硅外延片背面边缘异常黑斑原因分析及研究

Cause Analysis and Research on Abnormal Black Patch on Backside Edge of Silicon Epitaxial Wafer

随着客户对外延片边缘的关注度不断增加,部门对质量意识的不断提升,针对硅外延片边缘异常黑斑进行原因分析及研究,分别从异物沾污、晶棒缺陷、衬底加工及外延工艺方面展开分析,最终确定此异常现象为衬底加工中倒角工艺过度研磨及外延生长中HCL抛光共同导致。由此,供应商通过进一步改善倒角工艺,提高了外延片边缘质量水平。

As customers pay more attention to the edge of the epitaxial wafer,and based on the continuous improvement of the quality awareness of the department,the cause analysis and research on the abnormal black patch on the edge of silicon epitaxial wafer are performed.The analysis is conducted from contamination,crystal defects,substrate processing and epitaxial process.It is finally determined that this anomaly is caused by excessive grinding of chamfering in substrate processing and HCL polishing in epitaxial process.As a result,the supplier improves the edge quality level of the epitaxial wafer by further improving the chamfering process.