Techniques for forming angled structures for reduced defects in heteroepitaxy of semiconductor films

摘要

In one embodiment, a method for etching a substrate includes providing a reactive ambient around the substrate when a non-crystalline layer is disposed over a first crystalline material in the substrate; generating a plasma in a plasma chamber; modifying a shape of a plasma sheath boundary of the plasma; extracting ions from the plasma; and directing the ions to the substrate at a non-zero angle of incidence with respect to a perpendicular to a plane of the substrate, wherein the ions and reactive ambient are effective to form an angled cavity through the non-crystalline layer to expose a portion of the first crystalline material at a bottom of the angled cavity, and the angled cavity forms a non-zero angle of inclination with respect to the perpendicular.

主权项

1. A method for etching a substrate, comprising:
providing a reactive ambient around the substrate when a non-crystalline layer is disposed over a first crystalline material in the substrate; generating a plasma in a plasma chamber; modifying a shape of a plasma sheath boundary of the plasma; extracting ions from the plasma; directing the ions to the substrate at a non-zero angle of incidence with respect to a perpendicular to a plane of the substrate, wherein the ions and reactive ambient are effective to form an angled trench through the non-crystalline layer to expose a portion of the first crystalline material at a bottom of the angled trench, the angled trench forming a non-zero angle of inclination with respect to the perpendicular; and forming a second crystalline material within the angled trench by epitaxial growth, wherein the first crystalline material and second crystalline material have mismatched lattice dimensions.