First IC :) – Sam Zeloof

sam.zeloof.xyz
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Article URL: http://sam.zeloof.xyz/first-ic/ Comments URL: https://news.ycombinator.com/item?id=28263714 Points: 1 # Comments: 0
Homemade computer chips / integrated circuits

Preface

I am very excited to announce details of the first homemade integrated circuit and share the journey that this project has taken me on over the past year. I hope that my success will inspire others and help start a revolution in home chip fabrication. When I set out on this project I had no idea of what I had gotten myself into, but in the end I learned more than I ever thought I would about physics, chemistry, optics, electronics, and so many other fields. Furthermore, my efforts have only been matched with the most positive feedback and support from the world; I owe a sincere thanks to everyone who has helped me, given me advice, and inspired me on this project. Especially my amazing parents, who not only support and encourage me in any way they can but also give me a space to work in and put up with the electricity costs… Thank you!

Let's democratize the tools of innovation.

I present the first homemade (lithographically-fabricated) integrated circuit – the "Z1" PMOS dual differential amplifier chip. I say "lithographically-fabricated" because Jeri Ellsworth made the first transistors and logic gates (meticulously hand wired with conductive epoxy) and showed the world that this is possible. Inspired by her work, I have demonstrated ICs made by a scalable, industry-standard, photolithographic process. Needless to say, this is the logical step-up from my previous replication of Jeri's FET fabrication work.

Design

I designed the Z1 amplifier looking for a simple chip to test and tweak my process. Layout was done in Magic VLSI for a 4 mask PMOS process (active/doped area, gate oxide, contact window, and top metal.) PMOS has advantages over NMOS as far as mobile ionic contamination that lends it to being fabricated in a garage. The masks are designed in 16:9 aspect ratio for easy projection.

The feature (gate) size is approximately 175μm although there are test features as small as 2μm on the chip. Each…
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