Low-thermal budget flash light annealing for Al sub(2)O sub(3) surface passivation

This value is achieved due to a very low interface trap density of below 10 super(10) eV super(-1) cm super(-2) and a fixed charge density of (2-3) 10 super(12) cm super(-2). In contrast, plasma ALD-grown Al sub(2)O sub(3) layers only reach carrier lifetimes of about 1 ms. This is mainly caused by a more than 10 times higher density of interface traps, and thus, inferior chemical passivation. The strong influence of the deposition parameters is explained by the limitation of hydrogen transport in Al sub(2)O sub(3) during low-thermal budget annealing. ( copyright 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) Al sub(2)O sub(3) passivation layers for solar cell applications require thermal activation, which is typically realized by annealing at 400 degree C. However, this temperature is not compatible with low-temperature cell architectures. In this study, millisecond flash light annealing is applied in 200 degree C/H sub(2) ambient. This low-thermal budget process reaches a level of passivation that is comparable to standard annealing.