Applications of Electrochemical Methods for Semiconductor Characterization: I . Highly Reproducible Carrier Concentration Profiling of VPE “Hi‐Lo”

Abstract

Factors which influence the accuracy and reproducibility of semiconductor carrier concentration profiling via capacitance‐voltage measurements and dissolution at an electrolytic Schottky barrier are critically examined. Attention is centered upon the capacitance contributions from the edge regions of the electrolyte contact area. It is shown that several properties of the electrolyte, and the measurement frequency, as well as the physical means of electrolyte confinement have an important influence. In particular, a suitable combination of electrolyte conductivity, wetting, and dissolution behavior can be met by 0.1M Tiron, for the profiling of using the “Post Office Profile Plotter.” Examples are given which demonstrate the high degree of reproducibility, both short‐ and long‐term, attainable for the profiling of “hi‐lo” structures. Optimization of the approach for other semiconductor materials, for which an “ideal” electrolyte may not be available, is also discussed.