Method of chemical gas phase precipitation for growing carbon doped silicon germanium alloy buffer layer and germanium film

Abstract

The invention relates to a chemical gas phase deposition growth carbon germanium-silicon alloy isolating switch and growth germanium thin film method, which uses GeH4, C2H4 as reacting gas at 700-850 deg. and 10-100Pa compression intensity, wherein the C2H4 divider board is 0.01-0.15 Pa; the GeH4 divider board 0.10-1.10 Pa; the gas souse reactes with Si to combine the Ge of the epitaxial layer so that it generates a layer of Ge component anamorphic Si1-xGex: C buffer layer on the substrate surface with the thickness 0.5-10 micrometer; and then it generates Ge thin film especially at 400-600 deg and 15-100Pa compression intensity, wherein the GeH4 divider board is 0.07-1.11Pa.

Description

1. Technical field [0001] The present invention relates to adopting the chemical vapor deposition (CVD) method to prepare the carbon-doped silicon-germanium alloy (Si) with germanium (Ge) composition gradient on Si substrate 1-x Ge x :C) buffer layer, followed by Si 1-x Ge x : Method for epitaxial growth of single crystal Ge film on C buffer layer. 2. Background technology [0002] As the first-generation semiconductor material, Ge has the advantage of high carrier mobility compared to Si; epitaxially grow Ge and Si with high Ge composition on Si 1-x Ge x Alloy, can be used for Si with high cut-off frequency (>100G Hz) 1-x Ge x Fabrication and research of novel devices such as / Si heterojunction bipolar transistors and long-wavelength photodetectors. [0003] There is a 4.2% lattice mismatch and a 5.6% thermal mismatch between Ge and Si. The Ge thin film obtained directly on the Si substrate has high density of structural defects, poor single crystal and photoelect...

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Problems solved by technology

However, this method has high requirements on the precise control of the flow rate of the reaction gas source, and the process is complicated and the cost is high.

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