Heteroepitaxy of vacuum-evaporated Ge films on single-crystal Si

Abstract

Heteroepitaxial Ge films on 〈100〉 and 〈111〉 Si substrates have been prepared by vacuum evaporation. The films were deposited in moderate vacuum (10−6 Torr) at a rate of ∼10 Å/sec, with the substrates heated to 350–750 °C. The crystalline perfection of the films depends on both substrate orientation and temperature. The best films were obtained on 〈100〉 Si substrates heated to 550 °C. Heteroepitaxial GaAs layers of excellent crystal quality have been grown by chemical vapor deposition on such Ge films. GaAs shallow-homojunction solar cells with conversion efficiencies up to 12% at AM1 have been successfully fabricated.

Structural Mapping of Functional Ge Layers Grown on Graded SiGe Buffers for sub-10 nm CMOS Applications Using Advanced X-ray Nanodiffraction

“…The integration of Ge materials is on the roadmap of advanced CMOS technology as key element for performance improvement beyond the 22 nm device node. − Furthermore, Ge virtual wafers can be used as a technology platform for Ge photonics application to realize true group IV or III–V/Si hybrid electronic–photonic integrated circuits , as well as a cost-effective substrate platform for high-efficiency concentrator photovoltaics . However, because of the lattice and thermal mismatch between the active Ge layer and the Si substrate, special techniques are required to achieve low-defect Ge epitaxial layers on Si.…”

Germanium-on-Silicon for Integrated Silicon Photonics

“…People soon found a great difficulty of growing germanium thicker than its critical thickness because there is 4% mismatch between the lattice constants of germanium and silicon. Although the earliest work of the epitaxy of germanium-silicon (GeSi) alloy on silicon dates back to 1962 (Miller & Grieco, 1962), good quality pure germanium films or high germanium content GeSi films have been Germanium-on-Silicon for Integrated Silicon Photonics 3 grown on silicon since late 1970s after the invention of molecular beam epitaxy (MBE) Garozzo et al, 1982;Kasper & Herzog, 1977;Tsaur et al, 1981). Despite the importance of the studies of germanium epitaxy by MBE, it is recognized by many researchers that MBE is not likely to be a good choice for massive device manufacturing.…”

Preparation and Optical Properties of GeBi Films by Using Molecular Beam Epitaxy Method

“…So far, Ge-based alloys were proved to be promising materials for infrared optoelectronic detectors. In 1984, AT& T.Bell Laboratories prepared GeSi film n-i-p devices by the molecular beam epitaxy (MBE) method, and the working wavelength was 1.45 μm [ 5 , 6 ]. In 2010, the University of Stuttgart prepared GeSn films with 0.5–3% Sn content using low growth temperatures and pin detectors with 1.2–1.6-μm operating wavelength [ 7 – 10 ].…”