Title :
Influence of layer structure on electrical properties of AlGaN/GaN HEMTs
Author :
Benko, P. ; Kovac, J. ; Chvala, Ales ; Florovic, M. ; Kordos, P. ; Skriniarova, J. ; Harmatha, L.
Author_Institution :
Inst. of Electron. & Photonics, Slovak Univ. of Technol., Bratislava, Slovakia
Abstract :
The C-V and I-V characteristics of the Ni/Al0.26Ga0.74N/GaN and Ni/Al0.20Ga0.80N/GaN Schottky diodes were measured for determination of structures electrical parameters as well as influence of metal-pad electrode to Schottky barrier height evaluation. From measured C-V curves, the sheet charge density of carriers in the channel was determined. The I-V characteristics were measured in the temperature range from 298 to 473 K and analyzed considering different current-transport mechanisms. The Schottky barrier height of both investigated structures with metal-pad show equal value ~1.3 eV at 298 K, while for structures without metal-pad the barrier height of the Schottky diodes was 2.23 eV and 2.02 eV for Ni/Al0.26Ga0.74N/GaN and Ni/Al0.20Gain0.80N/GaN sample, respectively. This results indicate the presence of excess oxide layer under Schottky contact at AlGaN surface during the contact processing.
Keywords :
III-V semiconductors; Schottky barriers; Schottky diodes; aluminium compounds; gallium compounds; high electron mobility transistors; nickel; wide band gap semiconductors; C-V characteristics; HEMT; I-V characteristics; Ni-Al0.20Ga0.80N-GaN; Ni-Al0.26Ga0.74N-GaN; Schottky barrier height; Schottky diodes; carrier sheet charge density; current transport mechanism; electrical parameters; layer structure; metal pad electrode; Aluminum gallium nitride; Capacitance-voltage characteristics; Gallium nitride; Nickel; Schottky barriers; Schottky diodes; Voltage measurement;
Conference_Titel :
Advanced Semiconductor Devices & Microsystems (ASDAM), 2012 Ninth International Conference on
Conference_Location :
Smolenice
Print_ISBN :
978-1-4673-1197-7
DOI :
10.1109/ASDAM.2012.6418559
