JPH05267156A - Manufacture of semiconductor and ashing device for performing the same - Google Patents

Abstract

PURPOSE:To provide a method semiconductor manufacture for performing an ashing process whose damage to a device is little after an etching process without corroding a metal part and an ashing device appropriate to be used for the method. CONSTITUTION:A semiconductor manufacturing method comprises steps of etching a metal film provided on the substrate with a resist pattern provided on the metal film as a mask, carrying the substrate in an inactive gas atmosphere to a portion for ashing the resist and ashing the resist by using ozone and further applying ultraviolet rays if necessary. In addition, a carrying means 4 for carrying the substrate in the inactive gas atmosphere between an etching chamber 3 and processing chambers 5, 5' for ashing is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing method involving a resist ashing step and an ashing apparatus for performing the same.

[0002]

2. Description of the Related Art Conventionally, when a semiconductor device is manufactured, a metal film is provided for wiring or the like, a resist pattern is formed on the metal film, and the metal film is etched in this pattern. Of the ashing apparatus, and the resist is ashed by this apparatus. On the other hand, as an ashing device, an ashing device that uses ozone and processes under atmospheric pressure, and an ashing device that further irradiates ultraviolet rays to the ashing device are being used. These ashing devices have the advantage that charged particles do not exist, and therefore the device is hardly damaged by charge-up or mobile ion contamination. Note that as a device related to this type of device, there are Hitachi Review Papers No. 73, No. 9 (1991-9), pages 37 to 42.

[0003]

After the conventional etching described above, in order to perform ashing using ozone or ozone and ultraviolet rays at atmospheric pressure, the vacuum of the etching apparatus is broken and the sample is opened to the atmosphere. It is necessary to move to an ashing device under atmospheric pressure. At this time, the etching gas such as chlorine remaining after etching absorbs moisture in the atmosphere and becomes a corrosive chemical solution such as hydrochloric acid, which causes a problem of corroding metal parts.

A first object of the present invention is to provide a semiconductor manufacturing method which carries out, after the etching step, an ashing step which does not corrode a metal part and less damages the device. A second object of the present invention is to provide an ashing device suitable for use in such a semiconductor manufacturing method.

[0005]

[Means for Solving the Problems] The first object is to:
(1) A step of etching a metal film provided on a substrate using a resist pattern provided on the metal film as a mask, and a part for ashing the resist in the inert gas atmosphere of the substrate. And a step of ashing the resist. (2) In the method of manufacturing a semiconductor according to the above 1, the step of ashing the resist uses ozone as a reaction gas. (3) The semiconductor manufacturing method as described in 1 above, wherein
The step of ashing the resist is performed by using ozone as a reaction gas and irradiating ultraviolet rays, (4) In the semiconductor manufacturing method according to the above 3, the ultraviolet rays are at least 254 nm.
(5) In the semiconductor manufacturing method according to any one of 1 to 4 above, the step of ashing the resist further includes heating the substrate. (6) In the semiconductor manufacturing method as described in any one of 1 to 5 above, the step of ashing the resist is performed in a processing chamber separated from the inert gas atmosphere. And a semiconductor manufacturing method.

The second purpose is (7) an etching chamber formed of a vacuum container, an etching means provided in the etching chamber, an inlet for introducing an inert gas into the etching chamber, and a substrate. A processing chamber for ashing the resist, a transport means for transporting the substrate from the etching chamber to the processing chamber in an inert gas atmosphere, and a second inlet for introducing a reaction gas into the processing chamber. (8) In the ashing device described in (7) above, the second introduction port is an introduction port for introducing ozone gas, (9) above 7. The ashing device according to claim 7 or 8, wherein the processing chamber has a light source for irradiating the processing chamber with ultraviolet rays. In the ashing device according to any one of 9, the treatment chamber is achieved by an ashing apparatus, characterized in that the structure is separated from the periphery thereof.

In the present invention, the inert gas is a broadly defined inert gas containing nitrogen gas in addition to a rare gas such as argon. Ozone is preferred as the reaction gas for ashing. Ozone is usually diluted with oxygen before use. In addition to ozone, an additive gas such as nitrogen gas or water vapor may be added and used.

[0008]

[Function] After the etching process, the vacuum of the etching apparatus is broken in an inert gas atmosphere and the sample is conveyed to an ashing apparatus using ozone or ozone and ultraviolet rays in the inert gas atmosphere, so that the sample does not come into contact with moisture. Therefore, a corrosive chemical solution is not generated and the metal is not corroded.

Further, the ashing device using ozone or ozone and ultraviolet rays supplies ozone at atmospheric pressure, and irradiates or does not irradiate ultraviolet rays, and further heats the sample if necessary, so that ozone is excited by oxygen atoms. To oxidize, decompose, and volatilize the resist.

When ashing is performed using this apparatus,
Since there are no charged particles, the wafer will not be damaged by charge-up. The mobile ions are mainly impurities such as sodium in the resist that have entered the device during ashing, and the mobile ions increase when the wafer is charged up. There is almost no mobile ion contamination in the ashing using the device of the present invention.

