Characterization of boron surface doping effects on PECVD silicon nitride passivation

In this paper, we investigate the dependence of surface recombination of B diffused and undiffused PECVD SiN_x passivated emitters on the net electrostatic charge density. We show that the application of positive surface charge results in a significant increase in the surface recombination of PECVD SiN_x passivated B diffused emitters, even for high B surface concentrations. On the other hand, negative charge causes a substantial reduction in surface recombination. Under accumulation conditions, the significant difference observed in J_0e between B diffused and undiffused samples implies that the B diffusion has resulted in some degradation of the Si-PECVD SiN_x interface. The results of J_0e under accumulation for samples with different B surface concentrations and sheet resistances suggest that the interface degradation is not a strong function of the B surface concentration or the surface orientation.