Detection of silicide formation in nanoscale visualization of interface electrostatics

Abstract

The ability to detect localized silicide formation at a buried metal semiconductor Schottky interface is demonstrated via nanoscale measurements of the electrostatic barrier. This is accomplished by mapping the Schottky barrier height of the Cr/Si(001) interface by ballistic electron emission microscopy (BEEM). Monte-Carlo modeling is employed to simulate the distributions of barrier heights that include scattering of the electrons that traverse the metal layer and a distribution of electrostatic barriers at the interface. The best agreement between the model and the data is achieved when specifying two barrier heights less than 60 meV from one another instead of a singular barrier. This provides strong evidence that localized silicide formation occurs that would be difficult to observe in averaged BEEM spectra or conventional current voltage measurements.

Internal Photoemission Metrology of Inhomogeneous Interface Barriers

“…This observation suggests there is a continuous distribution of barrier heights across the electrode area rather than the presence of spots with several well defined barrier values. In fact, the latter conclusion would also be consistent with the continuous BEEM threshold distributions recently reported on metal/silicon interfaces …”

“…Similarly, the lateral resolution of the CV method is determined by the Debye length of chosen semiconductor and is usually of the order of 0.1 μm . Significantly better lateral resolution of interface barrier quantification can be achieved by BEEM . However, in order to achieve a sufficiently high electrode transparency, most of these works focus on relatively low metal/semiconductor barriers.…”