AVS 49th International Symposium
    Plasma Science Wednesday Sessions
       Session PS+TF-WeP

Paper PS+TF-WeP28
Reduction of Particle-contamination in Plasma Etching Equipment by Dehydration of Chamber Wall

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Plasma Etching & Deposition
Presenter: N. Ito, NEC Corp., Japan
Authors: N. Ito, NEC Corp., Japan
F. Uesugi, NEC Corp., Japan
T. Moriya, NEC Corp., Japan
M. Matsumoto, Lam Research Co., Ltd., Japan
S. Liu, Lam Research Corporation
Y. Kitayama, Lam Research Co., Ltd., Japan
Correspondent: Click to Email
For reduction of particles sticking on the wafers in the poly-gate (WSi/poly-Si) etching by real transfer couple d plasma (TCP) equipment, we have investigated the behavior and the outbreak of particles above the wafers by using lase r light scattering method. Numbers of particles on the wafers were also investigated by wafer-level inspection machines. Most particles were observed at rf power turned-off in case of the process gas containing fluoride. The main compositio n of particles were Al and F. And upside of the process chamber wall coated with Al@sub 2@O@sub 3@ was corroded. Therefo re it was inferred that these particles were generated by a reaction of the fluoride gas and Al@sub 2@O@sub 3@ surface. Moreover, numbers of particles above and on wafers were drastically increased after the wet cleaning of the chamber wall . It showed that the reaction of generating particles was activated by moisture. From the knowledge, dehydration process inserted after wet cleaning of a process chamber achieved the particle-contamination reduction. In the conventional mai ntenance, it took 30 hours to reduce the number of particles until acceptable quantity after wet cleaning. However it wa s shorten to 2 hours by inserting dehydration process.