The integration of ultra-thin gate oxide, especially at sub-10 nm region, is one of the principle problems in MoS2 based transistors. In this work, we demonstrate sub-10 nm uniform deposition of Al2O3 on MoS2 basal plane by applying ultra-low energy remote oxygen plasma pretreatment prior to atomic layer deposition. It is demonstrated that oxygen species in ultra-low energy plasma are physically adsorbed on MoS2 surfaces without making the flakes oxidized, and is capable of benefiting the mobility of MoS2 flake. Based on this method, top-gated MoS2 transistor with ultrathin Al2O3 dielectric is fabricated. With 6.6 nm Al2O3 as gate dielectric, the device shows gate leakage about 0.1 pA/μm(2) at 4.5 MV/cm which is much lower than previous reports. Besides, the top-gated device shows great on/off ratio of over 10(8), subthreshold swing (SS) of 101 mV/dec and a mobility of 28 cm(2)/Vs. With further investigations and careful optimizations, this method can play an important role in future nanoelectronics.
No takes yet. Share an insight, caveat, or question.
Yang et al. (2015) studied this question.