Here is a link to a promotional video by Commodore Germany. About 3 minutes in, they take you on a 15 minute tour of the MOS Technologies semiconductor facility in Norristown, PA. The video shows the Commodore 64 VIC-II chip being made, but this would be the same process as the 6502.

http://video ...

There is a Hungarian website that has a very high-resolution image of the 6502 die. The fellow has also reverse engineered a schematic diagram of the actual 6502 circuitry.

http://impulzus.sch.bme.hu/6502/6502/

The schematic and high-resolution image are at:

http://impulzus.sch.bme.hu/6502/letolt ...