NDT profiling of dopants and photoconductivity in Si with high spatial resolution using evanescent microwave probes

Abstract

Nondestructive and non-intrusive profiling of doping concentration in semi conductors has attained a renewed importance in the ever important field of Ultra-Large-Scale integrated circuits (ULSI). In ULSI, the drain and source doping concentration is very high (>10 ∧19 1/cc) and their depth is very shallow (<500 Angstrom). These so-called “Shallow Junctions” are very difficult to non-destructively characterize. Here we present some preliminary results regarding doping profiling in silicon using a novel technique that uses an evanescent microwave probe (EMP) to detect and monitor the field-effect conductivity modulation of semiconductor surfaces. EMP is a local probe with very high spatial resolution of better than 0.4 micrometer at 1 GHz and it can be used to image the microwave properties of a variety of materials including metals, semiconductors, insulators, composites, and biological and botanical samples. The operation principles of the EMP and its applications in semiconductors will be presented. Mor...