δ-doped AlGaAs and AlGaAs/InGaAs high electron mobility transistor structures grown by metalorganic chemical vapor deposition

Abstract

We have successfully grown δ-doped AlGaAs structures and δ-doped AlGaAs/InGaAs pseudomorphic high electron mobility transistor (HEMT) structures by atmospheric pressure metalorganic chemical vapor deposition (MOCVD). Capacitance-voltage (C-V) profiles with full-width at half-maximum as small as 32 Å demonstrate very narrow doping profiles of δ-doped AlGaAs layers grown at 650–700 °C. Theoretical C-V profiles of δ-doped AlGaAs have been self-consistently calculated with the L valley taken into account and compared with the experimental results. A δ-doped AlGaAs/InGaAs pseudomorphic HEMT structure with a 30 Å spacer layer yields a sheet carrier concentration of 2.25×1012 cm−2 with an electron mobility of 20 300 cm2/V s at 77 K.