[1B01-05] Sputtering and Plasma Processes 

2:00 PM - 2:30 PM JST(5:00 AM - 5:30 AM UTC)

[1B01【依頼講演】] Ultra-low damage deposition of amorphous silicon by facing target sputtering: application to silicon wafer surface passivation

*Shinsuke Miyajima¹ (1. Institute of Science Tokyo (Japan))

Silicon solar cells have reached record efficiencies above 28% toward the 29% theoretical limit, enabled by superior surface passivation. Amorphous silicon (a-Si:H/a-Si) is critical, functioning directly in SHJ cells or indirectly via converted poly-Si in TOPCon cells. Both structures require damage-free a-Si deposition. Currently, conventional CVD methods dominate but require highly explosive $SiH_4$ gas, inflating process costs due to mandatory gas scrubbers and safety maintenance. To address this, we focused on sputtering as a safer alternative. However, standard sputtering degrades passivation quality due to surface damage from electron, ion, and recoiled Ar bombardment. While minimizing this damage under RF sputtering previously sacrificed the deposition rate, we demonstrate that facing target sputtering (FTS) with a DC power supply overcomes this trade-off, achieving excellent passivation even at high deposition rates comparable to CVD. This presentation reviews our decade-long research on FTS-based a-Si fabrication.

Password required to view