Optical emission Spectral analysis of pulse modulated plasma

摘要

Microelectronics manufacturing standards are increasingly demanding, plasma etching process is facing 22nm or even smaller size of the node, which requires higher requirements on plasma processing technology. Pulse modulated plasma has been used since it has more advantages than traditional RF plasma. Pulse modulation plasma is difficult to measure due to the high frequency and the single pulse period is short, and optical emission spectroscopy (OES) is non-immersion test analysis means, in the plasma physics, atomic and molecular physics research has a wide range of applications. For non-constant states of the plasma, the emission spectrum also changes with time, and some of them change rapidly, such as pulse-modulated plasma, the current main photodetector ICCD camera and photoelectric multiplier tube (PMT) cannot meet the requirements, it is difficult to carry out effective measurement. In order to understand the complex physical and chemical processes in the plasma, a spectral analysis system based on PMT array was constructed based on the advantages of ICCD camera and photomultiplier tube. This paper mainly introduces the principle of spectrum analysis system based on PMT array, and uses this system to measure and analyze pulse modulation plasma.