AVS 47th International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP2
Effect of Wafer Temperature on High Aspect Ratio Hardmask Etching

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: S. Lee, Winbond Electronics Corporation, Taiwan
Authors: S. Lee, Winbond Electronics Corporation, Taiwan
Y.C. Tien, Winbond Electronics Corporation, Taiwan
Y.D. Chang, Winbond Electronics Corporation, Taiwan
Correspondent: Click to Email
Fluorocarbon-based chemistries were used to study the effect of wafer temperature on the etch of high aspect ratio hardmask composed of BSG and Si@sub 3@N@sub 4@ layers. It is found that etch stop can occur easily at high temperature. The rate of polymer deposition plays an important role in etch stop. The etching rates were found to be inversely proportional to the wafer temperature. Such a relation indicates a negative activation energy in hardmask etching using fluorocarbon plasma. It also implies that in hardmask etching, complicated gas-surface reactions, but not simple one-step reaction, are involved. Different wafer surface temperature can provide different degree of activation for etching reactions. It is also observed that etching rates are very sensitive to the chamber condition, as indicated by optical emission spectroscopy. Analysis of etching rate and emission intensity trends indicates that CF@sub x@ may contribute more than F does in the etch of BSG and Si@sub 3@N@sub 4@, since polymer-rich etching chemistries were used. Reaction models are proposed to interpret the observed trends.