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Garage MOSFETS

Click here to go to our main page on microwave semiconductor tradeoffs

New for September 2021.  Here are some videos from Sam Zeloof, a young man with a unique hobby.  He produces semiconductors and integrated circuits in his garage laboratory! These are not admittedly microwave devices, but the videos provide a full description on how semiconductor ICs are created, and how to work around everyday lab equipment problems when you have a low budget. Learn more about Sam on his website (warning, site is not secure) or check him out on Twitter. According to Wikipedia, he was born in either 1999 or 2000. Our guess is he will have no problem securing employment when he graduates from college, but on the other hand, why should he work for someone that is half as smart? Wouldn't you want to work for him? Be sure to check out his YouTube channel for other videos.

Thanks to Terry for suggestion!

In the first video, Sam explains stepper lithography. His homemade stepper uses a digital light processing (DLP) projector he bought on Amazon, Sam made it when he was a junior in high school. Tons of hacks went into this system, to up the UV content of the light source, fool the color wheel synchronizer, collimate the projector beam, etc. Stepper lithography is way more versatile than using masks, much easier to modify and of course saves a lot of expenses down the road.  Very Cool Sam, thank you!

Stepper lithography

In the next video, Sam shows off a homemade reactive ion etch (RIE) system using carbon tetrafluoride and sulfur hexafluoride,  which allows him to etch poly-silicon and silicon dioxide. Gases are introduced into a vacuum chamber and then their molecular bonds are broken using high voltage (plasma) to create extremely reactive fluorine atoms. Sam employs optical spectrometer and mass spectrometer for endpoint detection. Hopefully Sam has considered the toxicity of some of the by-products of this type of setup and takes suitable precautions. Love the X-box joystick on the microscope, its now an XY-box! Learn more about Nomarski interference contrast (NIC) imaging on Wikipedia.

Reactive ion etching (RIE)

The third video shows one of Sam's silicon creations being wire-bonded into a dual in-line package (DIP). He uses a commercial, manual bonder to make wedge bonds with 1-mil (25um) gold wire. We were surprised that he didn't create his own wire-bonder using a hypodermic needle and an old Morse code key!

Wire bonding

Be sure to check out Sam Zeloof's YouTube channel for other videos and updates!

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