CN102891071A - Novel normal pressure plasma free radical cleaning spray gun - Google Patents

Abstract

A new type of atmospheric pressure plasma radical cleaning spray gun, including two radio frequency electrodes, a dielectric barrier layer, three ground electrodes and a radio frequency power supply, is characterized in that the radio frequency electrodes and the ground electrodes are arranged in an alternate array to form four nozzles , the radio frequency electrode is wrapped by a dielectric barrier layer, the working gas is a mixture of argon and oxygen, under normal pressure, when the radio frequency electrode is connected to the radio frequency power supply and the ground electrode is grounded, the argon oxygen is broken down between the radio frequency electrode and the ground electrode The mixed gas produces glow plasma. The upper end of the spray gun is connected to the air inlet, the lower end is the nozzle, and the surrounding is sealed with a metal plate. The high-density plasma free radicals generated in the electrode area are ejected from the nozzle under the airflow.

Description

A New Atmospheric Pressure Plasma Free Radical Cleaning Spray Gun

【Technical field】

The invention relates to a new type of normal-pressure plasma free radical cleaning spray gun. The plasma is generated by dielectric barrier discharge in the spray gun, which is sprayed out through four nozzles at the lower end of the spray gun under a certain pressure to form a high-concentration active free radical beam, reaching After cleaning the surface of silicon wafers, it reacts with photoresist or other organic substances to achieve the purpose of cleaning the surface of silicon wafers.

【Background technique】

In the microelectronics industry, the cleaning of silicon wafer photoresist is a very important link in the whole process. Commonly used photoresist cleaning methods include wet and dry methods. Traditionally, the wet chemical method is used, which has disadvantages such as inaccurate control, incomplete cleaning, repeated cleaning, easy introduction of new impurities, and environmental pollution. The current dry deglue is carried out in a vacuum state, the operation of the equipment is complicated, the cost is high, and the generated plasma is easy to cause damage to the etching lines on the surface of the silicon wafer. With the further reduction of the feature size of the micro-device, currently The current wet and dry photoresist cleaning technologies are facing more and more difficulties, and are no longer suitable for technologies below the 32nm node.

In addition, the application of new materials also brings the problem of difficult glue removal. For example, a strong oxidizing agent will cause serious denitrification of the hafnium-based high-k gate dielectric film.

The invention introduces a new normal-pressure plasma free radical cleaning spray gun. The spray gun has an alternating array of two RF electrodes and three ground electrodes. The plasma discharge of the spray gun adopts the form of dielectric barrier radio frequency discharge. The mixed gas of argon and oxygen is used as the working gas to generate a high-density free radical beam, which is sprayed onto the surface of the silicon wafer through four nozzles to achieve a clean light. Resist or other organic purposes.

【Content of invention】

A new atmospheric pressure plasma free radical cleaning spray gun includes two radio frequency electrodes, a dielectric barrier layer, three ground electrodes and a radio frequency power supply.

The atmospheric pressure plasma free radical cleaning spray gun is characterized in that the three ground electrodes are made of flat metal. The ground electrode is connected to the metal body of the spray gun and grounded.

The atmospheric pressure plasma free radical cleaning spray gun is characterized in that the two radio frequency electrodes are covered by a dielectric barrier layer, the material of the dielectric barrier layer is ceramic, and the gap between the dielectric barrier layer and the ground electrode is 1.0-1.5mm.

The atmospheric pressure plasma free radical cleaning spray gun is characterized in that two radio frequency electrodes are connected with radio frequency power supply.

The atmospheric pressure plasma free radical cleaning spray gun is characterized in that two radio frequency electrodes and three ground electrodes are arranged alternately and at intervals to form four nozzles, and each nozzle can eject high-density free radicals.

The atmospheric pressure plasma free radical cleaning spray gun is characterized in that: the working gas of the plasma discharge is an argon-oxygen mixed gas, the gas flow rate is 10-15 liters/minute, and the free radical beam flow generated by the discharge is ejected from the nozzle, The free radical beam does not contain ion components, and can clean silicon wafers without damage.

