Integrated MoS₂ n-MOSFETs and black phosphorus p-MOSFETs with HfO₂ dielectrics and local backgate electrodes

Two-dimensional (2D) semiconductors are of interest for numerous device applications, as they can provide excellent scalability and ease of integration onto arbitrary substrates and high performance transistors have been demonstrated with various 2D materials [1-2]. In particular, MoS₂ and black phosphorus (BP) are both promising 2D materials for use in metal-oxide-semiconductor field-effect transistors (MOSFETs). MoS₂ is particularly useful for n-MOSFETs [3], but p-type MoS₂ devices are difficult to fabricate. On the other hand, recent reports of BP p-MOSFETs have shown excellent performance [4]. However, the only reports of logic circuits based upon material combination have utilized devices with Al₂O₃ dielectrics [5]. In this paper, we report the co-integration of black phosphorus n-MOSFETs with BP p-MOSFETs using local backgates with high-K HfO₂ dielectrics and demonstrate their operation both before and after passivation to create air-stable devices. The devices show high transconductance and excellent matching between p-and n-FET characteristics, and these results pave the way for creating high-performance logic circuits using 2D semiconducting materials.