#homecmos IRC log for Sunday, 2011-10-09

Action: azonenberg waits eagerly for new batch of wafers to arrive tuesday00:11
mrdatamm... wafers00:11
B0101Hi azonenberg03:33
B0101azonenberg: ever programmed anything?03:53
B0101other than your FPGA's i mean03:53
azonenbergI have half a million lines of C/C++/x86 asm/MIPS asm/PIC asm/verilog sitting around my laptop's hard drive03:54
azonenbergall of which i wrote03:54
azonenbergso, i guess the answer is yes :p03:54
azonenbergMy degree is in computer science03:54
azonenbergEE and nanotech are just hobbies to me03:54
B0101I am pretty sure that you have a backup03:56
azonenbergOf the code? You've gotta be kidding me lol03:58
azonenbergMy laptop's hdd is a cache03:58
azonenbergnot storage03:58
azonenbergeverything important is SVN checkouts from a repository stored on RAID103:59
azonenbergthe repos are backed up nightly offsite to another raid array03:59
azonenbergMy rule is, if i cannot lose one of my installations (home, office, parents house, etc) entirely03:59
azonenbergand one hard drive from every surviving computer03:59
azonenbergthat i dont have enoguh redundancy03:59
azonenbergIOW, if i would lose *any* critical data from such a disaster, i'm doing it wrong04:00
B0101hmm, i keep my code backed up on offsite servers04:06
B0101each running RAID 504:10
flyback- http://www.theregister.co.uk/2011/10/07/unix_time_zone_database_destroyed/ <--- here's another company for anonymous to destroy04:11
flyback-I was talking about the company that sued the unix maintainer guy, people04:27
flyback- sheesh04:28
Action: flyback- sleeps04:31
azonenbergB0101: so why were you asking again?04:35
B0101I only asked once04:35
azonenbergno, i mean04:36
azonenbergwhy were yo uasking04:36
B0101oh, just for the fun of it04:36
B0101bart416: thanks for giving me the link to the quantum computing videos07:23
bart416Though as azonenberg pointed out you probably already knew all of that07:25
B0101btw, do you know about Einsteins theory of relativity? He might have been wrong07:28
B0101CERN has done an experiment on their collider which shows neutrinos can go faster than speed of light07:29
B0101and if so, Einstein was wrong when he said nothing could go faster than the speed of light07:30
bart416and do you know that experiment might have forgotten to take into account relativity :P07:38
bart416Paper at http://xxx.lanl.gov/PS_cache/arxiv/pdf/1109/1109.6160v2.pdf07:40
B0101bart416: interesting paper08:31
bart416azonenberg, ?10:50
bart416http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,400,789&Prod=NEXYS2 or http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,400,897&Prod=NEXYS310:56
azonenbergbart416: i have the atlys13:22
azonenbergthe next model up13:22
bart416Yeah, but budget is 150 euro13:22
bart416Cause that's what the guy who ruined my old fpga board is paying me13:23
azonenbergDefinitely go for the spartan-613:23
azonenbergand lol, how did he do that13:23
bart416Good question13:23
bart416He borrowed it for a few weeks and got a text earlier today that he'll pay me 150 euro for it cause he ruined it lol13:23
bart416won't the spartan 3e allow bigger logic circuits though?13:24
bart416That particular 6 has less equivalent logic cells :(13:24
azonenberghmm, the lx16 vs the 3e 1200 *looks up*13:25
bart416I'm a bit worried about it13:25
bart416Cause I'm looking at building another oscilloscope13:25
bart416This time with 4 8 bit 100 MSa/s FPGAs to achieve 300-400 MSa/s13:26
azonenbergwell, the lx16 is def better than the 500k cell s3e13:27
azonenbergLooks like the lx16 is, gate wise, about equivalent to ~900k cells of 3e13:28
azonenbergExcept the lx16 has more block ram than even the 1200 3e and probably more mults too13:28
azonenbergso it basically becomes a tradeoff, would you rather have a few more slow cells in the 3e, or more block ram, more mults, and faster cells in the 613:28
azonenbergi'd go for the 6 unless i was area limited13:28
azonenbergs3 is really pretty much obsolete13:29
B0101hi azonenberg13:33
B0101well, what do I look for when I choose a FPGA board?13:34
azonenbergDepends on what you're trying to do and how much budget you have :p13:35
B0101Well, I am want to build a CPU on a FPGA (I am looking for fast speed and more memory for cache)13:37
azonenbergA cpu13:38
azonenbergthat's a pretty broad term13:38
azonenbergi've seen 4-bit toy cpus in 800 gate CPLDs13:38
azonenbergand full 32 bit designs on big fpgas13:38
azonenbergall the way up to full ARM cores13:38
azonenbergso what kind of cpu do you want? Not necessarily architecture, more along the lines of speed/capabilities13:39
azonenbergi designed an 8-bit 3-stage pipelined core that ran at 85 MHz on a 50k gate spartan-3a13:39
azonenbergwith room to spare13:40
B0101as I said, I want a CPU with a fast speed, and more cache memory13:40
azonenbergDefine fast13:40
azonenberg50 mhz? 500?13:40
B0101around 700MHZ to 1 GHZ13:40
azonenbergGood luck lol13:40
azonenbergFPGAs are meant for parallelism, not speed13:40
azonenbergyou'd need one of the ridiculously expensive ones for that13:41
azonenberglike, five figurep rice tag13:41
azonenbergif its even possible13:41
azonenbergTypical clock rates for entry-level FPGA designs are O(100 MHz)13:43
bart416The trick with a FPGA is that you don't have to work in a synchronous fashion13:48
bart416But essentially you're limited by your amount of LUTs13:54
azonenberghi ashaw14:10
ashawhey azonenberg14:11
