FABRICATION OF GALLIUM NITRIDE LAYERS BY LATERAL GROWTH

摘要

An underlying gallium nitride layer (104) on a silicon carbide substrate (10 2) patterned with a mask (109) that includes an array of openings therein, and is etched through the array of openings to define post s (106) in the underlying gallium nitride layer and trenches (107) therebetween. The posts each include a sidewall (105) and a top having the mask thereon. The sidewalls of the posts are laterally grown into the trenches to thereby form a gallium nitride semiconductor layer (108a). During this lateral growth, the mask prevents nucleation and vertical growth from the tops of the posts. Accordingly, growth proceeds laterally into the trenches, suspended from the sidewalls of the posts. The sidewalls of the posts may be laterally grown into the trench es until the laterally grown sidewalls coalesce in the trenches to thereby form a gallium nitride semiconductor layer. The lateral growth fr om the sidewalls of the posts may be continued so that the gallium nitride layer grows vertically through the openings in the mask and laterally overgrows onto the mask on the tops of the posts, to thereby form a gallium nitride semiconductor layer (108b). The lateral overgrowth can be continued until the grown sidewalls coalesce on the mask to thereby form a continuous gallium nitride semiconductor layer. Microelectronic devices (110) may be formed in the continuous gallium nitride semiconductor layer.