Title :
Atomic Layer Deposition of
for AlGaN/GaN MOS-HFETs
Author :
Kirkpatrick, Casey J. ; Lee, Bongmook ; Suri, Rahul ; Yang, Xiangyu ; Misra, Veena
Author_Institution :
Dept. of Electr. & Comput. Eng., North Carolina State Univ., Raleigh, NC, USA
Abstract :
This letter investigates the electrical properties of SiO2 gate dielectric on GaN heterostructures deposited by atomic layer deposition (ALD). ALD SiO2 has a dielectric constant of 3.9 and a bandgap of 8.8 eV. ALD SiO2 provides a good interface to GaN and minimizes the interfacial layer growth. The threshold voltage of metal-oxide-semiconductor heterojunction field-effect transistors with ALD SiO2 dielectric is -1.5 V, owing to a fixed charge concentration of -1.6 × 1012 cm-2. It was also found that devices with ALD SiO2 dielectric exhibit three orders of magnitude reduction in gate leakage current compared to conventional Schottky gate HFETs.
Keywords :
III-V semiconductors; MOSFET; Schottky gate field effect transistors; aluminium compounds; atomic layer deposition; dielectric materials; energy gap; gallium compounds; high electron mobility transistors; leakage currents; permittivity; semiconductor growth; silicon compounds; wide band gap semiconductors; ALD; AlGaN-GaN-SiO2; MOS-HFET; Schottky gate HFET; atomic layer deposition; dielectric constant; electrical properties; fixed charge concentration; gate dielectric; gate leakage current; heterostructures; interfacial layer growth; magnitude reduction; metal-oxide-semiconductor heterojunction field-effect transistors; voltage -1.5 V; Aluminum gallium nitride; Dielectrics; Gallium nitride; HEMTs; Logic gates; MODFETs; $hbox{SiO}_{2}$; Atomic layer deposition (ALD); GaN; heterostructure field-effect transistor (HFET); metal–oxide–semiconductor heterojunction field-effect transistor (MOS-HFET);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2012.2203782