Sensitivity of polarized laser scattering detection to subsurface damage in ground silicon wafers

Silicon is the primary substrate material in the semiconductor industry. Since surface integrity of a silicon wafer is crucial to the performance of an IC chip made of the wafer, the subsurface damage (SSD) induced by machining to a silicon wafer has been intensively investigated. However, detecting SSD is a challenge due to a lack of an effective method. This study presents a novel method, the polarized laser scattering (PLS) method, for detecting SSD in ground silicon wafers. A PLS system is established to detect the grinding-induced SSD which is also evaluated by the destructive methods. The study shows that the PLS signal is sensitive to the SSD depth with a detection resolution of approximately 0.1 μm. In addition, the detectability of the PLS method is demonstrated and a relationship between the PLS signal and SSD depth is established to facilitate the practical applications of the PLS method.