摘要
用XPS和AES电子能谱的方法对等离子体辅助分子束外延 (MBE)生长的GaN薄膜进行了表面分析和深度剖析 .发现红外分子束外延 (RF MBE)生长的富镓GaN薄膜实际表面存在O和C吸附层 ,C主要为物理吸附 ,而O在GaN表面形成局域化学键产生氧络合物覆盖层 ,并形成一定的深度分布 .杂质O在GaN带隙中导带底形成杂质带同时引入深受主能级 ,使得带隙变窄室温光吸收谱向低能方向移动 ,光致发光谱出现宽带发光峰 .
The surface composition of GaN grown by plasma-assisted MBE was investigated using X-ray photoelectron spectroscopy and Auger election emission spectroscopy( AES), while the depth profile was analyzed by AES with Ar iron sputtering. The experimental results indicated that unintentional doped semi-in salating films formed by plasma-assisted MBE had a rich-gallium surface. It was found that the impurity carbon was chiefly adsorbed onto the surface while oxygen diffused into the bulk to distribute in a certain depth. Consequently, the oxygen-related impurity band and an acceptor level could be simultaneously formed in the layer. This influenced the optical and electrical properties of the films.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2001年第12期2429-2433,共5页
Acta Physica Sinica
基金
国家自然科学基金 (批准号 :198740 49)资助的课题~~
