February 2022 - Libresilicon-developers

Reminder - Mumble session on Sunday 2022-01-207 @ 18:00 UTC
by Hagen SANKOWSKI 26 Feb '22

26 Feb '22

Hello List! This is our weekly reminder for our next Mumble Sessions on Sunday 2022-02-27 @ 18:00 UTC. Please join us as usual at our Mumble Server murmur.libresilicon.com at Port 64738, the Channel is IC. We like to follow-up our topics from mumble sessions before. Regards, Hagen.

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Reminder - Mumble session on Sunday 2022-01-20 @ 18:00 UTC
by Hagen SANKOWSKI 18 Feb '22

18 Feb '22

Hello List! This is our weekly reminder for our next Mumble Sessions on Sunday 2022-02-20 @ 18:00 UTC. Please join us as usual at our Mumble Server murmur.libresilicon.com at Port 64738, the Channel is IC. We like to follow-up our topics from mumble sessions before. Regards, Hagen.

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Particle sensor
by David Lanzendörfer 13 Feb '22

13 Feb '22

Hi everyone A buddy of mine on Fediverse is working on the particle sensor thing from IKEA, Hagen has been talking about. I already told him, we wanna use it for the clean room. He's hacking on it right now and it starts looking really good: https://lupyuen.github.io/articles/ikea?90#connect-to-pinedio-stack-bl604 He speaks English, Cantonese and ALSO Mandarin, so I'm REALLY looking forward to his progress and welcoming him onto the team some time. Cheers -lev

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Re: [Libre-silicon-devel] Wafers with polysilicon pre-applied
by David Lanzendörfer 06 Feb '22

06 Feb '22

Hi Martin Damn! That's a good point! O_O Gotta share this with the mailing list, because that's an important information! Hmm... Guess I've gotta go back to the drawing board then... Seems we've gotta figure out some way to react undeadly chemicals into Polysilicon then after all... Hmm Cheers -lev On Saturday, February 5, 2022 4:16:14 PM WET Martin Geisse wrote: > Hi, > > This discussion suggests that you still need either a really good vacuum or > H2, as any O2 or H2O will oxidize the silicon. > https://www.researchgate.net/post/Why-Silicon-is-not-getting-deposited-by-rf > -sputtering > > As for the cheating, you have to draw the line somewhere since you won't be > making your own wafers either. But goals are goals, and it's not my > intention to convince you of anything :) > > Greetings, > Martin > > > On Sat, Feb 5, 2022 at 5:06 PM David Lanzendörfer < > > leviathan(a)libresilicon.com> wrote: > > Hi > > The more I think about it, the more it starts to look feasible. > > For the gate formation, we can just "abuse" the sputterer for depositing > > the > > silicon layer, and for the isolation, we can use the spin coater with a > > silicone solution and react it in the furnace into silicon oxide. > > I think I'll sit down and start working out the chemical formulas... > > would be easier, if I'd actually be a chemist tho... Haha > > Any chemists here on the mailinglist anyway? > > > > Cheers > > -lev > > > > On Saturday, February 5, 2022 3:56:45 PM WET David Lanzendörfer wrote: > > > Hi > > > With a sputterer we could just sputter the silicon for forming the > > > > gates... > > > > > What do you think? > > > > > > Cheers > > > -lev > > > > > > On Saturday, February 5, 2022 3:48:57 PM WET David Lanzendörfer wrote: > > > > Hi > > > > We already have been looking at Sam's process flow a while ago and > > > > already > > > > > > noticed that he's "cheating", by using specialized wafers. > > > > However. My goal is to develop a full stack manufacturing process, > > > > without > > > > > > skipping essential parts. > > > > I rather wanna find alternative chemical recipes for growing poly and > > > > oxide > > > > which do not require military-grade poisonous gases :-) > > > > > > > > Cheers > > > > -lev > > > > > > > > On Saturday, February 5, 2022 3:34:52 PM WET Martin Geisse wrote: > > > > > Hi, > > > > > > > > > > I just found something in Sam Zeloof's latest design (08/2021) that > > > > > I > > > > > overlooked first and I'm not sure if it has been discussed here > > > > yet... > > > > > > > He > > > > > uses wafers which are pre-doped for p-wells, and gate oxide and > > > > > polysilicon > > > > > pre-applied without any mask. He then patterns, etches and n-dopes > > > > > source/drain regions, using the poly as a mask and then adds > > > > "hard-baked > > > > > > > photoresist as a dielectric" to separate the poly gate from the > > > > > above > > > > > metal > > > > > layer. This requires some changes in the process and will only allow > > > > > n-type > > > > > transistors, but he completely avoids the problems with poly > > > > deposition > > > > > > > AND > > > > > doesn't have to grow field oxide -- so I'm actually not sure if he > > > > needs > > > > > > > a > > > > > high-temp furnace at all. > > > > > > > > > > Link: top article on http://sam.zeloof.xyz/category/semiconductor/ > > > > > > > > > > Opinions? > > > > > > > > > > Greetings, > > > > > Martin > > > > > > > > _______________________________________________ > > > > Libresilicon-developers mailing list > > > > Libresilicon-developers(a)list.libresilicon.com > > > > https://list.libresilicon.com/mailman/listinfo/libresilicon-developers > > > > _______________________________________________ > > Libresilicon-developers mailing list > > Libresilicon-developers(a)list.libresilicon.com > > https://list.libresilicon.com/mailman/listinfo/libresilicon-developers -- (\__/) (='.'=) This is Ninja Bunny. (")_(") Copy and paste Bunny into your signature to help him gain world domination

