| wolfspraul | hi qi-bot | 02:19 |
|---|---|---|
| azonenberg | wolfspraul: is that your CIA bot? | 02:19 |
| wolfspraul | no irc logging | 02:19 |
| wolfspraul | wait I need to test a bit more | 02:19 |
| azonenberg | Ah | 02:20 |
| azonenberg | Let me work on setting up CIA then | 02:21 |
| B0101 | how do you add the CIA bot? | 02:31 |
| azonenberg | B0101: cia.vc | 02:31 |
| azonenberg | I'm still configuring it | 02:31 |
| azonenberg | There we go | 02:36 |
| azonenberg | Anybody here interested in getting added to the Google Code project? You'll start out as a contributor plus edit permissions on the wiki | 02:39 |
| azonenberg | just send me your googlecode email address | 02:39 |
| B0101 | Can I do it? | 02:41 |
| wolfspraul | azonenberg: I think it works http://en.qi-hardware.com/homecmos-logs/ | 02:41 |
| wolfspraul | search works too | 02:41 |
| azonenberg | B0101: can you join the googlecode project? Sure, PM me your googlecode email | 02:43 |
| B0101 | Ok... Gimme a second | 02:44 |
| azonenberg | wolfspraul: hmm... this means my email shows up in logs *wonders if there's a way to spamproof this* | 02:46 |
| wolfspraul | sorry got disconnected | 02:49 |
| wolfspraul | azonenberg: those logs are updated every 30 minutes | 02:50 |
| azonenberg | ah | 02:50 |
| azonenberg | Can you clear them? CIA dumped an email address i'd rather not get too spammed into the channel | 02:50 |
| azonenberg | working on a new filter that'll spam-sanitize emails | 02:50 |
| wolfspraul | no need to do more instantaneous, I think. From my experience so far, the most important is a good search feature, and that works. | 02:50 |
| wolfspraul | sure, will do | 02:50 |
| wolfspraul | as for the logs themselves, I can totally give you server access and you can do with them whatever you like | 02:50 |
| wolfspraul | so later we can always cleanup, move all to one domain, or whatever you want | 02:51 |
| wolfspraul | I'm not an information hoarder :-) | 02:51 |
| azonenberg | Lol | 02:51 |
| azonenberg | Yeah, as of now i just want the info to be out there where people can find it | 02:51 |
| wolfspraul | just email me your public key (wolfgang@sharism.cc) | 02:51 |
| azonenberg | SSH or GPG? | 02:51 |
| wolfspraul | ssh | 02:52 |
| wolfspraul | so I think 'search' is what most people use | 02:52 |
| wolfspraul | it works quite well | 02:52 |
| azonenberg | Yeah, agreed | 02:52 |
| azonenberg | wolfspraul: For now i can't see any easy way of doing search-and-replace on usernames, and since googlecode insists on using emails as usernames i'll just not include the author in the CIA message | 02:55 |
| azonenberg | just the files and log message | 02:55 |
| berndj | "pyrex" isn't pyrex anymore; "pyrex" is just a trademark, and modern cookware labelled "pyrex" is no longer borosilicate, but just tempered soda-lime glass | 02:55 |
| azonenberg | berndj: Interesting | 02:55 |
| azonenberg | I knew pyrex was a trademark but i just assumed it was all borosilicate | 02:55 |
| azonenberg | Most of my actual labware is Borosil brand | 02:56 |
| azonenberg | And i know for a fact that's borosilicate still :P | 02:56 |
| CIA-67 | [removed] * r78 /wiki/FreeEDATools.wiki: Created wiki page through web user interface. | 02:57 |
| azonenberg | I thought i fixed that, hmm | 02:57 |
| berndj | labware would typically be borosilicate, i imagine | 02:58 |
| azonenberg | Let's try this again... | 02:59 |
| berndj | amateur telescope makers greatly regret the decreasing availability of borosilicate | 02:59 |
| CIA-67 | 79 wiki/FreeEDATools.wiki Dummy commit to test new CIA bot configuration | 02:59 |
