One area of silicon reverse engineering which has interested me is the delayering of a chip to see each layer which allows superior visibility into the circuitry. I know of two ways: chemical etch and mechanical means.
In this video I try to make a mechanical grinder which can take micron levels of material away: a partial success. Parts are ground but I was not able to keep the silicon absolutely flat. More study of the commercial units is warranted!
See the full post on electronupdate blog.