ZnS-ZnMgS-ZnS Lattice-Matched Gate Insulator as an Alternative for Silicon Dioxide on Silicon in Quantum Dot Gate FETs (QDGFETs)

Abstract

This paper presents characteristics of two fabricated Si quantum dot gate field-effect transistors, one with SiOx-cladded Si dots on silicon dioxide as the gate insulator, and another with the same quantum dots on lattice-matched high-κ ZnS-ZnMgS-ZnS as the gate insulator. Simulations show that the oxide thickness should be within 80 A to generate a third state in the transfer characteristic of the quantum dot gate field-effect transistor. In the practical device, the silicon dioxide thickness varies between 20 A and 40 A. In this work we use high-κ dielectric thickness around 75 A to 80 A, which is equivalent to 32 A to 35 A of silicon dioxide.