MOVPE GROWTH OF GAINP GAAS HETERO-BIPOLAR-TRANSISTORS USING CBR4 AS CARBON DOPANT SOURCE/

Carbon doping of GaAs with carbon tetrabromide (CBr4) in low pressure MOVPE has been investigated and applied to the fabrication of GaInP/Ga As HBTs. Especially the hydrogen incorporation and the associated acce ptor passivation has been studied. The hydrogen found in single GaAs:C layers is predominantly incorporated during cooling the sample under AsH3 after growth. n-Type capping layers can block this H indiffusion and GaAs:C base layers in HBTs show much lower H concentrations than G aAs:C single layers without a cap. A further reduction of acceptor pas sivation is possible by optimization of the growth procedure. First HB Ts processed from layers with a base that was doped using CBr, show pr omising DC and HF performance (beta = 45, f(T) = 26 GHz for 2 x 20 mu m(2) devices).