| lekernel | bart416, i've read that sputtering outside of a vacuum gives bad result... the deposition is not uniform, is brittle, oxidizes, etc. | 09:10 |
|---|---|---|
| bart416 | lekernel, yeah but it's possible | 09:11 |
| lekernel | probably not for microelectronics :) | 09:11 |
| bart416 | SolidRaven> The thing is, you could theoretically sputter coat at atmospheric pressure | 09:11 |
| lekernel | even for depositing aluminum on potato chips bags they use vacuum | 09:12 |
| Action: bart416 once again points at theoretically :P | 09:21 | |
| bart416 | You'd just need a strong electric field to force the ions in the right direction | 09:24 |
| Laurenceb | ive spluttered paper in air | 11:32 |
| Laurenceb | with graphite, using a large cap | 11:32 |
| Laurenceb | and 1KV XD | 11:32 |
| Laurenceb | propelling pencil lead | 11:36 |
| Laurenceb | are there processes for two component aluminium deposition? | 12:30 |
| Laurenceb | anyone here? | 13:21 |
| azonenberg | Just got up but heading to work shortly | 13:22 |
| Laurenceb | heh | 13:22 |
| Laurenceb | are there processes for two component aluminium deposition? | 13:22 |
| Laurenceb | im sure ive seen two component alu deposition using sprays | 13:23 |
| Laurenceb | btw, have you seen jeri ellsworths work with diy mosfets? | 13:23 |
| azonenberg | Laurenceb: Yes, that was actually the inspiration for this work | 13:25 |
| azonenberg | I wanted to do a process shrink on her basic design | 13:25 |
| Laurenceb | iirc i saw a video on low volume cd production | 13:27 |
| Laurenceb | they had a two component alu deposition spray thing | 13:27 |
| azonenberg | Hmm | 13:27 |
| Laurenceb | wish my chemistry was better :( | 13:27 |
| azonenberg | very interesting but i'm not familiar with the process | 13:28 |
| azonenberg | It'd have to be something like sol-gel | 13:28 |
| Laurenceb | i remember we did chrome deposition in liquid state in 6th form | 13:28 |
| azonenberg | But the problem is that Al oxidizes sooooo easily | 13:28 |
| azonenberg | You'd almost certainly have to do it under inert gas | 13:28 |
| azonenberg | Though possibly not low pressure | 13:29 |
| Laurenceb | im trying to work out if you could do a liquid state process, like jeris but without the lame comductive epoxy | 13:29 |
| azonenberg | Yeah | 13:29 |
| Laurenceb | *con | 13:29 |
| azonenberg | I'm going to be playing with an evaporator on campus shortly | 13:29 |
| azonenberg | Prepping samples tonight/tmrw and running the experiment thursday | 13:29 |
| Laurenceb | nice, its not very complex but vacuum complicates things | 13:29 |
| azonenberg | Yeah | 13:29 |
| Laurenceb | i like jeris oven+nitrogen, very basic | 13:29 |
| Laurenceb | i also like the idea of liquid microjets, but i know its a little mad | 13:30 |
| azonenberg | I'd probably use argon since i'd use it for sputtering | 13:30 |
| azonenberg | Even if it costs a bit more, cheaper than two tanks | 13:30 |
| azonenberg | But in any case i'll be playing with lift-off and normal etching on ~100nm Cu films | 13:30 |
| azonenberg | If it's even remotely successful i plan to build one of my own over the coming months | 13:31 |
| Laurenceb | interesting | 13:32 |
| Laurenceb | http://en.wikipedia.org/wiki/Electrospray | 13:32 |
| Laurenceb | theres got to be a use for that | 13:32 |
| azonenberg | Deposition of particles for nanostructures? Hmm | 13:33 |
| azonenberg | The thing is, you're depositing single particles | 13:33 |
| azonenberg | you'd have a giant polycrystal with no cohesion between grains | 13:33 |
| Laurenceb | yeah but if you used it for dopants | 13:33 |
