C PLANE GaN SUBSTRATE

To provide a c plane GaN substrate consisting of a GaN crystal to be grown without providing means for extremely reducing an impurity concentration and capable of preferably suppressing offcut angle fluctuation.SOLUTION: The c plane GaN substrate has a Si concentration of 5×1016 atoms/cm3 or more, a H concentration of 1×1017 atoms/cm3 or less and an O concentration of 6×1015 atoms/cm3 or more; a dislocation density on one main surface is less than 1×106 cm-2; and the range of fluctuation of an off angle in the x direction component on a first line extended in the x direction through the center of the one main surface and the range of fluctuation of an offcut angle in the y direction component on a second line extended in the y direction vertical to the x direction through the center of the one main surface are 0.16 degrees or less in an interval having a length of 40 mm, respectively.SELECTED DRAWING: Figure 1 【課題】不純物濃度を極度に低減する手段を講じることなく成長させ得るＧａＮ結晶からなり、オフカット角度の変動が好ましく抑制された、ｃ面ＧａＮ基板を提供すること。【解決手段】５×１０１６ａｔｏｍｓ／ｃｍ３以上のＳｉ濃度、１×１０１７ａｔｏｍｓ／ｃｍ３以下のＨ濃度および６×１０１５ａｔｏｍｓ／ｃｍ３以上のＯ濃度を有し、一方の主面における転位密度が１×１０６ｃｍ−２未満であり、かつ、該一方の主面の中央を通りｘ方向に延びる第一のライン上におけるオフカット角のｘ方向成分の変動幅と、該一方の主面の中央を通り該ｘ方向に垂直なｙ方向に延びる第二のライン上におけるオフカット角のｙ方向成分の変動幅が、それぞれ、長さ４０ｍｍの区間内で０．１６度以下である、ｃ面ＧａＮ基板が提供される。【選択図】図１