On the measurement of the thickness of epitaxial and polycrystalline silicon layers in the submicron range

Abstract

The thickness of epitaxially grown silicon layers, less than 1 μm thick, can be measured directly with a mercury probe and an, eventually automated, capacitance bridge. The thickness measured in this way with a precision of about 400 Å, is found to be about 10% smaller than the metallurgical thickness. The submicron thickness of polycrystalline layers can be measured similarly and agrees with the metallurgical thickness within the measurement precision of about 200 Å.