- Libresilicon-developers - libresilicon.com

Status update
by David Lanzendörfer 20 May '19

20 May '19

Hi So today I finally got access to the Cirie200 metal dry etcher. I was running my test sample for measuring the nickel etch rate, when I noticed, that it wasn't etching at all and that the Cl2 flow rate was totally off in respect to the recipe, and the Cirie200 was giving me errors. I consulted with the technician who admitted to me, that the Main Flow Control (MFC) had broken a while ago but they didn't replace it, because apparently no one was noticing, that they were not etching according to the recipe, but had in fact random Aluminum etch rates, basically, because of random variation of the Cl2 flow... -.-' Anyway... Now he has to purge the entire Cl2 line with N2 and then he can replace the main flow control for the Cl2, so that I've got the proper Cl2+Argon mix for dry etching the Nickel. I also isolated the issue, why I haven't managed to produce switching transistors until now. And mia culpa, I right now wanna beat myself... really hard into the face. The Titanium etched nice. But when you only sputter 100nm aluminum and wet etch it without the Titanium coverage, you see, that it's over etching the exact same way, as Nickel does with the wet etching. So, as soon as Bao gets the valve fixed interconnect to the devices should actually work quiet fine. Cheers -lev

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Reminder - Next Mumble session on Sunday, 21.00 HKT
by reminder＠libresilicon.com 18 May '19

18 May '19

Hello List! Just a small reminder for our next Mumble Sessions on this Sunday, at 21.00 Hong Kong Time. Please join us as usual at our Mumble Server murmur.libresilicon.com at Port 64738, the Channel is IC. Thanks for the attention!

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ESD protection
by David Lanzendörfer 17 May '19

17 May '19

Hi The progress in the lab is slowed down by machines, which already have been booked and yesterday, it took me half an hour until someone told me, that the cooler for the Poly dry etcher wasn't broken, but the pump just turned off from now on, when not being in use, because I'm essentially the only person etching polysilicon, because no one else works on a CMOS process at NFF... ^^' Anyway. I'm now so far, that we've got the new poly gates on a STI isolated surface: https://twitter.com/LibreSilicon/status/1126815745734692864 On Monday it's Buddhas birthday, so the lab is closed... again... Hong Kong. Those folks have so many holidays... If I wouldn't be here already, I'd be jealous =^_^=~~ Tuesday I'll attend the formal training for the Cirie200 (nickel dry etch machine), as well as finalize implant stop, nimplant, pimplant, annealing, nitride spacers + silicide block, and then I put it into the furnace for LTO deposition. After LTO, I can etch the contact holes and sputter Nickel+Aluminum+Nickel. Now that I anyway have to sputter and dry etch Nickel, I decided, that I use Nickel instead of Titanium for the interface layers. This will reduce the via resistance by a factor 10. Cheers David

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Reminder - Next Mumble session on Sunday, 21.00 HKT
by reminder＠libresilicon.com 11 May '19

11 May '19

Hello List! Just a small reminder for our next Mumble Sessions on this Sunday, at 21.00 Hong Kong Time. Please join us as usual at our Mumble Server murmur.libresilicon.com at Port 64738, the Channel is IC. Thanks for the attention!

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Update: Dry etching Nickel
by David Lanzendörfer 08 May '19

08 May '19

Hi everyone So today I tried to etch the Nickel+Aluminum+Titanium stack with the dry etcher in order to get nice sharp wires and contact pads. Well, now the long story: Everyone told me "we can't guarantee that works" and "no one has tried to dry etch nickel at NFF before" I asked Bao to help me try dry etch it and the result was absolutely shit. The Nickel didn't etch away but instead the Titanium and Aluminum started to over etch. I consulted with CK (Bao's boss) and gave him the attached PDF to read. He then came back to me with a printout of the paper and told me that in principle, it should be possible to do this with the AST. While he was checking through the recipe list, he then discovered that there is already a recipe from the factory from which they bought it from, which does exactly what's described in the paper :D Unfortunately, for bureaucratic reasons, I'm only getting full access to the machine on Tuesday, so I can't etch the wires before Tuesday, because wet etching does not work with a feature size of around 0.5 to 1.0 microns... We need the dry etcher in order to avoid over etch. So we have to wait until Tuesday, for the first preliminary SPICE models :-( -lev

