| AVS 66th International Symposium & Exhibition | |
| Electronic Materials and Photonics Division | Monday Sessions |
| Session EM+PS+TF-MoA |
| Session: | New Devices and Materials for Logic and Memory |
| Presenter: | Connor McClellan, Stanford University |
| Authors: | C. McClellan, Stanford University E. Yalon, Stanford University K. Smithe, Stanford University C. English, Stanford University S. Vaziri, Stanford University C. Bailey, Stanford University A. Sood, Stanford University M. Chen, Stanford University E. Pop, Stanford University |
| Correspondent: | Click to Email |
This talk will present recent highlights from our research on two-dimensional (2D) materials and devices including graphene, and transition metal dichalcogenides (TMDs). The results span from fundamental measurements and simulations, to devices, to system-oriented applications which take advantage of unusual 2D material properties.
Using the low cross-plane thermal conductance, we found unexpected applications of graphene as an ultra-thin electrode to reduce power consumption in phase-change memory [1]. We have also demonstrated wafer-scale graphene systems for analog dot product computation [2]. We have grown monolayer 2D semiconductors by chemical vapor deposition over cm2 scales on amorphous oxides, including MoS2 with low device variability [3], WSe2, and MoSe2.
Using a self-aligned process, we demonstrated 10 nm gate-length monolayer MoS2 transistors with excellent switching characteristics and approaching ballistic limits [4]. Using sub-stochiometric oxides, we achieved high electron doping to reduce electrical contact resistance down to 480 Ω∙μm and increase on-current up to a record of 700 μA/μm in monolayer MoS2 [5]. We also directly measured the saturation velocity in monolayer MoS2, finding it is thermally-limited (i.e. by device self-heating and phonon scattering) to about one-third that of silicon and about one-tenth that of graphene [6]. Using Raman thermometry, we uncovered low thermal boundary conductance (~15 MW/m2/K) between MoS2 and SiO2, which could limit heat dissipation in 2D electronics [7]. We are presently exploring unconventional applications including thermal transistors [8], which could enable nanoscale control of heat in “thermal circuits” analogous with electrical circuits. These studies reveal fundamental limits and new applications of 2D materials, taking advantage of their unique properties.
References: [1] A. Behnam et al., Appl. Phys. Letters. 107, 123508 (2015). [2] N. Wang et al., IEEE VLSI Tech. Symp., Jun 2016, Honolulu HI. [3] K. Smithe et al., ACS Nano 11, 8456 (2017). [4] C. English et al., IEEE Intl. Electron Devices Meeting (IEDM), Dec 2016. [5] C. J. McClellan et al., IEEE Device Research Conference (DRC), June 2017. [6] K. Smithe et al., Nano Lett. 18, 4516 (2018). [7] E. Yalon, E. Pop, et al., Nano Lett. 17, 3429 (2017). [8] A. Sood, E. Pop et al. Nature Comm. 9, 4510 (2018).