Cl{sub 2}/Ar and CH{sub 4}/H{sub 2}/Ar dry etching of III{endash}V nitrides
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)
- Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
Electron-cyclotron-resonance (ECR) and reactive ion etching (RIE) rates for GaN, AlN, InN, and InGaN were measured using the same reactor and plasma parameters in Cl{sub 2}/Ar or CH{sub 4}/H{sub 2}/Ar plasmas. The etch rates of all four materials were found to be significantly faster for ECR relative to RIE conditions in both chemistries, indicating that a high ion density is an important factor in the etch. The ion density under ECR conditions is {approximately}3{times}10{sup 11} cm{sup {minus}3} as measured by microwave interferometry, compared to {approximately}2{times}10{sup 9} cm{sup {minus}3} for RIE conditions, and optical emission intensities are at least an order of magnitude higher in the ECR discharges. It appears that the nitride etch rates are largely determined by the initial bond breaking that must precede etch product formation, since the etch products are as volatile as those of conventional III{endash}V materials such as GaAs, but the etch rates are typically a factor of about 5 lower for the nitrides. Cl{sub 2}/Ar plasmas were found to etch GaN, InN, and InGaN faster than CH{sub 4}/H{sub 2}/Ar under ECR conditions, while AlN was etched slightly faster in CH{sub 4}/H{sub 2}/Ar plasmas. The surface morphology of InN was found to be the most sensitive to changes in plasma parameters and was a strong function of both rf power and etch chemistry for ECR etching. {copyright} {ital 1996 American Institute of Physics.}
- Research Organization:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 389016
- Journal Information:
- Journal of Applied Physics, Vol. 80, Issue 7; Other Information: PBD: Oct 1996
- Country of Publication:
- United States
- Language:
- English
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