EXPERIMENTAL STUDY OF LOW-FIELD TRANSPORT IN HIGHLY CONFINED ARSENIDE-ANTIMONIDE QUANTUM WELL HETEROSTRUCTURES

Open Access
Author:
Agrawal, Ashish
Graduate Program:
Electrical Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
July 12, 2011
Committee Members:
  • Suman Datta, Thesis Advisor
  • Srinivas A Tadigadapa, Thesis Advisor
Keywords:
  • Relaxation Time Approximation
  • Low field transport
  • Arsenide Antimonides
  • Scattering
  • QMSA
  • Effective mass
Abstract:
As Si approaches end of the roadmap, finding a new transistor technology that allows the extension of Moore’s law has become a problem of great technical challenge and significance. Among the various candidates, III-V based MOSFETs are recognized as a very promising substitute. Specifically, low effective mass materials with high electron velocities, such as InAs and InSb are of great interest. Mixed anion InAsySb1􀀀y quantum wells (QW) with high electron mobility are candidates for direct integration with high hole mobility InxGa1􀀀xSb for ultra low power complementary applications. In order to understand the intrinsic performance of these high mobility materials, it is imperative to comprehend the factors that limit the mobility and how it changes as we scale the device for better short channel effects. In this work, a comprehensive model based on the Momentum Relaxation Time approximation is formulated to determine the mechanisms limiting the mobility in the fabricated As-Sb quantum wells. The effect of conduction band nonparabolicity in the narrow bandgap InAsSb quantum well in transport and confinement direction of the E-k has been studied and incorporated in the transport model. All major scattering mechanisms, including acoustic phonons, polar optical phonons, alloy disorder, remote ionized impurities, interface roughness and interface charge scattering have been taken into account. The low-field electron transport properties of the 2DEG in the AlInSb/InAsSb quantum wells is studied as a function of temperature. Our model simultaneously explains the low-field electron transport in wide and scaled As-Sb devices. Finally, based on the calibrated model, we predict the low field performance for ultra scaled HEMT device for sub-10nm technology nodes.