Fabrication of InP heterostructure bipolar transistors for 40 Gb/s communication systems

InP heterostructure bipolar transistors (HBT) are known for their high speed and easy integration with optical devices. Its technology is in general still developing. High frequency InP HBTs were fabricated. Some device and layer structure design improvements for 40 Gbit/s communications systems applications are suggested. The necessary conditions to manufacture the devices are presented. Various collector structures are used to increase the breakdown voltage while maintaining speed and gain.