Making your own transistors, diodes, ICs .. - Page 1
Forum section: electronics / general

author: saturation
author_rank: Super Contributor
timestamp: August 09, 2011, 04:01:35 pm
content: I'm try to assess if teaching and fabricating in lab, your own ICs and semiconductors are taught in EE school, whether grad or undergrad. I've been out of touch of decades.If you've done it in school, what would you need to put together a transistor with equipment in your home lab?

author: IanB
author_rank: Super Contributor
timestamp: August 09, 2011, 05:35:27 pm
content: Have you checked out Jeri Ellsworth's work on the subject?My impression is that the practical side is not too hard, but the theoretical side is not well known outside the industry. There are apparently some undocumented tricks needed for success that are not found in textbooks.Jeri's experimental technique strikes me as clumsy and lacking in finesse, yet in spite of that she has succeeded in making working devices.Anyone with the inclination could put together the hardware needed in a home lab, but producing a successful result with that equipment will elude all but the most dedicated.

author: IanB
author_rank: Super Contributor
timestamp: August 09, 2011, 05:38:57 pm
content: Incidentally, thisis the most absorbing video I think I have ever seen. If I talk about "finesse", this is what I mean.

author: Neilm
author_rank: Super Contributor
timestamp: August 09, 2011, 07:16:07 pm
content: When I was at university (mid '90s) I did a course on designing an IC but the design was tinkered with by a post grad before they were made. (incedently, none of the chips worked due to a manufacturing cock up)Neil

author: gregariz
author_rank: Frequent Contributor
timestamp: August 09, 2011, 07:42:25 pm
content: Yes, I had a course on cmos design when I went through. We used the mosis service for fabrication of the chips (it has been very popular I believe). We used L-edit for layout of the chip.www.mosis.orgI think you will find that research in semiconductor fabrication is very common in EE schools. Moreover, alot of physics schools have semiconductor physics research groups where they will work on things like Silicon on Insulator wafer technology. There are a heap of variations on the idea.With the limited time available within EE programs, my belief is that a 'lets build a transistor from silicon' class is of absolutely no value to an EE student. It may have some interest factor for Physics schools. EE programs have struggled for many years to include what is of value to the graduates.. sometimes they get it right, usually they get it wrong IMO.

author: saturation
author_rank: Super Contributor
timestamp: August 09, 2011, 07:48:10 pm
content: Thank IanB, yes familiar with Jeri's exploits; she is one of the few available on the net. My question does cover what you mention, if commercial grade fab skills are taught to undergrad EE students or limited to basics & fundamentals [ like knowing how to wind your own transformer, versus what is done commercially].Jeri's bio says she is self taught.http://en.wikipedia.org/wiki/Jeri_EllsworthQuote from: IanB on August 09, 2011, 05:35:27 pm

author: gregariz
author_rank: Frequent Contributor
timestamp: August 09, 2011, 08:17:42 pm
content: Heres a simple home made FEThttp://sparkbangbuzz.com/cds-fet/cds-fet.htm

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 10, 2011, 02:16:27 am
content: Texas A&M offers a class that involves working in a small fab. I haven't taken that class, but I know someone who has. It's basically like recreating the day TI invented the IC, although with more modern technology.Back in high school chemistry class, one of the experiments involved making a photodiode by torching a strip of copper, then putting a drop of salt water on the oxidized end and touching it with a copper wire. When illuminated with a halogen lamp, it outputs a few microamps. I also knew someone who made organic solar cells out of lettuce juice and broken LCDs for a science fair project...