Defect control methods for SIMOX SOI wafer manufacture and processing

The layered structure of thin film silicon-on-insulator (SOI) wafers introduces new considerations for defect detection, particularly for optical metrology tools used to characterize and control SOI wafer processing. Multi-layer interference, as well as subsurface features of the material, can complicate the detection of surface defects. Non-particle defect types which scatter light, such as mounds, pits (including so-called “HF” defects), and slip lines, can be efficiently detected and classified with advanced operating modes of state-of-the art optical metrology tools. Such capabilities facilitate improvements in the wafer manufacturing process, and result in improved defect detection capabilities and material quality. This work describes defect characterization of SIMOX-SOI wafers using the KLA-Tencor Surfscan 6420 and SP1^TBI