JPH0281430A - Treatment apparatus for semiconductor device - Google Patents

Abstract

PURPOSE:To remove an unnecessary deposited film on the surface of an etched substrate easily and completely without giving damage to the substrate by a method wherein the surface cleaning treatment of the etched substrate is performed by the thermal reaction of cleaning gas assisted by a photo-chemical reaction and, moreover, the transition from the etching treatment to the deposited film removing treatment is carried out without exposing the etched surface of the substrate to the air. CONSTITUTION:By controlling the atmosphere in a reaction chamber 2 immediately after an etching process through immediately before a deposited film removing process, creation of contaminants and a spontaneous oxide film on a semiconductor substrate 6 after being subjected to the etching process is avoided. After that, in the deposited film removing process, a rotary support table 4 is rotated and an ultraviolet radiation emitted from a light source 1 is applied to the surface of the semiconductor substrate 6 in the reaction chamber 2 through an ultraviolet radiation introducing window 3 and, at the same time, heaters 5 are operated to heat the semiconductor substrate 6 and, for instance, hydrogen chloride gas is introduced into the reaction chamber 2 through a supply tube 7 to induce a thermal reaction assisted by a photochemical reaction on the semiconductor substrate 6 surface for removing the deposited film on the semiconductor substrate 6 surface.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a processing apparatus for semiconductor devices, and in particular to etching processing of a substrate by RIE using a resist mask, etc.
The present invention also relates to an apparatus for removing a deformed film after the treatment.

[Conventional technology]

Because the characteristics of electronic devices are extremely influenced by the presence of impurities introduced intentionally or unintentionally during device manufacturing, the cleanliness of the manufacturing environment must be maintained at an extremely high level throughout the entire process. Advanced cleaning and purification technologies are used to manufacture the materials used and create the processing atmosphere.

By the way, in the manufacture of thin film devices, etching patterns are formed using various thin film masks and etching techniques in the etching process, and cleaning techniques unique or partially common to each etching technique have been developed. Among these, an important and basic cleaning operation is a surface deformation film removal process after etching such as RIE using a resist as a mask. In such a post-treatment process, oxygen plasma treatment or the like is usually performed for the purpose of removing unnecessary deposited films. Although these oxygen plasma processing methods are currently widely adopted as established techniques, they have the disadvantage that they damage the semiconductor substrate if the unnecessary deposit film is completely removed.

On the other hand, thin film formation involves the formation of a high melting point metal film on epitaxially grown polysilicon, the formation of a so-called polycide structure, the formation of wiring for electrical contact with the substrate, the formation process of ultra-thin insulating films, and film formation. There are many processes in which the deposited film on the immediately preceding substrate has a decisive negative effect on the quality of the thin film, and it can be said that the importance of such film forming processes is increasing.

As described above, in the production of thin film devices, there is a strong demand for a thin film formation method that not only removes harmful impurities taken into the deposited film but also controls the interface structure well with the substrate.

Currently, as a means to meet such demands, a method is used in which the substrate after etching is introduced into an ashing device, the resist is removed, and then the deformed film is removed using oxygen gas plasma.

[Problem to be solved by the invention]

However, in this method of removing a deformed film, since the deformed film is a contaminant film that is a complex combination of the resist as a mask and the part of the semiconductor substrate removed by etching, the semiconductor substrate may have various shapes after etching. There is a problem in that it is difficult to completely remove the deposited film adhering to the semiconductor substrate using high-temperature plasma without damaging the semiconductor substrate.

Furthermore, when the semiconductor substrate is taken out from the etching apparatus after etching, it is exposed to air, which causes a natural oxide film and some contaminants to adhere to the substrate, making it even more difficult to completely remove the deformed film. Ta.

The present invention has been made in order to solve the above-mentioned problems, and provides a semiconductor device processing apparatus that can easily and completely remove unnecessary deposited films on the surface of a substrate without damaging the substrate. The purpose is to obtain.

[Means to solve the problem]

A semiconductor device processing apparatus according to the present invention includes a heating means for heating a semiconductor substrate subjected to an etching process, and a light irradiation means for irradiating the surface of the semiconductor substrate with light at the same time as the heating and the introduction of a purifying gas into the reaction vessel. The etched substrate surface purification process is performed by assisting the thermal reaction of the purification gas with a photochemical reaction, and the transition from the etching process to the debo film removal process is performed by exposing the etched surface of the substrate to the atmosphere. This was done in such a way that it would not be exposed.

