论文部分内容阅读
Atomic-layer-deposited(ALD) aluminum oxide(Al_2O_3) has demonstrated an excellent surface passivation for crystalline silicon(c-Si) surfaces, as well as for highly boron-doped c-Si surfaces. In this paper, water-based thermal atomic layer deposition of Al_2O_3 films are fabricated for c-Si surface passivation. The influence of deposition conditions on the passivation quality is investigated. The results show that the excellent passivation on n-type c-Si can be achieved at a low thermal budget of 250℃ given a gas pressure of 0.15 Torr. The thickness-dependence of surface passivation indicates that the effective minority carrier lifetime increases drastically when the thickness of Al_2O_3 is larger than 10 nm. The influence of thermal post annealing treatments is also studied. Comparable carrier lifetime is achieved when Al_2O_3 sample is annealed for 15 min in forming gas in a temperature range from 400℃ to 450℃. In addition, the passivation quality can be further improved when a thin PECVD-SiN_x cap layer is prepared on Al_2O_3, and an effective minority carrier lifetime of2.8 ms and implied Voc of 721 mV are obtained. In addition, several novel methods are proposed to restrain blistering.
Atomic-layer-deposited (ALD) aluminum oxide (Al_2O_3) has demonstrated an excellent surface passivation for crystalline silicon (c-Si) surfaces, as well as for highly boron-doped c-Si surfaces. The influence of deposition conditions on the passivation quality is investigated. The results show that the excellent passivation on n-type c-Si can be achieved at a low thermal budget of 250 ° C given a gas pressure of 0.15 Torr. The thickness-dependence of surface passivation that the effective minority carrier lifetime increases drastically when the thickness of Al_2O_3 is larger than 10 nm. The influence of thermal post annealing treatments is also studied. Comparable carrier lifetime is achieved when the A1_2O_3 sample is annealed for 15 min in forming gas in a temperature range from 400 ° C to 450 ° C. In addition, the passivation quality can be further improved when a thin PECVD-SiN_x cap layer is prepared on Al 2 O 3, and an effective minority carrier lifetime of 2.8 ms and implied Voc of 721 mV are obtained. In addition, several novel methods are proposed to restrain blistering.