| azonenberg | You'd need to heat it to near the melting point to densify the film (still polycrystalline but at least they stick together) | 13:34 |
| Laurenceb | and alu maybe | 13:34 |
| azonenberg | Doping is trivial | 13:34 |
| azonenberg | Spin coat doped SiO2 and pattern with HF | 13:34 |
| azonenberg | Then bake and let it diffuse | 13:35 |
| Laurenceb | i dont understand the spin coating agent | 13:36 |
| Laurenceb | its dissolved in alcohol? | 13:36 |
| azonenberg | I dont know the exact chemistry for spin coating SiO2 but its a silicate compound of some sort | 13:36 |
| Laurenceb | i see | 13:36 |
| azonenberg | that upon drying and gently heating (200C ish) decomposes to SiO2 | 13:37 |
| Laurenceb | so how is it converted to SiO2? | 13:37 |
| Laurenceb | ah i see | 13:37 |
| azonenberg | So basically you'd pattern the doped film with photoresist and HF | 13:37 |
| bart416 | air | 13:37 |
| azonenberg | Then bake to drive it in | 13:37 |
| Laurenceb | yeah | 13:37 |
| azonenberg | You could also backfill the entire wafer with SiO2 to prevent further oxidation | 13:37 |
| azonenberg | and do dopant drive-in in the air | 13:37 |
| Laurenceb | so you could print the dopant | 13:38 |
| azonenberg | Theoretically, yes | 13:38 |
| Laurenceb | and you can print HF | 13:38 |
| azonenberg | But in that case it'd be just dopant and not oxide too | 13:38 |
| azonenberg | You dont need to | 13:38 |
| azonenberg | Coat the entire wafer | 13:38 |
| azonenberg | Just print the masking layer | 13:38 |
| Laurenceb | oh course | 13:38 |
| azonenberg | The only reason you'd print is if its easier than the alternate method | 13:38 |
| Laurenceb | hmm i need to understand latlor cones | 13:39 |
| azonenberg | And for somethign like a wet etch, it isnt | 13:39 |
| Laurenceb | *taylor | 13:39 |
| azonenberg | In any case i'll be running some experiments tonight involving diluting photoresist and doing tantalum oxide liftoff using thinner layers | 13:41 |
| azonenberg | But for now, off to work for me | 13:41 |
| Laurenceb | cya | 13:42 |
| Laurenceb_ | azonenberg: i was looking at microjets | 20:55 |
| Laurenceb_ | looks very hard | 20:55 |
| azonenberg_work | Agreed | 21:00 |
| azonenberg_work | They're interesting but i have no plans to pursue them | 21:00 |
| Laurenceb_ | there are a few research groups working on the same idea | 21:00 |
| Laurenceb_ | so its not totally mad, but getting consistent drops that are small enough is very hard | 21:00 |
| azonenberg_work | Yeah | 21:00 |
| Laurenceb_ | http://www.google.com/url?sa=t&source=web&cd=2&ved=0CBsQFjAB&url=http%3A%2F%2Fwww.atm.ox.ac.uk%2Fgroup%2Feodg%2Fmphys_reports%2F2008_Blaxter.pdf&rct=j&q=aerosol%20sampling%20aopp%20laurence%20blaxter&ei=ufAlToDVJ5GKhQe9gZnwCQ&usg=AFQjCNEisI-sLWqMHj8ObxWTuCQS2ArvUA&cad=rja | 21:01 |
| Laurenceb_ | arg stupid google | 21:02 |
| azonenberg_work | lol where's the actual paper? | 21:02 |
| Laurenceb_ | www.atm.ox.ac.uk/group/eodg/mphys_reports/2008_Blaxter.pdf | 21:02 |
| Laurenceb_ | i was getting down to 350nm or less with a nebuliser | 21:03 |
| Laurenceb_ | - page 11 | 21:03 |
| azonenberg_work | This is you? | 21:03 |
| Laurenceb_ | yes | 21:04 |
| Laurenceb_ | i was using NaCl in water and an ultrasonic nebuliser | 21:05 |
| azonenberg_work | Still reading | 21:06 |
| azonenberg_work | RPI's electronics club did a high altitude balloon launch two summers ago but i wasnt involved | 21:07 |
| azonenberg_work | And it was a proof-of-concept that just took photos and didnt carry any other sensors | 21:07 |
