Necessity is the mother of invention, and the RAM crisis is driving people to some pretty creative measures to avoid paying through the nose to upgrade their computer’s memory. Recently, we covered one man’s brave attempts to run a computer without RAM—spoiler, that idea is kind of a non-starter—and now a YouTuber who calls himself Dr Semiconductor has upped the ante by building functioning memory cells himself… in his garden shed.
I honestly thought the title of this video was a joke until I started watching, and it’s hard to overstate how wild this is. This isn’t a case of soldering together a few logic gates—this guy has managed to construct a semiconductor fabrication setup in the sort of shed that looks like it should be hosting a rusty lawnmower, a few half-full cans of paint, and a wheelbarrow with a flat tire. In a video released last month, the good doctor catalogued the construction of his DIY cleanroom, and in the follow-up video, he narrates the process of putting together a functioning RAM cell.
If you’ve ever wondered how modern chips are fabricated, the video doubles as a pretty great description of the process. The good doctor explains each step as he goes, walking us through the deposition of the initial oxide layer on the silicon wafer, then the processes of photolithography, etching, thin-film deposition, and testing. These processes use some pretty gnarly chemicals to clean the chips and strip away unneeded material. And if you’re familiar with chip fabrication and find yourself wondering whether he uses hydrofluoric acid and piranha solution: Hell yes, he does. (There’s no sign of the delight that is chlorine trifluoride, though, perhaps because getting hold of it puts you on all manner of watch lists.)
The video also provides an excellent explanation of how RAM cells actually work. One thing that you might not know—I certainly didn’t until fairly recently—is that current drains constantly from RAM cells, which means they need constant recharging. Dr Semiconductor’s cells need recharging every couple of milliseconds, but as he explains, even commercial DRAM needs to be recharged every 64 milliseconds or so. This is why RAM is volatile, and doesn’t retain data when you turn your computer off. (As an aside: computer science YouTuber Laurie Wired recently made an excellent video about why RAM works like this.)
Anyway, by the end of the video, Dr Semiconductor has a few fully functioning RAM cells, each of which is in the order of microns in size. And again: this is insane. There are other channels on YouTube where people have successfully put together home photolithography setups, but actually producing functioning RAM with micron-scale cells is a whole other level. Of course, it’s not like the Doctor has magicked up several gigabytes of RAM—this video is basically a proof of concept, something its creator readily admits. However, it sounds like he’s not done—he ends the video by explaining his plans to “take these cells, stitch them together … and hook [them] up to a PC.”
If you’d asked me yesterday whether this was remotely possible, my answer would have been “lol no.” But now? I mean, I wouldn’t bet against him.