| wolfspraul | azonenberg: I'll clean it later if you don't mind | 02:59 |
| wolfspraul | during the day the log file is open, so I have to restart the bot (don't know better) | 03:00 |
| azonenberg | No rush, i just dont want to leave it up there for a long time to get spidered | 03:00 |
| wolfspraul | I'll go through tomorrow and remove the address... | 03:00 |
| azonenberg | Ok, thx | 03:00 |
| CIA-67 | homecmos r80 | wiki/FreeEDATools.wiki | Edited wiki page FreeEDATools through web user interface. | 03:01 |
| azonenberg | There we go | 03:01 |
| azonenberg | B0101: You're now a contributor (can file tickets on the bug tracker, comment on tickets, and comment on wiki pages) plus EditWiki permissions | 03:02 |
| azonenberg | if i see good work you may get full commit access in the future | 03:03 |
| azonenberg | Anybody else? | 03:03 |
| azonenberg | B0101: The FreeEDATools wiki page is just a start, if you're looking for something to work on feel free to add some more content there | 03:03 |
| B0101 | ok | 03:05 |
| azonenberg | As with all of the other wiki pages, of course, but that's one that i specifically know needs work | 03:05 |
| azonenberg | Going to grab a bite, then off to the lab for some testing of liftoff patterning using a slightly thicker hardmask than yesterday | 03:10 |
| berndj | i just checked, magic's native file format looks pretty merge-friendly | 03:19 |
| azonenberg | berndj: Interesting, I might have to take a look at that | 03:19 |
| berndj | its UI does however look like something that escaped from 1980 | 03:19 |
| azonenberg | I'm not really tied down to Glade very much, i only have a few test patterns and i can always dump them into a GDS and pull them into another tool | 03:19 |
| berndj | but i found i got used to it fairly quickly | 03:19 |
| azonenberg | Want me to set you up on the googlecode project too? You can add such info to the wiki | 03:20 |
| berndj | i don't think i'll be much of a contributor, but do as you like ;) | 03:20 |
| azonenberg | well if you're interested pm me your googlecode email | 03:21 |
| CIA-67 | homecmos r81 | wiki/FreeEDATools.wiki | Edited wiki page FreeEDATools through web user interface. | 03:55 |
| CIA-67 | homecmos r82 | wiki/FreeEDATools.wiki | Edited wiki page FreeEDATools through web user interface. | 03:55 |
| B0101 | Oh, CIA logs any changes to the wiki... | 03:58 |
| azonenberg_lab | Time to have some fun... | 04:12 |
| azonenberg_lab | B0101: There seems to be a little formatting glitch on the EDA tools page - i think you need a blank line after the heading marker for it to format right | 04:15 |
| azonenberg_lab | Other than that, good start | 04:15 |
| B0101 | ok noted | 04:16 |
| azonenberg_lab | W00t | 05:45 |
| azonenberg_lab | This one looks pretty good | 05:45 |
| azonenberg_lab | Gonna try baking it and KOH'ing | 05:45 |
| azonenberg_lab | Some residue in areas that should have been lifted off but the hardmask looks undamaged where it should be | 05:45 |
| azonenberg_lab | pics coming shortly | 05:46 |
| Action: azonenberg_lab opens 4-inch cassette labeled "Furnace carrier wafer" (aka "cookie sheet") | 05:46 | |
| CIA-67 | homecmos r83 | trunk/lithography-tests/labnotes/azonenberg_labnotes.txt | Updating lab notes for today's experiments. | 05:48 |
| azonenberg_lab | Pics uploading in a few | 05:48 |
| azonenberg | Uploading... | 05:51 |
| azonenberg | http://colossus.cs.rpi.edu/~azonenberg/images/homecmos/2011-06-19/S7300889.JPG | 06:00 |
