Title :
Atomic Layer Epitaxy AlN for Enhanced AlGaN/GaN HEMT Passivation
Author :
Koehler, Andrew D. ; Nepal, Neeraj ; Anderson, Travis J. ; Tadjer, Marko J. ; Hobart, Karl D. ; Eddy, Charles R. ; Kub, Francis J.
Author_Institution :
Naval Res. Lab., Washington, DC, USA
Abstract :
Enhancements in AlGaN/GaN high-electron-mobility transistor (HEMT) performance have been realized through ultrathin (4 nm) AlN passivation layers, formed by atomic layer epitaxy (ALE). A combination of ex situ and in situ surface cleans prepare the surface for deposition of ALE AlN. HEMTs passivated by high crystallinity AlN, grown at 500 °C, show improvements in 2-D electron gas sheet carrier density, gate leakage current, off-state drain leakage current, subthreshold slope, and breakdown voltage. In addition, degradation of dynamic on resistance during pulsed off-state voltage switching stress is suppressed by ~50% compared with HEMTs passivated by conventional plasma enhanced chemical vapor deposition SiNx.
Keywords :
III-V semiconductors; aluminium compounds; atomic layer epitaxial growth; carrier density; electric breakdown; electron gas; gallium compounds; high electron mobility transistors; leakage currents; passivation; stress effects; wide band gap semiconductors; 2D electron gas sheet carrier density; ALE; AlGaN-GaN; AlN; HEMT passivation; HEMT performance; atomic layer epitaxy; breakdown voltage; gate leakage current; high crystallinity; high-electron-mobility transistor; off-state drain leakage current; pulsed off-state voltage switching stress; resistance degradation; size 4 nm; subthreshold slope; surface deposition; temperature 500 C; ultrathin passivation layers; Aluminum gallium nitride; Gallium nitride; HEMTs; III-V semiconductor materials; Logic gates; MODFETs; Passivation; Atomic layer epitaxy (ALE) passivation; GaN; current collapse; dynamic ON-resistance; high-electron-mobility transistor (HEMT) AlN;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2013.2274429
