Patent ID: 9269569
Filing Date: 2016-02-23
CPC Classification: H01L

Claim Text:
1. A method of forming a semiconductor device comprising a germanium (Ge) film, the method comprising: growing epitaxially a first Ge film directly on a silicon (Si) substrate or a silicon germanium (SiGe) substrate, wherein the Ge film comprises an outer surface and a plurality of threading dislocations (TDs); annealing the first Ge film to the substrate at an annealing temperature in a range of from about 750° C. to about 900° C. before polishing the outer surface of the first Ge film and before growing a second Ge film over the first Ge film; after annealing the first Ge film to the substrate and before etching the outer surface of the first Ge film, polishing the outer surface of the first Ge film, wherein at least some of the threading dislocations (TDs) intersect the polished outer surface; after polishing the outer surface, etching the polished outer surface to create etch pits where the TDs intersect the polished outer surface, wherein each etch pit extends from the outer surface of the first Ge film into the first Ge film; coating the etched outer surface by depositing Al coating the deposited Al etching the coated outer surface until a top portion of the etch pits is reached, thereby planarizing the outer surface and exposing the first Ge film surrounding the etch pits and the Al removing the polymer in the etch pits following planarization of the outer surface, thereby exposing the lined etch pits; and after removing the polymer in the etch pits, growing the second Ge film by epitaxial lateral overgrowth (ELO) directly on the annealed first Ge film.