Chips made on modern processes are dominated by capital costs. Old chips are made on old foundries, which are fully depreciated and therefore have no capital co

Chips made on modern processes are dominated by capital costs. Old chips are made on old foundries, which are fully depreciated and therefore have no capital costs. If you made a 90nm foundry today, then it probably couldn't sell those microcontrollers for less than $100 each, just like a modern CPU. >why can't existing chip companies, some startup or GM themselves spend $10's of millions building a fab that can unblock $100's of millions of product, and alleviate the shortage? They can't do it fast enough. Standing up a new foundry takes years under the best circumstances, and today you couldn't do it all, since all the tooling is sold out and deeply backordered. If GM could snap their fingers today and magic a cleanroom into existence, they'd still be waiting a hell of a long time to put tools in it. Secondly on the price question, microcontrollers just have way fewer gates than a desktop CPU. A dozen registers, a thousand bytes of RAM, a few kilobytes of flash. This makes them physically smaller, which lets you put more on a wafer, and makes the unit price cheaper. The total die area of the ATmega8 is just 7.9 square millimeters... at the 500nm node! https://zeptobars.com/en/read/atmel-atmega8 https://zeptobars.com/en/read/atmel-atmega8 This gets you 8,100 dies from a single 300mm wafer. (If there are any 300mm foundries at 500nm, which there probably aren't) Thirdly, what makes you think anyone could build a 90nm foundry at all? Take a look at a list of foundries: https://en.wikipedia.org/wiki/List_of_semiconductor_fabrication_plants https://en.wikipedia.org/wiki/List_of_semiconductor_fabricat... I don't see anything making 90nm after 2014. Which makes sense. Fabs don't make all their tools in-house, that's done by vendors. As an example of one tool, by one vendor, the NXE:3400B EUV stepper by ASML. Unit cost, $175 million: https://www.tomshardware.com/news/tsmc-euv-tools-order https://www.tomshardware.com/news/tsmc-euv-tools-order These are ultra-bespoke, super-low-volume machine tools. ASML makes a couple dozen or a hundred steppers of a given model, then shuts down production and starts upgrading to the next node. Is it even possible to buy a new 90nm stepper today? I'm sure they have all the documentation and could roll back to the previous generation easily enough, if they had to. (Which they don't! They are maxed out just supplying current-gen tools) But given all the voodoo in semiconductor lithography, people retiring etc, I bet that rolling back two decades would pretty much require starting from scratch.