Reduction of size of byproduct particles generated from cleaning process using low-pressure plasmas for improvement of vacuum pump durability

Abstract

Dust particles are considered as an important source of device contamination in the semiconductor industry. Deposition process is followed by cleaning process, when dust particles are changed into volatile gaseous species that are exhausted from a processing chamber. Cleaning process, however, can't completely remove dust particles so that large amounts of residual particles still head downstream of the processing chamber. These byproduct particles are accumulated on internal components of a vacuum pump, which results in a decrease in vacuum pump durability. A plasma reactor placed before a vacuum pump is proposed for reducing the size of byproduct particles, thereby for increasing the vacuum pump lifetime. The sizes of byproduct particles for plasma on and off are compared using the scanning electron microscope. The influence of the plasma reactor on the byproduct gases is investigated by analyzing the spectra resulting from Fourier transform infrared spectroscopy measurements. Finally, the applicability of lowpressure plasmas to the extension of vacuum pump lifetime is discussed based on the experimental results.