Effects of O2 addition on in-plasma photo-assisted etching of Si with chlorine
- Univ. of Houston, TX (United States)
Addition of oxygen was used to control the in-plasma photo-assisted etching (PAE) of p-type Si(100) and poly-Si in a high density, inductively coupled, Faraday-shielded, Ar/Cl2 (225/25 SCCM), 60 mTorr plasma. After etching, samples were transferred under vacuum to an UHV x-ray photoelectron spectroscopy chamber for surface analysis. Samples etched under PAE conditions (ion energies below the ionassisted etching, IAE, threshold) had a thicker surface oxide and lower [Cl] surface concentration, when compared to samples etched under IAE conditions (ion energies above the IAE threshold). PAE was found not to be affected by 0.1 or 0.25 SCCM O2 addition, while etching stopped with more than 0.5 SCCM O2 addition. IAE with RF power on the sample stage, resulting in -65 V self-bias, was not affected by up to 2 SCCM of oxygen addition but decreased rapidly when more than 5 SCCM O2 was added to the plasma. These results imply that PAE may be completely suppressed, while IAE occurs unobstructed. The implications of these findings are discussed in view of applications involving continuous wave and pulsed-plasma processes.
- Research Organization:
- Univ. of Michigan, Ann Arbor, MI (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- Grant/Contract Number:
- SC0001939; DE -SC0001939
- OSTI ID:
- 1801522
- Alternate ID(s):
- OSTI ID: 1644150
- Journal Information:
- Journal of Vacuum Science and Technology A, Vol. 38, Issue 5; ISSN 0734-2101
- Publisher:
- American Vacuum Society / AIPCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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