| --- Sun Jan 8 2012 | 00:00 | |
| barrettfriedman | Hello. | 18:35 |
|---|---|---|
| azonenberg | hi :) | 18:35 |
| azonenberg | I'm serious about the "home" part btw lol | 18:35 |
| barrettfriedman | I evidently need more sleep. I misread for a second... "Hebrew" CMOS and MEMS foundry design | 18:36 |
| azonenberg | Mostly been pushing lithography, i have 20 micron patterning working reliably and am working on shrinking to 2ish using commercially made 8000DPI film masks | 18:36 |
| azonenberg | i have the beginnings of a vacuum setup but still use an evaporator on campus for doing film deposition | 18:37 |
| azonenberg | all of the spin coating, lithography, and etching are in my home lab | 18:37 |
| barrettfriedman | Keeping it simple I see. | 18:37 |
| azonenberg | Admittedly my lab is a bit better equipped then your average hobbyist http://imgur.com/a/Y3m0L#3 | 18:37 |
| azonenberg | yes that's a 4" wafer prober on the right | 18:38 |
| barrettfriedman | How are you dealing with the vapors involved in etching processes? | 18:38 |
| azonenberg | http://imgur.com/a/Y3m0L#5 | 18:38 |
| azonenberg | Homebrew fume hood | 18:38 |
| azonenberg | 2 foot cube, 1x2 foot opening below the sash | 18:38 |
| azonenberg | 240CFM after leaks aroudn side of the sash is about 100 linear feet per minute airflow | 18:38 |
| azonenberg | well within the recommended range | 18:39 |
| barrettfriedman | That's pretty professional looking. | 18:39 |
| azonenberg | Thx :D | 18:39 |
| barrettfriedman | Is that a... toaster? | 18:39 |
| azonenberg | i can cook a beaker of RCA-2 on the hot plate and not smell HCl vapor at all | 18:39 |
| barrettfriedman | http://imgur.com/a/Y3m0L#5 | 18:39 |
| barrettfriedman | On the left. | 18:39 |
| azonenberg | Yes | 18:39 |
| azonenberg | It's being stored there for now | 18:39 |
| azonenberg | will be turning into a reflow oven once my thermocouple arrives | 18:39 |
| barrettfriedman | Why do you do all this? | 18:39 |
| azonenberg | i have a Quincy Lab oven as well but the toaster goes hotter | 18:39 |
| azonenberg | Why not? :P | 18:39 |
| azonenberg | i'm a grad student in computer science bored with doing everythign in software | 18:40 |
| azonenberg | So i started dabbling in EE on the side | 18:40 |
| azonenberg | before long i was building a fab in the living room lol | 18:40 |
| barrettfriedman | You should just join the EE department! | 18:40 |
| azonenberg | barrettfriedman: my thesis work is in computer architecture and i'm taking some EE classes | 18:40 |
| barrettfriedman | Then you won't have to populate your apartment with all this clutter. | 18:40 |
| azonenberg | i'm right on the edge | 18:40 |
| azonenberg | and i *want* home fab | 18:40 |
| barrettfriedman | I see. | 18:40 |
| azonenberg | the goal is to get it down to something you can do in a high school chemistry lab etc | 18:41 |
| barrettfriedman | So you like teaching? | 18:41 |
| azonenberg | sure, maybe single-die rather than full-wafer processing | 18:41 |
| azonenberg | and micron-scale features | 18:41 |
| azonenberg | i do hope to push experimentally to the 500-350nm range but i don't think i will need to go that small for any of my planned devices | 18:41 |
| azonenberg | MEMS is the main goal anyway since that's less sensitive to trace ion contamination | 18:41 |
| azonenberg | And i like solving complex problems :p | 18:42 |
| azonenberg | http://colossus.cs.rpi.edu/pictures/2011/December/12-22-2011%20-%20lab/S7302297_sm.jpg is an action shot of me working | 18:43 |
| azonenberg | I try hard to keep the lab run as properly as I can, i have an MSDS book on the shelf where the landlord can find it and a written policy manual | 18:43 |
| azonenberg | incompatibles are isolated from each other, drip trays under all liquid storage | 18:44 |
| azonenberg | full sprinkler coverage and two fire extinguishers | 18:44 |
| soul-d | lol hope my pic isn't showed as "how it's not supposed to be " :P | 18:44 |
| azonenberg | soul-d: lol | 18:44 |
| azonenberg | I will say your lab isn't the tidiest i've seen | 18:45 |
| azonenberg | And i'm a bit OCD about mine | 18:45 |
| azonenberg | since a friend got in some trouble last year with the local PD as a result of being less pedantic | 18:45 |
| azonenberg | a friend of mine (PhD student in chemistry at my school) says my lab is cleaner than some of the ones on campus he's worked in lol | 18:45 |
| soul-d | your lab is actualy yours :P | 18:46 |
| azonenberg | i'm even by the book about waste disposal, all of the used etchants etc are stored in plastic jars with labels as to contents and a NFPA diamond hazard label | 18:46 |
| azonenberg | and taken down to the county disposal site a few times a year when they get full | 18:46 |
| azonenberg | that's for both the etch and the first rinse of the beaker during cleaning | 18:47 |
| azonenberg | the only thing i dump down the drain is photoresist developer, which is just 1% NaOH in water | 18:47 |
| azonenberg | and that's after titrating to neutral with HCl | 18:47 |
| azonenberg | so its just salt water :p | 18:47 |
| azonenberg | barrettfriedman: anyway, so back to your question | 18:48 |
| azonenberg | Describe the process you're planning | 18:48 |
| azonenberg | you said something about wanting to do high aspect ratio features by sputtering? | 18:48 |
| barrettfriedman | azonenberg: Oh, yes. There are plenty of applications where the dimensions of a device define its behavior so I got interested in lithography as one way to establish a device's geometry. I like keeping things simple as well, so I was wondering if I could simplify the lift off process as specified by the Wikipedia article. | 19:17 |
| barrettfriedman | azonenberg: After step 4 in http://upload.wikimedia.org/wikipedia/commons/b/b5/Lift-off_%28microtechnology%29_process.svg, if you can reach into the well and make some kind of measurement (electrical contact, illuminating a junction of some kind, etc.), then you don't need to worry about actually "lifting off" the photoresist layer, correct? | 19:21 |
| azonenberg | barrettfriedman: There might still be residue along the sidewalls | 19:45 |
| azonenberg | But all you have to do is soak it in acetone and maybe sonicate after that | 19:45 |
| azonenberg | If you can do evaporation and lithography there's no reason not to do the normal liftoff process | 19:46 |
| --- Mon Jan 9 2012 | 00:00 | |
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