Measurements of the presheath in an electron cyclotron resonance etching device
- 1 August 1992
- journal article
- Published by IOP Publishing in Plasma Sources Science and Technology
- Vol. 1 (3) , 147-150
- https://doi.org/10.1088/0963-0252/1/3/001
Abstract
The first direct measurement of a collisional Bohm presheath from plasma potential measurements is given. By measuring the presheath thickness in front of a grounded wafer stage, a determination of the collision mean free path for ions in an electron cyclotron resonance etching tool has been made. Presheaths were measured in N2 and CF4 plasma using an emissive probe. The presheath thickness in N2 was found to be linearly dependent on the mean free path. Measurements of CF4 plasmas, for which the collision cross sections are unknown, have shown results similar to those found for nitrogen. This result has enabled an extrapolation to be made of the effective cross section for collisions in plasmas created from CF4.Keywords
This publication has 8 references indexed in Scilit:
- The Bohm criterion and sheath formationJournal of Physics D: Applied Physics, 1991
- Measurement of pre-sheath flow velocities by laser-induced fluorescenceJournal of Nuclear Materials, 1990
- Plasma sheath thickness in radio-frequency dischargesJournal of Applied Physics, 1990
- Laser-induced fluorescence measurements of transverse ion temperature in an electron cyclotron resonance plasmaApplied Physics Letters, 1990
- A model of the chemical processes occurring in CF4/O2 discharges used in plasma etchingPlasma Chemistry and Plasma Processing, 1986
- Measurement of Plasma PresheathIEEE Transactions on Plasma Science, 1985
- Inflection-point method of interpreting emissive probe characteristicsReview of Scientific Instruments, 1979
- Microwave Plasma EtchingJapanese Journal of Applied Physics, 1977