#homecmos IRC log for Saturday, 2011-10-01

B0101hi azonenberg01:50
azonenberghow's the quantum computing going?01:51
azonenbergi'm just writing up a lab manual for my lab that describes some of the more common processes01:51
B0101the SQUID problem is not fixed yet01:52
B0101I might try QDs soon but not untill SQUIDS are done01:53
azonenbergi see01:53
azonenbergB0101: ?02:27
azonenbergswkhan: if you are still interested in SiO2 stuff i can mail you a 4" <100> single-side-polish wafer this weekend02:28
azonenbergPM me the address02:28
azonenbergDo what you want with it, all i ask is that i get at least half of it back02:28
azonenbergpreferably with thermal oxide on it02:28
B0101azonenberg: i found that my silicon is being destroyed slowly by an unknown substance02:31
azonenbergDestroyed slowly02:31
azonenbergas in, you have a contaminant on it?02:31
azonenbergI cant say i'm surprised02:32
azonenbergThere are only really two ways for a semiconductor device to fail02:32
azonenbergeither something that belongs is in the wrong place (design error, electromigration, etc)02:32
azonenbergor something that doesnt belong is there02:32
azonenbergHave you made any progress in isolating the contamination?02:33
B0101hmm, not yet i believe is something from the fab process02:33
B0101ok it looks like the silicon can no longer conduct, at all02:34
B0101i don't know if you know what may cause that to happen02:35
azonenbergOxide growth?02:36
azonenbergsurface contamination?02:36
azonenbergPost details of your fab process and i can take a look at it02:36
azonenbergstick it in your wiki page02:36
B0101i will do it asap02:37
azonenbergif you are not already, you should be keeping lab notes02:38
azonenbergmakes it much easier to go back and look at what processing was applied to a given sample02:39
B0101i do keep lab notes, all of them are in my notebook02:39
azonenbergi see02:39
azonenbergWell, if you dont mind sharing please do02:39
azonenbergi understand if you dont want to publish everything just yet02:39
B0101not everything but just important stuff02:40
azonenbergi see02:41
azonenbergWell again, post what you have on the process and i'll take a look02:41
azonenbergi dont know much about SQUIDs though02:41
B0101out of topic: have you ever thought of silicon based nuclear reactors?02:43
azonenbergradioactive silicon?02:44
B0101idk, but i have heard that the US is researching solid state nuclear reactor s02:45
B0101idk if that may happen but heard that details are confidential02:48
swkhanazonenberg: i asked my professor just in case and CC'd the relevant people who could do it for you in our lab (i don't actually own / use the machine that could grow it for you)02:56
swkhanazonenberg: i can PM you by the end of tonight =)02:56
swkhanazonenberg: any special precautions you would advocate?02:57
azonenbergswkhan: back03:08
azonenbergand from what i understand, dry oxidation is pretty simple03:08
azonenbergStick in furnace, heat03:08
azonenbergThe hotter it is, the faster it grows03:08
swkhanthere's a guy in my lab who built an ozone generator03:08
azonenberg800-1200C is the usual range03:08
azonenbergThe thicker the oxide is, the slower it grows03:09
swkhanand he has compressed oxygen go through a filter03:09
azonenbergbecause you get diffusion limited03:09
swkhaner compressed air go through an oxygen filter03:09
azonenbergi see03:09
azonenbergYou dont want to use that03:09
swkhanwhat would you want to use?03:09
azonenbergEither air or steam03:09
swkhano_O air?!03:09
swkhanwhy wouldn't you use pure oxygen?03:09
azonenbergToo uncontrollable i think03:09
azonenbergIf you want it to grow faster add water vapor03:10
azonenberghttp://www.cleanroom.byu.edu/OxideTimeCalc.phtml will calculate the time required to grow oxide of a given thickness03:11
azonenbergbased on the native oxide thickness, the temp, crystal orientation, and wet or dry conditions03:11
azonenbergdry=air, wet=water vapor03:11
azonenbergI havent used the process myself but i understand the theory03:11
swkhani wish the temperature could have been lower. i think the furnace can go up to 1100 C04:28
azonenbergwell, do the math for whatever thickness you want to grow04:29
azonenbergi suggest trying for 100-200nm04:29
swkhanwhatever thickness _you_ want me to grow for you =)04:29
azonenbergLol, i assume you want to use it for something too04:29
azonenberglet's see, dry oxidation at 1000C on <100>04:30
swkhanwell maybe. i haven't figured out why you would want a very thick layer of silicon dioxide if you aren't making transistors or MOS capacitors, etc.04:30
