Electrical characterization and physical analysis of epitaxial CoSi2 grown from the Si<100>/Ti/Co system

The electrical and structural properties of epitaxial CoSi2 layers grown on Si by solid-state interaction between Ti/Co bimetallic layers and Si(100) substrates have been investigated. The Schottky barrier height (SBH) of the CoSi2-Si contact determined by current-voltage characteristics at room temperature varies between 0.64 and 0.71 eV on the n-type substrates and between 0.47 and 0.43 eV on the p-type substrates. The variation of the SBH is found to be related to the Interfacial properties at the CoSi2-Si contact which is in turn determined by the heat treatment used for the CoSi2 formation. The formation of polycrystalline CoSi2 is found to be responsible for the low SBH deviated from 0.71 eV on the n-type substrates and the high SBH deviated from 0.43 eV on the p-type substrates. The formation of a ternary compound, identified as Co16Ti6Si7, within the epitaxial CoSi2 does not seem to affect the SBH on the n-type substrates. A permeable base transistor (PBT) was fabricated using the epitaxial CoSi2 for self-aligned contact metallization. The current-voltage characteristics of the PBTs are presented. (C) 1996 American Institute of Physics.