| azonenberg | Other files in the dir are other shots from the same session but this one is a nice overview of the successful die at 100x | 06:01 |
| Action: azonenberg waits another 45 mins for wafer to bake | 06:16 | |
| azonenberg_lab | Die is in KOH now, here's hoping it works... | 07:19 |
| CIA-67 | homecmos r84 | trunk/lithography-tests/labnotes/azonenberg_labnotes.txt | Updating lab notes | 07:24 |
| azonenberg_lab | :( didnt work | 07:24 |
| azonenberg_lab | hardmask broke off during the etch | 07:24 |
| azonenberg | Some pattern was visible though | 07:29 |
| azonenberg | So i'm not sure what happened | 07:29 |
| azonenberg | Suspecting thermal shock during baking | 07:29 |
| B0101 | hi | 11:48 |
| CIA-67 | homecmos r85 | wiki/FreeEDATools.wiki | Edited wiki page FreeEDATools through web user interface. | 11:49 |
| B0101 | Azonenberg: Fixed the problem | 11:50 |
| B0101 | I am going to find and add more links... | 11:51 |
| CIA-67 | homecmos r86 | wiki/FreeEDATools.wiki | Edited wiki page FreeEDATools through web user interface. | 11:54 |
| CIA-67 | homecmos r87 | wiki/FreeEDATools.wiki | Edited wiki page FreeEDATools through web user interface. | 12:29 |
| CIA-67 | homecmos r88 | wiki/FreeEDATools.wiki | | 12:48 |
| CIA-67 | Edited wiki page Free EDA Tools through web user interface. | 12:48 |
| CIA-67 | Edited most of the links and edited summary | 12:48 |
| B0101 | Hi | 21:33 |
| B0101 | Azonenberg: Did your etch succeed? | 21:33 |
| azonenberg | B0101: Not as well as I'd like | 21:33 |
| azonenberg | The hardmask cracked during baking and broke off | 21:33 |
| azonenberg | But i'm very close | 21:34 |
| azonenberg | i think i just need to do slower heat/cool cycles and use a slightly thinner hardmask | 21:34 |
| azonenberg | if it's too thick it cracks more readily | 21:34 |
| azonenberg | I noticed the first coat was too thin so i did a second | 21:34 |
| azonenberg | but the second i spun too slowly and it got way thicker than i had intended | 21:34 |
| azonenberg | i overcompensated | 21:34 |
| B0101 | oh, by the way, i did editing to the Free EDA tools wiki | 21:35 |
| B0101 | I have got all the links | 21:35 |
| B0101 | You could take a look to see if my edits were OK. | 21:37 |
| azonenberg | I glanced through them an hour or so ago, they look fine | 21:38 |
| azonenberg | Kinda busy atm, will hopefully be free later today | 21:39 |
| B0101 | ok | 21:39 |
| bart416 | azonenberg, did you already modify an oven so you can control it with a computer? | 22:16 |
| azonenberg | bart416: no | 22:16 |
| azonenberg | I have a lab oven with a decently accurate thermostat but no custom profile capabilities | 22:16 |
| azonenberg | The furnace i am looking at, iirc, has a programmable controller | 22:16 |
| bart416 | Ah | 22:17 |
| bart416 | My contraption for reflow is working pretty well I think | 22:17 |
| bart416 | the temperature control is getting along | 22:17 |
| bart416 | But it causes pretty big spikes using PWM, so need to figure out a way to fix that | 22:18 |
| azonenberg | i see | 22:19 |
| azonenberg | I do have a toaster oven that i was planning to turn into a reflow rig | 22:19 |
| azonenberg | Just havent done it yet | 22:19 |
| Action: azonenberg wonders how hard it might be to buy some solder balls and make his own FCBGA | 22:19 | |
| azonenberg | rather than using wire bonding | 22:19 |
| azonenberg | if the pad pitch is nice and large it might not be to bad | 22:20 |
| azonenberg | too* | 22:20 |
| bart416 | Did you see those methods to put ICs in flexible flat cables? | 22:20 |
| bart416 | Or flexible prints? | 22:20 |
