S. A. Denisov

Methods for the doping of silicon layers in growth by sublimation MBE

Epitaxial layers doped with various impurities were grown by sublimation MBE on Si (100) substrates. Doping with phosphorus was controlled at electron densities ranging from 2×1013 to 1019 cm−3. A high dopant concentration of ∼1020 cm−3 was obtained from the evaporation of partly molten Si sources. It shown that the type and concentration of an impurity in the sublimation MBE process can be controlled by the fabrication of multilayer p+−n+ structures.

Epitaxially Grown Monoisotopic Si, Ge, and Si1–xGex Alloy Layers: Production and Some Properties

The technology of the growth of Si, Ge, and Si1–xGex layers by molecular-beam epitaxy with the use of a sublimation source of monoisotopic 30Si or 28Si and/or gas sources of monogermane 74GeH4 is demonstrated. All of the epitaxial layers are of high crystal quality. The secondary-ion mass spectroscopy data and Raman data suggest the high isotopic purity and structural perfection of the 30Si, 28Si, 74Ge, and 30Si1–x74Gex layers. The 30Si layers doped with Er exhibit an efficient photoluminescence signal.

A device for heating a substrate during molecular beam epitaxy

A device for uniform heating of both optically opaque silicon and transparent sapphire large-area substrates (with a diameter of up to 100 mm) in vacuum to high temperatures of 1250–1450°C is described. Using the device, it is possible to carefully prepare silicon and sapphire substrates in situ for growing Si and SiGe epitaxial layers by molecular beam epitaxy method.

A device for growing silicon films on standard wafers using a sublimation source

A device for depositing silicon films from a sublimation source on standard silicon wafers with diameters of 52−100 mm is described. The source is a silicon single crystal heated to a preset temperature of 1300−1380°C. The uniform thickness and homogeneous doping over the wafer area are obtained by moving the sublimation source relative to the wafer.

Si1 − xGex/Si heterostructures grown by molecular-beam epitaxy on silicon-on-sapphire substrates

The growth of heterostructures with Si1 − xGex layers on

Structural perfection of heteroepitaxial silicon layers grown on sapphire by sublimation-source molecular beam epitaxy

left( {1bar 102} right)

A silicon sublimation source for molecular-beam epitaxy

sapphire substrates by molecular-beam epitaxy with a silicon sublimation source and a germanium gas source (GeH4) is reported. The systematic study of the influence of substrate temperature and thickness of the silicon buffer layer shows that the optimal conditions for growing epitaxial Si1 − xGex layers are provided at a temperature of TS = 375–400°C. There are significant differences in the orientations of Si1 − xGex layers, depending on the thickness d of the Si buffer layer: the preferred orientations are (100) at d ≥ 100 nm and (110) for thinner layers. Heterostructures with thick (∼1 μm) Si1 − xGex layers, doped with erbium atoms, exhibit intense photoluminescence at λ = 1.54 μm.

Thin single-crystal Ge layers on 2″ Si substrates

Controlled boron doping of Si1 − xGex epilayers has been achieved during low-temperature growth of SiGe/Si(100) heterostructures by sublimation of boron-doped silicon in a germane medium. Boron-doped single-crystalline silicon plate was sublimed by resistive heating to ∼1300°C. Using this source, heterostructures with selectively doped layers, sharp dopant concentration profiles, and a maximum boron concentration of ∼1 × 1019 cm−3 were obtained.