Nikaido Marmelstein Murray & Oram LLP
In-situ cleaning of plasma treatment chamber
 A cleaning of a plasma chamber is done by a NF.sub.3 plasma treatment (typically under 1 to 1.5 Torr). The etching rate of an oxide layer can be improved by inserting, between the NF.sub.3 plasma treatments, a low pressure (lower than 10.sup.-1 Torr) plasma treatment preferably in a plasma of oxygen, water vapor, silane, fluorine, a hydrate compound, nitrogen trifluoride, or a mixture of nitrogen trifluoride with at least one of hydrogen fluoride, fluorine, water vapor and hydride compounds. 
Fujitsu Limited Fujitsu VLSI Limited
C C
C23C C09K
inventional inventional
Junya Masahiko Shoji Hideaki Hirofumi
Nakahira Doki Okuda Kikuchi Watatani