Experimental development and incorporation of strain in p-type GaAsSb/InAlAs single metal heterostructure field effect transistors

The incorporation of bi-axially compressive strain has been experimentally designed into GaAsSb/InAlAs heterostructures grown on InP substrates for improved electronic transport. The bi-axially compressive strain results from growing the GaAsSb off the lattice match to InP, through increased antimony composition. Dual Group V (As Sb) compositional control is achieved during molecular beam epitaxial growth through desorption mass spectroscopy and is found to be consistent with post deposition X-ray data. The bi-axially compressive stress level measured after the heterostructure growth was on the order of 1 Gpa. The GaAsSb channel region is left unintentionally doped during processing to minimize Coulombic scattering of the carriers by the ionized impurities. A novel, self-aligned, ion-implanted, single metal, electron-beam/optical lithography process is used to fabricate deep submicron p-type GaAsSb/InAlAs HFETs. Lattice-matched, enhancement-mode, 0.15 μm GaAsSb/InAlAs p-HFETs demonstrated a transconductance (g_m) of 16 mS/mm and a cutoff frequency (f_t) of 4 GHz