Abstract
We investigated the effects of the thermal stability of atomic layer deposition (ALD) oxidants on the surface passivation of ALD-Al2O3 film. The results showed good passivation at temperatures not greater than 780 °C. However, we found that Al2O3 films with an ozone oxidant showed better surface passivation at high temperatures than the water-based samples. The Al2O3 films with a water oxidant yielded an additional interfacial oxide upon high-temperature annealing. In the case of the ozone-based samples, the interfacial Si–O bonds that formed during deposition were more stable. This structural change degraded chemical passivation, which increased the interface-trap density to ~1012 eV−1 cm−2. The passivation performance of ALD-Al2O3 films showed that at temperatures over 780 °C the passivation quality was affected more by defective passivation at the Si/SiOx interface than by a negative-fixed charge.
Original language | English |
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Pages (from-to) | 57-60 |
Number of pages | 4 |
Journal | Thin Solid Films |
Volume | 649 |
DOIs | |
State | Published - 1 Mar 2018 |
Keywords
- Alumina
- Aluminum oxide
- Atomic layer deposition
- Ozone
- Silicon-based solar cells
- Surface passivation
- Thermal stability