PROCESS FOR PRODUCING GROUP III NITRIDE CRYSTAL, GROUP III NITRIDE CRYSTAL SUBSTRATE, AND GROUP III NITRIDE SEMICONDUCTOR DEVICE

摘要

This invention provides a process for producing a large-size group III nitride crystal in which the dislocation density of at least the surface thereof is wholly low. The production process is characterized in that it comprises the step of providing a base substrate (1) comprising a group III nitride seed crystal having a main area (1s) and a polarity reversed area (1t) having polarity reversed in direction to the main area (1s), and the step of growing a group III nitride crystal (10) by a liquid phase method on the main area (1s) and the polarity reversed area (1t) in the base substrate (1), and a first area (10s) having a higher growth rate of the group III nitride crystal (10) grown on the main area (1s) covers a second area (10t) having a lower growth rate of the group III nitride crystal (10) grown on the polarity reversed area (1t).