Electrical characterisation of epitaxially overgrown Si in Si/CoSi2/Si metal base transistor

Abstract

Epitaxial Si/CoSi2/Si heterostructures have been grown using molecular beam epitaxy (MBE) apparatus with the overgrown Si layer doped by Sb coevaporation. Electrical characteristics of the top CoSi2/Si epitaxial Schottky barriers are presented. Current/voltage (I/V), capacitance/voltage (C/V) characteristics and deep level transient spectra (DLTS) show that the overgrown Si material is deviceworthy. Furthermore, transconductance measurements between the emitter and collector of the metal base transistor (MBT) indicate that the high Si quality is obtained with a negligible pinhole density in the base. Measurements of the current gain α in the MBT confirm a value of the CoSi2 ballistic mean free path of 90 Å ± 20 Å.