Gas etching

Abstract

Abstract PURPOSE:To eliminate the deposition of sulfur and to shorten a predetermined time by employing etching gas made of SF6 gas and O2 gas and having specific range of molar ratio to remove a generated solid contaminating substance by a gas etching method when a glow discharge is produced to form an amorphous semiconductor film. CONSTITUTION:A silicon contaminating substance is etched by SF6 gas, gasified as SiF4 gas, solid sulfur is reacted with O2 gas, and gasified as SO2 gas. This etching gas is preferably set at the ratio of the SF6 gas to the O2 gas to a range of 6:4 to 9:1 of molar ratio and more preferably 7:3 to 9:1. If this ratio is out of 6:4, its etching velocity is decelerated, a large quantity of the O2 gas is introduced into an exhaust gas processor for processing decomposed remaining gas (SiH4 gas and the like) of the glow discharge, and there is danger of explosion. If the ratio is not 9:1, the gas etching of the sulfur becomes insufficient.

Inventors

• 👤 Akinori Iwasaki
• 👤 Daigoro Okubo
• 👤 Hisashi Higuchi

Bibliographic Details