JP2001308070A - Dry etching apparatus and method of treating semiconductor substrate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems of stability of reliability in wiring-forming process and in resist-stripping process where a metal-wiring layer is corroded by residual chlorine before treating with a chemical liquid or wherein reaction products formed by the reaction between etching gas and a substance to be etched or remaining of a photoresist film cannot be removed, even by chemical-liquid cleaning in the subsequent process. SOLUTION: The photoresist film on a substrate surface is removed to clean the surface by keeping reduced pressure in an etching apparatus, and continuing to the etching treatment, performing ozone-water ashing or deionized-water ashing. The means is to spray heated and vaporized functional water, which is ozone water obtained by forcing ozone gas be contained in deionized water, or which is ozone water obtained by electrolyzing deionized water onto the substrate after the dry etching, and to execute plasma processing to remove the photoresist film on the substrate surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to processing of metal wiring in a method of manufacturing a semiconductor device or a liquid crystal display device, and more particularly to processing of a substrate after dry etching of a metal wiring containing aluminum or copper as a main component. That is, it relates to the removal of the photoresist.

[0002]

2. Description of the Related Art In a conventional semiconductor device including a flat panel such as a liquid crystal display device, a method of forming a metal wiring layer using aluminum or an aluminum alloy (hereinafter referred to as Al or Al alloy) is specifically described as follows. Is done as follows.

[0003] First, a first thin titanium film (hereinafter referred to as Ti) and an Al or Al alloy are formed on a semiconductor substrate on which a predetermined diffusion layer or an insulating film is formed by sputtering or CVD. A metal wiring layer having a two-layer structure of electrodes is formed, or a metal wiring layer having a three-layer structure of a first thin Ti film, an Al or Al alloy film, and a second thin Ti film is formed. Then, a photoresist film having a predetermined shape is patterned on the upper surface, and etching is performed using the photoresist film as a mask. In recent years, electrode materials such as Al and Ti have been dry-etched. For this dry etching, a reactive ion etching (RIE) method, an ICP method, or the like is used. The atmosphere at the time of dry etching is generally boron trichloride (BCl ₃ ) and chlorine (C
l ₂ ), or a gas obtained by adding a small amount of chlorofluorocarbon-based gas (for example, SF ₆ or CHF ₃ ) to the mixed gas.

The semiconductor film subjected to the dry etching is subjected to a predetermined process to remove the photoresist film.
These processes after dry etching are shown below.

While maintaining the reduced pressure, the etching process
Photo by oxygen plasma ashing
The resist film is removed. After rinsing with pure water, dry the substrate
Dry and carry out from the device. The removed substrate is SPM
Cleaning (H_TwoSO_Four/ H_TwoO_Two, H _TwoSO_Four/ O_Three/ H_TwoO)
And clean it.

After the photoresist film is removed by oxygen plasma ashing while maintaining the reduced pressure state and continuing from the etching process, the photoresist film is removed by a hot plate or the like.
Irradiation with ultraviolet rays is performed while heating to 00 to 300 ° C. for cleaning.

While maintaining the reduced pressure state, the residual chlorine is replaced with fluorine while performing ashing removal of the photoresist film by using a mixed gas plasma of an oxygen gas and a fluorine-based gas continuously with the etching process.

After the above-mentioned treatment, heating is performed in a steam atmosphere.

While maintaining the reduced pressure state, a gas containing H atoms such as alcohol is turned into plasma and the photoresist film is removed continuously with the etching process.

While maintaining the reduced pressure, a heat treatment is performed in an N ₂ atmosphere during the etching to remove Cl adsorbed on the photoresist film. After being taken out of the etching apparatus, the photoresist film is removed using a chemical solution for removing the photoresist, and a cleaning process is performed with ultrapure water.

While maintaining the reduced pressure state, the photoresist film is removed by ashing in which heated pure water is turned into steam, following the etching process. After rinsing with pure water, the substrate is dried and carried out of the apparatus. The taken-out substrate is subjected to removal of the photoresist film using a chemical solution for removing the resist, and cleaning treatment with ultrapure water.

While maintaining the reduced pressure state, the photoresist film is removed by ashing with oxygen plasma, taken out of the etching apparatus, and cleaned by an ozone ashing process, following the etching process.

