单晶硅片磨削损伤的透射电子显微分析

为了揭示硅片自旋转磨削加工表面层损伤机理,采用透射电子显微镜对硅片磨削表面层损伤特性进行了分析.结果表明:粗磨Si片的损伤层中有大量微裂纹和高密度位错;半精磨和精磨si片的损伤层中除了微裂纹和位错外,还存在非晶硅和多晶硅(Si-I相和Si-III相).从粗磨到半精磨,Si片的非晶层厚度从约Onm增大到约110nm;从半精磨剑精磨,Si片的非品层厚度由约110nm减小至约30nm,且非晶层厚度的分布均匀性提高.从粗磨到精磨,Si片损伤深度、微裂纹深度及位错滑移深度逐渐减小,材料的去除方式由脆性断裂方式逐渐向塑性方式过渡.

TEM Observation on the Ground Damage of Monocrystalline Silicon Wafers

In order to understand the damage mechanism of the wafer rotation ground surface layer,this paper analyzes the ground damage characteristic with the aid of TEM.The results show that rough ground wafer surface layer damage is composed of a large quantity of microcracks and high density dislocations.Apart from the microcracks and dislocations,amorphous silicon and polycrystalline silicon (Si-I phase and Si-III phase) exist in the semi-fine and fine ground wafer surface layer damage.From rough grinding to semi-fine grinding,the amorphous layer depth increases from about 0 to about 110nm.From semi-fine grinding to fine grinding,the amorphous layer depth decreases from about 110 to about 30nm and the amorphous layer depth becomes uniform.From rough grinding to fine grinding,the subsurface damage depth,the depth of the microcracks,and the dislocation glide decrease gradually.From rough grinding to fine grinding,the material removal mode gradually changes from micro-fracture mode to ductile mode.