| learningc | not so empty here | 04:51 |
|---|---|---|
| azonenberg | Not at all, its picking up | 04:51 |
| azonenberg | slowly but surely | 04:51 |
| azonenberg | we now have several people doing lab work | 04:51 |
| azonenberg | i'm focusing on bulk micromachining of <110> Si by KOH wet etch using Cr hardmask | 04:51 |
| azonenberg | as well as metal patterning | 04:52 |
| azonenberg | swkhan is doing research elsewhere on ALD techniques (in a real lab) but is interested in our work | 04:52 |
| azonenberg | B0101 is starting out with josephson junctions | 04:52 |
| azonenberg | ashaw wants to build a laser direct-write lithography rig | 04:52 |
| azonenberg | those are the main efforts i know off the top of my head | 04:52 |
| azonenberg | check out the die pics on the googlecode page | 04:53 |
| learningc | oh so you are most here from the same university or...? | 04:56 |
| azonenberg | Nope | 04:58 |
| azonenberg | i'm at RPI | 04:58 |
| azonenberg | ashaw is in australia | 04:58 |
| azonenberg | B0101 is in singapore | 04:58 |
| azonenberg | and swkhan is in california | 04:58 |
| azonenberg | lol | 04:58 |
| learningc | cool, I just saw hobbyist-friendly at the google page | 05:00 |
| learningc | I can make the circuits at home too | 05:01 |
| azonenberg | Thats the idea, yes | 05:01 |
| azonenberg | There will definitely be some investment in optics etc | 05:01 |
| azonenberg | and some basic chem knowledge will be required | 05:01 |
| azonenberg | but we want to keep it simple, of the magnitude of PCB etching | 05:01 |
| azonenberg | build your own single layer PCBs at home? Fine | 05:01 |
| learningc | how much does it cost in tools and equipments investment though? | 05:01 |
| azonenberg | Build your own 2-metal ASICs at home? | 05:01 |
| azonenberg | Fine too | 05:01 |
| azonenberg | learningc: We havent gotten it working yet lol | 05:01 |
| azonenberg | Techniques are gradually evolving | 05:02 |
| learningc | what kind of investment in optics? what kind of microscope? | 05:03 |
| azonenberg | Depends on the process size you want | 05:03 |
| azonenberg | 200um is doable dirt cheap | 05:04 |
| ashaw | By the way, The imaging device I am designing has a cost of about 700-1000 | 05:04 |
| azonenberg | 20um costs a bit more | 05:04 |
| azonenberg | 350nm will not be cheap but may be feasible eventually | 05:04 |
| ashaw | I am targeting 350nm | 05:04 |
| azonenberg | ashaw: A bit high but it will hopefulyl be one of the most expensive parts of the setup | 05:04 |
| azonenberg | And lets see how it turns out | 05:04 |
| ashaw | that is 12st rev | 05:04 |
| azonenberg | Remember you need not be able to make masks at that size | 05:04 |
| azonenberg | I envision building a stepper at some point | 05:04 |
| azonenberg | with maybe 4x reduction | 05:05 |
| azonenberg | get some nice olympus microscope objectives | 05:05 |
| ashaw | stepper? | 05:05 |
| azonenberg | or mitutoyo | 05:05 |
| azonenberg | yes, to do multiple dies on a wafer | 05:05 |
| ashaw | oh, yeah | 05:05 |
| azonenberg | using a single mask | 05:05 |
| azonenberg | Thats much further out | 05:05 |
| ashaw | or, as I go directly | 05:05 |
| azonenberg | initially i'm using my cheap microscope as a projection aligner since it gets the job done | 05:05 |
| azonenberg | ashaw: not sure if you heard when i said a little while ago but i just got two new blank wafers | 05:06 |
| ashaw | the DMD device I have has a resolution of 7.6uM | 05:06 |
| azonenberg | 2 inch <110> both sides polished | 05:06 |
| azonenberg | tomorrow if time permits i'll be depositing a micron of Cr on both sides of one | 05:07 |
| ashaw | the other expensive thing will be the CMP machine, no? | 05:07 |
| azonenberg | CMP? No, i think that could be made cheaply | 05:07 |
| azonenberg | depending on the precision required | 05:07 |
| azonenberg | it could share parts with the spin coater | 05:07 |
| ashaw | probably not actually | 05:08 |
| azonenberg | like i said i'm targeting 20um | 05:08 |
| azonenberg | at 350nm things get a bit harder :p | 05:08 |
| ashaw | as the wafer must be mounted upside down | 05:08 |
| azonenberg | CMP is on the roadmap but i dont need it yet | 05:08 |
| azonenberg | So i havent put much work into it | 05:09 |
| learningc | 2 metals asic? what type of metals involved? | 05:09 |
| azonenberg | i've been developing processes as they become necessary | 05:09 |
| azonenberg | learningc: 2 metal layers | 05:09 |
| azonenberg | as in, one for the gates and one interconnect layer | 05:09 |
| azonenberg | is a bare minimum | 05:09 |
| azonenberg | 3 is prefrable | 05:09 |
| azonenberg | and probably filament evaporated aluminum | 05:09 |
| ashaw | my goal is CMP with electrolytic copper | 05:10 |
