Method For Growing Germanium Epitaxial Films

A method for growing germanium epitaxial films is disclosed. Initially, a silicon substrate is preconditioned with hydrogen gas. The temperature of the preconditioned silicon substrate is then decreased, and germane gas is flowed over the preconditioned silicon substrate to form an intrinsic germanium seed layer. Next, a mixture of germane and phosphine gases can be flowed over the intrinsic germanium seed layer to produce an n-doped germanium seed layer. Otherwise, a mixture of diborane and germane gases can be flowed over the intrinsic germanium seed laser to produce a p-doped germanium seed layer. At this point, a bulk germanium layer can be grown on top of the doped germanium seed layer.