Patent ID: 9401404
Filing Date: 2016-07-26
CPC Classification: B82Y,H01L,H01S

Claim Text:
1. A method of fabricating a semiconductor heterostructure of gallium arsenide on germanium comprising the steps of: protecting a surface comprising germanium by a shutter covering the surface in an environment having a partial pressure of arsenic that is less than 10 epitaxially growing a layer of gallium on the surface immediately after opening the shutter to expose the surface; and epitaxially growing a layer of gallium arsenide on the gallium covered surface; wherein the shutter is positioned directly covering the surface to keep the surface substantially free of arsenic prior to the step of epitaxially growing a layer of gallium; wherein said germanium surface is a (001) oriented germanium substrate off-cut by between 1° and 6° towards the [110] direction, wherein a further heterostructure comprises at least one quantum dot on a substrate comprising a germanium layer or germanium-silicon alloy layer on a silicon substrate; and wherein the quantum dot is between an upper cladding layer and guiding layer and a lower cladding layer and guiding layer.