Patent ID: 9184050
Filing Date: 2015-11-10
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor substrate having a trench and an inverted trapezoidal recess below the trench, the trench disposed between trench isolation regions, sidewalls of the trench comprising the trench isolation regions, the trench isolation regions extending to at least a top of the inverted trapezoidal recess, sidewalls of the inverted trapezoidal recess spaced apart from the trench isolation regions and having a (111) crystal orientation, a ratio of a depth of the trench to a length of the sidewalls of the inverted trapezoidal recess being equal to or greater than 0.5, at least a portion of the inverted trapezoidal recess extending lower than the trench isolation regions; and a group III-V epitaxial layer formed in the trench and the inverted trapezoidal recess; wherein the inverted trapezoidal recess extends from above a bottommost surface of the trench isolation regions to below the trench isolation regions.