Surface morphology of Ge(001) during etching by low-energy ions

Journal Article · Fri Dec 15 04:00:00 EST 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.52.16696· OSTI ID:147795

Chey, S J; Van Nostrand, J E; Cahill, D G ^[1]

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1. Department of Materials Science, the Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)

The roughening of a crystalline semiconductor during etching by low-energy ions is characterized using {ital in} {ital situ} scanning tunneling microscopy. Ge(001) surfaces are bombarded by 240-eV Xe ions using a wide range of exposure times and temperatures. Ge dimers are resolved for surfaces etched at {ital T}{gt}+165 {degree}C and imaged at room temperature. For fixed ion exposure, the roughness increases with increasing temperature; a maximum surface roughness is reached for etching at {congruent}250 {degree}C. At {ital T}{congruent}270 {degree}C the character of the surface morophology changes from a relatively disordered arrangement of mounds to a more regular pattern of pits. The isotropy of this pattern formation and the dependence of the in-plane length of the roughness on exposure time suggest that asymmetric kinetics for the attachment of dimer vacancies at ascending versus descending steps drives roughening during etching.

• Research Organization: University of Illinois
• DOE Contract Number: FG02-91ER45439
• OSTI ID: 147795
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 23 Vol. 52; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DIMERS
ETCHING
GERMANIUM
ION IMPLANTATION
ROUGHNESS
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
TIME DEPENDENCE