| kristianpaul | (cheap autonomous sonde) highaltitude balloons have interestinhg aplications | 21:08 |
| azonenberg_work | Yep | 21:08 |
| azonenberg_work | Laurenceb_: It's probably bad that i understand a lot of your math dealing with the aerodynamics of the particles | 21:10 |
| azonenberg_work | Despite having a degree in comp sci :P | 21:10 |
| Laurenceb_ | im sure theres errors in there... but i got a first for it so :P | 21:11 |
| azonenberg_work | lol | 21:12 |
| azonenberg_work | Your mean free path looks a little long, i recall 58nm, but i think the delta is due to STP vs room temperature | 21:12 |
| azonenberg_work | And very interesting on the thermal precipitator | 21:12 |
| azonenberg_work | How often is that used? | 21:13 |
| Laurenceb_ | its quite common aiui | 21:13 |
| azonenberg_work | Hmm... the electrostatic seems interesting too | 21:14 |
| Laurenceb_ | i was origionally thinking the particle size range was interesting, but maybe electrostatic coating could have uses | 21:14 |
| azonenberg_work | And lol @ impactor | 21:16 |
| bart416 | 'nite | 21:19 |
| azonenberg_work | Probably not the most effective method to use at low velocity... | 21:30 |
| azonenberg_work | What kind of SEM were you using? I dont recognize the pin design | 21:38 |
| azonenberg_work | Looks too short for a Jeol and too tall for a Zeiss | 21:38 |
| Laurenceb_ | it was modified on a lathe | 21:42 |
| Laurenceb_ | to reduce the diameter so it would fit in the precipitator | 21:42 |
| azonenberg | I see | 21:59 |
| azonenberg | Laurenceb_: So are you at Oxford? | 22:04 |
| Laurenceb_ | no | 22:04 |
| Laurenceb_ | i got a job in the real world after graduating | 22:04 |
| azonenberg | Graduated already? Ah | 22:05 |
| Laurenceb_ | 2008 - i had a bit of a 'crisis' after a while | 22:05 |
| azonenberg | I see - with me it was "in for a penny in for a pound" | 22:06 |
| Laurenceb_ | decided to do a phd | 22:06 |
| azonenberg | Same here | 22:06 |
| azonenberg | As of now i plan to go through with it | 22:06 |
| azonenberg | You bailed and got a real job instead? | 22:06 |
| Laurenceb_ | yes, but didnt enjoy it | 22:06 |
| Laurenceb_ | i worked for ~1year at surrey satellite technology on galileo | 22:07 |
| azonenberg | Interesting | 22:07 |
| azonenberg | I've been a de facto grad student for a while lol | 22:07 |
| azonenberg | My grades started slipping last year as an undergrad because i was so into my research i spent less time on class work | 22:07 |
| Laurenceb_ | i didnt like work in a largish company as there was no room for creativity | 22:08 |
| Laurenceb_ | im now working at nottingham university doing a PhD on biomedical sensing | 22:09 |
| Laurenceb_ | at sstl i was stuck in a team working on vhdl for decoder ics | 22:11 |
| azonenberg | Interesting | 22:11 |
| Action: azonenberg prefers verilog | 22:11 | |
| azonenberg | I'm actually ordering a whole load of Xilinx CPLDs (5 to 10 units each of four types, ranging from 36 to 144 macrocells) to fool around on | 22:12 |
| azonenberg | FPGAs will come later, they pretty much need massively multilayer boards | 22:13 |
| azonenberg | due to the multiple power rails etc | 22:13 |
| Laurenceb_ | yeah | 22:13 |
| azonenberg | I've done some FPGA designs but only run them on simulations | 22:13 |
| Laurenceb_ | anyway i need some sleep, 11.15pm here | 22:13 |
| azonenberg | CPLDs look cheaper to actually USE | 22:13 |
| Laurenceb_ | cya | 22:13 |
| azonenberg | Its only 18:15 here, and ttyl | 22:13 |
| --- Wed Jul 20 2011 | 00:00 | |
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