C Effect] In this invention, since the thermal reaction between the substrate and the purification gas is assisted by a photochemical reaction, the heat treatment can be performed at a low temperature so as not to damage the substrate.
Unnecessary deposition films can be completely removed without damaging the good substrate surface condition.

In addition, since the etching process is changed to the removal process of the deposited film without exposing the semiconductor substrate to the atmosphere, the semiconductor substrate is not contaminated, meaning that natural oxide films and contaminants do not adhere to the substrate surface. Therefore, the deposited film can be easily removed.

〔Example〕

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

FIG. 1 is a schematic diagram showing a semiconductor device processing apparatus according to an embodiment of the present invention. In the figure, 2 is the ultraviolet incident window 3
．． Supply pipe 7 for supplying etching gas. and an etching-resistant sealed reaction container having an exhaust pipe 8 for exhausting gas after the reaction; 4 is a semiconductor substrate rotation support stand provided inside the container 2, on which a semiconductor substrate 6 is placed; a heater 5;
is included. 1 is a low-pressure mercury lamp and a high-pressure mercury lamp, which are light sources for causing photochemical reactions.

Alternatively, a lamp such as a mercury-xenon lamp, 20 a high-frequency electric scraper for etching, 16 a high-frequency power source, and 17 a matching box.

Next, the operation will be explained.

In the etching process, a plurality of semiconductor substrates 6 are placed on the rotating support table 4 by a transport system (not shown)! l! At the same time, an etching gas such as hydrogen chloride gas or hydrogen gas is introduced into the reaction vessel 2 through the supply pipe 7, and high-frequency The power source 16 and matching box 17 are operated to form a high frequency electric field from the high frequency power source 16 in the reaction vessel 2, thereby etching the substrate. At this time, the atmospheric pressure in the reaction vessel 2 is set to Q, 1 Torr or more, and the heating temperature of the substrate is set to 200 to 8
00℃.

By controlling the atmosphere in the reaction vessel 2 from immediately after the etching process to immediately before the debo film removal process, contaminants and natural oxide films are prevented from being formed on the semiconductor substrate 6 after the etching process.

Thereafter, in the debo film removal step, the rotating support 4 is rotated, and the surface of the semiconductor substrate 6 in the reaction container 2 is irradiated with ultraviolet rays emitted from the light source 1 through the ultraviolet ray entrance window 3, and at the same time, the heater 5 is operated. By heating the semiconductor substrate 6 and introducing, for example, hydrogen chloride gas into the reaction vessel 2 through the supply pipe 7, a thermal reaction is caused on the surface of the semiconductor substrate 6 using a photochemical reaction, and a deformation film on the surface of the semiconductor substrate 6 is caused to occur. Remove.

As described above, in this embodiment, the etching process of the semiconductor substrate 6 and the process of removing the unnecessary deposited film after this process are performed in the same container, so that the semiconductor substrate after the etching process is not exposed to the atmosphere. In particular, contamination of the substrate surface can be prevented. In addition, since the thermal reaction during removal of the unnecessary deposited film is assisted by a photochemical reaction, the thermal reaction is performed at a sufficiently lower temperature than the conventional hydrogen reduction method that uses only a thermal reaction, and it is possible to almost eliminate damage to the substrate.

Further, FIG. 2 is a schematic diagram showing a processing apparatus for a semiconductor device according to another embodiment of the present invention.

In FIG. 2, reference numeral 2 denotes an etching-resistant sealed reaction vessel in which an etching process using a photochemical reaction and a subsequent deburring film removal process are carried out, including an apparatus front chamber 13, an etching process chamber 11. It consists of a debo film removal chamber 12° and a rear chamber 14 of the device. Each of the above chambers is partitioned by a lock valve 10, and each chamber 11-14 is provided with a gas supply pipe 7 and a gas exhaust pipe 8, respectively. Further, a semiconductor substrate transport system 9 is installed in the front chamber 13 and rear chamber 14 of the apparatus, and in addition to the transport system 9, a semiconductor substrate support 4 having a heater 5 is installed in the etching processing chamber 11 and the debo film removal chamber 12. is installed. Reference numeral 3 denotes an ultraviolet light incident window formed in a part of the peripheral wall of the deformation film removal chamber 12 for introducing light for photochemical reaction into the chamber 12; and 15 an etching window disposed in the etching processing chamber 11. The other configurations are the same as in the above embodiment.

