采用射频磁控反应溅射法在Si(111)和Si(100)两种衬底上制备了AlN薄膜,用X射线衍射(XRD)对AlN薄膜进行了表征,研究了衬底Si(111)、Si(100)取向以及N2百分比对AlN(002)薄膜c-轴择优取向的影响。实验结果表明,Si(100)较适合生长c-轴择优取向AlN薄膜,而且N2百分比为40%时,AlN薄膜的c-轴取向最好,具有尖锐的XRD峰,此时对应于AlN(002)晶向。计算了(002)取向AlN和两种Si衬底的失配度,Si(111)面与AlN(002)面可归结为正三角形晶系之间的匹配,失配度为23.5%;而Si(100)面与AlN(002)面可归结为正方形晶系与正三角形晶系之间的匹配,失配度为0.8%,可以认为完全共格。理论分析和实验结果相符。
Aluminum nitrogen(AlN) films are successfully deposited on single-crystal Si(111) and Si(100) substrates by the radio frequency(RF) magnetron reactive sputtering technique,respectively.The influence of substrate orientation and N2 percentage on preferentially orientated AlN(002) thin film is studied experimentally and theoretically.The orientation of the films is characterized by X-ray diffraction(XRD).The experimental results show that the films on Si(100) with 40% N2 exhibit best crystal properties with sharp XRD peaks,corresponding to AlN(002) crystalline orientation.The lattice mismatch of AlN(002)/Si(111) can be considered as that between triangle crystal systems,and the lattice mismatch of AlN(002)/Si(100) can be considered as that between triangle crystal system and square crystal system.By calculation,the mismatch of the former is 23.5% and that of the latter is 0.8%.Si(100) plane and AlN(002) plane can be considered as lattice fully-coherent.Therefore,the theory analysis is consistent with experimental results.