Tunneling Emitter Bipolar Transistor as a Characterization Tool for Dielectrics and their Interfaces

The metal insulator semiconductor and metal insulator metal structures are of interest for transistor technology and resistive switching based memory. We propose the tunneling emitter bipolar transistor as a complementary characterization tool of both structures. Using this technique one can distinguish between electron and hole injection through the insulator and detect the presence of recombination centers at the dielectric-semiconductor interface. In addition, the base-collector p-n junction adjacent to the dielectric is a sensitive detector for material damage. We have examined two dielectric materials: Al2O3 and Si3N4 using a tunneling emitter bipolar transistor based upon the InP/GaInAs material system. The main conclusion drawn from the experiments is that the dominant transport mechanism through the insulators is filamentary defect assisted transport. Thermal treatment of both materials significantly reduced the interface recombination velocity.