| AVS 55th International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS1-ThA |
| Session: | Plasma Diagnostics, Sensors, and Control II |
| Presenter: | B. Jacobs, University of California - Los Angeles |
| Authors: | B. Jacobs, University of California - Los Angeles W. Gekelman, University of California - Los Angeles M. Barnes, Intevac Corporation P. Pribyl, University of California - Los Angeles |
| Correspondent: | Click to Email |
Plasma reactors used in semiconductor processing require precise control over both ion bombardment energy and ion flux to the substrate surface; furthermore these parameters must be uniform over the entire substrate. We report on Laser-Induced Fluorescence (LIF) measurements of the vertical and radial argon ion velocity distributions in a vertical plane above the wafer in an Inductively Coupled Plasma (ICP) Plasma Reactor with a 700 kHz ICP source and a 2 MHz capacitively coupled bias to a 300 mm silicon wafer substrate. The ICP source is capable of pulsed operation with periods of 1 - 100 ms and variable duty cycles. The LIF diagnostic measures ion velocities at over 30,000 points simultaneously in a 10 cm x 8 cm region with a 500 µm spatial and 10 ns temporal resolution. The laser can be phase-locked to either the ICP or capacitive substrate bias source. In this manner, two-dimensional ion distribution functions are investigated as a function of the RF phase of the capacitively coupled substrate bias as well different phases of the ICP pulse period. By combining the LIF data with Langmuir probe and microwave interferometer measurements, we obtain previously unavailable data in relation to the ion dynamics over a 300mm substrate - including ion energy and angular distributions, ion drifts and heat flux, and their spatial variations.