不同退火温度下Mo/4H-SiC肖特基接触势垒不均匀及XRD分析

Analysis of the Inhomogeneous Barrier and XRD of Mo/4H-SiC Schottky Contacts Formed at Different Annealing Temperatures

为探究退火温度对Mo/4H-SiC肖特基接触势垒不均匀程度的影响,对在不同退火温度下形成的Mo/4H-SiC肖特基接触进行了不同测试温度下的电流-电压（I-V）及电容-电压（CV）测试,运用Tung理论模型和＂T0反常＂中的T0值评价势垒不均匀程度,X射线衍射（XRD）分析肖特基接触的物相组成。分析结果表明,测试温度升高时I-V测试提取的势垒高度接近于C-V测试提取的势垒高度,退火温度500℃及以上时Mo与4H-SiC发生反应,且导致较低的势垒高度。退火温度为600℃时,肖特基接触具有最低的势垒不均匀程度,且此退火温度下势垒高度相对500℃及700℃时较高,物相组成为Mo2C及Mo4.8Si3C0.6。

In order to investigate the effect of annealing temperature on the degree of barrier inhomogeneity of Mo/4H-SiC Schottky contacts,the current-voltage（I-V）and capacitance-voltage（C-V）characteristics of the Mo/4H-SiC Schottky contacts formed at different annealing temperatures were measured at different testing temperatures.The degree of barrier inhomogeneity was evaluated with Tung theoretical model and T_0 value of ＂T_0 anomaly＂,and the phase components of the Schottky contacts were analyzed by X-ray diffraction（XRD）.The analysis result shows that the barrier height obtained from the I-Vtest at high testing temperatures is close to the barrier height obtained from the C-Vtest,and Mo reacts with 4H-SiC at the annealing temperature of 500 ℃ and above,leading to the low barrier height.The Schottky contact has the lowest degree of barrier inhomogeneity at the annealing temperature of 600 ℃,and the barrier height at the annealing temperature of 600 ℃is relatively higer than those at the annealing temperature of 500 ℃ and 700 ℃.The phase components are Mo2C and Mo4.8Si3C0.6.