azonenbergwill take just over three hours04:30
azonenbergfor 100nm04:31
azonenbergand 8 hours for 200nm04:31
azonenberg100nm is a dark red-violet and 200 is a pale yellowish04:32
swkhanthere's a really sweet guy in my lab who cleaned a quartz tube for you just in case =)04:32
swkhanoooh thin film interference04:32
swkhanyou know everything =\04:32
azonenbergi tried using it for Ta2O5 but it was hard to guess because i didnt have the refractive index of the film too accurately04:32
azonenberg1250A would be first order blue04:33
azonenbergnice and easy to see when i test HF etch rates on it04:33
azonenbergjust over four hours by dry oxidation at 1000C04:33
azonenbergoh, wow04:33
azonenbergat 1100 its waaay faster04:34
azonenbergonly an hour and a half for 1250A04:34
azonenbergfour hours would get up to 275004:34
azonenbergtbh i am not currently to the point that i need any specific thickness that accurately04:34
swkhanwe have a 3k tube furnace hooked up to a wet pump04:34
azonenbergi just want >100nm04:34
swkhanokay =)04:34
azonenbergwet pump, meaning you can do steam?04:35
swkhani just want you to be happy =004:35
swkhannot steam, a wet pump meaning it uses oil04:35
azonenbergyou mean a vacuum furnace?04:35
azonenbergCan it run at atmospheric pressure?04:35
azonenbergok, well trying to oxidize something by heat in vacuum doesnt usually go well :p04:35
swkhanwe have leaks =\04:35
azonenbergOh, i see04:35
swkhanso might as well be atmosphere04:36
swkhani'll keep the vacuum pump off though04:36
swkhanit works so-so though no research coming from it anyway04:36
azonenbergI see lol04:36
swkhanmy professor gave the go ahead =D04:36
swkhani'll send you the address04:36
azonenbergWell, anywhere over two hours at >1000C should be thick enough for my work, i just want a) a nonconductive surface i can use for experiments in metal patterning, and b) to test patterning of SiO2 for future MOS fab04:36
azonenbergthe wafer is a 4-inch so you'll have to scribe it up04:37
azonenbergif you cant fit all of the pieces in the tube at once, and have time for more than one run04:37
azonenbergtwo or three thicknesses might be nice04:37
azonenbergThis is the exact item http://www.mtixtl.com/siwafer1004diax05mm1spptypebdopedresistivities7-13ohm-cm-1-1.aspx04:42
swkhanit's costing you $40?!04:42
azonenbergMTI is my current wafer supplier of choice as most others wont touch you unless you want to buy by the boat04:42
azonenbergThe prices are a bit higher per unit but i dont have to buy 2504:43
swkhanwe have extra wafers lying around04:43
swkhani can do that for free for you04:43
swkhani wasn't sure what you had04:43
swkhan(i just checked with my professor, i didn't want to offer until i knew i could)04:43
azonenbergIf you have extras you can afford to get rid of, i'm not gonna turn down free silicon :)04:43
azonenbergi just dont want to be a drain on anyone's resources if they're helping me for free04:44
swkhanwell i was basically asking you to pay me $20!04:44
swkhanyou've helped me so much. i've been a drain on your resources =p04:44
azonenbergLol, i would never pay anyone $20! - i cant afford that much04:44
azonenberg2.4E18 dollars?04:45
swkhanwell if i kept half of that wafer that's like $2004:45
azonenbergthats more than even bill gates could afford04:45
azonenbergby a couple orders of magnitude :p04:45
swkhanoh lol!04:45
azonenberg20 factorial dollars lol04:45
swkhani seriously initially thought you were that poor04:45
swkhanpoor guy... can't afford a few pizzas04:46
azonenbergWell, i am indeed running this lab on a grad student's salary04:46
azonenbergBut its one of my few expenses other than food and rent04:46
azonenbergand i use such tiny amounts of supplies that stuff lasts me a long time04:46
azonenbergi buy one or two wafers, do a film deposition on campus04:46
azonenbergand use the result of that for several months of work04:47
azonenbergright now i have wafers (or parts thereof) that are bare Si, Si with evaporated Cu, Si with sol-gel Ta2O5, Si with evaporated Cu over Cr, and Si with Cu over Cr over Ta2O504:47
azonenbergThe one thing i dont have is oxide04:48
azonenbergAnd to be perfectly honest you're welcome to that half of a wafer - i dont need it04:48
azonenbergmy entire work to date has been using four 2-inch wafers, most of which are no more than half consumed04:48
azonenbergi have no clue what i'd ever do with a whole 4-incher lol04:49
azonenbergbuying it was a mistake, since then i've been getting 2s04:49
