A method for regenerating Bell jar in ETCH equipment for semiconductors

Abstract

The invention discloses a method for regenerating Bell jar in ETCH equipment for semiconductors, comprising soaking in nitric and hydrofluoric acid: protecting the sealing surface of the Bell jar to be regenerated with 3M tape, and removing the film with a mixture of nitric acid and hydrofluoric acid; sandblasting the inner surface of the Bell jar with a wet sandblasting machine; polishing the inner surface of the Bell jar with a nylon brush; soaking with warm water; high-pressure water cleaning the polished inner surface of the Bell jar; transporting the components to a Class 100 clean room for ultrasonic cleaning, and then rinsing with ultrapure water, and finally drying with nitrogen. Drying: The dried components are placed in a dust-free oven for heating and drying. Some processes need to be repeated multiple times. Through the regeneration method, repeated and stable utilization of the Bell jar is achieved.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor equipment parts repair and regeneration, and in particular relates to a method for regenerating a Bell jar in an ETCH device for semiconductors. Background Art

[0002] Semiconductor integrated circuit manufacturing technology continues to develop rapidly, and its process is accelerating towards miniaturization, high density and high integration. The ETCH process in semiconductor manufacturing equipment is an indispensable part of the chip manufacturing process. During the production process of the dry etching machine, a layer of polymers, organic attachments, etc. are gradually deposited on its surface. These pollutants will fall off during operation, or their presence will cause insufficient subsequent adhesion, forming particles in the cavity, causing defects. Therefore, the surface state and cleanliness of semiconductor parts become very important.

[0003] The Bell jar made of quartz has extremely low thermal expansion coefficient, high temperature resistance, excellent chemical stability, excellent electrical insulation, low and stable ultrasonic delay performance, the best ultraviolet spectrum performance, visible light and near infrared spectrum performance, and has higher mechanical properties than ordinary glass. It has high dielectric strength and extremely low conductivity, that is, it can still maintain high dielectric strength and resistance under high temperature, high pressure and high frequency, and there is almost no dielectric loss in the applied frequency band. Therefore, quartz is an excellent high-temperature dielectric insulation material. As a large-scale equipment component used in the semiconductor industry, the procurement cost of quartz components is high, which makes it impossible to replace them frequently. They need to be regenerated through cleaning and reused.

[0004] At present, the film is removed by soaking in nitric and hydrofluoric acid and dry spraying, and then regenerated by high-pressure water and ultrasound. This process can meet the basic needs of 8-inch process or low-end process, but there is a most critical particle problem that often occurs, which directly affects the stability of the machine, greatly shortens the service life of the machine, and increases the cost of PM (machine maintenance). Summary of the invention

[0005] In order to solve the shortcomings of the prior art, the present invention provides a method for regenerating Bell jars in semiconductor ETCH equipment, which includes six regeneration processes: mixed acid cleaning, wet sandblasting, nylon brush grinding, high-pressure water washing, ultrasonic cleaning and drying. Some of the processes need to be repeated multiple times. Through the regeneration method, repeated and stable utilization of Bell jars can be achieved.

[0006] In order to achieve the above object, the present invention is implemented by the following technical solution: a method for regenerating Bell jar in ETCH equipment for semiconductor, the specific steps are as follows:

[0007] Step 1: First nitric and hydrofluoric acid soaking;

[0008] Protect the sealing surface of the Bell jar component to be regenerated with 3M tape, then place the Bell jar component on a fixed platform with the inner surface facing up and the outer surface facing down, then pour a mixture of 18% hydrofluoric acid and 23% nitric acid into the Bell jar component and soak it for 20-30 minutes;

[0009] Step 2: wet sandblasting;

[0010] The Bell jar parts were sandblasted using a wet sandblaster and white corundum;

[0011] Step 3: First polishing;

[0012] Use a nylon brush to clean the inner surface of the Bell jar component, and avoid the nylon brush body plastic touching the inner wall of the component;

[0013] Step 4: First high pressure water washing;

[0014] Step 5: Second nitric and hydrofluoric acid soaking;

[0015] First, make sure the tape on the sealing surface of the Bell jar component is still intact, then place the entire component in a mixture of 18% hydrofluoric acid and 23% nitric acid for 1-2 minutes;

[0016] Step 6: Second polishing;

[0017] Use a nylon brush to clean the inner surface of the Bell jar component, and avoid the nylon brush body plastic touching the inner wall of the component;

[0018] Step 7: Second high pressure water washing;

[0019] Step 8: Soak in warm water;

[0020] Step 9: Third polishing;

[0021] Use a nylon brush to clean the inner surface of the Bell jar component, and avoid the nylon brush body plastic touching the inner wall of the component;

[0022] Step 10: High pressure water washing for the third time;

[0023] Step 11: First drying;

[0024] Step 12: Ultrasonic cleaning;

[0025] The Bell jar parts were transported to a Class 100 clean room for ultrasonic cleaning, then rinsed with ultrapure water for 1 min, and finally dried with nitrogen;

[0026] Step 13: Second drying;

[0027] The blow-dried parts are placed in a dust-free oven for heating and drying. The oven temperature is set to 140-160°C and the constant temperature time is set to 100-140 minutes. After the program is completed, the oven is opened below 40°C for dust-free packaging.