| ashaw | personally | 05:10 |
| learningc | using this technique to build transistors? | 05:10 |
| azonenberg | ashaw: the thing about copper is that you need a barrier layer and everything | 05:10 |
| azonenberg | and adhesion layers | 05:10 |
| azonenberg | sputtered Ta will work | 05:10 |
| ashaw | no, that is front end of line | 05:10 |
| azonenberg | i was thinking damascene actually | 05:10 |
| azonenberg | for when i got to copper | 05:11 |
| azonenberg | sol-gel SiO2 | 05:11 |
| azonenberg | litho with negative of metal pattern | 05:11 |
| azonenberg | sputter Ta then Cu without breaking vacuum | 05:11 |
| azonenberg | into the trenches | 05:11 |
| learningc | what are the semiconductors used? | 05:11 |
| azonenberg | then CMP until its flat | 05:11 |
| azonenberg | learningc: silicon | 05:11 |
| learningc | doped with? | 05:12 |
| azonenberg | The ones i have are mostly P type B doped | 05:12 |
| azonenberg | but i've been doing mostly MEMS | 05:12 |
| azonenberg | so i dont really care | 05:12 |
| ashaw | probably p doped | 05:12 |
| azonenberg | My handful of CMOS masks are for an N-well process on P type wafers | 05:13 |
| azonenberg | but there's plenty of room for change between now and then | 05:13 |
| azonenberg | in any case its 0100 here and i need sleep lol | 05:13 |
| azonenberg | Keep the discussion going, i'll be back in the morning | 05:13 |
| ashaw | learningc | 05:14 |
| ashaw | What are you interested in about this? | 05:14 |
| learningc | I'm exploring the ideas only | 05:14 |
| ashaw | my LDI head will work with PCBs too :) | 05:15 |
| learningc | and see how far we can make our own devices | 05:15 |
| ashaw | same machine | 05:15 |
| learningc | LDI? | 05:15 |
| ashaw | Laser direct imagnig | 05:15 |
| learningc | oh, I have no access to a laser though | 05:15 |
| ashaw | Bluray laser | 05:16 |
| learningc | of those | 05:16 |
| ashaw | diode based | 05:16 |
| learningc | what's the power of these? | 05:16 |
| ashaw | 300mW | 05:16 |
| azonenberg | You dont need much | 05:16 |
| azonenberg | thats actually overkill | 05:16 |
| ashaw | yeah | 05:16 |
| azonenberg | you need aroudn 200 mJ/cm^2 for my photoresist | 05:16 |
| ashaw | huge | 05:16 |
| learningc | you can go far with 300mW | 05:17 |
| azonenberg | so 20 mW would need 10 sec for a 1cm^2 die if you could get it all onto the die | 05:17 |
| azonenberg | 300mW would need under a second and would actually probably have to be PWMed | 05:17 |
| ashaw | you would probably need 1mW | 05:17 |
| learningc | but I suppose the optics is critical? | 05:17 |
| azonenberg | learningc: yes | 05:17 |
| ashaw | and driving the DMD device | 05:18 |
| learningc | or do you use the same optics in the bluray instead? | 05:18 |
| ashaw | no different | 05:18 |
| ashaw | very | 05:18 |
| ashaw | more like a digital projector | 05:18 |
| ashaw | but using a bluray laser as a light source | 05:18 |
| ashaw | and not expanding it | 05:19 |
| learningc | did you do any prototype of the laser imaging device? | 05:20 |
| ashaw | I am designing it now. | 05:20 |
| learningc | what about others? | 05:21 |
| ashaw | and will build it soon | 05:21 |
| ashaw | not a new idea | 05:21 |
| ashaw | used for a long time in PCB industry | 05:21 |
| learningc | but it's a challenge if you DIY | 05:21 |
| ashaw | I am scaling it down, in cost, and in feature size | 05:21 |
| ashaw | yeah | 05:21 |
| learningc | is it like a cnc machine? | 05:22 |
| ashaw | the main movement stage is, yes | 05:22 |
| learningc | and what kind of resolution are you targetting? | 05:23 |
| learningc | or precision | 05:23 |
| ashaw | I want to image at 500nm | 05:24 |
| ashaw | 10 allow a 1um process | 05:24 |
| azonenberg | ashaw: Hmm | 16:49 |
| azonenberg | You want to put the laser head on an x-y table? | 16:50 |
| azonenberg | I thought you were going to do single 1024x768 or whatever masks | 16:50 |
| azonenberg | You will have alignment issues since your stages will probably not be that accurate | 16:50 |
| azonenberg | I mean, it'd be fine at 5-10um scales probably | 16:50 |
| azonenberg | But going smaller will not be easy | 16:50 |
| ashaw | I intend to have a movable head, but before magnification | 22:11 |
| ashaw | azonenberg | 22:11 |
| azonenberg | h/o busy | 22:12 |
| learningc | azonenberg: which microchip wifi module do you recommend since I'm believing you have a bit of experience with them? | 22:31 |
| learningc | azonenberg: never mind, only 2 versions one with antenna build-in and the other external | 22:46 |
| learningc | I think I'll go for the external one | 22:47 |
| --- Thu Oct 13 2011 | 00:00 | |
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