Smoothing of Si{sub 0.7}Ge{sub 0.3} virtual substrates by gas-cluster-ion beam

Journal Article · Mon Sep 05 00:00:00 EDT 2005 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2041829· OSTI ID:20709730

Chen, H; Chen, F; Wang, X M; Yu, X K; Liu, J R; Ma, K B; Chu, W K; Cheng, H H; Yu, I S; Ho, Y T; Horng, K Y ^[1]

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1. Department of Physics and Texas Center for Superconductivity at University of Houston, University of Houston, Houston, Texas 77204 (United States)

The planarization of the SiGe virtual substrate surface is crucial for the fabrication of high-performance strained-Si metal-oxide-semiconductor field-effect transistors. In this letter, we report on the smoothing of the inherently crosshatched rough surfaces of SiGe deposited by molecular beam epitaxy on Si substrates by gas cluster ion beams. Atomic force microscopy measurements show that the average surface roughness (R{sub a}) of the SiGe layer could be reduced considerably from 3.2 to 0.7 nm without any crosshatched pattern. Rutherford backscattering in combination with channeling was used to study the damage produced by cluster bombardment. No visible surface damage was observed for the normal-incidence smoothed SiGe with postsmoothing glancing angle cluster ion beam etching.

• OSTI ID: 20709730
• Journal Information: Applied Physics Letters, Vol. 87, Issue 10; Other Information: DOI: 10.1063/1.2041829; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMIC FORCE MICROSCOPY
ETCHING
FABRICATION
FIELD EFFECT TRANSISTORS
GERMANIUM ALLOYS
GERMANIUM SILICIDES
ION BEAMS
ION PAIRS
LAYERS
MOLECULAR BEAM EPITAXY
OXIDES
PERFORMANCE
ROUGHNESS
RUTHERFORD BACKSCATTERING SPECTROSCOPY
SEMICONDUCTOR MATERIALS
SILICON ALLOYS
SUBSTRATES
SURFACES