| bart416 | They basically seem to just put them in circuit and solder the traces directly onto it | 22:21 |
| azonenberg | You're talking COF (chip on flex)? | 22:23 |
| azonenberg | I havent studied it in too much depth | 22:24 |
| bart416 | Dunno, I've seen a couple of methods when studying methods for reflow soldering | 22:24 |
| azonenberg | I just mean COF in particular | 22:24 |
| azonenberg | So tonight I'll be running a test using my comb drive mask from the mems-tests directory | 22:25 |
| bart416 | Don't know if it's that particular method, but the advantages were rather interesting | 22:25 |
| bart416 | :D | 22:25 |
| bart416 | How thick is your hardmask now? | 22:25 |
| azonenberg | It'll be on <100> and therefore will not be etchable deep enough to work | 22:25 |
| azonenberg | But i have more of that and its cheaper | 22:26 |
| azonenberg | So i'll test on that and when i get good yields switch to the <110> | 22:26 |
| azonenberg | And actually, thickness is TBD lol | 22:26 |
| azonenberg | When i spin coat on a blank wafer it's 225nm ish | 22:26 |
| azonenberg | But with liftoff its harder to really tell | 22:26 |
| azonenberg | The thickness i had in that last image was huge *looks up chart to estimate* | 22:26 |
| bart416 | Somebody showed something interesting in ##electronics yesterday | 22:27 |
| bart416 | A DIY electron microscope | 22:27 |
| azonenberg | SEM or TEM? | 22:27 |
| azonenberg | Or AFM? | 22:27 |
| bart416 | SEM | 22:27 |
| azonenberg | I think i saw that one, was the guy imaging a big nut or something? | 22:27 |
| azonenberg | Something large and not getting nearly enough magnification to be useful yet | 22:27 |
| bart416 | Yeah, it's the same guy, but he later on went to do a grid | 22:28 |
| bart416 | And was already going into the micrometer range | 22:28 |
| azonenberg | Interesting | 22:28 |
| bart416 | He said he's going to publish his documentation on it on the internet | 22:28 |
| azonenberg | Nice | 22:28 |
| bart416 | So maybe with some luck some nut comes along and makes something you can actually use | 22:28 |
| azonenberg | Lol, perhaps | 22:29 |
| berndj | btw, what's a good keyword to add when searching for people who do stuff only Big Industry (tm) is supposed to be doing? | 22:29 |
| berndj | calling it "homemade" can seem inaccurate | 22:29 |
| azonenberg | Yeah, i have no idea | 22:29 |
| azonenberg | Makes it hard to find others | 22:29 |
| bart416 | DIY | 22:29 |
| azonenberg | Thats what i used | 22:30 |
| berndj | sometimes i have luck just googling the jargon | 22:30 |
| azonenberg | Btw - by counting intereference fringes it looks like the hardmask in my last test was something over 800nm thick | 22:30 |
| azonenberg | Which explains the cracking | 22:30 |
| azonenberg | thats like 4x thicker than it should be | 22:30 |
| bart416 | wow, 800 nm is really thick | 22:31 |
| azonenberg | I did a double coat AND dropped the RPMs | 22:31 |
| azonenberg | one or the other is fine, but both is too much | 22:31 |
| azonenberg | One layer at max rpm without photoresist in the way gives, as i mentioned, somewhere around 225nm | 22:31 |
| bart416 | You could probably calculate the thickness of the layers if you bothered with it | 22:31 |
| azonenberg | Again all of these values are estimates | 22:31 |
| azonenberg | I dont know the refractive index is the thing | 22:31 |
| azonenberg | since its spin coated the nubmers are different than for bulk | 22:31 |
| azonenberg | its not as dense | 22:31 |
| azonenberg | I'm estimating it to be comparable to SiO2, but it isnt | 22:32 |
