Patent ID: 7470970

Claim:
An oxygen doped n-type gallium nitride freestanding single crystal substrate having oxygen atoms as an n-dopant, having a hydrogen concentration of less than or equal to 2×10 17 cm −3 , and having a C-plane surface, produced by the steps of: preparing a foreign material single crystal seed having a three-fold rotational symmetry or a C-plane gallium nitride single crystal seed having a C-plane surface, supplying the foreign material seed or the C-plane gallium nitride seed with material gases including a gallium material, a nitrogen material and an oxygen material without silicon, growing a gallium nitride bulk crystal with facets having non-C-planes upon the foreign material seed or the C-plane gallium nitride seed in vapor phase, maintaining the facets having the non-C-planes on the growing gallium nitride bulk crystal, doping the growing gallium nitride bulk crystal with oxygen via the non-C-planes of the facets, eliminating the foreign material seed or the C-plane gallium nitride single crystal seed from the grown gallium nitride bulk crystal by etching or polishing, and polishing the faceted surface of the grown gallium nitride bulk crystal for eliminating the facets.