JPH01258424A - Method and device for ashing - Google Patents

Abstract

PURPOSE:To completely remove any inorganic impurity contained in resist by a method wherein resist is irradiated with ultraviolet ray to remove a resist film and then the inorganic matter contained in the resist are removed by wet processing to lessen the damage to an element. CONSTITUTION:A wafer 7 not yet processed is contained in a wafer cassette 1. The wafer 7 is placed by a carrier on a stage 6 serving also as a heater in a chamber 3. The wafer 7 is supplied with oxygen gas containing ozone from a nozzle 4 and then irradiated with ultraviolet rays in beam wavelength of 185nm and 254nm, etc. The wafer 7 wherefrom resist is removed in the chamber 3 is contained in another wafer cassette 9 by another carrier 8. The cassette 9 is immersed in a vessel 11 by the other carrier 11 to remove any inorganic impurities and residual resist by ozone and liquid chemicals 12 such as sulfuric acid. Through these procedures, the inorganic impurities contained in resist can be completely removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to resist ashing, and particularly to an ashing device that completely removes inorganic substances contained in resist with low damage.

(Conventional technology) The conventional ashing device is Nikkei Microdevice 198.
As described in page 114 of the November 2006 issue, the resist was removed by flowing oxygen gas onto the surface of the substrate coated with resist and turning it into plasma, and then the inorganic substances were removed by flowing etching gas.

(Problems to be Solved by the Invention) In the above-mentioned conventional technology, the substrate is placed in plasma, which causes great damage to the substrate, making it unsuitable for the manufacturing process of LSI devices, which are becoming increasingly dense. The cause of damage is damage to the element due to charged particles in the plasma and charging.

An object of the present invention is to provide an ashing device that causes less damage and completely removes inorganic substances.

[Means to solve the problem]

The above purpose is to install a first processing mechanism in which a substrate coated with a resist is placed on a stage that also serves as a heater, the atmosphere is set to ozone-containing oxygen, and the substrate surface is irradiated with ultraviolet rays; This can be achieved by providing a second processing mechanism for removing resist and inorganic substances.

[Operation] Here, ozone is separated by ultraviolet rays into highly active atoms called excited oxygen atoms, which act on the resist film to cause an oxidation reaction, converting the resist into COz and Hx 2 O, and removing it. The heater also heats the substrate to promote this reaction. Further, in order to remove inorganic substances contained in the resist that cannot be removed by the above method, a subsequent wet treatment is performed. This treatment is also effective in removing some resist remaining on the back surface of the substrate.

〔Example〕 An embodiment of the present invention will be described below with reference to FIG.

A wafer cassette 1 contains unprocessed wafers. This wafer 7 is placed on a heater stage 6 in the chamber 3 by the carrier 2. Nozzle 4 on this wafer
Oxygen gas containing more ozone is supplied, and ultraviolet rays having line wavelengths of 185 nm, 254 nm, etc. are irradiated from the ultraviolet lamp 5. The wafer from which the resist has been removed in the chamber 3 is stored in a wafer cassette 9 by a carrier 8.

Further, each wafer cassette is immersed in a container 11 for wet removal using a transporter 10, and inorganic impurities and residual resist are removed using a chemical solution 12 such as ozone and sulfuric acid.

Here, the chamber 3 may be a batch type instead of a single wafer type,
Furthermore, the wet method may be a single-wafer method instead of a patch method. Also,? ! i! The chemical solution used in the formula method may be sulfuric acid and other treatment solutions such as fuming nitric acid.

Note that illustration of the ozone generator, etc. is omitted.

In this example, when a photoresist (thickness: 1 μm) coated on a 5-inch wafer was processed, the resist film could be completely removed without leaving any residue.

At that time, the wafer temperature was 250℃ and the ozone concentration was 5Vo.
Q%, flow rate is 5 Q/win, ultraviolet light (254nm
The illuminance of the light was 130 mW, /aJ.

〔Effect of the invention〕

According to the invention, no plasma is used.

There is little damage to the elements, and since a wet method is also used, it is effective in completely removing inorganic impurities in the resist.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the configuration of an ashing device according to an embodiment of the present invention. 1.9...Wafer cassette, 2,8.10...Transfer machine, 3...Chamber, 4...Nozzle, 5...Lamp, 6...Heater double-use stage, 7... Wafer, 11... Wet container, 12... Chemical solution.

Claims (1)

[Claims] 1. Supplying a gas containing ozone to the surface of the substrate coated with the resist, irradiating the resist with ultraviolet rays, and removing the resist film; and wet processing to remove the resist film. An ashing method characterized by comprising a step of removing inorganic substances. 2. A first processing mechanism comprising a means for supplying a gas containing ozone to the surface of the substrate coated with the resist and a means for irradiating ultraviolet rays onto the resist; An ashing device comprising: a second processing mechanism for removing by processing. 3. The ashing apparatus according to claim 2, wherein the first processing mechanism is provided with means for heating the substrate.