AVS 54th International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS2-ThM

Paper PS2-ThM5
Application of an RF Biased Langmuir Probe to Etch Reactor Chamber Matching, Fault Detection and Process Control

Thursday, October 18, 2007, 9:20 am, Room 607

Session: Plasma Diagnostics I
Presenter: D.L. Keil, Lam Research Corporation
Authors: D.L. Keil, Lam Research Corporation
J.-P. Booth, Lam Research Corporation
N. Benjamin, Lam Research Corporation
C. Thorgrimsson, Lam Research Corporation
M. Brooks, San Jose State University / Lam Research Co.
G. Curley, Ecole Polytechnique / Lam Research Co.
L. Albarede, Lam Research Corporation
D. Cooperberg, Lam Research Corporation
Correspondent: Click to Email

As feature size shrinks below 45 nm the demand for precision plasma etch process monitoring has increased. The final etched profile is determined by physical processes occurring at the wafer-plasma interface which are typically driven by neutral flux, ion flux and ion energy. However, typically only the RF delivery, gas flow, and chamber temperature are monitored. These measurements are too far removed from the actual physical processes of interest to be of value in tool matching, fault detection and advanced process control. This work examines the usefulness of an RF -biased planar Langmuir probe approach.1 This method delivers precise real-time (10 Hz) measurements of the ion flux and tail weighted electron temperature and is insensitive to contamination and deposition on the probe. Data was taken during wafer processing, and indicates the utility of this approach for tool matching, process diagnosis, tool fault detection and advanced process control.

1 J.P. Booth, N. St. J. Braithwaite, A. Goodyear, and P. Barroy, Rev. Sci. Inst., Vol. 71, No 7, July 2000, pgs. 2722-2727.