Effects of plasma-enhanced chemical vapor deposition (PECVD) on the carrier lifetime of Al2O3 passivation stack

We investigated the effect on the minority carrier lifetime of atomic layer deposition (ALD) Al 2 O 3 passivation by a plasma-enhanced chemical vapor deposition (PECVD) SiON layer in Si/Al 2 O 3 /SiON-passivated structure. The lifetime variation of the Al 2 O 3 /SiON stack layer was found to depend on both the plasma power and the deposition temperature during the PECVD SiON process and to show better thermal stability than the Al 2 O 3 /SiNx:H stack under the same deposition conditions. The lifetime after a high-temperature firing process was improved dramatically at the PECVD deposition temperature of 200 °C. Our results provide a significant clue to reason for the improvement of the passivation performance for passivated emitter and rear contact (PERC) silicon solar cells.