Title :
Unstrained InAlN/GaN HEMT structure
Author :
Neuburger, M. ; Zimmermann, T. ; Kohn, E. ; Dadgar, A. ; Schulze, F. ; Krtschil, A. ; Günther, M. ; Witte, Herbert ; Bläsing, J. ; Krost, A. ; Daumiller, I. ; Kunze, M.
Author_Institution :
Dept. of Electron Devices & Circuits, Ulm Univ., Germany
Abstract :
InAlN has been investigated as barrier layer material for GaN-HEMT structures, potentially offering higher sheet charge densities (Kuzmik, 2002) and higher breakdown fields (Kuzmik, 2001). Lattice matched growth of the barrier layer can be achieved with 17% in content, avoiding piezo polarization. In this configuration the sheet charge density is only induced by spontaneous polarization. First experimental results of unpassivated undoped samples realized on 111-Si substrate exceed a DC output current density of 1.8 A/mm for a gate length of 0.5 μm. Small signal measurements yield a ft = 26 GHz and fmax = 14 GHz, still limited by the residual conductivity of the Si-substrate. A saturated output power at 2 GHz in class A bias point yielded a density of 4.1W/mm at VDS = 24 V.
Keywords :
III-V semiconductors; aluminium compounds; current density; elemental semiconductors; gallium compounds; high electron mobility transistors; indium compounds; microwave field effect transistors; polarisation; semiconductor device measurement; silicon; wide band gap semiconductors; 0.5 micron; 111-Si substrate; 14 GHz; 2 GHz; 24 GHz; 26 GHz; InAlN-GaN; Si; barrier layer material; breakdown fields; current density; lattice matched growth; piezo polarization; residual conductivity; sheet charge densities; spontaneous polarization; unpassivated undoped samples; unstrained HEMT structure; Aluminum gallium nitride; Compressive stress; Gallium nitride; HEMTs; Indium; Lattices; MODFETs; Polarization; Sheet materials; Tensile stress;
Conference_Titel :
High Performance Devices, 2004. Proceedings. IEEE Lester Eastman Conference on
Print_ISBN :
981-256-196-X
DOI :
10.1109/LECHPD.2004.1549688
