@kenshirriff I have a sort of weird question. Are all industrially fabricated chips this dirty? In this image, for instance, you can see a lot of defects in the metallic regions, even in the transistors area. I work in a small lab with a cleanroom and I fabricate small chips for biological applications. I never had to do anything at an industrial level, as I mostly do research on new types of chips. But we use mostly the same technology used in CMOS fabrication, and if my chips had this amount of defects I would not be confident in their performance. Is it a question of the metal you used? I have used AlSiCu (mostly aluminum with some Cu and Si for enhanced conductive properties), and when dry etching we noticed some defects that could be considered similar to this.