| azonenberg | i could be off by 30% either way | 22:32 |
| azonenberg | But it's still way thicker than it should be, that much is certain | 22:32 |
| berndj | 800nm already accounting for Ta2O5's highish index of refraction? | 22:32 |
| azonenberg | berndj: 800nm assuming SiO2 | 22:32 |
| azonenberg | Otherwise, it might be more | 22:32 |
| berndj | err, less? as in, you need less Ta2O5 to give the same optical path length? | 22:33 |
| azonenberg | Oh, good point | 22:33 |
| azonenberg | Sorry about that | 22:33 |
| azonenberg | For SiO2 it would be either 890 or 1510 in the thickest part | 22:34 |
| azonenberg | I couldnt tell if one spot on the edge was one fringe or two | 22:34 |
| azonenberg | And given how high the index is, my previous estimate of 50nm might actually be overkill for what i had in my old tests | 22:34 |
| azonenberg | it might be more like 30 | 22:34 |
| berndj | do you count under white light? | 22:34 |
| azonenberg | berndj: Yes | 22:34 |
| azonenberg | Halogen microscope lamp | 22:34 |
| berndj | i guess your chart is made for broadband light, but in general, fringes show up much more under narrowband light. CFLs work quite well | 22:36 |
| azonenberg | Yeah | 22:36 |
| azonenberg | If you want to try giving a better estimate than me, feel free http://colossus.cs.rpi.edu/~azonenberg/images/homecmos/2011-06-19/S7300900.JPG | 22:36 |
| azonenberg | This is actually Ta2Cl10 | 22:36 |
| azonenberg | before baking | 22:36 |
| bart416 | I wouldn't worry about it too much, just make sure it's not too thick so it doesn't crack again | 22:36 |
| azonenberg | Yeah, thats why i didnt recalculate either | 22:37 |
| azonenberg | It didnt seem worth the effort | 22:37 |
| azonenberg | Thoguh getting a ta2o5 color chart would be nice if anyone wants to run the math | 22:37 |
| bart416 | First get it working, then fine tune it | 22:37 |
| azonenberg | And yeah | 22:37 |
| azonenberg | Tonight i'll be doing some more tests and we'll see what happens... | 22:37 |
| azonenberg | I feel like we're getting close | 22:44 |
| azonenberg | Once I get lithography of silicon working pretty reliably it opens up a ton of possibilities | 22:44 |
| azonenberg | The next big unsolved problem is metal deposition | 22:45 |
| azonenberg | Patterning of metal can be done with an HCl : H2O2 : H2O etch which is CMOS compatible and won't diffuse through my photoresist | 22:45 |
| azonenberg | I've used it on copper in the past with good results | 22:45 |
| azonenberg | And it wont be nearly as difficult as patterning of, say, SiO2 or Si | 22:45 |
| azonenberg | Metal deposition can be done by evaporation or sputtering, pretty much | 22:46 |
| azonenberg | Both require vacuum | 22:46 |
| B0101 | hi, back from Breakfast, what have I missed? | 22:46 |
| azonenberg | But sputtering needs a much less deep vacuum since you're actually letting inert gas into the chamber | 22:46 |
| azonenberg | something like 7E-1 torr vs 1E-6 for evaporation | 22:47 |
| azonenberg | Sputtering has its own set of problems, though | 22:47 |
| azonenberg | Even if you ignore the need for inert gas supply | 22:48 |
| azonenberg | Since you arent pumping down really deep, there may be traces of oxygen | 22:48 |
| azonenberg | and nitrogen | 22:48 |
| azonenberg | Meaning that you may get oxide/nitride contamination if you are sputtering anything reactive | 22:48 |
| azonenberg | vs gold or platinum or another noble metal | 22:48 |
| azonenberg | Noble metals, however, are very tough to pattern | 22:48 |
| azonenberg | by anything but liftoff | 22:48 |
