Title :
Interface Charge Engineering for Enhancement-Mode GaN MISHEMTs
Author :
Ting-Hsiang Hung ; Pil Sung Park ; Krishnamoorthy, Sriram ; Nath, Digbijoy ; Rajan, Sreeraman
Author_Institution :
Dept. of Electr. & Comput. Eng., Ohio State Univ., Columbus, OH, USA
Abstract :
We demonstrate an efficient approach to engineer the dielectric/AlGaN positive interface fixed charges by oxygen plasma and post-metallization anneal. Significant suppression of interface fixed charges from 2 × 1013 to 8 × 1012 cm-2 was observed. Experimental and theoretical electron mobility characteristics and the impact of remote impurity scattering were investigated. The reduction in oxide/semiconductor interface charge density leads to an increase of electron mobility, and enables a positive threshold voltage.
Keywords :
III-V semiconductors; MIS devices; electron mobility; gallium compounds; high electron mobility transistors; impurity scattering; wide band gap semiconductors; dielectric-AlGaN positive interface fixed charges; electron mobility characteristics; enhancement-mode GaN MISHEMT; interface charge engineering; oxide-semiconductor interface charge density; oxygen plasma; positive threshold voltage; post-metallization annealing; remote impurity scattering; Aluminum gallium nitride; Aluminum oxide; Capacitance-voltage characteristics; Gallium nitride; III-V semiconductor materials; Plasmas; Scattering; ALD; AlGaN/GaN HEMT; E-mode; MISHEMT; electron mobility; interface fixed charges; normally-off; oxygen plasma; post-metallization anneal (PMA); remote impurity scattering;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2013.2296659