【Description of drawings】

Fig. 1 is a schematic diagram of the principle of a novel atmospheric pressure plasma free radical cleaning spray gun of the present invention.

Please refer to Fig. 1, this atmospheric pressure plasma free radical cleaning spray gun comprises two radio frequency electrodes 104, a dielectric barrier layer 103 covering the radio frequency electrodes, three ground electrodes 105, a radio frequency power supply 102, a housing 101, a gas supply source 106, a flow meter 107 and an air supply pipeline 108. Three ground electrodes are connected to the grounded case. The gas supply source 108 provides argon and oxygen. When the gas passes through the flowmeter 107, a mixed gas is formed in a certain proportion. After passing through the gas supply conduit 108, the mixed gas evenly enters the gap between the ground electrode 105 and the dielectric barrier layer 103. When the radio frequency After the electrode 104 is connected to the RF power supply 102, plasma is generated in the four gaps, and the free radicals 109 in the plasma are ejected from the nozzle under the airflow and reach the surface of the silicon wafer, etc., and the photoresist or other organic matter on the surface The reaction produces products such as oxides and water.

Fig. 2 is a structure diagram of a novel atmospheric pressure plasma free radical cleaning spray gun of the present invention.

Please refer to Fig. 2, in this atmospheric pressure plasma free radical cleaning spray gun, the working gas enters the inside of the spray gun through the air inlet 202 at the upper end, and there are four nozzles between the ground electrode 105 and the dielectric barrier layer 103 coated on the outside of the radio frequency electrode, The generated plasma radicals are ejected from the nozzle at the lower end of the spray gun under the air flow, and the RF electrode and the grounded shell 101 are isolated by an insulating block 201 .

The present invention has been described above in conjunction with specific embodiments with reference to the accompanying drawings. However, it should be noted that, for those skilled in the art, without departing from the spirit and scope of the present invention, the above-mentioned implementation can be made There are many changes and modifications, which fall within the scope of the invention defined by the claims.

Claims (5)

1. A novel atmospheric pressure plasma radical cleaning spray gun, comprising two radio frequency electrodes, a dielectric barrier, three ground electrodes and a radio frequency power supply, is characterized in that: the radio frequency electrodes and the ground electrodes are arranged in an alternate array, forming four The RF electrode is wrapped by a dielectric barrier layer, and the working gas is a mixture of argon and oxygen. Under normal pressure, when the RF electrode is connected to the RF power supply and the ground electrode is grounded, the argon is broken down between the RF electrode and the ground electrode. The mixed gas of oxygen produces glow plasma. The upper end of the spray gun is connected to the air inlet, the lower end is the nozzle, and the surrounding is sealed with a metal plate. The high-density plasma free radicals generated in the electrode area are ejected from the nozzle under the airflow . 2. The atmospheric pressure plasma free radical cleaning spray gun according to claim 1, characterized in that: the three ground electrodes are made of flat metal, and the ground electrodes are connected to the metal shell of the spray gun and grounded. 3. the atmospheric pressure plasma free radical cleaning spray gun as claimed in right 1, is characterized in that: two radio frequency electrodes are coated by dielectric barrier layer, and dielectric barrier layer material is pottery, and dielectric barrier layer and grounding electrode gap are 1.0- 1.5mm. 4. The atmospheric pressure plasma free radical cleaning spray gun as claimed in right 1, is characterized in that: two radio frequency electrodes and three grounding electrodes are arranged alternately at intervals to form four nozzles, and each nozzle can eject high density of free radicals. 5. Atmospheric pressure plasma free radical cleaning spray gun as claimed in right 1, is characterized in that: the working gas of plasma discharge is argon-oxygen mixed gas, and gas flow rate is 10-15 liters/minute, and the free radical beam current that discharge produces Sprayed from the nozzle, the free radical beam does not contain ion components, and can clean silicon wafers without damage.

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