| azonenberg | And liftoff of a sputtered film is difficult because the coating is pretty conformal | 22:49 |
| azonenberg | But if we can figure out how to sputter something like aluminum or copper we're in decent shape | 22:49 |
| bart416 | 10^-6 is in the range of a normal vacuum pump | 22:49 |
| azonenberg | Except copper has its own set of problems when used with CMOS | 22:49 |
| azonenberg | bart416: Um, i dont think so | 22:49 |
| bart416 | well, with normal I mean non expensive azonenberg :| | 22:50 |
| azonenberg | The lowest i've ever hit with a mechanical pump was 1.2E-1 torr | 22:50 |
| berndj | in the old days people made mirrors with some weird amalgam process | 22:50 |
| azonenberg | 2 stage rotary vane | 22:50 |
| berndj | no vacuum needed! | 22:50 |
| azonenberg | A diffusion or turbopump or similar is pretty much necessary to go much deeper | 22:50 |
| azonenberg | The best mechanical pump i've ever seen was advertised as hitting 4E-2 torr which is still high for evaporation | 22:51 |
| azonenberg | But realistic for sputtering | 22:51 |
| bart416 | mechanical is normal for you? | | 22:51 |
| bart416 | The most normal for me is using a water stream to cause negative pressure differential | 22:51 |
| azonenberg | bart416: Normal meaning 2-stage rotary vane like http://unitednuclear.com/index.php?main_page=product_info&cPath=28_52&products_id=405 | 22:51 |
| azonenberg | bart416: Those things cant go below the vapor pressure of water | 22:52 |
| azonenberg | I've used them once | 22:52 |
| bart416 | azonenberg, you're confusing my definitions of normal with yours | 22:52 |
| berndj | put a piece of sodium inside as a getter | 22:52 |
| azonenberg | Diffusion pumps are very similar but use oil or something with a lower vapor pressure | 22:52 |
| bart416 | Normal in what sense? | 22:52 |
| bart416 | first with normal I meant non expensive | 22:52 |
| bart416 | But you define normal as mechanical and other simple designs | 22:52 |
| azonenberg | And $300 isnt that bad for a vacuum pump | 22:52 |
| azonenberg | Turbos cost >$5K | 22:53 |
| bart416 | Mechanical not being normal for me as there are so much sub divisions in it :| | 22:53 |
| azonenberg | A diffusion pump, though, can probably be done pretty cheap | 22:53 |
| berndj | the diy laser guys sometimes make their own diffusion pumps, iirc | 22:53 |
| azonenberg | berndj: Interesting | 22:53 |
| berndj | or cryotraps | 22:53 |
| bart416 | You can probably get one fairly cheaply from an old lab equipment sale | 22:53 |
| azonenberg | I've never tried doing a cryopump | 22:54 |
| azonenberg | But i imagine it's doable | 22:54 |
| berndj | i imagine you can get hold of some liquid N2 fairly cheaply | 22:54 |
| bart416 | http://www.belljar.net/forum/dp001.pdf | 22:54 |
| bart416 | Looks achievable enough if you have access to a lathe | 22:55 |
| lekernel | is that a diffusion pump? | 22:55 |
| bart416 | Yes | 22:55 |
| azonenberg | I do, my school machine shop has several manuals and one CNC | 22:55 |
| berndj | azonenberg, that H-shape fringe thing i'm looking at, is the fringey bit the Ta2Cl layer? | 22:55 |
| azonenberg | berndj: The background is silicon | 22:56 |
| azonenberg | The fringes are Ta2Cl10 | 22:56 |
| berndj | ah. those edges make it real difficult to count :( | 22:56 |
| lekernel | azonenberg: cryopumps are super simple, they're just a bottle of zeoliths frozen with liquid nitrogen | 22:56 |
| azonenberg | the active ingredient in Tantalumfilm (solvent is denatured alcohol which has already evaporated) | 22:56 |
