How do foundries actually dope silicon when chipmaking? 407 viewsOctober 7, 2019 Question34.21K October 7, 2019 1 Answer So i get that transistors are basically 2 diodes sandwiched together and photo-etched onto silicon but how do you make those negative and positively doped zones that a transistor needs when we’re talking about nanometers in terms of dimensions? In: Engineering incruente commented October 7, 2019 The entire ingot can be doped by including certain impurities when making it (or by exposing it to a powerful neutron flux from a nuclear reactor). But the tiny individual doping operations are done photographically. A compound is placed on the wafer, and a mask is used to expose certain areas of it to light to harden it. The parts that did not get hardened can be washed away with chemicals, leaving only specific areas of silicon exposed to be doped. Then, the hardened areas are removed with other chemicals. Rinse and repeat. 0 Answers ActiveVotedNewestOldest Register or Login Other Questions You Might Be Interested In: Can someone please explain network entropy. I've read the wikipedia and I'm still confused. I unders...eli5: Why is self-defense against sexual assault criminalized? (Law)16bit v. 32bit v. 64bit operating systemshow does swatting your hand towards your face in a hot day provide cold breeze instead of hot air?What is the difference between Enterprise Value and Market Capitalization?In particle physics, what is a jet?