Passivation of c-Si surfaces by sub-nm amorphous silicon capped with silicon nitride
Yimao Wan, Di Yan, James Bullock, Xinyu Zhang, Andres Cuevas
APPLIED PHYSICS LETTERS | AMER INST PHYSICS | Published : 2015
A sub-nm hydrogenated amorphous silicon (a-Si:H) film capped with silicon nitride (SiNx) is shown to provide a high level passivation to crystalline silicon (c-Si) surfaces. When passivated by a 0.8 nm a-Si:H/75 nm SiNx stack, recombination current density J0 values of 9, 11, 47, and 87 fA/cm2 are obtained on 10 Ω·cm n-type, 0.8 Ω·cm p-type, 160 Ω/sq phosphorus-diffused, and 120 Ω/sq boron-diffused silicon surfaces, respectively. The J0 on n-type 10 Ω·cm wafers is further reduced to 2.5 ± 0.5 fA/cm2 when the a-Si:H film thickness exceeds 2.5 nm. The passivation by the sub-nm a-Si:H/SiNx stack is thermally stable at 400 °C in N2 for 60 min on all four c-Si surfaces. Capacitance-voltage measur..View full abstract
This work has been supported by the Australian government through the Australian Renewable Energy Agency (ARENA). Responsibility for the views, information or advice expressed herein is not accepted by the Australian Government. Plasma enhanced chemical vapour deposition and Ellipsometer facilities at the Australian National Fabrication Facility were used in this work.