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Title: High-k shallow traps observed by charge pumping with varying discharging times

In this paper, we investigate the influence of falling time and base level time on high-k bulk shallow traps measured by charge pumping technique in n-channel metal-oxide-semiconductor field-effect transistors with HfO{sub 2}/metal gate stacks. N{sub T}-V{sub high} {sub level} characteristic curves with different duty ratios indicate that the electron detrapping time dominates the value of N{sub T} for extra contribution of I{sub cp} traps. N{sub T} is the number of traps, and I{sub cp} is charge pumping current. By fitting discharge formula at different temperatures, the results show that extra contribution of I{sub cp} traps at high voltage are in fact high-k bulk shallow traps. This is also verified through a comparison of different interlayer thicknesses and different Ti{sub x}N{sub 1−x} metal gate concentrations. Next, N{sub T}-V{sub high} {sub level} characteristic curves with different falling times (t{sub falling} {sub time}) and base level times (t{sub base} {sub level}) show that extra contribution of I{sub cp} traps decrease with an increase in t{sub falling} {sub time}. By fitting discharge formula for different t{sub falling} {sub time}, the results show that electrons trapped in high-k bulk shallow traps first discharge to the channel and then to source and drain during t{sub falling}more » {sub time}. This current cannot be measured by the charge pumping technique. Subsequent measurements of N{sub T} by charge pumping technique at t{sub base} {sub level} reveal a remainder of electrons trapped in high-k bulk shallow traps.« less
Authors:
; ;  [1] ;  [2] ;  [3] ; ; ; ;  [2] ; ;  [4] ;  [5] ; ; ;  [6]
  1. Department of Electronics Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China)
  2. Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China)
  3. (China)
  4. Department of Embedded System Engineering, Peking University, Beijing, P.R.China (China)
  5. Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan (China)
  6. Device Department, United Microelectronics Corporation, Tainan Science Park, Taiwan (China)
Publication Date:
OSTI Identifier:
22257809
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 17; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CONCENTRATION RATIO; ELECTRIC POTENTIAL; FIELD EFFECT TRANSISTORS; HAFNIUM OXIDES; METALS; PUMPING; SEMICONDUCTOR MATERIALS; THICKNESS; TRAPPING; TRAPS