Lateral dopant profiling with 200 nm resolution by scanning capacitance microscopy

Abstract

Measurement of dopant density in silicon with lateral resolution on the 200 nm scale has been demonstrated with a near‐field capacitance technique. The technique is based upon the measurement of local capacitance between a 100 nm tip and a semiconducting surface. Lateral dopant imaging is achieved by the measurement of the voltage‐dependent capacitance between tip and sample due to the depletion of carriers in the semiconductor, as the tip is scanned laterally over the surface. Measurements of dopant density have been demonstrated over a dopant range of 10¹⁵–10²⁰ cm⁻³. Capacitance‐voltage measurements have been made on a submicrometer scale.