Patent ID: 8754449

Claim:
High Electron Mobility Transistor (HEMT), comprising layers of at least one Group XIII element nitride (IUPAC, 1989), wherein said high electron mobility transistor includes a substrate of a gallium-containing nitride, said substrate being made of a single crystal obtained by crystallization from a supercritical ammonia-containing solution, said substrate having a surface dislocation density approximately 10 2 /cm 2 and said substrate has a curvature radius of crystalline lattice exceeding 15 m and wherein a two-dimensional electron gas (2DEG) is present in a layer adjacent to said substrate, and wherein said substrate is made of a single crystal obtained by growth on a seed, wherein at least a part of the single crystal is grown only in one direction at a time, the one direction at a time including in a direction essentially perpendicular to a direction of seed growth or in a direction essentially parallel to a direction of seed growth.