Optimization of GaN channel conductivity in AlGaN/GaN HFET structures grown by MOVPE Conference

Hubbard, SM, Zhao, G, Pavlidis, D et al. (2005). Optimization of GaN channel conductivity in AlGaN/GaN HFET structures grown by MOVPE . 831 641-646.

cited authors

  • Hubbard, SM; Zhao, G; Pavlidis, D; Cho, E; Sutton, W

authors

abstract

  • Optimization of GaN channel conductivity in AlGaN/GaN Heterojunction Field Effect Transistor (HFET) structures was performed using High Resistivity (HR) GaN templates grown by Metal-organic Vapor Phase Epitaxy (MOVPE). The GaN sheet resistance was tuned using final nucleation layer (NL) annealing temperature. Using an annealing temperature of 1033°C, GaN with sheet resistance of 1010 Ω/sq was achieved, comparable to that of Fe-doped GaN. X-Ray Diffraction (XRD) and Photoluminescence (PL) analysis show that the high resistance GaN is achieved due to compensating acceptor levels introduced through edge-type threading dislocations. XRD analysis also shows optimization of annealing temperature provided a means to maximize GaN sheet resistance without significantly degrading material quality. AlGaN/GaN HFET layers grown using HR GaN templates gave surface and interface roughness of 14 and 7 Å, respectively. The 2DEG Hall mobility and sheet charge of HFETs grown using HR GaN templates was comparable to similar layers grown using unintentionally doped (UID) GaN templates. © 2005 Materials Research Society.

publication date

  • August 25, 2005

start page

  • 641

end page

  • 646

volume

  • 831