Benchmarking monolayer MoS2 and WS2 field-effect transistors

Abstract

Here we benchmark device-to-device variation in field-effect transistors (FETs) based on monolayer MoS2 and WS2 films grown using metal-organic chemical vapor deposition process. Our study involves 230 MoS2 FETs and 160 WS2 FETs with channel lengths ranging from 5 μm down to 100 nm. We use statistical measures to evaluate key FET performance indicators for benchmarking these two-dimensional (2D) transition metal dichalcogenide (TMD) monolayers against existing literature as well as ultra-thin body Si FETs. Our results show consistent performance of 2D FETs across 1 × 1 cm2 chips owing to high quality and uniform growth of these TMDs followed by clean transfer onto device substrates. We are able to demonstrate record high carrier mobility of 33 cm2 V−1 s−1 in WS2 FETs, which is a 1.5X improvement compared to the best reported in the literature. Our experimental demonstrations confirm the technological viability of 2D FETs in future integrated circuits.

Improved Performances of CVD‐Grown MoS2 Based Phototransistors Enabled by Encapsulation

“…We note that the mobility of pristine grown‐MoS 2 is poor compared to that in the recently reported monolayer MoS 2 grown by the MOCVD method. [ 18 ] We then encapsulated the MoS 2 with ALD‐Al 2 O 3 , and the mobilities are much improved up to 33.5–62.5 cm 2 Vs −1 and around 6.7–28.6 cm 2 Vs −1 for MoS 2 triangle crystal and MoS 2 film, respectively.…”

“…[ 13–17 ] Recently, Das group has developed the high quality and uniform growth of TMDs using the metal‐organic chemical vapor deposition (MOCVD) technique and benchmarked device‐to‐device variation in transistors across 1 × 1 cm 2 chips, a record high carrier mobility of 46 and 33 cm 2 Vs −1 is demonstrated for monolayer MoS 2 and WS 2 , respectively. [ 18 ] The high quality of monolayer MoS 2 has enabled the ultrasensitive photodetectors with high speed and low energy expenditure of ≈100 pico Joules, [ 19,20 ] which can be further applied successfully in collision avoidance systems as low‐power biomimetic collision detector. [ 21 ]…”

Annealing Accelerator for Ising Spin Systems based on In-memory Complementary 2D FETs

“…First, unlike quantum computers operating at cryogenic temperatures, our demonstration is based on room temperature, and second, we exploit analog subthreshold conduction and analog programmability to design unique computing primitives and annealing schedule which achieve better energy and area efficiency compared to large memristive cross-bar arrays. Note that earlier works have already demonstrated the scalability and technological viability of 2D materials [29][30][31]. Additionally, in-memory and near-memory technologies based on 2D materials have been used recently for various computing tasks overcoming the von-Neumann bottleneck [32][33][34].…”

“…2e-f, respectively. We have used monolayer MoS2 grown using metal organic chemical vapor deposition technique as described in our earlier reports [32,43,44] (see Methods section for details on n-type MoS2 FET fabrication). .…”

“…5d shows the convergence accuracy for 100 randomly oriented × ferromagnetic spin systems as a function of total number of spins ( 2) and total number of SA iterations. Even for = 10, SA requires only ~ 3500 iterations or maximum number of spin flips in comparison to ~10 30 maximum number of spin flips required for an exhaustive search demonstrating the tremendous improvement in acceleration (~ 10 26 X). Fig.…”