Semiconducting Behavior and Logic in Ultrathin Rhenium Disulfide Field Effect Transistors
Recently, Transition Metal Dichalcogenide (TMD) materials have been explored as an alternative two dimensional material for post-Si CMOS applications. Here we report the fabrication and device characterization of ultra-thin, dual-gated Rhenium Disulfide (ReS2) field effect transistors (FETs). ReS2 was exfoliated on to oxidized highly doped Si substrates, and then contacted in various configurations to probe device performance and the differences in field effect and intrinsic carrier mobility. A top-gate was added after e-beam evaporation of an alumina gate dielectric. Evidence of varying Schottky barriers heights at the metal/TMD interface was seen in the device performance for several different contact metals with Cr/Au being the lowest barrier found. The maximum intrinsic mobility was 26 cm2V−1s−1 at 77 K. These devices showed current saturation, a subthreshold swing of 87 mV/decade, device conductance of 15 nS, and a transconductance of 160 nS indicating voltage gain. A nearly band-gap independent of layer number combined with voltage gain in the FETs indicate potential for using ReS2 in future logic based integrated circuit designs. To demonstrate this we fabricated an NMOS inverter where a voltage gain of 1.6 and an on/off ratio of 4.5 were achieved.
Sunday, Sept. 20, 2015, 8 a.m. — Tuesday, Sept. 22, 2015, 10 p.m. CT
Austin, TX, United States
Technical conference and networking event for SRC members and students.