Elimination of NPN C-E leakage yield loss in SiGe:C HBT BiCMOS technology through optimization of critical wet chemical wafer treatments

The optimization of wet chemical wafer cleans has been performed to eliminate collector-emitter leakage yield loss within a SiGe:C HBT BiCMOS technology. Analysis of spatial defect patterns and NPN leakage distributions were used to evaluate the effects of various factors associated with the wet chemical treatments. A significant improvement in both large NPN array and integrated circuit yields was achieved through the modification of wet cleans within the process modules prior to the growth of the HBT SiGe:C base epitaxy. This work highlights the importance of considering the possible impact of all wet chemical treatments used in the fabrication of SiGe:C HBT BiCMOS integrated circuits.