InGaP/GaAs single- and double-heterojunction bipolar transistors grown by organometallic vapour phase epitaxy

InGaP/GaAs single-heterojunction bipolar transistors (HBTs) and double-heterojunction bipolar transistors (DHBTs) grown by organometallic vapour phase epitaxy are reported. A current gain beta =40 was obtained for 90 mu m diameter HBT devices at a base-collector bias of 0 V. The base carbon-doping concentration for the devices was 2*10¹⁹ cm^-3 and the sheet resistivity ( rho _s) of the base layer was 600 Omega / Square Operator . For the DHBTs, a current gain beta =27 was obtained for a base-collector bias of 2 V. The carbon doping concentration in these devices was 8*10¹⁸ cm^-3 with rho _s=1400 Omega / Square Operator . This represents the first successful fabrication of DHBTs for this material system.