[0013]

It is difficult to completely remove the residual chlorine by the conventional method, so that the residual chlorine may corrode the metal wiring layer before the chemical treatment or may cause a reaction between the etching gas and the etching target. There was a problem in the stability and reliability of the wiring processability, because the product and the residue of the photoresist film could not be removed even in the subsequent chemical cleaning treatment.

[0014] In addition, equipment costs and operation costs related to the process were required, such as the necessity of a dry etching apparatus, an ozone ashing apparatus, and a chemical cleaning apparatus.

[0015]

According to the present invention, a photoresist film on a substrate surface is removed by performing ozone water ashing or ultrapure water ashing continuously with an etching process while maintaining a reduced pressure state of an etching apparatus. To clean. The means uses ozone water or ozone water obtained by electrolyzing ultrapure water containing ozone gas in ultrapure water as functional water, and sprays the heated and steamed substrate onto the substrate after the dry etching, One that removes the photoresist film on the substrate surface by plasma treatment, and that in which the pure water vapor is sprayed onto the substrate after the dry etching in an environment to which ozone gas is added, and the plasma treatment is performed, the photoresist film on the substrate surface is removed. Is to be removed. Instead of the cleaning method using a variety of treatments, etching, removal of a resist film, and substrate cleaning effects are obtained in a single apparatus (etching apparatus).

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention relates to a case where ultrapure water or functional water is supplied from outside a dry etching apparatus such as a central supply as a processing environment for removing a photoresist. The invention according to claim 2 is characterized in that ultrapure water is supplied centrally and a part for producing functional water is attached to the dry etching apparatus. The invention according to claim 3 has a feature in an apparatus environment for spraying ultrapure steam in an ozone gas atmosphere, and the invention according to claim 4 comprises etching and ashing in the same chamber. The inventions described in the fifth, sixth and seventh aspects are characterized in that the functional water supplied into the chamber is ozone water. Is intended Sekiru the method of treating a semiconductor substrate using a dry etching apparatus having a single removal function, according to claim 11 is intended Sekiru the type of the semiconductor substrate. And it has the following effects. That is, (First Embodiment) This embodiment is shown in FIG. 1 and described below.

The ashing chamber 1 uses a system for supplying at least ultrapure water 2 and functional water 3 and a dry etching apparatus 6 comprising a flow control unit 4 and a heating unit 5 for these waters. The substrate on which the material to be etched is formed is placed on one electrode, and the pressure is adjusted to a predetermined pressure while supplying a predetermined fluorine-based or chlorine-based etching gas into the chamber. After the material to be etched is dry-etched by generating plasma with high-frequency power between the electrodes, a fluorine-based or chlorine-based etching gas in the etching chamber is exhausted and replaced with nitrogen, and the substrate is transferred from the etching chamber 7 to the ashing chamber 1. Is transferred to the substrate surface and exposed to functional water vapor, and a plasma is applied between the electrodes to form a photoresist film. Removed by ashing, further after subjected to substrate cleaning by pure water vapor, measuring the cleaning of the semiconductor substrate by drying the substrate. This has the effect of completely removing the photoresist that has been altered by ion doping or dry etching, the reaction product between the gas during dry etching and the etching target, and the photoresist film residue.

(Second Embodiment) This embodiment is shown in FIG. 2 and will be described below.

The ashing chamber 1 is provided with a system for supplying at least ultrapure water 2, a production section 3b for supplying functional water 3, a flow rate control section 4 for the water, a heating section 5 and a dry etching apparatus 6 comprising the above. As in the first embodiment, a substrate on which an etching target material is formed is disposed between the first and second electrodes, and a predetermined fluorine-based or chlorine-based etching gas is supplied into the chamber. The pressure is adjusted, plasma is generated between the first electrode and the second electrode by high frequency power to dry-etch the material to be etched, and then the fluorine-based or chlorine-based etching gas in the etching chamber is discharged. After purging with nitrogen and transferring the substrate from the etching chamber 7 to the ashing chamber 1, plasma is applied between the electrodes while exposing functional water vapor to the substrate surface. After removing the photoresist film by ashing, and further cleaning the substrate with pure water vapor,
The substrate is dried to clean the semiconductor substrate.
As a result, as in the first embodiment, the photoresist has a function of completely removing the photoresist that has been altered by ion doping or dry etching, the reaction product between the gas during dry etching and the etching target, and the photoresist film residue. .

