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Title: Study on the Ge{sub 1−x}Sn{sub x}/HfO{sub 2} interface and its impacts on Ge{sub 1−x}Sn{sub x} tunneling transistor

In this paper, we employ first-principle calculation to investigate the Ge{sub 1−x}Sn{sub x}/HfO{sub 2} interface, and then evaluate its impacts on Ge{sub 1−x}Sn{sub x} tunneling field-effect transistor (TFET). First-principle calculations of Ge{sub 1−x}Sn{sub x}/HfO{sub 2} interfaces in the oxygen-rich process atmosphere indicate that the interface states originate from the Ge and Sn dangling bond, rather than Hf-bond. The total density of state shows that there are more interface states in the semiconductor bandgap with increasing Sn fraction. By further incorporating the material and interface parameters from density functional theory calculation into advanced device simulation, the electrical characteristics of Ge{sub 1−x}Sn{sub x} TFET are investigated. Removing the Sn atom from the first atom layer of Ge{sub 1−x}Sn{sub x} in device processes is found to be beneficial to reduce the degradations. For the degradation mechanisms, the trap-assisted-tunneling is the dominant mechanism at the low Sn fraction, and enhanced Shockley-Read-Hall recombination induced by traps becomes the dominant mechanism with increasing Sn fraction. The results are helpful for the interface optimization of Ge{sub 1−x}Sn{sub x} TFET.
Authors:
; ; ;  [1]
  1. Key Laboratory of Microelectronic Devices and Circuits, Institute of Microelectronics, Peking University, Beijing 100871 (China)
Publication Date:
OSTI Identifier:
22304028
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 23; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPUTERIZED SIMULATION; DENSITY FUNCTIONAL METHOD; FIELD EFFECT TRANSISTORS; GERMANIUM ALLOYS; HAFNIUM OXIDES; INTERFACES; LAYERS; OPTIMIZATION; OXYGEN; RECOMBINATION; SEMICONDUCTOR MATERIALS; TIN ALLOYS; TRAPS; TUNNEL EFFECT