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Gate-First A1GaN/GaN HEMT Technology for High-Frequency Applications.
- Source :
- IEEE Electron Device Letters; Dec2009, Vol. 30 Issue 12, p1254-1256, 3p, 2 Graphs
- Publication Year :
- 2009
-
Abstract
- This letter describes a gate-first AIGaN/GaN high-electron mobility transistor (HEMT) with a W/high-k dielectric gate stack. In this new fabrication technology, the gate stack is deposited before the ohmic contacts, and it is optimized to stand the 870 °C ohmic contact annealing. The deposition of the W/high-k dielectric protects the intrinsic transistor early in the fabrication process. Three different gate stacks were studied: W/HfO<subscript>2</subscript>, W/AI<subscript>2</subscript>O<subscript>3</subscript>, and W/HfO<subscript>2</subscript>/Ga<subscript>2</subscript>O<subscript>3</subscript>. DC characterization showed transconductances of up to 215 mS/mm, maximum drain current densities of up to 960 mA/mm, and more than five orders of magnitude lower gate leakage current than in the conventional gate-last Ni/AU/Ni gate HEMTs. Capacitance-voltage measurements and pulsed-IV characterization show no hysteresis for the W/HfO<subscript>2</subscript>/Ga<subscript>2</subscript>O<subscript>3</subscript> capacitors and low interface traps. These W/high-k dielectric gates are an enabling technology for self-aligned AIGaN/GaN HEMTs, where the gate contact acts as a hard mask to the ohmic deposition. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 07413106
- Volume :
- 30
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- IEEE Electron Device Letters
- Publication Type :
- Academic Journal
- Accession number :
- 47107168
- Full Text :
- https://doi.org/10.1109/LED.2009.2032938