School;
of;
Microelectronics,;
Xidian;
University,;
Key;
Laboratory;
of;
Ministry;
of;
Education;
for;
Wide;
Band-Gap;
Semiconductor;
Matemals;
and;
Devices,;
Xi'an;
710071,;
China;
Applied;
Materials;
Inc,;
Sunnyvale,;
CA,;
94086,;
USA;