JPH0777189B2 - Method of removing organic film - Google Patents

Description

The present invention relates to a method and an apparatus for removing an organic film in a dry state, and more particularly to a method for removing a resist film used for manufacturing a semiconductor device.

(Prior Art) In the case of manufacturing a semiconductor device, a substrate such as silicon having a resist film on which a circuit pattern is drawn is subjected to a treatment such as etching by a photographic processing technique or X-ray irradiation, electron beam irradiation or the like. It is necessary to remove the resist film later.

The resist film is removed by a wet process of immersing in a liquid having oxidizing power, or a dry process of oxygen plasma, ultraviolet rays, ozone, or the like.

In the wet treatment with a solution, waste liquid treatment is troublesome and impurities contained in the liquid adversely affect the semiconductor device, and thus there is an increasing demand for a dry treatment.

The oxygen plasma method, which has been the center of dry processing, may damage the semiconductor device due to the plasma.
Attention has been paid to the removal method using ozone or ultraviolet rays.

(Problems to be Solved by the Invention) Removing the organic film while heating the semiconductor substrate in the housing to which ozone is supplied is disclosed in, for example, Japanese Patent Application Laid-Open
Known as No. 52-20766. By this method,
When the removal of the organic substance film is continued, various organic compounds are found to be deposited in the processing chamber including the ozone injection nozzle of the removing device. The adhered substance is a solvent such as a resist, a low molecular weight organic substance, or a substance generated by decomposition. There is a problem in that such deposits cause contamination of the device and eventually the semiconductor substrate to be processed.

Further, it is essential that the ozone generator is continuously operated in order to stabilize the ozone generation. Corresponding to the continuous operation of the ozone generator, in order to keep the ozone supply continuous,
It has been proposed that a substrate to be treated is continuously introduced by a conveyor system or the like and sealed with nitrogen gas. However, in order to remove the organic film on the circular substrate having a diameter of 12.5 cm to 20 cm uniformly and in a short time, it is effective to rotate the substrate to be processed, but a conveyor system has a substrate rotating mechanism. Providing is a very complex mechanism.

Therefore, when a substrate rotating mechanism is provided, it is preferable to employ batch type processing. It is possible to take the substrate in and out of the batch type apparatus, and to stop the injection of ozone by means of a seal gas or the like, but ozone is wasted and it is extremely uneconomical.

(Means for Solving Problems) Therefore, in the present invention, in order to reduce the adhesion of organic substances to the inner wall of the processing chamber, the substrate is heated while flowing a large amount of gas before the treatment with ozone, or the external By heating while sucking and removing the gas without supplying gas from the substrate, preheating of the substrate and the organic solvent and low-molecular substances generated from the organic film on the substrate can be promptly removed to the outside to remove the organic film. In order to reduce the adhesion of organic substances to the wall surface of the processing chamber and to continuously operate the processing chamber for removing the organic film, the ozone generator can be continuously operated.

The above-described preheating of the substrate and pretreatment of the organic solvent or the low molecular weight substance may be performed in a room different from the processing chamber for removing the organic film, or a plurality of processing chambers may be provided to supply and exhaust gas pipes. By switching the treatment chamber between the pretreatment chamber and the organic substance film removal chamber by switching the above, it is possible to simultaneously perform preheating of the substrate, pretreatment of the organic solvent or low molecular weight substance, and treatment with ozone.

By doing so, it becomes possible to remove the organic solvent and the low molecular weight compound contained in the organic film in advance while preheating the substrate from which the organic film should be removed, and the ozone injection nozzle and other parts can be removed. In the processing chamber,
Since it is possible to very effectively prevent the adhesion of various organic substances, it is possible to significantly reduce the time loss of stopping the operation and removing the adhered substances.

When preheating of the substrate and pretreatment of the organic coating are carried out in separate chambers, it is possible to reduce the adhesion of various organic substances to the inner wall of the processing chamber for removing the organic coating, but the area of the equipment is small. There is a disadvantage in that the size of the substrate becomes large, a device for moving the substrate is required, and the temperature of the substrate that has been preheated decreases when the substrate is moved. On the other hand, a method of providing a plurality of processing chambers for removing the organic film and performing pretreatment by switching the processing chambers is inferior to the former in terms of adhesion of organic substances to the wall surface of the processing chamber, but the device is simple, It has the advantage that the size of the device is also small.

In the pretreatment of the substrate, either a method of flowing a large amount of gas or a suction removal method can be adopted, but if a large amount of gas is caused to flow, the temperature of the substrate will decrease and preheating will take a long time. A method of suction removal is preferable to a method of flowing a large amount of gas.

Further, by performing the treatment with ozone in parallel with the pretreatment for sucking and removing the gas while preheating the substrate, continuous operation is possible without stopping the ozone generator, which is also preferable for the ozone generator. Productivity is also improved.

Hereinafter, the present invention will be described with reference to the accompanying drawings regarding a method of providing a plurality of processing chambers and switching the processing chambers. FIG. 1 shows an apparatus for treating an organic film for carrying out the method of the present invention. This apparatus has two processing chambers 1 and 2. Since the respective processing chambers have the same structure, only one of them will be described.

In the processing chamber 1, there is a substrate support device 4 on which a semiconductor substrate 3 to be processed is placed, and the substrate support device is provided with a rotation mechanism. A heating device 5 is provided below the substrate supporting device, and a high-concentration ozone supply pipe 6 is provided in the processing device.
The supply pipe is surrounded by a cooling pipe 7. The ozone supply pipe is connected to a plurality of nozzles 8 for injecting ozone onto the semiconductor substrate, and is cooled by a cooling pipe.

A gas suction pipe 9 and a gas discharge pipe 10 are provided in the upper part of the processing chamber. The position and the number of the gas suction pipes and the gas discharge pipes can be appropriately selected, but in consideration of the gas flow in the processing chamber and the contamination of the inner wall of the processing chamber and the substrate, the gas suction pipe is provided at the upper part of the processing chamber. Further, it is preferable that the gas discharge pipe is provided in the lower part of the processing chamber.

As the constituent materials such as the processing chamber, the ozone supply pipe and the nozzle, various materials can be used as long as they are materials having corrosion resistance to ozone, such as stainless steel, and the number of nozzles to be processed is the substrate to be processed. Can be appropriately set according to the size of the. Ozone is generated in the ozone generator 11 and supplied to one of the processing chambers by the switching device 12.

A gas suction device 14 is connected to the gas suction pipe via a switching device 13, and an ozone decomposing device 16 is connected to the gas discharge pipe via a switching device 15.

The substrate from which the organic film is removed is carried into one of the processing chambers, and the gas in the processing chamber is sucked and removed while preheating to a temperature required for ozone treatment by a heating device. At this time, a small amount of ozone may be injected. After performing pretreatment for 20 to 40 seconds, switch the gas suction device, ozone generator, and ozone decomposing device by the switching device to inject high-concentration ozone onto the substrate that has been preheated and pretreated with organic solvent or low-molecular substance. Then, the organic film is removed.

While removing the organic film in one processing chamber,
In the other processing apparatus, it is preferable to carry in, carry out, preheat, or suck and remove the gas in the processing chamber of the substrate to be processed. By doing so, the ozone generator can be continuously operated and produced. The property is improved. Also, it goes without saying that the switching of each process can be automated by an arbitrary control device using a microcomputer or the like.

(Examples) The present invention will be described below based on Examples.

Tokyo Ohka Kogyo Co., Ltd. positive photoresist OFPR-800 1.
The substrate coated with 5 μm and developed was placed on a sample support device rotating 2.5 times per minute, and the gas in the processing chamber was absorbed and removed for 30 seconds while the substrate was heated to 300 ° C. by an electric heater.

Then, the switching device was operated to stop the suction removal, and oxygen containing about 60,000 ppm of ozone was sprayed onto the substrate from a nozzle having an inner diameter of 0.7 mm at a rate of 6 liters per minute. This treatment was performed for 1 minute and 30 seconds, and after purging the internal ozone with nitrogen gas, the substrate was taken out from the treatment chamber.

While performing the treatment with ozone, preheating and pretreatment were performed in other treatment chambers.

In the pre-treatment, it was confirmed that vapor was generated from the organic film on the substrate, and the generated vapor could be trapped in the trap installed in front of the suction device, and the contamination of the inner wall of the treatment chamber could be reduced. .

(Effects of the Invention) In a method of removing a coating film from a substrate having an organic coating film, while preheating the substrate having the organic coating film to the removal temperature of the coating film, the gas in the room is removed by suction to remove the organic material in the coating film. By removing the film after removing the solvent and low molecular weight substances, it is possible to reduce the adhesion of organic substances to the inner wall of the processing chamber for removing the organic substance film, and to keep the ozone generator operating continuously. And productivity is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an apparatus used in the method for removing organic substances of the present invention. . 1, 2 ... Processing chamber 3 ... Substrate support device 4 ... Semiconductor substrate 5 ... Heating device 6 ... Ozone supply pipe 7 ... Cooling pipe 8 ... Nozzle 9 ... Gas suction pipe 10 ... Gas discharge pipe 11 …… Ozone generator 12 …… Switching device 13 …… Switching device 14 …… Gas suction device 15 …… Switching device 16 …… Ozone decomposing device

Claims (4)

[Claims] 1. A method for removing an organic coating from a substrate having an organic coating formed thereon, wherein a plurality of processing chambers for removing the organic coating are provided, and during the heating treatment for removing the gas in the processing chamber while heating the organic coating. In addition, a method for removing an organic film, comprising spraying ozone on the surface of the organic film of a substrate which has been heat-treated in another processing chamber under heating. 2. The method for removing an organic film according to claim 1, wherein the treatment with ozone is continuously performed in the treatment chamber in which the heating treatment for sucking and removing the gas in the treatment chamber while heating is performed. . 3. The heat treatment for sucking and removing the gas in the treatment chamber while heating the organic coating, is performed in a treatment chamber different from the treatment chamber for performing the ozone treatment. Method for removing organic coating of. 4. A method for removing an organic coating according to any one of claims 1 to 3, wherein a small amount of ozone is injected during the heat treatment for sucking and removing the gas in the processing chamber while heating the organic coating. .