Effects of Simultaneous Phosphorus and Arsenic Diffusions on Emitter Push and Dislocation Generation

摘要

High Concentration phosphorus diffusions into single crystalline silicon damages the silicon material producing anomalous diffusion effects and degrading device performance. Dislocations and a supersaturation of point defects are created to reduce the lattice strain caused by the presence of the undersized phosphorus atoms. A consequence of the lattice damage is the emitter push effect observed in double diffused structures (i.e., bipolar junction transistors). Simultaneous phosphorus and arsenic diffusions from CVD dual dopant SiO2 sources are reported by M. Watanabe et. al. to be dislocation free and eliminate emitter push in double diffused structures. This study investigated the effects of simultaneous phosphorus and arsenic drive-in diffusions from predeposition diffusions using dual dopant SiO2 spin-on emitter push and dislocation generation. Although no reduction in emitter push was observed in this study, a minimization in dislocation density was exhibited in the dual dopant diffused layer surfaces near the optimum ratios reported by M. Watanabe et. al. It is recognized that both the present study and the M. Watanabe et. al., study are early investigations into this new technology. Both studies indicate that this new process shows promise to improve semiconductor device performance. (Author)