Mobility Deception in Nanoscale Transistors: An Untold Contact Story
Abstract
Mobility is a critical parameter that is routinely used for benchmarking the performance of field‐effect transistors (FETs) based on novel nanomaterials. In fact, mobility values are often used to champion nanomaterials since high‐performance devices necessitate high mobility values. The current belief is that the contacts can only limit the FET performance and hence the extracted mobility is an underestimation of the true channel mobility. However, here, such misconception is challenged through rigorous experimental effort, backed by numerical simulations, to demonstrate that overestimation of mobility occurs in commonly used geometries and in nanomaterials for which the contact interface, contact doping, and contact geometry play a pivotal role. In particular, dual‐gated FETs based on multilayer MoS2 and WSe2 are used as case studies in order to elucidate and differentiate between intrinsic and extrinsic contact effects manifesting in the mobility extraction. The choice of 2D layered transition metal dichalcogenides (TMDCs) as the semiconducting channel is motivated by their potential to replace and/or coexist with Si‐based aging FET technologies. However, the results are equally applicable to nanotube‐ and nanowire‐based FETs, oxide semiconductors, and organic‐material‐based thin‐film FETs.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 14, 2018
- Source ID
- 10.1002/adma.201806020
Entities
People
- Amritanand Sebastian
- Daniel S. Schulman
- Joseph R. Nasr
- Mark W. Horn
- Saptarshi Das
Organizations
- Air Force Office of Scientific Research
- National Science Foundation
- Pennsylvania State University
- Semiconductor Research Corporation