| azonenberg | Which hydrolyzes to Ta2O5 after baking | 22:56 |
| azonenberg | lekernel: I know | 22:56 |
| azonenberg | It just means keeping cryogenics around | 22:56 |
| azonenberg | one more thing to add to the supplies list | 22:56 |
| azonenberg | A diffusion pump might be doable though | 22:56 |
| bart416 | Liquid nitrogen doesn't come cheap... | 22:57 |
| lekernel | there is an article explaining how to DIY them in Amateur Scientist | 22:57 |
| lekernel | liquid nitrogen is 10 cents a liter unless you get ripped off | 22:57 |
| bart416 | You get it at 10 cents a liter? | 22:57 |
| bart416 | Wow o_O | 22:57 |
| berndj | yup | 22:57 |
| bart416 | Where the hell do you buy it? | 22:57 |
| berndj | big industrial users of oxygen have tanks of liquid oxygen | 22:58 |
| berndj | at the gas yard :) | 22:58 |
| bart416 | Only place where I can get it here is a small lab about 5km down the road | 22:58 |
| berndj | if you have an interesting story (and you do) you could twist someone's arm to let you "find" some while they aren't looking | 22:58 |
| azonenberg | lol | 22:59 |
| berndj | you don't really care about purity though; just the low temp | 22:59 |
| bart416 | lol | 22:59 |
| azonenberg | True, since i'm not exposing it to the chamber directly | 22:59 |
| azonenberg | Just through conduction | 22:59 |
| berndj | don't lol, that's how a model rocketry guy i know got his oxidizer! | 23:00 |
| azonenberg | o_O | 23:00 |
| bart416 | berndj, mind you these are the same guys that were willing to sell me nitroglycerine... | 23:00 |
| berndj | now you made me lol | 23:00 |
| bart416 | Not much but still o_O | 23:01 |
| bart416 | You know where you might find some info on building a good vacuum pump | 23:01 |
| bart416 | All those fusor project websites | 23:02 |
| bart416 | You need a pretty good vacuum pump for that | 23:02 |
| azonenberg | Yeah, good point | 23:02 |
| berndj | hmm, i vaguely recall there being a yahoo group specifically for vacuum stuff | 23:02 |
| azonenberg | I was going to save that until I had lithography working, but if anyone wants to do the research and post info to the wiki that'd be great | 23:02 |
| azonenberg | Evaporation is a lot easier to do than sputtering and also has better liftoff profiles | 23:02 |
| azonenberg | And i'd prefer it, but i need a way of getting deep vacuum | 23:03 |
| berndj | does silver count as "noble"? | 23:03 |
| azonenberg | berndj: I dont think so | 23:03 |
| azonenberg | gold, platinum, ruthenium | 23:03 |
| azonenberg | palladium | 23:03 |
| berndj | as in, can you etch silver | 23:03 |
| azonenberg | I believe so | 23:03 |
| azonenberg | Just not sure with what | 23:03 |
| bart416 | btw, this is one of the results for DIY vacuum pump: http://tubedevices.com/alek/pwl/lc1d/homemade_nixie_tubes.pdf | 23:03 |
| berndj | if you want to / have to avoid vacuum (for now), could that silvering process + electroplating help? | 23:03 |
| azonenberg | berndj: No, i have other deposition needs that cant be done without vacuum | 23:04 |
| azonenberg | For example, polysilicon | 23:04 |
| berndj | ah, ok | 23:04 |
| azonenberg | I have five silicon crystals suitable for evaporation (5mm cubes) sitting around waiting for a suitable chamber, pump, etc lo | 23:04 |
| bart416 | wtf, somebody is building a linac in his garage o_O | 23:05 |
| berndj | i thought for polysilicon you run some silane (SiH4) CVD type process? | 23:05 |
| berndj | yup bart416 | 23:05 |
| azonenberg | berndj: CVD is the most common method | 23:05 |
| azonenberg | But you can evaporate or sputter too | 23:05 |
