High performance transistors based on two dimensional materials

摘要

In this paper, high performance black phosphorus (BP) p-type filed effect transistors (pFET) have been demonstrated by using atomic layer deposition (ALD) HfLaO as the back-gate dielectrics. Compared with traditional dielectric layer of SiO₂, the ALD high-K HfLaO is expected to better screen impurities and reduce surface charge scattering, leading to a larger mobility and higher current. High I_on(at V_d= -2 V) of 468 μA/μm at T = 300 K and 921 μA/μm at T = 20 K have been achieved, which is the new record high output current of BP transistors to date. Systematic study on Al₂O₃encapsulation by Physical Vapor Deposition (PVD) of 2 nm Al as seeding layer has been carried out, the encapsulated BP transistors show high air stability up to 6 weeks.