ABSTRACT
The interest in p-doping of the active layer of quantum well lasers (QWLs) is motivated by high-speed and integration prospects. In addition, heavily p-doped quantum wells sandwiched by two suitably graded n-doped confinement layers can simultaneously serve as the base of a double heterojunction bipolar transistor (DHBT) and the active layer of a quantum well laser. The multifunctional epi-structure appears very promising since integration of high performance lasers and HBTs is possible through the use of standard process technologies. The authors show that, using a Ta cracker As2 source, it is possible to grow high-quality lasers and HBTs at intermediate temperatures (580 - 630°C). They also demonstrate the first ridge waveguide QWL with lateral injection through the base, that also operates as an HBT. A theoretical model of the QWL-HBT predicts the best parameters of the structure for optimized device operation.
