Optimization of strained Ga1-xInxAs/InP heterostructures towards high channel conductivity for HEMT application

The authors tailored a low pressure metal organic vapor phase epitaxial grown Ga_1-xIn_xAs/InP quantum well structure that was symmetrically doped on both sides of the well so that the highest possible conductivity in the channel was achieved. First the electron concentration in the channel was adjusted to its maximum by means of self-consistent calculations of the conduction band profile in a lattice matched quantum well structure while avoiding parallel conduction. Then the carrier mobility was systematically increased by increasing the In-content in the channel and optimizing the channel width. Finally the dopant distribution was varied and optimized with respect to highest possible conductivity again avoiding parallel conduction. A mobility as high as 98,400, 59,200 and 11,010 cm² /Vs for a sheet carrier concentration of 3.1×10¹² cm^-2 was obtained at 4, 77 and 300 K, respectively. These values are comparable to best molecular beam epitaxy grown AlInAs/GaInAs/InP high electron mobility transistor (HEMT) structures