[0028] Furthermore, in step 2, the wet sandblasting pressure is set at 2-3 kg / cm 2 , the sand material model is 60 mesh, the distance between the component and the sandblasting gun is between 10-20cm, and the angle between the component and the sandblasting gun is between 45-90°. This process is to adjust the surface abnormalities caused by acid etching, and wet sandblasting can reduce the impact force on quartz and reduce the loss of components.

[0029] Furthermore, in step 3, step 6 and step 9, the inner surface of the Bell jar component is polished and scrubbed with a nylon brush for 1-3 minutes.

[0030] Furthermore, the high pressure water washing of step 4, step 7 and step 10 is specifically as follows: the interior of the Bell jar component is rinsed with a high pressure water gun for 1-2 minutes at a pressure of 100 psi.

[0031] Furthermore, step eight of warm water soaking is specifically as follows: soak in 90±5°C warm water for 50-70 minutes to remove residual acid on the surface of the component.

[0032] Furthermore, the first drying in step eleven is specifically as follows: use an air gun to blow dry the moisture on the surface of the component.

[0033] Furthermore, step twelve, ultrasonic cleaning is specifically as follows: the Bell jar parts are transported to a Class 100 clean room for ultrasonic cleaning, the ultrasonic frequency is 40 to 80 KHz, the ultrasonic cleaning time is 25 to 35 minutes, and then rinsed with ultrapure water for 1 to 2 minutes, and finally blown dry with nitrogen.

[0034] The beneficial effects of the present invention are as follows:

[0035] In the method for regenerating the Bell jar in the semiconductor ETCH equipment provided by the present invention, the deposited film is removed by a combination of chemical and physical methods.

[0036] 1. Reduce component costs: reduce component consumption, increase the number of reuses, and reduce component procurement costs;

[0037] 2. Stable quality: Excellent technology ensures the cleanliness of components and solves the most important particle abnormality problem;

[0038] 3. Reduced maintenance costs: Reduced the number of PMs for the machine, saving a lot of manpower and material resources;

[0039] 4. Increased production capacity: Excellent quality ensures the normal operation of the machine and greatly increases production capacity.

[0040] In addition, compared with the existing cleaning process, the new regeneration treatment method has the following two advantages:

[0041] 1. Rigorous cleaning process ensures the stable quality of components

[0042] 2. The life time of the components on the machine can meet the standard usage requirements, solving the abnormal PM caused by particle problems. DETAILED DESCRIPTION

[0043] The implementation of the present invention is described in detail below in combination with the process and embodiments of the present invention. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0044] The raw materials and equipment used in the present invention can be obtained from the market. The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturers.

[0045] The examples are as follows:

[0046] The Bell jar regeneration method for integrated circuit manufacturing in this embodiment includes the following steps:

[0047] 1. First nitric and fluoric acid soaking:

[0048] Protect the sealing surface of the Bell jar component to be regenerated with 3M tape, then place the Bell jar component with the inner surface facing up and the outer surface facing down on a fixed platform, then pour a mixture of 18% hydrofluoric acid and 23% nitric acid into the Bell jar component and soak it for 20-30 minutes.

[0049] 2. Wet sandblasting:

[0050] Use wet sandblasting machine and white corundum to blast the parts. The pressure is set at 2-3kg / cm 2 ,The sand material model is 60 mesh, the distance between the component and the sandblasting gun is between 10-20cm, and the angle between the component and the sandblasting gun is between 45-90°.

[0051] 3. First polishing:

[0052] Use a nylon brush to scrub the entire inner surface of the Bell jar for 2 minutes, and avoid the nylon brush body plastic touching the inner wall of the component.

[0053] 4. The first high pressure water washing:

[0054] Use a high-pressure water gun to rinse the inside of the component for 1 minute at a pressure of 100 psi.

[0055] 5. Second nitric and fluoric acid soaking:

[0056] First, make sure that the tape on the sealing surface of the Bell jar component is still intact, then place the entire component in a mixture of 18% hydrofluoric acid and 23% nitric acid and soak for 1-2 minutes.

[0057] 6. Second polishing:

[0058] Use a nylon brush to scrub the entire inner surface of the Bell jar for 2 minutes, and avoid the nylon brush body plastic touching the inner wall of the component.

[0059] 7. Second high pressure water washing:

[0060] Use a high-pressure water gun to rinse the inside of the component for 1 minute at a pressure of 100 psi.

[0061] 8. Soak in warm water

[0062] Soak in warm water at 90±5℃ for 60 minutes to remove residual acid on the surface of the parts.

