Effect of the thermionic emission on the recombination and electron beam induced current contrast at the interface of a metallic precipitate embedded in a semiconductor matrix

Abstract

The barrier height and the recombination velocity at the interface between a metallic precipitate and a semiconductor matrix are investigated with a new self consistent procedure based both on the analysis of the recombination and emission balance rates for electrons and holes and on the determination of the size-dependent electronic structure of the embedded precipitate. In the present work, the precipitate is modeled within the spherical well potential framework. The main result is the dependence of the recombination features on the electronic structure of the metal precipitate unlike the models based only on the Shockley-Read-Hall theory. The behaviors of the surface charge density on the metallic precipitate and the barrier height versus the precipitate size are similar to our previous studies. Unlike previous works, the recombination velocity reaches a constant non-zero value for sizes smaller than a critical size which is dependent on the defect concentration at the interface. The new dependencies of the recombination parameters are illustrated by the calculation of the electron beam induced current (EBIC) contrast at the interface.