I only have a vague understanding. The technique used to manufacture integrated circuits is called photolithography. Basically, these circuits need such tiny features etched into them that we can't do it through traditional means. Instead, we draw a picture of the circuit we want, hundreds of times larger, shine a light through it, and use lenses to shrink the pattern down to size. This big pattern is called a "mask".

So what's the deal with the demonic sigils above? As we make our circuits smaller, the physics gets stranger. For instance, there's this effect called quantum tunneling where electrons just teleport to a part of the circuit we would not expect based on classical physics. Due to these kinds of effects, we have to do crazy things to the masks if we want the circuit to behave correctly.

Disclaimer: I am not an electrical engineer and I have no idea what I'm talking about.