工艺参数对磨削硅晶圆亚表面损伤裂纹的影响

Effects of Grinding Parameters on the Subsurface Cracks of Ground Wafers

为研究粗磨硅晶圆亚表面微裂纹,采用截面显微观测法,实验研究了粗磨工艺下砂轮进给速率、砂轮转速和硅晶圆转速对晶圆亚表面裂纹的影响.结果表明:磨削后晶圆亚表面斜线裂纹和折线裂纹占70%,中位裂纹、分叉裂纹和横向裂纹占30%,裂纹形状与工艺参数的关系不大.裂纹深度从晶圆圆心向外逐渐增大,〈110〉晶向裂纹深度稍大于〈100〉晶向.裂纹深度随砂轮进给速率增大单调增加,随砂轮转速增大单调减小.裂纹深度与晶圆转速之间的关系复杂,晶圆转速增大时,裂纹深度先是减小,然后增大.提出了磨削工艺参数的优化措施.

In this paper,a cross-section microscopy method was used to examine the shape and depth of subsurface cracks of ground wafers under nine sets of rough grinding parameters.Results show that 70%of the cracks are diagonal and chevron crack,and 30% of the cracks are median,fork and lateral cracks.Crack shapes are independent of grinding parameters.The depth of crack increases with increasing distance from the wafer center,and the crack depth in 〈110 〉crystal orientation are greater than that in 〈100 〉 crystal orientation.With the increase of the wheel feed rate,the crack depth increases.With the increase of the wheel rotation speed,the crack depth decreases.With the increase of the wafer rotation speed,the cracks depth decreases first in the range of 150-200 r/min,and then increases in the range of 200-250 r/min.Based on the experimental results,an optimized grinding condition is proposed.