Patent ID: 7638856

Claim:
An optoelectronic transmitter integrated circuit comprising: a semi-insulating substrate; an electroabsorption (EA) modulator disposed in a first region on the semi-insulating substrate and having a first sub-collector layer, a first clad layer, a multi-quantum well (MQW) absorption layer, and a second clad layer; and a double heterojunction bipolar transistor (DHBT) disposed in a second region adjacent to the first region on the semi-insulating substrate and having a second sub-collector layer, a collector layer, an MQW insertion layer, a base layer, an emitter layer, and an ohmic layer, wherein the MQW insertion has a smaller thickness than that of the MQW absorption layer, wherein the MQW insertion layer comprises an InGaAs MQW insertion layer, and wherein the EA modulator and the DHBT are integrated as a single chip using a one time selective metal organic chemical vapor deposition (MOCVD) growth process for independently optimizing the EA modulator to have a high modulation efficiency and the DHBT to have a stable driving characteristic caused by a high voltage breakdown.