激光分子束外延法制备AlN/Si异质结的电学性质

Electrical Properties of AlN/Si Heterostructure Prepared by Laser-MBE

采用激光分子束外延法在Si(111)衬底上制备出沿c轴取向的AlN薄膜,在此基础上制备了Au/AlN/Si金属-绝缘体-半导体(MIS)结构。研究了结构的电流传输机制、AlN/Si界面处的界面态密度值及分布情况。结果表明:AlN/Si异质结具有很好的整流特性,电流传输符合空间电荷限制传输机制,理想因子为2.88;结构的界面态密度约为1.1×10^(12) eV^(-1)·cm^(-2),主要分布在距离Si衬底价带顶0.26eV附近,由生长过程中引入的O杂质、N空位/N替代和Si原子代替N原子形成的Al-Si键组成。

Aluminum nitride（AlN）films with c-axis orientation were grown on（111）Si substrates by laser molecular beam epitaxy.The current transport mechanisms and the density of interface state of Au/AlN/Si MIS structure were studied.The AlN/Si heterojunctions exhibited a typical rectifying characteristic,which was attributed to the space-charge-limited current mechanism.The ideality factor was 2.88 and the interface state density of AlN/Si was about 1.1×10^12 eV^-1·cm^-2,mainly distributed in 0.26 eV distancing the top of valence band of Si,and consisted of O impurities,N vacancy and Al—Si bond formed from Si atoms in place of N atoms during the AlN films growth.