PENDEOEPITAXIAL GROWTH OF GALLIUM NITRIDE LAYERS ON SAPPHIRESUBSTRATES

摘要

Gallium nitride semiconductor layers may be fabricated by etching an underlying gallium nitride layer (104) on a sapphire substrate (102a), to define at least one post (106) in the underlyi ng gallium nitride layer and at least one trench (107) in the underlying gallium nitride layer. The at least one post includes a gallium nitride top and a gallium nitride sidewall (105). The at least one trench includes a trench floor. The gallium nitride sidewalls are laterally grown into the at least one trench, to thereby form a gallium nitride semiconductor layer. In a preferred embodiment, the at least one trench extends into the sapphire substrate such that the at least one post further includes a sapphire sidewall an a sapphire floor. A mask (201) may be included on the sapphire floor and an alluminum nitride buffer layer (102b) also may be included between th e sapphire substrate and the underlying gallium nitride layer. A mask (209) also may be included on the gallium nitride top. The mas k on the floor and the mask on the top preferably comprise same material.