In short, the apparatus of the embodiment shown in FIG. 2 performs the etching process and the debossing film removal process in different reaction chambers, and the operation will be explained in detail below.

First, the semiconductor substrate 6 is housed in the front chamber 13 of the device, and the front chamber 1
After the pressure inside the etching chamber 3 is reduced from atmospheric pressure, the substrate 6 is conveyed to the etching chamber 11 by a conveying system 9 through a rock pulp 10. In the etching chamber 11, an etching gas is introduced from the supply pipe 7, and the substrate 6 is heated by the heater 5. At the same time, the high frequency power source 16 and the matching box 17 are operated to apply a high frequency electric field to the etching chamber 11 from the high frequency electrode 15. forming a substrate, thereby performing an etching process on the substrate,
After etching is completed, the pressure inside the etching processing chamber is reduced,
The semiconductor substrate 6 is transported to the debo film removal chamber 12 by the Wi transport system 9.

In the debo film removal chamber 12, the ultraviolet rays emitted from the light source 1 are irradiated onto the surface of the semiconductor substrate 6 inside through the ultraviolet incidence window 3, and the heater 5 in the semiconductor substrate support 4 is operated to heat the semiconductor substrate 6. At the same time, a deformed film removing gas is introduced into the deformed film removing chamber 12 through the supply pipe 7. As a result, a thermal reaction assisted by a photochemical reaction occurs on the surface of the semiconductor substrate 6, and the deposited film on the semiconductor substrate 6 is removed. In this case as well, the type of etching gas, the atmospheric pressure in the debo film removal chamber, and the substrate heating temperature are set to the same values as in the above embodiment.

After the debo film removal process is completed, the semiconductor substrate 6 is transported to the rear chamber 14 of the apparatus, where the indoor air pressure is adjusted and taken out of the container.

In this embodiment as well, like the embodiment device shown in FIG. 1 above,
This has the effect that unnecessary deposited films on the semiconductor substrate can be easily and completely removed without damaging the semiconductor substrate.

In this embodiment, the etching chamber and the deposited film removal chamber are placed adjacent to each other, but an intermediate chamber having a pressure reducing function may be provided between them, and the same effect can be achieved in this case as well.

〔Effect of the invention〕

As described above, the semiconductor device processing apparatus according to the present invention includes a heating means for heating a semiconductor substrate subjected to an etching process, and a method for irradiating light onto the surface of the semiconductor substrate during the heating and introduction of the purifying gas. A light irradiation means is provided to purify the surface of the etched substrate by assisting the thermal reaction of the purification gas with a photochemical reaction, and to perform the transition from the etching treatment to the deformation film removal treatment on the etched surface of the substrate. This was done without exposing it to the atmosphere, so
It is possible to lower the substrate heating temperature during the deposit film removal process, and prevent the adhesion of natural oxide films and contaminants to the substrate.This allows unnecessary deposit films to be removed easily and completely without damaging the substrate. There is an effect that can be removed.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a sectional view showing a semiconductor device processing apparatus (RIE apparatus) according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a semiconductor device processing apparatus according to another embodiment of the present invention. FIG. In the figure, 1 is a light source, 2 is a sealed reaction vessel, 3 is an ultraviolet incident window, 4 is a semiconductor substrate rotation support stand, 5 is a heater, 6 is a semiconductor substrate, 7 is an etching gas supply chamber, 8 is an exhaust pipe,
15. 20 is a high frequency electrode for etching, 16 is a high frequency power source, and 17 is a matching box. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Ken Hayase - 5sLn<D to Ichi

Claims (1)

[Claims] (1) In a semiconductor device processing apparatus that performs an etching process on a semiconductor substrate in a sealed reaction vessel, and then performs a surface purification process by reacting a purifying gas with the surface of the substrate using heat, the etching process described above is performed. a heating means for heating the semiconductor substrate, and a light irradiation means for irradiating the surface of the semiconductor substrate with light during the heating and introduction of the purifying gas; A semiconductor device processing device characterized in that the processing is assisted by a photochemical reaction.