Electrical Activity of Epitaxial Stacking Faults

Abstract

Listen

Translate article

The scanning electron microscope has been used in the electron beam induced current (EBIC) mode to measure the electrical activity of stacking fault polyhedra formed during the epitaxial growth of (111) and (100) silicon from. Epitaxial films were grown in three different epi reactor facilities on wafers processed in two different facilities. Schottky barriers were used to collect the electron beam induced current. Defining electrical activity as carrier recombination seen at zero or low reverse bias (well below avalanche), two main observations are made: i) The occurrence of electrical activity is related to the facility in which buried layer processing and wafer cleaning were done prior to epi deposition, and is not due to the epi reactor. One facility in which buried layer processing was carried out was found to be contaminated with heavy metal impurities; all epi faults on wafers processed in this facility were found to be active primarily at the corners of the fault polyhedra; faults on samples which received buried layer processing in another facility were found to be electrically inactive. (ii) Transmission electron microscope studies of the identical faults examined in EBIC show that the degree of electrical activity is correlated with the mass of precipitate present at the corner of a fault polyhedron, and both vary from corner to corner within the polyhedron.