1. Yaoxi Wu and M. A. Lieberman
Influence of Antenna Configuration and Standing Wave Effects on Density Profile in a Large Area inductive Plasma Source
SFR Workshop
November 8, 1999
Yaoxi Wu and M. A. Lieberman
Berkeley, CA
This work aims to investigate the influence of antenna standing wave effects on plasma density distribution to improve the plasma uniformity
4/19/2019

2. Large Processing Area Antenna coil embedded in the plasma
Eight quartz tubes threaded by copper antenna tubes
Eight vertical gas feeding lines with equally spaced pin-holes
36.0cm×46.5cm processing area
4/19/2019

3. Driving Circuit Traveling waves are launched by a tuning network
(a) Power supply
(b) Matching network
(c) Tuning network
(d) Antenna and plasma system
4/19/2019

4. Eight rod serpentine coil difficult to match Alternative Configurations
6 rods powered
4 rods powered
8 rods powered
4/19/2019

5. Six Rods Powered – Experimental Results
Density profile for p = 5.8 mTorr, varying power
Density profile for P  1211 W, varying pressure
4/19/2019

6. Four Rods Powered - Vary voltage with tuning network
Density profile for p = 5.8 mTorr, varying voltage profile
Density profile for p = 14 mTorr, varying voltage profile
4/19/2019

7. Eight Rods Powered Density profile - without tuning
Density profile - with tuning
4/19/2019

8. Progress vs Milestones
Year 1
Develop spatially resolved Langmuir probe for measurements of plasma properties (done)
Initiate measurements of plasma uniformity in LAPS using spatially resolved diagnostics (done)
Year 2
Experimental study of plasma and process uniformity using Langmuir probe and OES (on-going)
Design matching networks for real-time control of standing wave ratio on LAPS and conventional tools (goal has changed to: Study effect of alternative coil configurations on plasma density profile; on-going)
4/19/2019

9. Future Work ( )
Investigate materials etching rate and uniformity; e.g., oxygen etching of photoresist, and correlate with plasma profiles (Year 1)
Optimize etching uniformity using alternative tuning networks to control antenna standing wave ratios (Year 1)
Investigate real time control of plasma uniformity using the tuning network. (Year 2)
4/19/2019