| bart416 | That sure as hell beats the fusor guys | 23:05 |
| azonenberg | Its just less popular for mass production | 23:05 |
| bart416 | But you aren't doing mass production... | 23:06 |
| azonenberg | Exactly | 23:07 |
| azonenberg | Hence sputtering or evaporation are preferred | 23:07 |
| azonenberg | i want to avoid keeping SiH4 around at all cost :p | 23:07 |
| azonenberg | A small amount of argon for sputtering, if i cant avoid it, ok | 23:07 |
| bart416 | Yeah, but argon isn't that expensive all things considered | 23:08 |
| bart416 | Unless if you want enough for the rest of your life | 23:08 |
| azonenberg | I'm more concerned about the safety implications of keeping giant cylinders of potentially toxic gases in the living room :P | 23:08 |
| azonenberg | A small 20 ft^3 lecture bottle of argon i can handle | 23:08 |
| bart416 | Argon isn't toxic :P | 23:08 |
| azonenberg | but SiH4 is both flammable and toxic and i dont want it around | 23:08 |
| bart416 | heh | 23:09 |
| azonenberg | Argon is inert and pretty harmless | 23:09 |
| bart416 | Maybe you can use helium, that'd be even cheaper | 23:09 |
| azonenberg | Especially if the cylinder is small enough that hypoxia from a leak isnt a serious concern | 23:09 |
| azonenberg | bart416: for sputtering you need a reasonably heavy gas | 23:09 |
| azonenberg | neon or argon work best | 23:09 |
| berndj | something's wrong in http://en.wikipedia.org/wiki/Silicon - check boiling point vs vapour pressure table. boiling point listed as 2628K, but 100kPa vapour pressure at 3537K??? | 23:09 |
| B0101 | Bye guys, off to work! | 23:10 |
| bart416 | berndj, go and get a good periodic table, don't use wikipedia! | 23:10 |
| berndj | i think even a big cylinder of argon won't displace enough of the air in your room to cause a problem | 23:10 |
| berndj | maybe the tiniest of bathrooms | 23:11 |
| bart416 | the only way I see it cause a problem if it releases its entire contents at once | 23:11 |
| azonenberg | berndj: 20 ft^3 isnt a concern | 23:11 |
| azonenberg | I just would be cautious about one of the several-hundred-ft^3 ones | 23:11 |
| bart416 | But then it's probably going to create some extra ventilation holes to compensate for that | 23:11 |
| azonenberg | Leaks of those (especially N2) have been known to make a decent sized room hypoxic | 23:11 |
| azonenberg | the trouble with inert gases is that you dont realize you're out of air until you keel over | 23:12 |
| azonenberg | vs CO2 you notice immediately | 23:12 |
| berndj | bart416: door-sized ventilation holes? | 23:12 |
| bart416 | berndj, I'd say that depends on the material the wall's made from :') | 23:12 |
| azonenberg | But in a nice large room (20-30 feet across) 20 ft^3 would be harmless even if released all at once | 23:12 |
| bart416 | In a nice large room worst case scenario you'd get a little bit light headed | 23:13 |
| berndj | 20ft room would be maybe 3200ft^3... displacing even several hundred ft^3 shouldn't kill you | 23:14 |
| bart416 | Damnit stop working in non SI units, it's confusing o_O | 23:14 |
| berndj | air is 20% O2, you'd need to halve that to kill. funny, was just reading about fire suppression | 23:14 |
| bart416 | <3 Halon :P | 23:15 |
| bart416 | It's a shame they banned it | 23:15 |
| bart416 | Best fire extinguishers ever :S | 23:15 |
| bart416 | Those regular ones in cars are crap | 23:16 |
| bart416 | You can't even put out a small camp fire with those | 23:16 |
| bart416 | Anyway 'nite | 23:17 |
| --- Mon Jun 20 2011 | 00:00 | |
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