Wafer-scale atomic layer etching of Al2O3 and 2D-MoS2 grown by plasma-enhanced atomic layer deposition

Abstract:
Manufacturing with sub-nanometer precision in both deposition and ablation is necessary for the industrial implementation of 2D material-based electronics. This paper presents a plasma enhanced atomic layer etching (PEALE) process using BCl3 and Ar plasmas, which is applicable to 2D MoS2 as a semiconductor and Al2O3 as a passivation/dielectric layer. This process enables the precise etching of Al2O3 at a rate of 2.0 A per cycle and MoS2 at a rate of 0.8 A per cycle. Etching has little influence on the properties of the MoS2 film and selective etching of Al2O3 can be achieved by choosing a suitable bias voltage of -15 V. As an example of an electronic preparation sequence, the production of a Al2O3/MoS2 material stack without a vacuum break using plasma-assisted ALD is demonstrated.