P-Type Doping of Solid-Phase Crystallized PVD-MoS₂ Film Using Nitrogen Annealing Accelerated by Hydrogen

The p-type doping of solid-phase crystallized molybdenum disulfide (MoS2) films deposited via radio-frequency magnetron sputtering has been achieved by nitrogen annealing accelerated by hydrogen using forming gas (3% H2/N2). The hydrogen reduces S-S and also Mo-S bondings on the PVD-MoS2 film surface formed by sulfur vapor annealing, allowing for the incorporation of nitrogen in the film and resulting in p-type doping. Based on the experimental results, the Fermi level of MoS2 film relative to valence band maximum shifted from 0.79 to 0.53 eV after forming gas annealing at 100∘C. Thus, it is suggested that the nitrogen annealing accelerated by hydrogen, with careful consideration of the balance between the effects of S-S bonding reduction and nitrogen incorporation, serves as a non-destructive p-type doping method for solid-phase crystallized PVD-MoS2 films compatible with the complementary metal-oxide-semiconductor (CMOS) process.