Si hetero-bipolar transistor with an SiC emitter thin epitaxial base

A Si-based heterojunction bipolar transistor (Si-HBT) with polycrystalline SiC as a wide-bandgap emitter has been fabricated, combined with a 50-nm-thick highly doped base. The poly-SiC was used for the wide-bandgap material because of its lower growth temperature. The poly-SiC seems to be thermally more stable than amorphous or microcrystalline SiC. The resistivity of the SiC was sufficiently low. The current gain of 15, in spite of the highly doped base and lightly doped emitter, indicates that the structure has advantages over the conventional homobipolar transistor.<>