감압대기 및 불활성가스 분위기에서 적합한 정전기 제거장치의 개발

Abstract

In LCD Display or semiconductor manufacturing processes, the anti-static technology of glass substrates and wafers becomes one of the most difficult issues which influence the yield of the semiconductor manufacturing. In order to overcome the problems of wafer surface contamination various issues such as ionization in decompressed vacuum and inactive gas(i.e. <TEX>$N_2$</TEX> gas, Ar gas, etc.) environment should be considered. Soft X ray radiation is adequate in air and <TEX>$O_2$</TEX> gas at atmospheric pressure while UV radiation is effective in <TEX>$N_2$</TEX> gas Ar gas and at reduced pressure. At this point of view, the "vacuum ultraviolet ray ionization" is one of the most suitable methods for static elimination. The vacuum ultraviolet can be categorized according to a short wavelength whose value is from 100nm to 200nm. this is also called as an Extreme Ultraviolet. Most of these vacuum ultraviolet is absorbed in various substances including the air in the atmosphere. It is absorbed substances become to transit or expose the electrons, then the ionization is initially activated. In this study, static eliminator based on the vacuum ultraviolet ray under the above mentioned environment was tested and the results show how the ionization performance based on vacuum ultraviolet ray can be optimized. These vacuum ultraviolet ray performs better in extreme atmosphere than an ordinary atmospheric environment. Neutralization capability, therefore, shows its maximum value at <TEX>$10^{-1}{\sim}10^{-3}$</TEX> Torr pressure level, and than starts degrading as pressure is gradually reduced. Neutralization capability at this peak point is higher than that at reduced pressure about <TEX>$10^4$</TEX> times on the atmospheric pressure and by about <TEX>$10^3$</TEX> times on the inactive gas. The introductions of these technology make it possible to perfectly overcome problems caused by static electricity and to manufacture ULSI devices and LCD with high reliability.