A new test structure for recombination measurements in thin si layers for VLSI structures

Abstract

The capability of two recently proposed measurements methods to evaluate recombination properties of thin layers is discussed. Both methods make use of a novel test structure which allows one to evaluate a) the lifetime profile along submicron epilayers and b) the recombination velocity set by a generic heavily doped layer. Measurements performed on 1 μm thick epilayers demonstrate that the recombination lifetime in these layers is not correlated with the doping level and it has values lower than those reported in thicker layers. Moreover, experimental data collected n+ layers of different technology suggest a phonon‐assisted lifetime value much lower than that reported in literature for uniformly doped bulk material.