Details

Autor(en) / Beteiligte

• Partida-Manzanera, T.
• Zaidi, Z. H.
• Roberts, J. W.
• Dolmanan, S. B.
• Lee, K. B.
• Houston, P. A.
• Chalker, P. R.
• Tripathy, S.
• Potter, R. J.

Titel

Comparison of atomic layer deposited Al2O3 and (Ta2O5)0.12(Al2O3)0.88 gate dielectrics on the characteristics of GaN-capped AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors

Ist Teil von

• Journal of applied physics, 2019-07, Vol.126 (3)

Ort / Verlag

Melville: American Institute of Physics

Erscheinungsjahr

2019

Link zum Volltext

Quelle

American Institute of Physics (AIP) Journals

Beschreibungen/Notizen

• The current research investigates the potential advantages of replacing Al2O3 with (Ta2O5)0.12(Al2O3)0.88 as a higher dielectric constant (κ) gate dielectric for GaN-based metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs). The electrical characteristics of GaN-capped AlGaN/GaN MOS-HEMT devices with (Ta2O5)0.12(Al2O3)0.88 as the gate dielectric are compared to devices with Al2O3 gate dielectric and devices without any gate dielectric (Schottky HEMTs). Compared to the Al2O3 MOS-HEMT, the (Ta2O5)0.12(Al2O3)0.88 MOS-HEMT achieves a larger capacitance and a smaller absolute threshold voltage, together with a higher two-dimensional electron gas carrier concentration. This results in a superior improvement of the output characteristics with respect to the Schottky HEMT, with higher maximum and saturation drain current values observed from DC current-voltage measurements. Gate transfer measurements also show a higher transconductance for the (Ta2O5)0.12(Al2O3)0.88 MOS-HEMT. Furthermore, from OFF-state measurements, the (Ta2O5)0.12(Al2O3)0.88 MOS-HEMT shows a larger reduction of the gate leakage current in comparison to the Al2O3 MOS-HEMT. These results demonstrate that the increase in κ of (Ta2O5)0.12(Al2O3)0.88 compared with Al2O3 leads to enhanced device performance when the ternary phase is used as a gate dielectric in the GaN-based MOS-HEMT.