Plasma-assisted molecular beam epitaxy and characterization of SnO{sub 2} (101) on r-plane sapphire

Journal Article · Mon Sep 15 04:00:00 EDT 2008 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.2966423· OSTI ID:21192425

White, M E; Tsai, M Y; Wu, F; Speck, J S ^[1]

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1. Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)

Plasma-assisted molecular beam epitaxy has been shown to be a viable and practical method for producing high quality tin oxide, SnO{sub 2}. Phase-pure epitaxial single crystalline SnO{sub 2} (101) thin films of 1 {mu}m in thickness were reproducibly grown on r-plane sapphire Al{sub 2}O{sub 3} (1012) substrates. The SnO{sub 2} epitaxy progressed in the Volmer-Weber growth mode. A minimum on-axis {omega}-scan full width at half maximum of 0.22 deg. for the SnO{sub 2} (101) peak was measured indicating relatively low film mosaic. An epitaxial relationship of [010]{sub SnO{sub 2}} parallel [1210]{sub sapphire} and [101]{sub SnO{sub 2}} parallel [1011]{sub sapphire} was determined between the film and substrate. A SnO{sub 2} film tilt of 1.3 deg. around the [010]{sub SnO{sub 2}} toward [0001]{sub sapphire} was measured. A dislocation density of 8x10{sup 9} cm{sup -2} was measured. Hall effect measurements quantified an unintentionally doped electron concentration for different samples in a range (0.3-3.0)x10{sup 17} cm{sup -3} with a corresponding electron mobility range of 20-100 cm{sup 2}/V s. The SnO{sub 2} growth behavior was determined to be in one of the two distinct growth regimes. An oxygen-rich regime was characterized by a linear increase in the film growth rate with increasing Sn flux; whereas, the films grown entirely in the Sn-rich regime showed a decrease in the growth rate with increased Sn flux.

• OSTI ID: 21192425
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 5 Vol. 26; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM OXIDES
DENSITY
DISLOCATIONS
DOPED MATERIALS
ELECTRON MOBILITY
ELECTRONS
HALL EFFECT
MOLECULAR BEAM EPITAXY
MONOCRYSTALS
OMEGA BARYONS
PLASMA
SAPPHIRE
SUBSTRATES
THICKNESS
THIN FILMS
TIN OXIDES