AVS 51st International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS-WeA

Paper PS-WeA2
Influence of Frequency on the Characteristics of UHF Capacitively Coupled Plasmas in a 300 mm Chamber

Wednesday, November 17, 2004, 2:20 pm, Room 213A

Session: Plasma Diagnostics
Presenter: G.A. Hebner, Sandia National Laboratories
Authors: G.A. Hebner, Sandia National Laboratories
E.V. Barnat, Sandia National Laboratories
P.A. Miller, Sandia National Laboratories
A.M. Paterson, Applied Materials, Inc.
J.P. Holland, Applied Materials, Inc.
T. Lill, Applied Materials, Inc.
Correspondent: Click to Email
We have investigated the characteristics of UHF capacitively coupled plasmas produced in a modified Applied Materials chamber. The chamber had a 14-inch diameter upper electrode (source) that was driven at 10 to 160 MHz and a 300 mm diameter electrostatic chuck with a ceramic process kit that was driven at 13.56 MHz (bias). Diagnostics employed include a microwave interferometer to measure the line-integrated electron density, a hairpin microwave resonator to measure the spatially resolved electron density, absorption spectroscopy to determine the argon metastable temperature and density, laser induced fluorescence (LIF) to determine the spatial distribution of the excited species, and spatially resolved optical emission. We found that for constant source rf power, the electron density increased with rf frequency. The argon 1s5 metastable temperature was slightly above room temperature (300 â?" 400K), significantly cooler than our previous measurements in inductively coupled plasmas. The metastable density was not a strong function of source frequency or rf power. The metastable spatial distribution was always peaked in the center of the chamber and had a weak dependence on frequency. Scaling of the plasma parameters with frequency, power and pressure, and implications to energy deposition models will be discussed. This work was supported by Applied Materials and Sandia National Laboratories, a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company for the United States Department of Energyâ?Ts National Nuclear Security Administration under contract DE-AC04-94AL85000.