硅片加工表面层损伤检测技术的试验研究

Experimental Investigation on the Detection Technique for Surface Layer Damage of Machined Silicon Wafers

单晶硅片超精密加工表面层损伤较小,检测评价比较困难。为了确定合适的检测技术,对多种硬脆材料表面层质量检测技术进行了系统的试验研究。结果表明,硅片加工表面宏/微观形貌可采用各种显微镜及3D表面轮廓仪等进行检测,表面损伤分布可采用择优腐蚀法和分步蚀刻法检测;粗加工和半精加工硅片的损伤深度宜采用角度抛光法检测,而精加工硅片的损伤深度较小,宜采用截面Raman光谱分析和恒定腐蚀速率法检测;损伤层的微裂纹、位错、非晶及多晶相变等微观结构可采用分步蚀刻法、平视和剖视TEM分析法及显微Raman光谱仪检测;表面层宏观残余应力分布可用显微Raman光谱仪检测,其微观应变可采用高分辨X射线衍射仪的双晶摇摆曲线的半高宽值来衡量。综合以上检测技术可以对硅片加工表面层损伤进行系统的评价。

It is difficult to evaluate the damage layer of the machined wafer because it is less.In order to determine the suitable measurement method,the measurement techniques which can be used to evaluate the hard and brittle materials surface layer damage are systemic studied in this paper.The results show that the surface macro/micro pattern can be observed by various microscopes and 3D surface profile meter.The surface defects can be measured by preferential etching and step etching.The subsurface damage depth（SSD） of rough and semi-fine machined wafers can be measured by angle polishing.The SSD of fine machined wafers is less so it should be measured by cross-sectional Raman microspectroscopy or constant corrosion rate method.The microstructure of damage layer,such as microcracks,dislocations,amorphous and polycrystalline phases,can be measured by step etching,TEM analysis and Raman microspectroscopy.The macro residual stress of the surface layer can be measured by Raman microspectroscopy.The micro strain can by evaluated by using HRXRD through the FWHM variation of the X-ray double crystal rocking curves.The machined surface layer damage of silicon wafers can be evaluated systematically by the above measurement techniques.