Raman-scattering and optical studies of argon-etched GaAs surfaces

Journal Article · Mon Apr 15 04:00:00 EDT 1991 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.43.9678· OSTI ID:5615896

Feng, G F; Zallen, R ^[1]; Epp, J M; Dillard, J G ^[2]

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1. Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (USa)
2. Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061 (USA)

We have studied the structual damage in low-energy argon-ion-bombarded (ion-etched) GaAs using Raman scattering and ultraviolet reflectivity. When combined with post-bombardment sequential chemical etching, the Raman results reveal a graded depth profile of the damage layer, with a nearly linear damage dropoff with depth. The total damage-layer thickness is about 600 A for high-fluence bombardment with 3.89-keV Ar{sup +} ions. The spectral effects produced by argon etching are very different from those produced by high-energy ion implantation. The longitudinal-optic Raman line seen for argon-etched GaAs is not shifted and broadened as in ion-implanted GaAs. More striking are the results of the reflectivity measurements. For argon-etched GaAs, the electronic interband peaks are both broadened and strongly red shifted relative to the crystal peaks; for ion-implanted GaAs, only the broadening occurs. Distinct nanocrystals, which account for the effects seen in ion-implanted GaAs, are evidently absent in argon-etched GaAs. Instead, the damage layer caused by argon etching appears to be characterized by a very high density of point defects, which previous work suggests may be arsenic vacancies.

• OSTI ID: 5615896
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 43:12; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360605* -- Materials-- Radiation Effects
ARGON IONS
ARSENIC COMPOUNDS
ARSENIDES
CHARGED PARTICLES
COLLISIONS
ELECTROMAGNETIC RADIATION
ETCHING
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
ION COLLISIONS
IONS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
PNICTIDES
RADIATION EFFECTS
RADIATIONS
RAMAN EFFECT
REFLECTIVITY
SURFACE FINISHING
SURFACE PROPERTIES
ULTRAVIOLET RADIATION