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Status update: Silicide
by David Lanzendörfer 06 May '19

06 May '19

Hi all So today I went with 2 probes down to the die frame with polysilicon and silicide on top and measured. The resistance was so low, that the measurement device just rounded it to zero ohms. I've made a Tweet about it: https://twitter.com/LibreSilicon/status/1125324508997382145 We're still waiting for the NFF RIE (dry etcher) to be functional again. If they can repair it until tomorrow morning, I can make the holes and sputter the interconnect wires, and then we should have the first switching curves around Wednesday (as promised) Cheers -lev

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Reminder - Next Mumble session on Sunday, 21.00 HKT
by reminder＠libresilicon.com 04 May '19

04 May '19

Hello List! Just a small reminder for our next Mumble Sessions on this Sunday, at 21.00 Hong Kong Time. Please join us as usual at our Mumble Server murmur.libresilicon.com at Port 64738, the Channel is IC. Thanks for the attention!

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"555" Repository + Schematic
by Hagen SANKOWSKI 03 May '19

03 May '19

Hello List! Today on our weekly Mumble session we talked about the "triple-5" once more. So I got itchy fingers and set up my personal repository for that on github (https://github.com/chipforge/CMOS-555) Well, no repository without content - please check the README file and see the Schematic I already draw now. For everybody which is lazy to install Lepton-EDA (as describted in the README) I attached a fency screenshot. Please check the Schematic, based on the Wikimedia SVG drawing, for mistakes I did. All dimensions for the transistors (Width, Length) and the restistors (Resistance) are still just generic. This task I suppose will do someone of you which is more an analog guy than me :-) BTW, Tatzelbrumm and Ference, do you like to clone the repository and we're merging each other? Or, otherwise I can shift the repository to the github.com/libresilicon group and we are working there. What do you prefer? Best Regards, Hagen. P.S.: Other versions of the CMOS "555" circuit I saw, will follow soon as schematics - one e.g. even has on BJT. -- "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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GoFundMe campaign for the clean room
by David Lanzendörfer 02 May '19

02 May '19

Hi folks So Andreas and I were brain storming on how we could ensure the next years rent without relying solely on the private money of a few individuals and came up with the idea of a gofundme-campaign. Seems to work for a lot of people with much less important financial problems, so we figured, it's worth a shot. In case you've got some cash to spare, it would be fantastic if you could contribute a bit to our campaign goal. The more you help out, the less we've gotta stem privately from loans and so. Also please share with everyone you know, in order to spread the message and help us finalize the PDK. Even if lots of you folks are too busy to actively participate on the mailing list, this is a chance to contribute something to the project. And it's only a few minutes of your time. Here is the campaign link: https://www.gofundme.com/libresilicon-cleanroom-rent Thanks David

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Re: [Libre-silicon-devel] Funding / products )do commodore chips
by Staf Verhaegen 01 May '19

01 May '19

Hagen SANKOWSKI schreef op wo 01-05-2019 om 14:46 [+0200]: > Hello Ludwig. > > Well, all this Commodore 8bit stuff is laying around at github.com and > elsewhere in the internet. Just google for the chip numbers together > with +verilog or +vhdl - or you looking for the C-One > (https://en.wikipedia.org/wiki/C-One) from *Jeri Ellsworth*. You'll find > the sources for sure. Next to the C-One, you have Suska for Atari and the Replay Board and MIST/MiSTer FPGA boards who reimplement most of the computers of that time. Enough code available to implement chips with; although license may be a road block. greets, Staf.

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