In semiconductor factories, the pressure range of nitrogen is not a fixed value, but is dynamically adjusted according to specific process requirements and equipment configuration. The following is a detailed analysis of the nitrogen pressure range of the semiconductor factory:
general range of 1. nitrogen pressure
conventional process links:
- in most semiconductor manufacturing processes, such as lithography, etching, deposition, etc., the inlet pressure of nitrogen is usually maintained 0.62 to 0.76MPa (I. e. 6.2 to 7.6kg/cm²) between. This range can meet the nitrogen pressure requirements of most processes, ensuring process stability and product quality.
- There is also a view that the pressure range of nitrogen in a semiconductor plant can be 0.05 to 0.8MPa to adapt to the needs of different process links.
Specific process links:
- in some process links with more stringent pressure requirements, such as wafer nitrogen baking, nitrogen pressure needs to be precisely controlled. For example, it is pointed out that during the wafer nitrogen baking process, the nitrogen pressure should be adjusted 0.03 to 0.05MPa to avoid excessive pressure leading to danger.
- In the chemical vapor etching chamber, the nitrogen pressure can be stabilized 1500 to 2500 mTorr (1.5 to 2.5Torr, about 0.2 to 0.33MPa) to ensure the accuracy and consistency of the etching process.
Influencing factors of 2. nitrogen pressure
nitrogen purity:
- high-purity nitrogen (e. g., 99.999 percent or more) is critical in semiconductor manufacturing to protect materials from oxidation or other unwanted chemical contamination during processing. However, the supply of high purity nitrogen may require a higher pressure to ensure a stable supply.
Pipeline transportation:
- the flow of nitrogen in the pipeline will cause pressure loss, and the amount of loss depends on the pipe diameter, length, number of elbows and flow rate. Therefore, when designing the nitrogen supply system, it is necessary to fully consider the pipeline layout and parameters to ensure that the nitrogen pressure can meet the process requirements.
Process requirements:
- different process links have different requirements for nitrogen pressure. For example, the photolithography process requires extremely high nitrogen purity and pressure stability to ensure the stability of the photoresist and the fidelity of the pattern, while the etching process may require higher nitrogen pressure to ensure the accuracy and consistency of the etching process.
Control and Regulation of 3. Nitrogen Pressure
pressure reducing valve and booster:
- in a semiconductor factory, a pressure reducing valve and a booster are usually used to adjust the pressure of nitrogen gas. The pressure reducing valve is used to reduce the nitrogen pressure to meet the needs of the low-pressure process, while the booster is used to increase the nitrogen pressure to meet the needs of the high-pressure process.
Purging and Purging:
- in the process of daily maintenance and process conversion of semiconductor manufacturing equipment, nitrogen purging can remove residues and impurities inside the equipment to ensure process stability and product quality. At the same time, the nitrogen purge also helps to maintain a stable pressure inside the apparatus.
Safety and stability of 4. nitrogen pressure
pressure stability:
- the stability of nitrogen pressure is critical to the semiconductor manufacturing process. Too high or too low nitrogen pressure may have adverse effects on the process, such as changes in photoresist properties, non-uniform etching, etc. Therefore, in a semiconductor factory, a series of measures need to be taken to ensure the stability of the nitrogen pressure.
Safety measures:
- in the semiconductor factory, the nitrogen supply system needs to be equipped with complete safety measures, such as pressure sensors, safety valves, etc., to ensure that timely measures can be taken when the nitrogen pressure is abnormal to avoid safety accidents.