(Third Embodiment) This embodiment is shown in FIG. 3 and will be described below.

The ashing chamber 1 uses a dry etching apparatus comprising at least a system for supplying ultrapure water 2 and ozone gas 8 and a flow control unit 4 for pure water and ozone gas and a heating unit 5 for pure water. As in the first embodiment.
Disposing a substrate on which an etching target material is formed between the second electrodes, adjusting the pressure to a predetermined pressure while supplying a predetermined fluorine-based or chlorine-based etching gas into the chamber, and adjusting the first electrode and the second electrode; After the material to be etched is dry-etched by generating plasma with high-frequency power between the electrodes, a fluorine-based or chlorine-based etching gas in the etching chamber is exhausted and replaced with nitrogen. After transferring the substrate,
The photoresist film is ashed by applying plasma between the electrodes while exposing the substrate surface to ultrapure water vapor with an ozone gas atmosphere in the ashing chamber. After the substrate is further cleaned with pure water vapor, the substrate is dried to clean the semiconductor substrate. As a result, as in the first and second embodiments, it is possible to completely remove the photoresist that has been altered by ion doping or dry etching, the reaction product between the gas during dry etching and the etching target, and the photoresist film residue. Has an action.

(Fourth Embodiment) This embodiment is shown in FIG. 4 and will be described below.

The chamber constituting the dry etching apparatus has the same chamber for etching and ashing, and a system for supplying at least ultrapure water 2 for removing the resist, a production section 3b for supplying functional water 3, and these waters. A substrate on which an etching target material is formed is disposed between first and second electrodes as in the first embodiment, and a predetermined fluorine is provided in the chamber. After adjusting the pressure to a predetermined value while supplying a system-based or chlorine-based etching gas, generating plasma by high-frequency power between the first electrode and the second electrode to dry-etch the material to be etched, and then performing the etching process. Exhaust a fluorine-based or chlorine-based etching gas and replace with nitrogen, exposing functional water vapor to the substrate surface, and applying plasma between the electrodes to form a photoresist. After the film is removed by ashing and the substrate is further cleaned with pure water vapor, the substrate is dried to clean the semiconductor substrate. As a result, as in the first embodiment, the photoresist has a function of completely removing the photoresist that has been altered by ion doping or dry etching, the reaction product between the gas during dry etching and the etching target, and the photoresist film residue. .

In the present invention, the structure relating to the resist removal uses the second embodiment. However, the chamber constituting the dry etching apparatus has the same chamber for etching and ashing. The related configuration may be the first or third embodiment.

[0025]

By maintaining the reduced pressure state of the etching apparatus and performing ozone water ashing or ultrapure water ashing continuously with the etching process, the surface of the substrate which could not be completely removed in the dry etching apparatus until now is obtained. The remaining reaction products and the photoresist film are removed for cleaning. Instead of the conventional cleaning method using various treatments, the etching, resist film removal and substrate cleaning effects are obtained in a single device (etching device), so that the wiring process is excellent in stability and reliability, and In addition to eliminating the need for ozone ashing equipment and chemical cleaning equipment in addition to the dry etching equipment, we have reduced equipment costs and operating costs related to the process.

[Brief description of the drawings]

FIG. 1 is a first dry etching apparatus configuration and a substrate processing flow chart of the present invention.

FIG. 2 is a second dry etching apparatus configuration and substrate processing flow chart of the present invention.

FIG. 3 is a diagram of a third dry etching apparatus configuration and a substrate processing flow of the present invention.

FIG. 4 is a fourth dry etching apparatus configuration and substrate processing flow chart of the present invention.

FIG. 5 is a flow chart of a conventional dry etching apparatus and ancillary equipment and substrate processing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ashing chamber 2 Pure water 3 Functional water 3a Functional water production part 4 Flow meter 5 Heating part 6 Dry etching device 7 Etching chamber 8 Ozone gas 9 Ancillary facilities

Claims (12)

