AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS2-WeA

Paper PS2-WeA3
Profile Simulation of Poly-Silicon Gate Features Etched with Cl2/HBr/O2 Plasmas

Wednesday, October 4, 2000, 2:40 pm, Room 311

Session: Feature Evolution
Presenter: L.B. Braly, Lam Research Corp.
Authors: L.B. Braly, Lam Research Corp.
D. Cooperberg, Lam Research Corp.
V. Vahedi, Lam Research Corp.
Correspondent: Click to Email
The stringent requirements for line-width control during etching of sub 0.18-micron features for polysilicon gate applications demand a better fundamental understanding of the basic mechanisms that lead to line-width variation. Several groups have proposed various mechanisms for sidewall deposition on etched profiles, as well as mechanisms for etching Si with Cl2/HBr/O2. We are using our feature profile simulator (along with diagnostics) to test various mechanisms. Measurements of ion flux and polysilicon etch rates under various conditions are used to determine polysilicon etch yields for Cl2 and HBr. The sidewall deposition model includes direct (line of site) and redepostion of etch products on the feature sidewalls. The validity of these mechanisms is tested by comparing predicted etched features against real etched features. The simulator is also calibrated using data from profile wafers and over-hang wafers. We will show comparisons between predicted profiles and etched profiles under conditions where line-width growth (CD gain) and line-width loss (CD loss) are observed.