[0063] 9. The third polishing:

[0064] Use a nylon brush to scrub the inner surface of the Bell jar for 2 minutes, and avoid the nylon brush body plastic touching the inner wall of the component;

[0065] 10. The third high pressure water washing:

[0066] Use a high-pressure water gun to rinse the inside of the component for 1 minute at a pressure of 100 psi.

[0067] 11. First drying:

[0068] Use an air gun to blow dry the moisture on the surface of the parts.

[0069] 12. Ultrasonic cleaning:

[0070] The Bell jar parts were moved to a Class 100 clean room for ultrasonic cleaning at a frequency of 40 to 80 KHz for 30 min, followed by rinsing with ultrapure water for 1 min and finally drying with nitrogen.

[0071] 13. Second drying:

[0072] The blow-dried parts are placed in a dust-free oven for heating and drying. The oven temperature is set to 150°C and the constant temperature time is set to 120 minutes. After the program is completed, the oven is opened at below 40°C for dust-free packaging.

[0073] The surface conditions of the Bell jars before and after cleaning were compared. According to the tests of the roughness meter and the particle counter, the cleaned parts can fully meet the use requirements of the parts.

[0074] The upper and lower limit embodiments of the present invention have been specifically described above, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A method for regenerating a Bell jar in an ETCH device for semiconductors, characterized in that: The Bell jar in the ETCH device is made of quartz; the specific steps are as follows: Step 1: First nitric and hydrofluoric acid soaking; Protect the sealing surface of the Bell jar component to be regenerated with tape, then place the Bell jar component on a fixed platform with the inner surface facing up and the outer surface facing down, then pour a mixture of 18% hydrofluoric acid and 23% nitric acid into the Bell jar component and soak it for 20-30 minutes; Step 2: wet sandblasting; Bell jar parts are sandblasted using a wet sandblasting machine and white corundum; the wet sandblasting pressure is set at 2-3kg / cm 2 , the sand material model is 60 mesh, the distance between the component and the sandblasting gun is between 10-20cm, and the angle between the component and the sandblasting gun is between 45-90°; Step 3: First polishing; Use a nylon brush to scrub the inner surface of the Bell jar component as a whole, and avoid the nylon brush body plastic touching the inner wall of the component; Use a nylon brush to scrub the inner surface of the Bell jar component as a whole for 1-3 minutes; Step 4: First high pressure water washing; Step 5: Second nitric and hydrofluoric acid soaking; First, make sure the tape on the sealing surface of the Bell jar component is still intact, then place the entire component in a mixture of 18% hydrofluoric acid and 23% nitric acid for 1-2 minutes; Step 6: Second polishing; Use a nylon brush to scrub the inner surface of the Bell jar component as a whole, and avoid the nylon brush body plastic touching the inner wall of the component; Use a nylon brush to scrub the inner surface of the Bell jar component as a whole for 1-3 minutes; Step 7: Second high pressure water washing; Step 8: Soak in warm water; Step 9: Third polishing; Use a nylon brush to scrub the inner surface of the Bell jar component as a whole, and avoid the nylon brush body plastic touching the inner wall of the component; Use a nylon brush to scrub the inner surface of the Bell jar component as a whole for 1-3 minutes; Step 10: High pressure water washing for the third time; Step 11: First drying; Step 12: Ultrasonic cleaning; The Bell jar parts were transported to a Class 100 clean room for ultrasonic cleaning, then rinsed with ultrapure water for 1 min, and finally dried with nitrogen; Step 13: Second drying; The blow-dried parts are placed in a dust-free oven for heating and drying. The oven temperature is set to 140-160°C and the constant temperature time is set to 100-140 minutes. After the program is completed, the oven is opened below 40°C for dust-free packaging.

2. The method for regenerating a Bell jar in an ETCH device for semiconductor use according to claim 1, characterized in that: The high pressure water washing of step 4, step 7 and step 10 is specifically as follows: Use a high pressure water gun to rinse the inside of the Bell jar parts for 1-2 minutes at a pressure of 100 psi.

3. The method for regenerating a Bell jar in an ETCH device for semiconductor according to claim 1, characterized in that: Step 8: Soak in warm water for 50-70 minutes to remove residual acid on the surface of the parts.

4. The method for regenerating a Bell jar in an ETCH device for semiconductor use according to claim 1, characterized in that: Step 11: The first drying is as follows: Use an air gun to blow dry the moisture on the surface of the parts.

5. The method for regenerating a Bell jar in an ETCH device for semiconductor use according to claim 1, characterized in that: Step 12: Ultrasonic cleaning is as follows: the Bell jar parts are moved to a Class 100 clean room for ultrasonic cleaning at an ultrasonic frequency of 40 to 80 kHz for 25 to 35 minutes, then rinsed with ultrapure water for 1 to 2 minutes, and finally dried with nitrogen.