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Title: Using in-process measurements of open-gate structures to evaluate threshold voltage of normally-off GaN-based high electron mobility transistors

The parameters of open-gate structures treated with different etching time were monitored during the gate recess process, and their impacts on the threshold voltage (V{sub th}) of final fabricated AlGaN/GaN high electron mobility transistors (HEMTs) based on open-gate structures were discussed in this paper. It is found that V{sub th} can exceed 0 V when channel resistance in the recessed region (R{sub on-open}) increases over ∼275 Ω mm, maximum current (I{sub Dmax}) decreases below ∼29 mA/mm, or recessed barrier thickness (t{sub RB}) is below ∼7.5 nm. In addition, t{sub RB} obtained by atomic force microscopy measurements and C-V measurements are also compared. Finally, theoretical common criteria based on the experimental results of this work for t{sub RB} and R{sub on-open} were established to evaluate the V{sub th} of a regular normally-off AlGaN/GaN HEMTs. The results indicate that these parameters of open-gate structure can be utilized to achieve normally-off HEMTs with controllable V{sub th}.
Authors:
; ; ; ;  [1] ;  [2] ; ; ; ;  [3]
  1. School of Advanced Materials and Nanotechnology, Xidian University, Xi'an 710071 (China)
  2. (China)
  3. Key Lab of Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071 (China)
Publication Date:
OSTI Identifier:
22485952
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 16; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ATOMIC FORCE MICROSCOPY; CURRENTS; ELECTRIC POTENTIAL; ELECTRON MOBILITY; ETCHING; GALLIUM NITRIDES; THICKNESS; TRANSISTORS