A wet etching method for few-layer black phosphorus with an atomic accuracy and compatibility with major lithography techniques

This paper reports a few-layer black phosphorus thickness pattern fabricated by a top-down nanofabrication approach. This was achieved by a new wet etching process that can etch selected regions of few-layer black phosphorus with an atomic layer accuracy. This method is deep-UV and e-beam lithography process compatible,and is free of oxygen and other common doping sources. It provides a feasible patterning approach for largescale manufacturing of few-layer BP materials and devices.