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I can speak for the process of fabricating the chips in broad terms. First, take your silicon wafers. They're cut from a single enormous crystal of silicon, usually 6-8 inches in diameter. Place a layer a few molecules thick of silicon oxide on it. (I think that's what the layers are made of) Coat the wafer in photo resist. expose the photoresist through the "negative" of the pattern for the first layer. Now wash off the unexposed photoresist and etch away the exposed oxide layer with acid. Now wash away the exposed photoresist. Now add another layer. Layers can be various things - silicon oxide, metal, etc. Some layers are conductors, some are insulators, some are semiconductors. Each layer has a pattern etched into it, and the registration between layers as well as the completeness of traces and so forth is checked with an electron microscope. How many layers? How fine a detail? I really can't talk about those things (even if I HAD memorised the actual numbers, which I didn't.) Lots of layers, and Texas Instruments recently announced that they can now etch down to .03 microns, and made it clear this was a LOT smaller than existing technology. Number of layers? I'd say "lots". How many microprocessors on an 8 inch wafer? How many of THEM are good? Again, trade secrets. "Lots" is all I can say. How the things are designed I have no clue. My days at Intel were spent in a production fab keeping the Unix equipment control computers breathing, and solving user problems with the big CAM system over the phone. (more caviets) I never actually was certified on any of the equipment that MAKES microprocessors. They gave me the 10,000 foot view so the names of the various machines my computers ran made sense to me, but frankly they could have been making potato chips and it wouldn't have changed MY job much. (except for not having to wear a bunny suit, and different hazardous materials. :) If you live in the SanFrancisco Bay area, Intel has a good illustration of the whole process (and cool video to watch the D2 fab - where I worked - in action) in the Intel museum, at Intel Santa Clara. (2200 Mission College Blvd, Santa Clara, CA) I *believe* the museum is open to the public, as it's inside the main office building off the lobby. -- Jim Strickland jim(a)DIESPAMMERSCUMcalico.litterbox.com ----------------------------------------------------------------------- Vote Meadocrat! Bill and Opus in 2000 - Who ELSE is there? -----------------------------------------------------------------------