Si/SiOx multilayer
structures with ultra-thin silicon-suboxide layers are fabricated with
molecular beam epitaxy. The silicon surface is oxidized during growth
interruptions at an oxygen pressure between 1.0×10−7mbar and 8.0×10−7 mbar. Overgrowth with Si of the oxidized surface is possible for
coverages of a few monolayers of O and improves with increasing substrate
temperature. X-ray diffraction shows that the silicon layers are single
crystalline. Transmission electron microscopy measurements show that the
suboxide layers are ~1nm thick,
pseudomorph, and exhibit crystalline order throughout the layer. In addition,
transmission electron microscopy shows that the oxygen concentration is
laterally inhomogeneous. The multilayer structures are thermally very stable,
as rapid thermal annealing up to 1000 °C shows no influence on the X-ray
diffraction patterns.
Highlights
• Epitaxial growth of ultra-thin silicon-suboxide layers
embedded in c-silicon.
• Growth of multilayer structures of Si/SiOx with
up to 20 repetitions.
• Simulation method to determine oxygen content of SiOx layers.
• SiOx layers are stable thermally up to
1000 °C for 5 min.
Source:Journal
of Crystal Growth
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