High C-doping of MOVPE grown thin AlxGa1-xAs layers for AlGaAs/GaAs interband tunneling devices

High hole concentrations in LP-MOVPE grown GaAs and AlGaAs layers can be ac hieved by intrinsic C-doping using TMGa and TMA1 as carbon sources. Free ca rrier concentrations exceeding 10(20) cm(-3) were realised at low growth te mperatures between 520-540 degrees C and V/III ratios < 1.2. The C-concentr ation increases significantly with the Al-content in AlxGa1-xAs layers. We observed an increase in the atom- and free carrier concentration from 5.10( 19) cm(-3) in GaAs to 1.5.10(20) cm(-3) in Al0.2Ga0.8As for the same growth conditions. Interband tunneling devices with n-type Si and p-type C-doped AlGaAs layers and barriers made of Al0.25Ga0.26In0.49P have been investigat ed.