical reaction (optical decomposition) of the contamination of the surface of the substrate, by brush rubbing, megasonic water cleaning, high-pressure spray water cleaning, or the like as a physical external pressure method, the residue substance on the substrate face after optically decomposed is eliminated, thereby purifying the face of the semiconductor substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cleaning a substrate in a process of manufacturing a silicon semiconductor substrate, a liquid crystal display substrate, an electronic component mounting substrate and the like.

[0002]

2. Description of the Related Art Conventionally, various chemicals have been used for inter-process cleaning in the manufacturing process of semiconductor devices and liquid crystal display devices in order to remove organic substances and metal impurities adhered to the substrate surface.

For example, in cleaning a semiconductor substrate, water peroxide
Wet cleaning method using chemical solution based on plain water (RC
A cleaning). H_TwoSO_Four/ H_TwoO_Two(SP
M) Cleaning is a method of oxidizing and removing organic substances.
This is a cleaning step indispensable for stripping the strike. Also, NH_FourOH / H
_TwoO_Two(APM) cleaning is used for particle removal, HCl / H _TwoO
_Two(HPM) cleaning is used to remove metal contamination
You. Most of these RCA cleanings are performed at high temperatures.
The change in the composition of the liquid is remarkable.
It is necessary to manage cleanliness in the clean room.

[0004] The cleanliness of the substrate surface has been evaluated and determined in the following manner. (1) Dust adhesion: Count the number of dust particles by particle counter. (2) Residual organic matter: The degree of water repellency / hydrophilicity of the substrate surface was measured by a contact angle measurement method. (3) Residualness of natural oxide film: Water repellency / hydrophilicity of the substrate surface was measured by a contact angle measurement method. (4) Residualness of metal impurities: Residualness of each metal type was measured by total reflection X-ray fluorescence analysis.

Further, for a large-sized substrate such as a liquid crystal substrate, cleaning with a chemical solution under the above-mentioned high temperature control is extremely difficult, and as an alternative thereto, removal of organic substances by a photoreaction is attracting attention.

[0006]

With respect to various cleaning effects using a clean silicon substrate, cleanliness evaluation / judgment was performed by the above-described conventional method.

First, the silicon substrate is individually cleaned by a photoreaction unit that emits excimer UV having a wavelength of 172 nm to photodecompose organic substances, and a brush water cleaning unit that supplies ultrapure water to a roll brush and rubs and cleans the substrate surface. This was performed using The results are shown in FIGS.

FIG. 4 is a comparison of particles remaining on the substrate surface for each test sample based on the particle counter data, and FIG. 5 is a comparison of the water repellency of the substrate surface for each sample based on the contact angle measurement data. And FIG.
This is a comparison of the residual levels of metal impurities for each sample based on total reflection X-ray fluorescence measurement data.

The cleaning results are summarized and compared (Table 1).

[0010]

[Table 1]

As described above, although the UV cleaning is considered to be effective for removing organic substances, the surface after the treatment shows hydrophilicity like an extremely clean substrate, but has a large amount of residual particles.

On the other hand, in the case of brush washing in which the effect of removing the residual particles was large, the water repellency of the substrate surface exceeded 10 °, and the result was considered to be organic residues.

[0013] It was confirmed that the metal impurities were not contaminated by individual cleaning, even though no chemical solution was used and no reduction effect could be expected.

[0014] From these results, it was confirmed that the cleaning effect was insufficient with the single cleaning.

[0015]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and achieves an overall cleaning effect by combining individual cleanings utilizing the cleaning effect of a single cleaning.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor substrate cleaning apparatus according to a first aspect of the present invention includes a light processing section for decomposing contaminants on a substrate surface by a chemical reaction under the same environment in which a clean level is controlled, and a substrate with a physical external pressure. It is characterized by having a water washing section for removing residual substances on the surface and a substrate drying section.

This has the following effects. That is, the substrate surface can be cleaned by decomposing contaminants on the substrate surface by a chemical reaction in the light processing section and desorbing residual substances on the substrate surface by physical external pressure in the washing section processing.

According to a second aspect of the present invention, there is provided the semiconductor substrate cleaning apparatus according to the first aspect, wherein the photoreaction unit has an ultraviolet lamp having a wavelength of 172 nm, and the water washing unit is ultrapure water or functional water or detergent. A supply means using shower spray or megasonic for the chemical is provided, and the substrate drying unit is provided with a spinner, a high-pressure nitrogen spray gas, or an infrared lamp.

This has the following effects. In other words, the wavelength of 172 nm increases the photodecomposition efficiency of organic substances, and ensures that the residual substances on the substrate surface are cleaned by brush cleaning with ultrapure water, functional water, detergents and chemicals in a water supply state using shower spray or megasonic. By rubbing and scraping off the substrate to clean it, and configuring the drying unit with a spinner, a high-pressure nitrogen spray gas or an infrared lamp, the substrate surface, which has been kept in the above-mentioned clean state, can be uniformly dried in a short time.

