Abstract
Traditionally, planar scanning capacitance microscopy has been conducted on samples which have been deprocessed to the level of the substrate and an oxide re-grown over the sample. However, HF used to etch the sample to the substrate can also dissolve shallow junctions. This article documents the ability of scanning capacitance microscopy to be utilized at the level of the contacts leaving the pre-metal dielectric intact. It demonstrates the scalability of this technique across three process generations spanning 0.18 micron, 0.13 micron, and 90 nm nodes. The article documents preliminary data on anomalous contrast observed in contacts at both 0.13 micron node and 90 nm node products. It also demonstrates the ability to distinguish between contacts going to a n-type diffusion, p-type diffusion, and transistor gate. The article also presents a simple model for the CV curves of defective contacts to source/drain diffusions.
