Development of a planar heterojunction bipolar transistor for very high speed logic
Abstract
The following report describes the results of research on III-V molecular beam epitaxial (MBE) growth, material characterization and the fabrication of heterostructure bipolar transistors (HBT) for very high speed logic applications. During the reporting period work on the InGaP/GaAs heterojunction (HJ) was completed. Isotype HJs were grown and evaluated by a CV reconstruction method in order to determine the energy band offsets. It was found that Ec=0.21 eV and Ev=0.25 eV for the lattice matched composition. A new direction toward improvement in performance and the fabrication techniques for the AlGaAs/GaAs HBT was successfully demonstrated. Graded-bandgap nonalloyed ohmic contacts using n+ InAs and GaAs for the AlGaAs emitter and p+ GaSb for the GaAs base were provided by selective epitaxial regrowth. The MBE growth conditions for grading from GaAs to InAs to GaSb were determined. Low specific contact resistances were observed for both contact types. A AlGaAs/GaAs graded-gap contact HBT was grown. A current gain of 20 was measured with only simple wire probes on the base and emitter.
- Publication:
-
Annual Technical Report
- Pub Date:
- March 1986
- Bibcode:
- 1986ucsb.reptQ....L
- Keywords:
-
- Bipolar Transistors;
- Heterojunctions;
- Molecular Beam Epitaxy;
- Transistor Logic;
- Aluminum Gallium Arsenides;
- Fabrication;
- Gallium Antimonides;
- Gallium Arsenides;
- High Speed;
- Indium Phosphides;
- Solid-State Physics