Heterojunction bipolar transistor (HBT) having an improved emitter-base junction

A method for making a heterojunction bipolar transistor (HBT), the method comprising the steps of:

• forming a collector;
• forming a base over the collector;
• and
• forming an emitter over the base, the emitter including an intermediate layer in contact with the base, the intermediate layer being substantially electrically transparent with respect to the base and the emitter, and where the intermediate layer has a lattice constant that conforms to the lattice constant of the base and the emitter.

A heterojunction bipolar transistor (HBT), comprising:

• a collector constructed using indium-phosphide (InP);
• a base located over the collector and constructed using gallium-arsenide-antimonide (GaAsSb);
• and
• an emitter located over the base and constructed using a plurality of layers, where a first layer includes an intermediate layer of InP in contact with the base, the intermediate layer being substantially electrically transparent, and where a second layer includes aluminum-indium-arsenide (AlInAs), and where the intermediate layer has a lattice constant that conforms to the lattice constant of the base and the second layer of the emitter.