swkhanwell it's a different resistivity than what we use (we use very highly doped wafers)04:49
azonenbergHigher than this?04:49
swkhanso maybe stealing a bit of yours could be worthwhile =)04:49
swkhanyes like 0.0005 ohm * cm04:49
azonenbergholy cow lol04:49
azonenbergdo they even sell those?04:49
swkhanmaybe it's 0.005 ohm * cm04:50
azonenbergi thought this was about the highest doping you could get without doing implantation yourself04:50
swkhanbut still very small04:50
azonenbergMTI offers the following ranges04:50
swkhani don't actually get these myself04:50
swkhanmy professor just gets them from some industry connections he has04:50
azonenberg0.01 - 0.02, 0.1 - 1, 1-10, 10-20, 0.3-0.6, 1-504:50
azonenbergactually, they do have one thats extreme04:50
swkhanhe worked at practically every big place you can imagine04:50
azonenberg0.004 - 0.00604:50
azonenbergand i see04:51
swkhani don't know if he pays for them04:51
swkhani don't know much =(04:51
azonenbergWell, if you have a use for it you're welcome to half of mine04:51
azonenberglike i said, i could never use a whole 4-inch at the rate i'm consuming silicon04:51
swkhanwell all right then. i'll try my best04:51
swkhani'll grow and see if i can sneak in some time on our fancy SEM too04:51
azonenbergwhat woudl you do wit hthe sem - cross section?04:52
swkhanit costs us $55 / hour, but if i put a few down that i'll be using then it could be worth it04:52
swkhani just got the cross sectional stage today04:52
azonenbergOoh, nice04:52
swkhanit's a hitachi S4800 i think04:52
azonenbergdont know the exact model04:52
azonenbergonly ever used zeiss and jeol04:52
azonenbergsupra 55 and jsm-84004:53
azonenbergthe 840 is a tungsten filament, the supra is a field emitter04:53
azonenbergthey have a jeol fesem as well, never used it (plan to at some point)04:53
swkhanhttp://www.hitachi-hta.com/products/electron-microscopes-and-focused-ion-beam/field-emission-sem/s-4800-uhr-fe-sem -> with BSE attachment and EDX attachment04:53
azonenbergas well as an afm and a couple of tems04:53
azonenbergand a dual beam sem/fib04:53
azonenbergthe supra, fib, and afm are in the cleanroom04:53
swkhani just got trained on the TEM... it's so coooool04:54
swkhanno cleanrooms here =(04:54
azonenbergboth jeols and the TEMs are in the mat sci department's non-clean microscopy lab04:54
swkhanjust one for photolithography04:54
azonenbergi linked you to rpi's cleanroom, right?04:54
swkhanFIB and DRIE soon04:54
azonenbergooh, nice04:54
swkhani think a while ago04:54
Action: azonenberg wants to play on a fib04:54
azonenbergtoo bad they're so expensive lol04:54
swkhani have a very good relationship with the lab manager here04:54
swkhanhe lets me use my samples when he's calibrating a new machine04:55
azonenbergme too (mat sci at least, the cleanroom guys are a little less flexible)04:55
azonenbergand nice lol04:55
swkhantypically the machines are totally configured so i don't pay anything =)04:55
swkhanand get a professional to give me nice pictures04:55
swkhanplus i get to learn some physics and stuff04:55
swkhanyou know, you should seriously apply for an NSF fellowship if you haven't already won that04:55
swkhanyou are so overqualified for it04:55
swkhani know i would give you one if i could04:56
swkhani would give you mine if i won one04:56
swkhanor at least half ;)04:56
azonenbergRight now i'm on a teaching assistantship but my advisor is asking me to work with him on a proposal for an NSF project for the coming year04:56
azonenbergi may be interning at lincoln labs this summer as well04:56
swkhanyou know about NSF fellowships right?04:56
swkhanwhoa lincoln =)04:56
azonenbergthe recruiter is an alum who i know well and actually had as a student while TAing once04:56
azonenbergwe played together in a wargame earlier today04:56
azonenberghe was visiting campus for the career fair and dropped in to pwn for a few minuts04:57
azonenberghacker club04:57
azonenbergremember, i'm technically comp sci lol04:57
swkhanhacker club lol04:57
azonenbergthrow a bunch of teams of hackers on a network04:57
azonenberggive them some servers04:57
azonenbergand watch the fun04:57
azonenbergsometimes its evry team vs the judges running the servers04:58
azonenbergsometeims its a free-for-all, keep your boxes up while hitting the opposing teams04:58
azonenbergand, rarely, defense only04:58
azonenbergIn any case, the guy wants me to work for him and apparently convinced my advisor to let him have me and my officemate for the summer lol04:58