[0011]

【Example】

Example 1 After forming a main part of a semiconductor device on a 6-inch wafer, an aluminum film (Al-Cu-Si) was provided, and a resist pattern was formed thereon. The wafer was transferred to an etching chamber, and the aluminum film was dry-etched using chlorine gas as an etching gas to form a wiring pattern. The vacuum in the etching chamber is broken by using nitrogen gas, and the wafer is transferred to the processing chamber of the ashing device in a nitrogen atmosphere at approximately atmospheric pressure by the arm-type transfer means, and ozone (5 vol%) is supplied as the ashing gas. The wafer was heated to 350 ° C. for ashing. At this time, the ambient atmosphere of the processing chamber was replaced with nitrogen gas. As a result, it was confirmed that aluminum did not corrode after ashing.

Further, when the processing chamber has a closed structure, the replacement gas can be saved. This will be described with reference to FIG. As in the above, a wafer having a resist pattern on an aluminum film is mounted on the cassette 1 and transferred to the load lock chamber 2, and the load lock chamber 2 is evacuated. The wafer is transferred to the etching chamber 3, the aluminum film is dry-etched by using chlorine gas as an etching gas, nitrogen gas is introduced into the etching chamber through an inlet (not shown) to break the vacuum, and the arm type transfer means 4 is used. The wafer is transferred to the processing chamber 5 of the ashing device in a nitrogen atmosphere, and the processing chamber is sealed. Thereafter, ashing was performed in the same manner as above. As a result, the replacement gas could be saved by 0.5 m ³ / min.

In the figure, 1'is a cassette for mounting wafers after ashing, 6 is an ozone generator, 7 is an ozone inlet, 8 is an additive gas inlet, and 9 is an ozone decomposer.

In each of the above examples, nitrogen was used as the replacement gas, but the same effect was obtained by using an inert gas such as argon.

Example 2 As in Example 1, a 6-inch wafer having a resist pattern on an aluminum film was used, and the aluminum film was dry-etched in an etching chamber using chlorine gas as an etching gas. The vacuum in the etching chamber was broken with nitrogen gas, and the wafer was transferred to the processing chamber of the ashing device in a nitrogen atmosphere by the arm-type transfer means. Ozone (5vol%)
And ultraviolet rays (main wavelengths: 185 nm and 254 nm) were supplied, and ashing was performed at a temperature of 250 ° C. At this time, the ambient atmosphere of the processing chamber was replaced with nitrogen gas. As a result, it was confirmed that aluminum did not corrode after ashing.

When the processing chamber had a closed structure as in Example 1, the replacement gas could be saved by 0.5 m ³ / min. Although nitrogen was used as the replacement gas, the same effect was obtained by using an inert gas such as argon.

[0017]

By using ozone or the like for the ashing, an ashing device with less damage to the element can be obtained, and since the transportation to the ashing device is performed in an inert gas atmosphere, the corrosion of the metal part is prevented. I was able to do it.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an etching apparatus and an ashing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 1, 1'cassette 2 load lock chamber 3 etching chamber 4 transfer means 5, 5'processing chamber 6 ozone generator 7 ozone inlet 8 added gas inlet 9 ozone decomposer

Claims (10)

[Claims] 1. A step of etching a metal film provided on a substrate using a resist pattern provided on the metal film as a mask, and a step of ashing the resist in the inert gas atmosphere of the substrate. A method of manufacturing a semiconductor, comprising a step of carrying to a part and a step of ashing a resist. 2. The semiconductor manufacturing method according to claim 1,
The semiconductor manufacturing method, wherein the step of ashing the resist is performed by using ozone as a reaction gas. 3. The semiconductor manufacturing method according to claim 1, wherein
A method for manufacturing a semiconductor, wherein the step of ashing the resist is performed by using ozone as a reaction gas and irradiating with ultraviolet rays. 4. The semiconductor manufacturing method according to claim 3,
The semiconductor manufacturing method, wherein the ultraviolet rays are ultraviolet rays having a wavelength of at least 254 nm. 5. The semiconductor manufacturing method according to claim 1, wherein the step of ashing the resist is performed by further heating the substrate. 6. The semiconductor manufacturing method according to claim 1, wherein the step of ashing the resist is performed in a processing chamber separated from the inert gas atmosphere. Production method. 7. An etching chamber consisting of a vacuum container, an etching means provided in the etching chamber, an inlet for introducing an inert gas into the etching chamber, a process for ashing a resist formed on a substrate. Chamber, a transport means for transporting the substrate from the etching chamber to the processing chamber under an inert gas atmosphere, and an ashing device having a second inlet for introducing a reaction gas into the processing chamber . 8. The ashing device according to claim 7,
An ashing device characterized in that the second inlet is an inlet for introducing ozone gas. 9. The ashing device according to claim 7, wherein the processing chamber has a light source for irradiating the processing chamber with ultraviolet rays. 10. The ashing device according to claim 7, wherein the processing chamber has a structure separated from its surroundings.