JPS6352411A - Heat treatment method and its device - Google Patents

Abstract

PURPOSE:To improve a processing speed, by supplying a mixed gas consisting of ozone and oxygen to the surface of a matter to be processed and heated at a definite temperature and radiating ultraviolet rays on the surface so that a prescribed process is performed. CONSTITUTION:A matter 3 to be processed is heated at a definite temperature by a heater mounted on a sample board 2 and rotated at a definite speed. Furthermore, a processing chamber 1 is exhausted through an exhaustion port 11, and besides on the central part of the matter 3 to be processed and mounted on the sample board 2, a mixed gas 8 consisting of ozone and oxygen is supplied under an atmospheric pressure through a nozzle 5. This mixed gas 8 consisting of ozone and oxygen is guided to a plate material 4 being disposed,with a definite gap, opposite to the matter 3 to be processed, and is made to flow in a streamline flow shape from the central part toward the peripheral part, along the whole surface of the matter 3 to be processed. Furthermore, from a light source 9, ultraviolet rays having a definite wavelength is made to pass through the transparent plate material 4 and radiated on the surface of the matter 3 to be processed. Hence, a speed in a process for removing the oxidation of a photoresist or the like oxidized by oxygen at its generation time can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to processing techniques and, more particularly, to techniques useful for removing photoresist deposited on semiconductor wafers using iδ.

[Prior art] Regarding the removal of photoresist adhered to semiconductor wafers, see "Electronic Materials J, November 1981 issue, special issue, pages 137~" published by Kogyo Research Association Co., Ltd., November 1981.
It is described on page 148.

By the way, in the manufacture of semiconductor devices by photolithography, after etching the semiconductor wafer, the following photoresist removal process may be performed in order to remove the photoresist that has hidden the surface into a predetermined concave shape. Conceivable.

In other words, while supplying oxygen gas to the surface of a semiconductor wafer heated to a predetermined temperature, ozone is generated by irradiating it with ultraviolet rays, and oxidation is caused by the chemically active nascent oxygen generated by the dissociation of this ozone. It oxidizes the photoresist by its action and removes it as carbon dioxide gas or water vapor.

[Problem that the invention seeks to solve]

However, as described above, in the method of simply supplying oxygen gas to the surface of the semiconductor wafer and generating ozone by irradiating it with ultraviolet rays, the concentration of the ozone generated is low, so the speed of the oxidation removal reaction of the photoresist is slow. The inventors have discovered that there is a problem in that the photoresist removal process takes a relatively long time.

An object of the present invention is to provide a processing technique that can improve processing speed.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

A brief overview of typical inventions disclosed in this application is as follows.

That is, a predetermined treatment is performed by irradiating ultraviolet rays while supplying a gas mixture of ozone and oxygen to the surface of a workpiece that is heated to a predetermined temperature.

(Function) According to the above-mentioned means, a relatively high concentration of ozone is applied to the treated object, compared to the case where the treatment is performed by simply supplying oxygen gas to the treated object and generating ozone by irradiating it with ultraviolet rays. Since it is supplied to objects, processing speed can be improved.

〔Example〕

FIG. 1 is an explanatory diagram showing the main parts of a processing device that is an embodiment of the present invention.

In this embodiment, the processing device is configured as a photoresist removal device.

Inside the processing chamber 1, a sample stage 2 with a built-in heater (not shown) is rotatably located.
A workpiece 3 such as a semiconductor evaporator whose surface is coated with photoresist or the like is placed thereon and heated to a predetermined temperature.

Near the top surface of the sample stage 2, a plate 4 made of synthetic quartz or the like and transparent to ultraviolet rays is arranged substantially parallel to the sample stage 2.

One end of a nozzle 5 passing through the plate 4 is opened in the center of the gap between the plate 4 and the sample stage 2, and the other end of the nozzle 5 is provided outside the processing chamber l. ozone generating means 6.

In this ozone generating means 6, a mixed gas 8 of ozone and oxygen is generated from oxygen gas 7 supplied from the outside, and is applied to the surface of the object to be processed 3 placed on the sample stage 2 via the nozzle 5. It is designed to be supplied at any time.

