Patent ID: 6831350
Filing Date: 2004-12-14
Classification: H01L

Abstract:
A semiconductor structure comprising:a substrate comprising a first relaxed semiconductor material with a first lattice constant; a semiconductor device layer overlying the substrate, the semiconductor device layer comprising a second relaxed semiconductor material with a second lattice constant different from the first lattice constant; and a dielectric layer interposed between the substrate and the semiconductor device layer, the dielectric layer having a programmed transition zone disposed within the dielectric layer for transitioning between the first lattice constant and the second lattice constant, the programmed transition zone comprising a plurality of layers, adjoining ones of the plurality of layers having different lattice constants with one of the adjoining ones having a first thickness exceeding a first critical thickness required to form defects and another of the adjoining ones having a second thickness not exceeding a second critical thickness, each adjoining layer of the plurality of layers forming an interface for promoting defects in the transition zone to migrate to an edge of the programmed transition zone.