一种快速检测单晶硅亚表面损伤层厚度的方法

为了保证单晶硅晶圆在精研与抛光过程中的品质与质量,亟待寻求一种快速、简单、经济的硅材料亚表面损伤程度的检测方法。基于HF溶液对单晶硅损伤层的选择性刻蚀特性,提出一种快速检测单晶硅亚表面损伤层厚度的方法。透射电镜观测结果显示,HF溶液能选择性地刻蚀单晶硅划痕区域的亚表面损伤层,证实了该方法检测结果的有效性。利用该方法研究了载荷和速度对单晶硅亚表面划痕损伤的影响。结果表明,当外加载荷为单晶硅临界屈服载荷的1.1倍及以下时,单晶硅亚表面的划痕损伤层厚度随刻画速度的增大而减小;而当外加载荷达到临界屈服载荷的12.5倍时,单晶硅亚表面的划痕损伤对刻画速度的变化不敏感。该方法可方便快捷地检测单晶硅划痕区域亚表面的损伤层厚度,有望应用于单晶硅晶圆平坦化过程的损伤检测与控制。

Rapid Detection on the Thickness of Sub-surface Damage Layer of Silicon

To ensure the quality of silicon wafer during the lapping and polishing process, it is essential to develop a rapid, simple and cheap detection method on the sub-surface damage layer of silicon. Based on the selective etching behavior of damage silicon layer in HF solution, a rapid detection method is proposed to detect the thickness of sub-surface damage layer of silicon. TEM analysis indicate that the sub-surface amorphous layer can be selectively etched off in HF solution. Such results confirme the validity of the method. Based on the proposed method, effects of applied load and sliding speed on the sub-surface damage of silicon are investigated during scratching process. When the applied load is below 1.1 times the critical load for the initial yield of silicon, the sub-surface damage layer becomes thinner with the increase of the sliding speed. However, when the load is 12.5 times the critical load, the thickness of the sub-surface damage layer not change with the variation of scratching speed. Since this method can conveniently detect the thickness of sub-surface damage layer of silicon, it is expected to be applied for the detection and control of the sub-surface damage of silicon during wafer planarization process.