Further, a plurality of light sources 9 such as low-pressure mercury lamps are provided on the top of the transparent plate 4, and ultraviolet rays of a predetermined wavelength are emitted through the transparent plate 4 and placed on the sample stage 2. It is configured to irradiate the surface of the object 3 to be processed.

A reflecting plate 10 is disposed above the light rA9 so that the surface of the object 3 to be processed is efficiently irradiated with the ultraviolet rays generated from the light source 9.

A plurality of exhaust ports 11 are provided at the bottom of the processing chamber 1, and the remaining materials such as photoresist deposited on the surface of the processing object 30 placed on the sample stage 2 are exposed to ozone and oxygen. Carbon dioxide, water vapor, and the like generated when removed by the oxidation effect of the mixed gas 8 are quickly exhausted to the outside.

The operation of this embodiment will be explained below.

First, a workpiece 3 such as a semiconductor wafer placed on the sample stage 2 is heated to a predetermined temperature by a heater (not shown) provided on the sample stage 2, and is rotated at a predetermined speed.

Furthermore, the inside of the processing chamber 1 is evacuated through the exhaust port 11, and the sample stage 2 is evacuated! ! ! A gas mixture 8 of ozone and oxygen is supplied through a nozzle 5 under atmospheric pressure to the center of the object 3 to be treated, and the gas mixture 8 of ozone and oxygen is supplied to the object 3 to be treated at a predetermined gap. The light a9 is guided by the plate body 4 which is opposed to the object 3 in a direction M from the center to the periphery along the entire surface of the object 3. Plate body 4 that is transparent to ultraviolet rays
The light passes through and is irradiated onto the surface of the object 3 to be processed.

The photoresist, which is made up of resists attached to the surface of the workpiece 3 such as a semiconductor wafer, is produced by the dissociation of oxygen and ozone in the ozone-oxygen mixture 8 excited by ultraviolet irradiation. It is oxidized by chemically active nascent oxygen, etc., and removed as carbon dioxide gas, water vapor, etc., and is discharged to the outside of the processing chamber 1 through the exhaust port 11.

Here, as mentioned above, there is f! In the oxidation removal process of photoresist etc. attached to the surface of the object 3, the amount of ozone supplied to the surface of the object 3 is increased, and the nascent oxygen generated by the dissociation of this ozone is removed. Increasing the A degree is important from the viewpoint of improving the removal rate, but in this example, a mixed gas of ozone and oxygen is supplied from the ozone generating means 6 provided outside the processing chamber 1 through the nozzle 5. 8 is supplied, the surface of the object to be processed 3 is reduced by the dissociation of ozone, compared to the case where, for example, only oxygen gas is supplied and nascent oxygen is formed by the dissociation of ozone generated by irradiation with ultraviolet rays. The concentration of nascent oxygen supplied to the nascent oxygen can be increased, and the speed of oxidation removal treatment of photoresist or the like by the nascent oxygen can be improved.

In this way, the following effects can be achieved in this embodiment.

n3 a sample stage 2 that heats a processed object 3 such as a semiconductor wafer to a predetermined temperature; a transparent plate 4 disposed opposite to the sample stage 2 with the processed object 3 interposed therebetween; This plate 4
A nozzle 5 has one end opened in the space between the object 3 and the object 3, and the other end connected to an ozone generating means 6 that supplies a mixed gas 8 of ozone and oxygen. The workpiece 3 is heated to a predetermined temperature and is supplied with a gas mixture 8 of ozone and oxygen while irradiating the workpiece 3 with ultraviolet rays, thereby irradiating the workpiece 3 with ultraviolet rays. Since oxidation removal processing is performed on the photoresist etc. attached to the surface of step 3, compared to, for example, simply supplying oxygen gas and forming nascent oxygen through the dissociation of ozone produced by ultraviolet irradiation. , the AK of the nascent oxygen supplied to the surface of the object 3 to be processed can be increased, and the rate of oxidation removal of photoresist and the like attached to the surface of the object 3 by the nascent oxygen can be increased. be able to.

(2) As a result of (1) above, it is possible to increase the number of objects 3 to be processed per unit time, and production in oxidation removal processing of photoresist attached to objects 3 such as semiconductor wafers can be increased. performance is improved.

