skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Properties of slow traps of ALD Al{sub 2}O{sub 3}/GeO{sub x}/Ge nMOSFETs with plasma post oxidation

Abstract

The realization of Ge gate stacks with a small amount of slow trap density as well as thin equivalent oxide thickness and low interface state density (D{sub it}) is a crucial issue for Ge CMOS. In this study, we examine the properties of slow traps, particularly the location of slow traps, of Al{sub 2}O{sub 3}/GeO{sub x}/n-Ge and HfO{sub 2}/Al{sub 2}O{sub 3}/GeO{sub x}/n-Ge MOS interfaces with changing the process and structural parameters, formed by atomic layer deposition (ALD) of Al{sub 2}O{sub 3} and HfO{sub 2}/Al{sub 2}O{sub 3} combined with plasma post oxidation. It is found that the slow traps can locate in the GeO{sub x} interfacial layer, not in the ALD Al{sub 2}O{sub 3} layer. Furthermore, we study the time dependence of channel currents in the Ge n-MOSFETs with 5-nm-thick Al{sub 2}O{sub 3}/GeO{sub x}/Ge gate stacks, with changing the thickness of GeO{sub x}, in order to further clarify the position of slow traps. The time dependence of the current drift and the effective time constant of slow traps do not change among the MOSFETs with the different thickness GeO{sub x}, demonstrating that the slow traps mainly exist near the interfaces between Ge and GeO{sub x}.

Authors:
; ; ; ;  [1]
  1. Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan and JST-CREST, K's Gobancho 6F, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076 (Japan)
Publication Date:
OSTI Identifier:
22594465
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM OXIDES; DENSITY; GERMANIUM OXIDES; HAFNIUM OXIDES; INTERFACES; LAYERS; MOSFET; OXIDATION; SILICON OXIDES; STACKS; THICKNESS; TIME DEPENDENCE; TRAPS

Citation Formats

Ke, M., E-mail: kiramn@mosfet.t.u-tokyo.ac.jp, Yu, X., Chang, C., Takenaka, M., and Takagi, S. Properties of slow traps of ALD Al{sub 2}O{sub 3}/GeO{sub x}/Ge nMOSFETs with plasma post oxidation. United States: N. p., 2016. Web. doi:10.1063/1.4958890.
Ke, M., E-mail: kiramn@mosfet.t.u-tokyo.ac.jp, Yu, X., Chang, C., Takenaka, M., & Takagi, S. Properties of slow traps of ALD Al{sub 2}O{sub 3}/GeO{sub x}/Ge nMOSFETs with plasma post oxidation. United States. doi:10.1063/1.4958890.
Ke, M., E-mail: kiramn@mosfet.t.u-tokyo.ac.jp, Yu, X., Chang, C., Takenaka, M., and Takagi, S. Mon . "Properties of slow traps of ALD Al{sub 2}O{sub 3}/GeO{sub x}/Ge nMOSFETs with plasma post oxidation". United States. doi:10.1063/1.4958890.
@article{osti_22594465,
title = {Properties of slow traps of ALD Al{sub 2}O{sub 3}/GeO{sub x}/Ge nMOSFETs with plasma post oxidation},
author = {Ke, M., E-mail: kiramn@mosfet.t.u-tokyo.ac.jp and Yu, X. and Chang, C. and Takenaka, M. and Takagi, S.},
abstractNote = {The realization of Ge gate stacks with a small amount of slow trap density as well as thin equivalent oxide thickness and low interface state density (D{sub it}) is a crucial issue for Ge CMOS. In this study, we examine the properties of slow traps, particularly the location of slow traps, of Al{sub 2}O{sub 3}/GeO{sub x}/n-Ge and HfO{sub 2}/Al{sub 2}O{sub 3}/GeO{sub x}/n-Ge MOS interfaces with changing the process and structural parameters, formed by atomic layer deposition (ALD) of Al{sub 2}O{sub 3} and HfO{sub 2}/Al{sub 2}O{sub 3} combined with plasma post oxidation. It is found that the slow traps can locate in the GeO{sub x} interfacial layer, not in the ALD Al{sub 2}O{sub 3} layer. Furthermore, we study the time dependence of channel currents in the Ge n-MOSFETs with 5-nm-thick Al{sub 2}O{sub 3}/GeO{sub x}/Ge gate stacks, with changing the thickness of GeO{sub x}, in order to further clarify the position of slow traps. The time dependence of the current drift and the effective time constant of slow traps do not change among the MOSFETs with the different thickness GeO{sub x}, demonstrating that the slow traps mainly exist near the interfaces between Ge and GeO{sub x}.},
doi = {10.1063/1.4958890},
journal = {Applied Physics Letters},
number = 3,
volume = 109,
place = {United States},
year = {Mon Jul 18 00:00:00 EDT 2016},
month = {Mon Jul 18 00:00:00 EDT 2016}
}