Subjects of research: Si[.xGex single crystals, mctal-Si|.xGex contacts, Schottky diodes.
Purpose of work: the purpose of this work is to study the properties of a mctal-Sq. xGex, depending on the type of metals, taking into account the germanium content and surface states in the Si|.xGex bulk alloys.
Method of research: electron beam floating zone technique, method of conductivity modulation, X-ray microanalysis, photoclcctrical and electrophysical methods of characterization,
The results obtained and their novelty: in this work, the growth technology of of Si|.xGex single-crystal has been improved. Homogeneous Si!.xGex single crystals with a low dislocation density (~ 102-104 cm'2) and high-lifetime (~ 600 ms) of minority current carriers has been grown by electron-beam floating zone technique;
- for the first time the data on the height of Schottky barriers based on Au, Al has been obtained. It sharply changes at small content of Ge, and then remains practically unchanged. The data confirm the conclusion on passivation of the alloy surface from the enrichment of the crystal surface by Gc atoms, proposed before on the basis of studies Au-Si|.xGex <Li>;
- for the Ti-Si|.xGex contact has been observed monotonic increase of the barrier with increasing of Ge content, whereas for Ni-Si].xGex due to formation of a nickel germanide layer the elcctrophysical properties is not described by well known expressions for IV and VF characteristics for Schottky barrier;
- the M-Si|.xGex Schottky diodes based on gold and aluminum fabricated on the surface with different surface states densities has been investigated for the first time. It has been shown that the height of the barrier correlates with the surface state density and the germanium content.
Practical value: the experimental results on fabricating the M-Si|.xGex Schottky barriers on the base of bulk Si].xGex solid solutions, and on effect of Ge content to the passivation of surface states is of interest to the physics of semiconductor solid solutions and can be used for manufacturing semiconductor devices, particularly for infrared and nuclear radiation detectors based on Si(.xGex solid solutions.
Degree of embed and economic effectivity: part of obtained scientific results was used for research of radiation hardness and elcctrophysical properties of Si|.xGex devices under irradiation by neutrons, electrons and X-ray.
Field of application: physics of solid state, semiconductor physics, instrumentation.
