High-purity NF3 intake control device and method of ultra-high vacuum system

Abstract

The invention discloses a high-purity NF3 air inlet control device and method of an ultrahigh vacuum system. The device comprises a primary pressure reducing valve, a secondary pressure reducing valve, a ball valve, an adjustable trace air inlet valve, a tee joint, a turbo molecular pump angle valve, a quadrupole mass spectrometer, a vacuum gauge, an ultrahigh vacuum activation chamber, a titaniumsublimation pump, a sputtering ion pump, a turbo molecular pump and a mechanical pump. The method comprises the following steps: firstly, closing the trace air inlet valve, and opening the first-stage pressure reducing valve, the second-stage pressure reducing valve and the ball valve, so that the pipeline is filled with NF3 gas; then closing the ball valve, opening an angle valve of the turbo molecular pump, and extracting residual gas in the gas inlet pipeline; then closing the angle valve, opening the ball valve, and flushing the air inlet pipeline with NF3; and finally, controlling the NF3 gas entering the ultrahigh vacuum system through an adjustable trace gas inlet valve, and respectively detecting the partial pressure of the NF3 and the vacuum degree of the system by using a quadrupole mass spectrometer and a vacuum gauge. Residual air in the air inlet pipeline can be removed, and the air inflow of NF3 can be slightly and accurately controlled.

Description

technical field [0001] The invention belongs to the field of vacuum science and technology, in particular to a high-purity NF3 intake control device and method for an ultra-high vacuum system. Background technique [0002] In the process of developing a negative electron affinity photocathode, the system vacuum degree is very high, usually requiring a vacuum degree of 10 -8 Pa or higher order of magnitude. In the process of activating III-V semiconductor materials to obtain negative electron affinity photocathode, it is necessary to fill the ultra-high vacuum system with NF 3 or O 2 Gas, and there will be residual air in the intake pipe during installation, so in order to ensure that it is filled with NF 3 or O 2 To ensure the purity of the gas, it is necessary to remove the residual air in the intake pipe. In the photocathode activation process, in addition to the high requirements on the vacuum degree, there are also requirements on the deposition amount of the active...

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Problems solved by technology

[0003] At present, foreign research on photocathode activation only briefly mentions the use of trace intake valves to control NF. 3 or O 2 The air intake, but about the connection of the intake line and the high-purity NF 3 There is no in-depth research on the precise control of the trace amount of gas, and the domestic use of NF 3 There is almost no research on gas-activated photocathode, so how to achieve a vacuum degree of less than 10 -7 High-purity NF in ultra-high vacuum system of Pa 3 The micro-control of the gas to meet the activation requirements of the photocathode needs to be solved urgently

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