背面氩离子轰击改善MOS系统界面特性和击穿特性

在室温下用低能量Ａｒ＾＋轰击ＭＯＳ电容器肾面，能改善ｉＯ２－Ｓｉ系统的界面特性和击穿特性。结果表明，随着轰击时间的增加，固定电荷密度、界面态密度和漏电流减少，高场击穿的比率增大，然后这些参数变化平缓并开始呈恶化趋势。轰击能量为５５０ｅＶ和束流密度为０．５ｍＡ／ｃｍ＾２时的效果比在３５０ｅＶ和０．３ｍＡ／ｃｍ＾２时的好。

IMPROVEMENT OF THE INTERFACE CHARACTERISTICS AND BREAKDOWN CHARACTERISTICS OF SiO_2-Si SYSTEM BY BACKSURFACE Ar+ BOMBARDMENT

Low energy argon ion-beam has been applied to bombard directly the backsurface of MOS capacitors, and the interface characteristics and electrical breakdown properties can be improved. The result shows that,as the bombardment time increases, the interface state density, the fixed charge density and the leakage current all decrease,and the percentage of high electrical field breakdown increases. However, these changes tend to slow down and even are reverse. The effects are better for 550eV of energy and 0. smA/cm2 of beam current density than for 350eV and 0. 3mA/cm2. As the thickness of silicon wafers decreases from 450Urn to 300Urn,the improvement is more effective. The barrier height is calculated in this paper, and the mechanism of impurity gettering and stress compensation are used to explain the experimental results.