In {TAIL ~ a nitride semiconductor single crystal wafer} having a flat principal surface, the crystallographic plane orientation of {HEAD ~ the principal surface} of the nitride semiconductor single crystal wafer varies locally within a predetermined angular range 
In { TAIL ~ a nitride semiconductor single crystal wafer } having a flat principal surface , the crystallographic plane orientation of { HEAD ~ the principal surface } of the nitride semiconductor single crystal wafer varies locally within a predetermined angular range
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH