Junction Passivation for Direct Silicon Bond Hybrid Orientation Technology

Direct silicon bonding (DSB) for hybrid orientation technology has recently generated a lot of interest due to the significant performance enhancements reported for PMOS devices that are fabricated on alternative substrate orientations. Significantly higher leakage was observed for P⁺/N diodes if the junction depletion region was located close to the interface between the (110) and (100) Si surfaces. Hydrogen and fluorine passivation of this interface by ion implantation resulted in an order of magnitude improvement in the reverse leakage. In this brief, the experiments that performed using several dose levels of H₂, F, and N implants are described. Electrical characterization data for reverse leakage, forward current, and ideality factors are presented in the form of cumulative probability plots, from which it is concluded that H and F passivation by ion implantation consistently provides a significant improvement in junction leakage, as compared to an unimplanted DSB wafer. An increase in the forward resistance was observed due to the implants, as compared to bulk Si (100) control samples.