[Claims] A first electrode having at least a first electrode and a second electrode facing the first electrode in a reaction chamber, and a substrate on which a material to be etched is formed is placed on the first electrode; A dry etching apparatus comprising: an etching chamber for generating plasma by high frequency power between two electrodes to dry-etch a material to be etched; and an ashing chamber for performing ashing by exposing oxygen plasma or water vapor plasma to a substrate; Comprises a system for supplying at least ultrapure water or functional water, a flow control unit for the water, and a heating unit. 2. A substrate having at least a first electrode and a second electrode facing the first electrode in a reaction chamber, and a substrate on which a material to be etched is formed is placed on the first electrode. A dry etching apparatus comprising: an etching chamber for generating plasma by high frequency power between two electrodes to dry-etch a material to be etched; and an ashing chamber for performing ashing by exposing oxygen plasma or water vapor plasma to a substrate; Is a system for supplying at least ultrapure water or functional water, a flow control unit for these waters, a heating unit, and a functional water producing unit. 3. A substrate having at least a first electrode and a second electrode facing the first electrode in a reaction chamber, and a substrate on which a material to be etched is formed is placed on the first electrode. A dry etching apparatus comprising: an etching chamber for generating plasma by high frequency power between two electrodes to dry-etch a material to be etched; and an ashing chamber for performing ashing by exposing oxygen plasma or water vapor plasma to a substrate; Is a system for supplying at least ultrapure water or ozone gas, a flow controller for pure water, and a heating unit. 4. The apparatus according to claim 1, wherein said chamber is used for etching and ashing in the same chamber.
The dry etching apparatus according to any one of claims 2 and 3. 5. The dry etching apparatus according to claim 1, wherein the functional water is an electrolysis method of ultrapure water or ozone water obtained by dissolving a gas in ultrapure water. 6. The dry etching apparatus according to claim 2, wherein the functional water producing section produces the ozone water by a method of electrolyzing ultrapure water. 7. The functional water producing unit according to claim 2, wherein the ultrapure water and ozone gas are mixed by ultrasonic waves or megasonic addition and dissolved to produce ozone water.
The dry etching apparatus as described. 8. A substrate on which a material to be etched is formed is placed on a first electrode in the etching chamber, and a predetermined pressure is adjusted while supplying a predetermined fluorine-based etching gas into the chamber. Generating plasma by high-frequency power between the first electrode and the second electrode to dry-etch the material to be etched, and after exhausting a fluorine-based etching gas in the etching chamber and replacing it with nitrogen,
A step of applying a plasma between the electrodes to ashing the photoresist film while exposing functional water vapor to the substrate surface, a step of cleaning the substrate with pure water vapor, and a step of drying the substrate Processing method. 9. A substrate on which a material to be etched is formed is placed on a first electrode in the etching chamber and adjusted to a predetermined pressure while supplying a predetermined chlorine-based etching gas into the chamber. Generating plasma by high frequency power between the first electrode and the second electrode to dry-etch the material to be etched, and discharging the chlorine-based etching gas in the etching chamber to replace it with nitrogen, and then transferring the gas to the ashing chamber And adjusting to a predetermined pressure;
A process of exposing the substrate surface to pure water vapor to apply plasma between the first and second electrodes of the ashing chamber to ashing and removing the photoresist film; and exposing a functional water vapor to the first and second ashing chambers. A method for treating a semiconductor substrate, comprising: a step of applying a plasma between electrodes to remove ashing of a photoresist film; a step of cleaning the substrate with pure water vapor plasma; and a step of drying the substrate. 10. A substrate on which a material to be etched is formed is placed on a first electrode in the etching chamber, and a predetermined pressure is adjusted while supplying a predetermined chlorine-based etching gas into the chamber. Generating plasma by high frequency power between the first electrode and the second electrode to dry-etch the material to be etched, and discharging the chlorine-based etching gas in the etching chamber to replace it with nitrogen, and then transferring the gas to the ashing chamber Adjusting the pressure to a predetermined pressure; exposing the substrate surface to pure water vapor to apply plasma between the first and second electrodes of the ashing chamber to remove the photoresist film by ashing; Applying a plasma between the first and second electrodes of the ashing chamber to remove the photoresist film by ashing; Process and method of processing a semiconductor substrate comprising the step of drying the substrate subjected to substrate cleaning by water vapor plasma. 11. The method according to claim 8, wherein the semiconductor substrate is an FPD substrate such as a silicon semiconductor or a liquid crystal display device. 12. A flat panel display such as a liquid crystal display device using a semiconductor substrate which has been subjected to a cleaning treatment of the substrate.