IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Manufacturing Science and Technology Tuesday Sessions
       Session MS-TuA

Paper MS-TuA4
Integrated RF Sensor for Accurate Control and Monitoring of on Wafer Process Performance

Tuesday, October 30, 2001, 3:00 pm, Room 131

Session: In Line and In Situ Process Control
Presenter: A.M. Paterson, Applied Materials
Authors: A.M. Paterson, Applied Materials
J.M. McChesney, Applied Materials
V. Todorov, Applied Materials
J. Holland, Applied Materials
M.S. Barnes, Applied Materials
Correspondent: Click to Email
As the semiconductor industry moves to 300mm wafer size, it has become essential to have accurate and reliable knowledge of the RF and DC parameters experienced by the wafer being processed. Use of a RF sensor integrated on to the tool will provide accurate information useful for process optimization and repeatability analysis, however, correct placement of the sensor in the RF circuit is essential. Placement of the sensor directly in the wafer pedestal can make the design complicated, more expensive, and less accessible. This paper describes a more reliable method for obtaining the absolute RF and DC parameters on the wafer. This method utilizes accurate knowledge of the complete cathode impedance and an accurate circuit model describing the observed impedance. Accurate knowledge of the cathode impedance allows the RF sensor to be remotely placed, in our case in the RF match box, so that complicated cathodes designs can be avoided. Extensive work has shown that knowing the RF parameters at the output of the match, and the impedance of the cathode, that the RF and DC parameters calculated at the wafer are in excellent agreement with those values actually measured on the wafer. This method then allows for accurate chamber matching, endpoint and process control. Voltage compensation of the electrostatic chuck voltage in order to offset the effects of DC bias is also determined from this integrated probe. Other features of the RF sensor will also be discussed.