People need to stop trying to tout decapping as and end-all solution. The 3DS isn't some 20 year old device that uses 60nm gates and is a single layer that can be observed with a high definition optical microscope. By the release date, it is likely 14nm or 20nm. It likely has 8-12 metal layers (each layer is about 1-2nm thick). You likely need an electron microscope to get the right resolution to read the gates. So even if you have the $20,000+ to access the right equipment, good luck finding the right technician! Most people with the skills to do this works for one of the couple large companies that do IP reverse engineering--they've likely spent years learning the right skills and developing the right recipes to each metal layer. The reason you haven't seen a high-def image of any modern chip is because it is very hard to do. Honestly, if you're going to get the bootrom, it'll be magnitudes easier to do with sw or hw attack rather than decapping.