For die photos, you want a metallurgical microscope, one that shines light down through the lens. A typical microscope shines the light from underneath, which works well for biological samples, but not so well for chips.

The tricky part is decapping the chip. The easy way is to get a ceramic package, which you can decap with a chisel. Or a metal can, which you can open with a hacksaw. With a standard epoxy package, you can heat it with a hot air gun and twist it, and you have maybe 50% chance of the die separating from a package. The best way for epoxy packages is boiling sulfuric and/or nitric acid, which has obvious issues.

The other aspect is that you need to stitch together a bunch of images to get a high-resolution photo. I use Hugin, which lets just say that it has a learning curve.