(3) By performing the processing while rotating the object 3 to be processed, such as a semiconductor wafer, the contact of the mixed gas 8 of ozone and oxygen to the surface of the object 3 to be processed is made uniform, and the surface of the object 3 to be processed is The photoresist attached to the substrate can be uniformly removed by oxidation.

(4) Since the oxidation removal process of photoresist and the like attached to the surface of the workpiece 3 such as a semiconductor wafer is performed under atmospheric pressure, evacuation equipment is not required, as in the case of ashing process using plasma, for example. The structure of the apparatus is simplified compared to the method in which the method uses the method described above, and it is possible to reduce the amount of foreign matter adhering to the object 3 to be processed.

As a result of (5) and (4) above, it is possible to improve the productivity of the wafer processing process in the manufacture of semiconductor devices.

Although the invention made by the present inventor has been specifically explained above based on actual examples, the present invention is not limited to the above-mentioned ¥A%4i・1, and various changes can be made without departing from the gist thereof. It goes without saying that there is.

For example, the nozzle 5 may be opened at a position eccentric to the object to be processed 3, and further, the nozzle 5 may be opened from the side of the object to be processed 3 into the gap between the object to be processed 3 and the plate 4. It's okay.

The above explanation has mainly been about the application of the invention made by the present inventor to the oxidation removal technology for photoresist attached to semiconductor wafers, which is the field of application behind the invention, but the invention is not limited to this. For example, it can be widely applied to cleaning techniques that require the removal of organic stains.

[Effects of the Invention] A brief summary of typical inventions disclosed in this application is as follows.

That is, a sample stand that heats the object to be processed to a predetermined temperature, a transparent plate disposed opposite to the sample stand with the object to be processed interposed therebetween, a plate member, and the object to be processed. A nozzle having one end opened in a space between the object and the other end connected to ozone generating means for supplying a mixed gas of ozone and oxygen, and irradiating the object to be treated with ultraviolet rays through the transparent plate. It has a structure in which a predetermined treatment is performed by irradiating ultraviolet rays while supplying a mixed gas of ozone and oxygen to the object to be treated, which is heated to a predetermined temperature.
For example, compared to processing by simply supplying oxygen gas to the workpiece and generating ozone by irradiating it with ultraviolet rays, a relatively high concentration of ozone is supplied to the workpiece, which reduces the processing speed. can be improved.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the main parts of a processing device that is an embodiment of the present invention. l...processing chamber, 2...sample stand, 3...processed object,
4...Plate body, 5...Nozzle, 6...Ozone generation means, 7...Oxygen gas, 8...Yabajin Masubuji Katsuo Ogawa

Claims (1)

[Scope of Claims] 1. A processing method characterized in that a predetermined treatment is performed by irradiating ultraviolet rays while supplying a mixed gas of ozone and oxygen to the surface of a workpiece to be heated to a predetermined temperature. 2. The processing method according to claim 1, wherein the object to be processed is a semiconductor wafer, and the processing is the removal of photoresist deposited on the surface of the semiconductor wafer. 3. The processing method according to claim 1, wherein the processing is performed under atmospheric pressure. 4. A sample stand that heats the object to be processed to a predetermined temperature; a transparent plate disposed opposite to the sample stand with the object to be processed interposed therebetween; A nozzle has one end opened in the space between the object to be treated and the other end connected to ozone generating means for supplying a mixed gas of ozone and oxygen, and a nozzle that irradiates ultraviolet rays to the object to be treated through the transparent plate. What is claimed is: 1. A processing apparatus comprising: a light source for irradiation; the processing apparatus is characterized in that it performs a predetermined treatment by irradiating ultraviolet rays while supplying a mixed gas of ozone and oxygen to the object to be processed, which is heated to a predetermined temperature; 5. The processing apparatus according to claim 4, wherein the object to be processed is a semiconductor wafer, and the processing is removal of photoresist adhered to the semiconductor wafer. 6. The processing apparatus according to claim 4, wherein the processing is performed under atmospheric pressure. 7. The processing apparatus according to claim 4, wherein the processing is performed while rotating the object to be processed.