Impact of Deposition of ITO on Tunnel Oxide Passivating Poly-Si Contact
Woojun Yoon1, Young-Woo Ok2, David Scheiman1, Ajeet Rohatgi2, Phillip Jenkins1
1Naval Research LAb, Washington, DC, United States
/2Georgia Institute of Technology, Atlanta, GA, United States

In this study, we investigate the impact of deposition of indium tin oxide (ITO) via DC magnetron sputtering on tunnel  oxide passivating poly-Si contact. The effective minority carrier lifetime is characterized using symmetric lifetime samples with tunnel SiOx passivating n+ poly-Si contact on the n-type Cz wafer. Compared to the implied open-circuit voltage (iVoc) of 697 mV and implied fill factor (iFF) of 80.9% obtained from the lifetime sample before ITO, the effective minority carrier lifetime of the ITO sputtered sample is almost fully recovered after thermal annealing, resulting in the iVoc of 695 mV and iFF of 80.4%. The characteristic of fully recovered effective lifetime attribute to unique sputtering conditions employing very low power density and at room temperature.