METHODS FOR MANUFACTURING GROUP III ELEMENT NITRIDE CRYSTAL SUBSTRATE AND GROUP III ELEMENT NITRIDE SEMICONDUCTOR DEVICE, AND GROUP-III-ELEMENT NITRIDE CRYSTAL SUBSTRATE AND GROUP-III-ELEMENT NITRIDE SEMICONDUCTOR DEVICE, OBTAINED BY THE METHOD

摘要

PROBLEM TO BE SOLVED: To provide a technology for preventing the diffusion of impurities in a group III element nitride crystal substrate grown in a liquid phase. SOLUTION: The group III element nitride crystal substrate 13 is formed by allowing nitrogen of a nitrogen-containing gas and a group III element to react to crystallize in a melt (a flux) containing at least one of alkali metal and alkaline earth metal. Impurities contained in the substrate 13 are converted into inorganic compounds (shown by 15 in Figure) by subjecting the substrate 13 to heat treatment. By the heat treatment, the diffusion of impurities such as alkali metal or alkaline earth metal, that might be contained in the substrate 13, from the substrate 13 can be prevented. Accordingly, it becomes possible to stably fabricate devices by this method for manufacturing the substrate. COPYRIGHT: (C)2006,JPO&NCIPI