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

Paper PS+TF-WeP8
Effect of NO Radical Produced by Additives to PFC on Global Warming during PECVD Chamber Cleaning Using a Remote ICP Source

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

Session: Plasma Etching & Deposition
Presenter: J.H. Kim, Sungkyunkwan University, Korea
Authors: J.H. Kim, Sungkyunkwan University, Korea
C.H. Oh, Sungkyunkwan University, Korea
S.S. Yoon, Jusung Engineering Co., Ltd., Korea
N.-E. Lee, Sungkyunkwan University, Korea
G.Y. Yeom, Sungkyunkwan University, Korea
Correspondent: Click to Email
N@sub 2@, N@sub 2@O, and NO were added as additive gases producing NO radical to C@sub 4@F@sub 8@/O@sub 2@ during PECVD(plasma enhanced chemical vapor deposition) silicon nitride chamber cleaning and the effects of these additive gases to the PECVD silicon nitride cleaning have been investigated. For plasma cleaning, a remote ICP(inductively coupled plasma) source was used and cleaning rate, DRE(destruction efficiency), and MMTCE(million metric tons of carbon equivalent) were investigated as a function of gas mixture ratio, working pressure, rf source power, and flow rate. Using this ICP source, high DRE more than 95% could be obtained for all of the investigated conditions due to the high dissociation of the feed gases. Adding N-based additive gases and O@sub 2@ to C@sub 4@F@sub 8@ not only significantly increased the cleaning rate by the surface reaction of NO radical generated by these additive gases but also decreased the MMTCE by decreasing the emitted CF@sub 4@ concentration which has the highest concentration among the emitted PFCs (perfluorocompounds) in addition to the high global warming potential. C@sub x@F@sub y@ is believed to decrease through the reaction between nitrogen from the additive gases and fluorine or carbon in C@sub x@F@sub y@ from the dissociated PFCs. In this experiment, remaining feed gas and emission species such as CF@sub 4@, C@sub 3@F@sub 8@, C@sub 2@F@sub 6@, COF@sub 2@, etc. were detected at the exhaust line during silicon nitride cleaning by FT-IR(fourier transform - infrared spectrometer). Also, F and NO radicals were observed by OES(optical emission spectroscopy) and QMS(quadrupole mass spectrometer) at the chamber.