Non-Contact Silicon Epilayer and Subsurface Characterization with UV/mm Wave Technique
SourceCarrier lifetimes and interface recombination velocities in p/p+ and n/n+ Si epitaxial wafers are determined from the photoconductivity decays (PCDs) measured using UV/mm-wave technique. Mo and Fe are found in p/p+ Si epitaxial wafers. Gate oxide integrity (GOI) is not dependent on roughness of Rrms (root-mean-square surface roughness) 0.097–0.247 nm but dependent on subsurface damage induced by chemical mechanical polishing (CMP). Photoconductivity amplitude (PCA) signal measured by the UV/mm-wave technique correlates closely the gate oxide integrity yield. CMP induced by subsurface damage is removed by SC1 cleaning and the procedure is monitored by the UV/mm-wave technique. Lifetimes in a denuded zone (DZ) and intrinsic gettering (IG) layer are determined from the PCA signal measured using the UV/mm-wave technique.