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Wafers with polysilicon pre-applied
by Martin Geisse 05 Feb '22

05 Feb '22

Hi, I just found something in Sam Zeloof's latest design (08/2021) that I overlooked first and I'm not sure if it has been discussed here yet... He uses wafers which are pre-doped for p-wells, and gate oxide and polysilicon pre-applied without any mask. He then patterns, etches and n-dopes source/drain regions, using the poly as a mask and then adds "hard-baked photoresist as a dielectric" to separate the poly gate from the above metal layer. This requires some changes in the process and will only allow n-type transistors, but he completely avoids the problems with poly deposition AND doesn't have to grow field oxide -- so I'm actually not sure if he needs a high-temp furnace at all. Link: top article on http://sam.zeloof.xyz/category/semiconductor/ Opinions? Greetings, Martin

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High-Temperature !! SOI 0.35u CMOS process as Ransomware???
by Hagen SANKOWSKI 04 Feb '22

04 Feb '22

Hello list! A while ago I came across a very interessting high-temperature CMOS process on SOI for a client of mine. https://www.ims.fraunhofer.de/en/Business_Units_and_Core_Competencies/High-… So, as I ask for manufacturing the manager told me, this process will be discontinued for economic reasons.. After some emails for and back offering help, publishing this process free and open, as Netscape did with their browser, I had a long call today with the higher management level. Well, he does not seems to be quite convinced to doing so. From his perspective, this would cost him money to support us, publishing all material they have in a god feasible way, mainly to pay his employees role. I guess, somewhere was the hope, another fab would licensed the stuff.. And he asked quite directly, what we would pay to get the process. As I understood, the process fits exactly into their machine park and has some quirk in exotic material and fabrication steps. So it wouldn't be a one-by-one transfer into a the public. My question is: Can we deal with that as Ransomware? Setting up a world-wide campaign of open-source enthusiasts to buy this process? I do not know about which amount of money he is thinking... I really know, if he put this process just into his safe, in a couple of years the process is dead for some reasons. All the developers are gone already, some old machines are already saled or scraped. He can not earn a batch of money with this process anymore, otherwise this would be still in usage, so he just likes to sale the leftovers. Can or should we offer, let's say, one or two million? Or not? How much would it cost him to pay a couple of engineers to release the information to us and we'll do the rework and publishing? Can we challenge this German Research institute in a way, it would give away the process "voluntarily"? E.g., can we argue with "public money - public code"? What do you think?? All creative thinking welcome :-) Regards, Hagen. -- "They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety." Benjamin Franklin (1775)

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DIY maskless stepper
by Hagen SANKOWSKI 02 Feb '22

02 Feb '22

Hello List. I found some video clips from a Dutch (ex Philips) Engineer who builds his own DIY maskless stepper :-) Part 1: Optisc https://www.youtube.com/watch?v=_w0Z2Y5vaAQ Part 2: Mechanics https://www.youtube.com/watch?v=MdRwiI6VLmk Part 3: Electronics and Software https://www.youtube.com/watch?v=ebv_9cmLNqo Part ?: Building a Small Cleanroom for Photolithography https://www.youtube.com/watch?v=bkmVmsMUsJU I think all videos here are a great source of inspiration. Regards, Hagen.

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Re: [Libre-silicon-devel] Batch loading... robot arms??
by Philipp Gühring 02 Feb '22

02 Feb '22

Hello, > Well, being cost-effective and reliable I'd suggest to use components > similar to CD or DVD players. Wait a moment. CD/DVD burners are using heat and lasers to burn holes into flat wafers in a rather high precision way. Isn't that something we could use instead of photo-lithography+etching? It's just a hole at a time instead of a whole stepped pattern (or even a whole wafer), and we might have some challenge to get the laser to produce the patterns that we need, but wouldn't that be usable somehow? Bluray writers should be able to produce 130nm x 150nm holes Best regards, Philipp Gühring

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Question: Robot arm design
by David Lanzendörfer 01 Feb '22

01 Feb '22

Hi everyone In all the designs for wafer transfer robots, I've seen so far on YouTube, they're horizontal only, with one linear actuator for changing the z-axis. I think however, that this design here is better, because we can also use it to load wafers into machines, which don't have horizontal loading: https://www.thingiverse.com/thing:1838120 What do you think? I just bought a 3D printer today and it should arrive in the next few days, then I can start prototyping. Cheers -lev

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