Selective suppression of photochemical dry etching using elevated surface impurity concentrations: A new technique for self-aligned etching

Journal Article · Sat Sep 01 00:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.346499· OSTI ID:6429596

Ashby, C I.H.; Myers, D R; Vawter, G A; Biefeld, R M ^[1]; Datye, A K ^[2]

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1. Sandia National Laboratories, Albuquerque, NM (USA)
2. Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, NM (USA)

High concentrations of recombination-promoting impurities in the near-surface region of a semiconductor can produce virtually complete suppression of carrier-driven photochemical etching processes. In-diffusion of Zn to levels appropriate for ohmic contact formation on GaAs (mid-10{sup 20}/cm{sup 3}) has been employed to reduce etching to an undetectable level in {ital n}-GaAs with {ital n}=1.0{times}10{sup 17} and 1.3{times}10{sup 18}/cm{sup 3} and to produce a greater than ten-fold reduction in etching of semi-insulating GaAs. Raman spectroscopy of the altered near-surface region shows enhanced electronic scattering, which indicates the presence of a sufficient impurity concentration to suppress etching. Transmission electron microscopy shows the near-surface region to be crystalline without significant numbers of defects following Zn diffusion. Possible applications of this process include self-aligned etching of transistor and laser structures.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6429596
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 68:5; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ARSENIC COMPOUNDS
ARSENIDES
ATOM TRANSPORT
CHEMISTRY
DIFFUSION
ELECTRON MICROSCOPY
ELEMENTS
ETCHING
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
IMPURITIES
METALS
MICROSCOPY
NEUTRAL-PARTICLE TRANSPORT
PHOTOCHEMISTRY
PNICTIDES
RADIATION TRANSPORT
RAMAN SPECTRA
RECOMBINATION
SPECTRA
SURFACE FINISHING
SURFACES
TRANSMISSION ELECTRON MICROSCOPY
ZINC