According to a third aspect of the present invention, there is provided a method of cleaning a semiconductor substrate, comprising: irradiating an ultraviolet lamp on the surface of the semiconductor substrate to photodecompose contaminants on the surface of the semiconductor substrate; Is desorbed.

According to a fourth aspect of the present invention, in the method of cleaning a semiconductor substrate according to the third aspect, the substrate requires cleaning of an interface or a surface at the time of stacking or connecting the films. It is characterized by.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As an embodiment of the present invention, an example in which a semiconductor silicon substrate is used for cleaning evaluation in a substrate cleaning apparatus of the present invention, and the cleaning evaluation results are shown in FIGS.

This substrate cleaning apparatus has a photoreaction unit, a brush water washing unit, and a drying unit arranged in an environment where a clean level is controlled, and a silicon substrate immediately after light treatment is washed with a brush water and dried.

FIG. 1 is a comparison of the particles remaining on the substrate between the cleaning sample and ref.Si-wf based on the particle counter data, and FIG. These are comparisons of water repellency. FIG. 3 shows the residual level of metal impurities based on the total reflection X-ray fluorescence measurement data.
It is compared with f.

The cleaning results of the present invention and the conventional single cleaning results are summarized in (Table 2).

[0027]

[Table 2]

In the substrate cleaning apparatus, a photoreaction unit, a brush washing unit, and a drying unit are arranged in an environment where a clean level is controlled.
By performing the continuous treatment, a synergistic effect utilizing the individual cleaning effect was obtained, and a comprehensive cleaning effect was obtained.

As a result, a clean state at the interface of the laminated film can be maintained, and good contact can be obtained in the contact processing portion, so that a high-performance semiconductor substrate can be obtained.

Since this effect is obtained by removing fine particles remaining on the substrate surface by photolysis by rubbing with a brush and rinsing, the residual fine particles are physically separated from the substrate surface. If possible, it is not limited to brush rubbing. The shape of the brush is not limited as long as the reattachment of the detached particles can be controlled. Furthermore, it goes without saying that the effect is enhanced by the combined use of a chemical solution and functional water as long as removal promotion and reattachment of the detached particles can be controlled.

[0031]

According to the substrate cleaning apparatus of the present invention, the photoreaction section, the brush washing section, and the drying section are arranged in an environment where the clean level is controlled, and the individual cleaning effect is utilized by performing continuous processing. A synergistic effect resulted in a comprehensive cleaning effect.

As a result, a clean state at the interface of the laminated film can be maintained, and good contact can be obtained in the contact processing portion, so that a high-performance semiconductor substrate can be obtained.

Since this effect is obtained by removing fine particles remaining on the substrate surface by photolysis by rubbing with a brush and rinsing, the residual fine particles are physically separated from the substrate surface. If possible, it is not limited to brush rubbing. The shape of the brush is not limited as long as the reattachment of the detached particles can be controlled. Furthermore, it goes without saying that the effect is enhanced by the combined use of a chemical solution and functional water as long as removal promotion and reattachment of the detached particles can be controlled.

[Brief description of the drawings]

FIG. 1 is a diagram showing a comparison of residual particles by a semiconductor substrate cleaning apparatus according to one embodiment of the present invention.

FIG. 2 is a diagram showing a comparison of water repellency of a sample surface by a semiconductor substrate cleaning apparatus according to one embodiment of the present invention.

FIG. 3 is a diagram showing a comparison of residual metal impurities by a semiconductor substrate cleaning apparatus according to one embodiment of the present invention.

FIG. 4 is a diagram showing a comparison of residual particles according to the related art.

FIG. 5 is a diagram showing a comparison of the water repellency of a sample surface according to a conventional technique.

FIG. 6 is a diagram showing a comparison of residual metal impurities according to the prior art.

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Claims (4)

[Claims] An optical processing unit for decomposing contaminants on a substrate surface by a chemical reaction in the same environment in which a clean level is controlled; a water washing unit for desorbing residual substances on a substrate surface by a physical external pressure; A semiconductor substrate cleaning apparatus comprising: a drying unit. 2. The substrate according to claim 1, wherein the photoreaction unit has an ultraviolet lamp having a wavelength of 172 nm, the washing unit has a supply unit using shower spray or megasonic for ultrapure water or functional water, or a detergent / chemical solution. 2. The semiconductor substrate cleaning apparatus according to claim 1, wherein the drying unit includes a spinner, a high-pressure nitrogen spray gas, or an infrared lamp. 3. A semiconductor substrate surface is irradiated with an ultraviolet lamp to photoly decompose contaminants on the surface of the semiconductor substrate, and then the residual material on the substrate surface after photolysis is desorbed by a physical external pressure. Semiconductor substrate cleaning method. 4. The method for cleaning a semiconductor substrate according to claim 3, wherein the substrate is a substrate that requires cleaning of an interface and a surface during film stacking and film connection.