[labnetwork] Microfabrication class

[Robert Pearson]

Hello Sergi,

My colleagues and I have been teaching a micro-fabrication class here at Rochester Institute of Technology, Microelectronic Engineering since 1982.
We have sophomores, seniors and beginning graduate students all take the class. The class and lab is taught by faculty (with faculty and TA's together in the lab)

Here are my thoughts on such a class and a very early reference to our first level course. I also recommend that you attend UGIM 2024 at MIT to hear first- hand what other universities are doing.

Reference (we have many other papers at UGIM about our curriculum):

R. Pearson, R. Turkman, L. Fuller, and S. Ramanan, PMOS Metal Gate Process, Ideal for Undergraduate Integrated Circuit Fabrication Projects, Proceedings of the Seventh Biennial University Government Industry Microelectronics Symposium, Rochester, NY, June 1987.

You need to teach with a meaningful electrical device as the primary focus, namely a transistor since it is the fundamental element of virtually every semiconductor circuit being made these days. It does not matter if it is NMOS, PMOS or CMOS just that it is a MOSFET.
Enhancement mode PMOSFETs can reliably and easily be made on n-type substrates. NMOSFETS tend to end up as depletion mode devices unless you do a specific threshold voltage adjustment (which might be educational but require outside processing). We here at RIT might be able to help you with that with our ion implanter for a small fee.

The metal-gate (aluminum) PMOS process is a simple 4 mask process and can be done in 7-8 weeks leaving time on the front end of the course for design (layout) and the backend for electrical testing.

If you have your own mask masking capability or direct write (Heidelberg laser writer?) each student can manufacture their own design as  part of a multi-student chip. We give each student a 12-pad (100 by 100 micron pads in two rows of 6) probe configuration (800 by 800 micron total area) to design in. The probe pads match our probe cards and greatly speeds up the electrical testing. We have lots of course and lab notes as well as Silvaco simulation input files that we can share.

You must be able to do doping of some sort to create the source and drain regions. We started by using spin on dopant sources for our drain/source areas and resistors. It is simple and safe. Uniformity can be an issue but it teaches good manufacturing lessons. You can also expand into doing other processes such as double diffused (non-isolated) or triple diffused (isolated) bipolar transistors and diodes.  These processes require more mask levels and longer processing time.

We have actually condensed the 4-level PMOS process into a one-week short course. Maybe you should come to Rochester Institute of Technology sometime and run though it with us.

I would be glad to talk to you further about helping you get your course off the ground.

Sincerely,

Rob Pearson, Ph.D.
RIT - Microelectronic Engineering
robert.pearson at rit.edu<mailto:robert.pearson at rit.edu>
Office: (585) 475-2924

From: labnetwork <labnetwork-bounces at mtl.mit.edu> On Behalf Of Sergi Lendinez
Sent: Friday, October 7, 2022 1:39 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Microfabrication class

Dear labnetwork community,

Here at LSU we are planning to start a microfabrication class soon, and I would like to ask for your opinions about setting up this kind of class at a university. I am not sure if this topic has been discussed here before, so I apologize for any possible duplication.

Any information would be very helpful, like do's and don't's, devices being fabricated, number of students, students/teacher ratio, course load, etc.

I'd like to fabricate some CMOS device, but we lack some critical equipment such as a diffusion tube furnace, cvd, or packaging tools, so I'm looking for alternate ideas: maybe a photodiode/detector, a Hall sensor or some micro-fluidic channels. If anyone has some experience fabricating these devices in a class setup, is there anything you'd be willing to share?

Many thanks,
Sergi

---
Sergi Lendinez, Ph. D.
Assistant Director NFF | Louisiana State University
Center for Advanced Microstructures and Devices (CAMD)
6980 Hefferson Highway, Baton Rouge, LA 70803
(225) 578-9378
sergilendi at lsu.edu<mailto:sergilendi at lsu.edu> | lsu.edu/nanofabrication<https://lsu.edu/nanofabrication>

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