A review of PECVD aluminum oxide for surface passivation

During the last few years aluminum oxide became an inescapable passivation layer in the Si photovoltaic field. The keys of its success are its excellent interface with the Si surface and its powerful field effect, which lead to best passivation quality ever reported on p-type silicon surfaces. Plasma-enhanced chemical vapor deposition (PECVD) allows the fabrication of high-quality aluminum oxide layers that can be used for the passivation of p-type silicon surfaces of a wide range of doping levels. In this paper, the properties of PECVD Al2O3 layers are reviewed, including the passivation of highly and lowly doped p-type surfaces and the suitability of these processes to industrial solar cell production