Post by lay1014 on Apr 21, 2020 2:37:07 GMT -5
High vacuum system with throttling
The pressure range of sputtering and other plasma processes is higher than that of all kinds of high vacuum pumps. Adding a throttle valve between the pump and the vacuum chamber can use these pumps in the range of 0.5 to 10 PA. This kind of throttle valve with small flow guide allows the gas from the high pressure and strong vacuum chamber to flow into the pump, while keeping the pressure of the air inlet of the pump below the maximum pressure or critical air inlet pressure of the pump. The diameter and height of the typical sputtering chamber with cathode diameter of 150-200mm are 5oomm and 250mm respectively.
The traditional pumping unit is equipped with a 6-in diffusion pump, but there are also low-temperature pumps or turbo molecular pumps that are equivalent to them. The maximum discharge capacity of such a pump is 100-200pa ยท L / s. The pump is bigger, and although it's more expensive, the gas removal rate is faster.
The problem of residual gas in sputtering system is much larger than that in high vacuum evaporation system. On the one hand, the plasma desorption of impurities on the wall is increased, on the other hand, the deposition rate of sputtering is much lower than that of typical evaporation rate. Even if the production rates of the two processes are in the same order of magnitude, the chance of the sputtered films exposed to residual gas impurities is more than that of the films condensed from the evaporation source. Electron ion collision desorption is an effective way to release gas from the wall of vacuum chamber. It is even more effective than light baking. In a plasma, the desorption gases appear as atoms, so that they can easily react with the sputtered film.
Dry Type Oilless Vacuum Pumps
Liquid Ring Vacuum compressor
industrial vacuum pumps,vacuum furnaces
The pressure range of sputtering and other plasma processes is higher than that of all kinds of high vacuum pumps. Adding a throttle valve between the pump and the vacuum chamber can use these pumps in the range of 0.5 to 10 PA. This kind of throttle valve with small flow guide allows the gas from the high pressure and strong vacuum chamber to flow into the pump, while keeping the pressure of the air inlet of the pump below the maximum pressure or critical air inlet pressure of the pump. The diameter and height of the typical sputtering chamber with cathode diameter of 150-200mm are 5oomm and 250mm respectively.
The traditional pumping unit is equipped with a 6-in diffusion pump, but there are also low-temperature pumps or turbo molecular pumps that are equivalent to them. The maximum discharge capacity of such a pump is 100-200pa ยท L / s. The pump is bigger, and although it's more expensive, the gas removal rate is faster.
The problem of residual gas in sputtering system is much larger than that in high vacuum evaporation system. On the one hand, the plasma desorption of impurities on the wall is increased, on the other hand, the deposition rate of sputtering is much lower than that of typical evaporation rate. Even if the production rates of the two processes are in the same order of magnitude, the chance of the sputtered films exposed to residual gas impurities is more than that of the films condensed from the evaporation source. Electron ion collision desorption is an effective way to release gas from the wall of vacuum chamber. It is even more effective than light baking. In a plasma, the desorption gases appear as atoms, so that they can easily react with the sputtered film.
Dry Type Oilless Vacuum Pumps
Liquid Ring Vacuum compressor
industrial vacuum pumps,vacuum furnaces