azonenbergthats the thing about my situation - i'm interested in so many skills that i could work almost anywhere05:00
azonenbergmems/ic stuff is just one of my few dozen interests05:01
azonenbergswkhan: also - on the topic of silicon usage05:05
swkhanwow. you're inspirational =)05:05
azonenbergis the sum total of my entire fab research to date lol05:05
swkhanomg pretty05:06
azonenbergF8-G1 are on a SEM pin mount kept elsewhere05:06
azonenbergJ4-10 are open05:06
azonenbergthis is box number 5 (1-4 are used for other stuff not related to fab work)05:06
azonenbergso once i make chip 5J10 i'll have to start using 3-part numbers05:06
azonenbergbox, row, column05:06
azonenbergand go on to 6A105:06
swkhani've done way more than that because each run had a cross configuration with one in the center. so 5 pieces a run. not to mention i'm a bad researcher. i do a lot more runs than i probably need to =(05:07
azonenbergi see05:07
azonenbergIn my case its partly due to lack of time - i can only get in a run every couple of evenings since i'm busy with class05:07
azonenbergi have to do lithography after dark since i dont have a darkroom05:08
azonenberg(though i can do etching and depositions in daylight)05:08
swkhanthat's so adorable05:08
azonenbergSo basically all of my litho is done on evenings when i don't have homework due the next day05:08
azonenbergand the number of dies i do depends on how early my first class the next day is :p05:09
azonenbergadorable? what is lol05:10
swkhanthat you do lithography at night05:10
azonenbergwhat else am i going to do?05:10
azonenberggo out drinking with girls?05:10
azonenbergi'm about as interested in drinking ethanol as methanol or acetone05:11
azonenbergand i go to an engineering school05:11
azonenbergYou saw my 21st birthday pic, right?05:11
azonenbergomg lol *finds link*05:11
azonenbergi wanted to make fun of people who get trashed the second they're old enough to walk into a bar05:12
azonenbergbut still celebrate my birthday with a bottle of alcohol05:12
swkhanomg lol!05:12
azonenbergJust not in the way "normal" people do lol05:12
azonenbergi think it served its purpose well lol05:13
azonenbergone of the best spoofs i've ever done05:13
swkhani don't drink either. why don't you drink?05:14
azonenbergi like my brain cells the way they are tyvm05:14
azonenbergand see no reason to alter their behavior05:14
swkhani'm going to the wrong school =\05:14
azonenberglol why do you say that?05:14
azonenbergthere are plenty of frat/drinking types here05:15
swkhani think a lot of schools people all think like "normal" people05:15
swkhanoh nvm then05:15
azonenbergBut the thing is, they arent everyone05:15
azonenbergeven at MIT you find party animals if you look hard enough05:15
azonenbergthe distinguishing factor is the percentage05:15
swkhani knew one girl who went to MIT who was a big party animal05:15
swkhanand seemingly every other girl from her robotics team went to MIT05:16
azonenbergBut i just seem to break the mold in general05:17
azonenbergi graduated college before i was old enough to celebrate the occasion with a beer (even if i had any interest in doing so)05:17
azonenbergi was a PhD student for a week before getting my bachelor's degree05:17
azonenbergthat last was a funny store05:19
azonenbergto get RA funding for the summer i had to be considered enrolled in the grad program effective summer05:20
azonenbergsummer semester started two weeks after finals week for the spring05:20
azonenbergbut a week before commencement05:20
azonenbergthe registrar didnt officialyl approve my undergrad degree application until thursday of that week05:20
azonenbergfrom monday to thursday i was in the system as a phd student but did not have a BS05:20
swkhanlol i see05:21
swkhani had something similar happen to me actually but it didn't involve the registrar being nice to me (when have they ever been nice =\ )05:21
swkhanmy professor had to work extra hard to push paperwork to make me be considered a student05:22
swkhani wasn't registered in the summer05:22
azonenbergah fun05:22
bart416azonenberg, that's not that bad :P06:06
bart416Cause of their efficiency *cough* they managed to forget to sign up all PhD students06:07
bart416So they decided to just push all the paper to one of the colleges in the assocation and get them signed up there for the meanwhile06:07
bart416And then afterwards have them fill out a large stack of paper to get them transfered06:07
bart416azonenberg, I'm going to do something sort of insane18:25
bart416See query xD18:25
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