摘要
对InN薄膜在氨气氛下的高温退火行为进行了研究.利用XRD,SEM和XPS对样品进行了分析.结果表明,InN薄膜的结晶质量和表面形貌并不随退火温度单调变化.由于高温退火时N原子的挥发,剩下的In原子在样品表面聚集形成In颗粒.当退火温度高于425℃时,In原子的脱吸附作用增加,从而导致样品表面的In颗粒在退火温度高于425℃时逐渐减少.XRD和SEM结果表明In颗粒密度最高的样品具有最差的结晶质量.这种现象可能是由于In颗粒隔离了其下面的InN与退火气氛的接触,同时,金属In和InN结构上的差异也可能在InN中导致了高密度的结构缺陷,从而降低了InN薄膜的结晶质量.
The characteristics of annealing of InN films with NH3 atmosphere are investigated. The XRD,SEM, and XPS are used to analyze the samples. The experiments indicate that the crystalline quality and morphology of InN do not evolve mo notonously with annealing temperatures. During the annealing, In atoms resulting from the volatilization of N atoms aggregate on the surface,and thus In grains form. When the annealing temperature is higher than 425℃, the density of In grains decreases due to the desorption of In atoms. The results of XRD and SEM indicate that the sample with most dense In grains has a low crystalline quality. Thus,we consider that In grains prevent the improvement of InN quality by the thermal annealing maybe due to the separation of subjacent InN from the ammonia environment and the structural mismatch between In and InN grains.
基金
国家重点基础研究发展规划(批准号:G2000068305)
国家高技术研究发展规划(批准号:2001AA311110
2003AA311060
2004AA311080)
国家自然科学基金(批准号:6039072
60476030)
国家杰出青年基金(批准号:60025411)
江苏省自然科学基金(批准号:BK2005210
BK2003203)资助项目~~
