Monday, July 22, 2013

Willis Whitfield



We have learned this week that Shockley invented the transistor, and then Jack Kilby had the idea to build multiple transistors, or complete circuits at the same time on Silicon. We now had the integrated circuit. With these techniques, people soon realized that you could batch fabricate 1,000 transistors on a circuit for no more cost than building one, if you just made the transistors smaller. Very quickly the race began to make smaller transistors, so more could be packed onto a chip, creating more powerful and capable circuits. This race very quickly came to a standstill. What happened is that as you try to make smaller transistors, manufacturing becomes very difficult because any speck of dust in the air that landed on the silicon during fabrication would ruin a transistor, making the entire circuit not work. People then tried to make ultra-clean rooms, but to no avail. The little particles would still end up flying around the room, eventually finding a circuit to ruin. This is where today's Genius came in . . . Willis Whitfield, who is pictured above with his invention. Willis realized that the way to get the particles all out of a room was to create a situation where the airflow was Laminar and not turbulent. That is, he designed a room where the airflow was directed straight down from the top of the room to the bottom of the room, out the floor, and then through filters, before being sent back into the top of the room. There were lots of technical details to creating Laminar Flow, but with success you create ultra-pristinely- clean manufacturing rooms. It was this idea of Laminar Flow Clean Rooms which allowed the manufacture of intgrated circuits to go beyond having a few transistors each to today's circuits which might have in excess of 10 Billion transistors each.

Willis Whitfield worked at Sandia National Laboratories. I worked at Sandia from 1983 to about 2000. I remember seeing Willis Whitfield, but I don't remember ever meeting him. The ironic thing is that I was responsible for managing Sandia's Microelectronic Manufacturing facilities. I knew about Willis, but just never had the chance to sit down and talk to him. He did come by one day later in life and have his picture taken at our state of the art Laminar Flow Clean Room. Picture is shown below.


7 comments:

  1. Very nice photos, especially the later one. And even better description to go along, thanks PJM!

    A question: why the orange color? Is it the lighting on the room (why?) or just tinted glass on the walls?

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    1. The orange light . . . computer chips are made with a photographic process where the image of the circuit is projected onto photosensitive material. As such the orange lights are like the lights in a dark room. The windows are tinted, and the lights inside are orange not unlike a dark room.

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  2. Ingenious week. Very interesting. Thanks.

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  3. nice steppers? in the background. I was wondering why you were so wafer tech savy. I have toured wafer fabs all around the world and still can't believe what they actually do inside..

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    1. Yes in fact, those are steppers in the background, and this is a photolith bay. Wafer fabs are sort of mind boggling. It is funny that it has gotten so complex that no one understands everything, but a lot of people with extremely specialized knowledge can work together to make chips with 10 billion transistors, without a single one malfunctioning.

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  4. Thanks for the clarifacation PJM.
    These people were with high intelligence,indeed.
    You were at Sandia too! Super awesome!

    Thanks for sharing all the excellent pictures and background stories to go with them.

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