ashawso you are doing electron beam lithography14:11
azonenbergashaw: not e-beam14:11
azonenbergOptical projection14:11
ashawhow are you making the mask?14:12
azonenbergLaser direct-write with a bluray diode is on the longer term todo list14:12
azonenbergRight now I print my masks out at 200um design rules (10x actual size) on laser printer transparency14:12
azonenbergthen reduce optically with a microscope objective and project onto the die14:12
azonenbergand expose14:12
azonenbergYou mean, design?14:13
azonenbergI make the GDS in glade or klayout, then export to dxf and print appropriately scaled14:13
azonenbergRight now my lambda is 4.233...  microns14:13
azonenbergwhich is 1/600 inch (resolution of my printer) divided down further by my 10x objective14:14
azonenbergdesign rule is five lambda min feature size14:14
ashawI have been looking at making a LDI machine14:14
ashawwith 1um resolution14:14
azonenbergi'm working on shrinking down 4x further, to 1.058um lambda and the same 5 lambda design rule, using a 40x reduction14:15
azonenbergbeen having yield issues14:15
azonenbergLDI = ?14:15
azonenberglaser direct write?14:15
ashawLaser direct imaging14:15
azonenbergYeah, thats on my todo list as well, if you'd like to collaborate let me know14:15
azonenbergmy idea was to use it for contact masks14:15
ashawMy idea is to directly print onto the wafer14:16
azonenbergI considered that14:16
azonenbergthe problem is alignment if you are doing >1 mask level14:16
azonenbergand direct writ eis slow14:16
azonenbergso i figure i'll do what the real fabs do except laser instead of ebeam for making the mask14:16
azonenbergThe other thing i need to do is build myself a stepper/scanner14:16
ashawthere is a way around doing i pixel at a time14:16
azonenbergput servos on the stage so i can move the field around the die/wafer14:16
ashawI want to point the laser head at a DLP picoprojector and reduce14:17
ashawdoing structured imagin14:17
azonenbergvery interesting14:17
ashawyeah you print a line about 1000 pixels long14:18
ashawat once14:18
ashawI've been workign at driving the projector from an FPGA14:18
ashawand modifying the potics14:19
azonenbergvery nice14:19
azonenbergif you get it working can i use you as a mask shop? ;)14:19
ashawmabe, I am in australia though14:19
azonenbergCheaper than photronics :p14:19
azonenbergAnd i want to build one of my own in the longer term14:19
azonenbergdo you plan to share designs?14:19
ashawof course14:20
ashawalso it is going to be designed with a removable reducer14:20
ashawso you can also use it to image PCBs14:20
azonenbergvery interesting14:20
azonenbergAre you using a prebuilt projector and sending hdmi out from the fpga?14:20
azonenbergand what drives the fpga - a GDS?14:20
ashawat the moment procedurally generated images14:21
ashawon the FPGA14:21
azonenbergwhich fpga btw?14:21
ashawa virtex 6 demo board.14:21
ashawgreatly underutalised14:22
Action: azonenberg is using an xc6slx45 atm14:22
ashawI have a couple other projects14:22
azonenbergvirtexes are too expensive14:22
ashawone that needs the space14:22
azonenbergI see14:22
azonenbergyou can get spartans that big, most likely14:22
azonenbergJust not as fast14:22
ashaw240K gate?14:22
azonenberg240k cell? oh14:23
azonenbergspartan6 maxes out at 150 i think14:23
azonenbergwhat are you building that big?14:23
ashawthat is the standard dev size14:23
ashawan Out-Of Order, dual issue MMIX CPU14:23
azonenbergout of order execution? Oh joy lol14:23
ashawI think cool.14:24
azonenbergAnd superscalar14:24
azonenbergI'm having enough trouble debugging pipeline glitches on my single-issue in-order mips1 core lol14:24
azonenberggood luck14:24
azonenbergOf course i havent worked on it in a while14:24
azonenbergbeen too busy with my current project, a JPEG encoder14:24
ashawi have been working on this for 2 yes14:24
azonenberg100 MHZ at one cycle per pixel14:24
azonenbergon s6 -2 speed14:25
azonenbergseems to work in simulation, i'm hookign up the final glue for a bare-metal test now14:25
azonenbergblock ram for source data, serial port printing out encoded results, etc14:25
ashawMy goal is to get a 1um design rule home fab process done, with a cost of less than $20 00014:26
azonenbergI would love that, i'm limited to 20 right now by my optics14:26
azonenbergthe 40x objective on my scope doesnt quite focus right14:26
azonenbergand immersion litho should hit 1um but i'm having trouble with that too14:27
azonenbergLDI would help that greatly14:27
azonenbergi could use the scope to align but use a contact mask for the actual exposure14:27
Action: azonenberg imagines friend coming over in 10 years and seeing an 8-inch karl suss mask aligner in the living room14:27
azonenbergmy lab atm, btw: http://imgur.com/a/Bnwst14:28
ashawyou're a lot further than I am atm14:29
azonenbergin any case it seems our goals are well aligned14:29
azonenbergSend me your google code email and i'll set you up with repository/wiki access14:29
ashawI want a bi-cmos process14:29
azonenbergI've been focusing on MEMS14:29
azonenbergi want to use a KOH wet etch over evaporated Cr hardmask to build a comb drive on a 20um design rule by end of this calendar year14:30
ashawI have not got very much documentation atm14:30
azonenbergWe can fix that14:30
ashawjust school is keeping me very busy14:30
azonenbergTop left pic is my first deep etch test14:30
azonenberg~100um deep into <110> wafer using Cr hardmask14:30
azonenbergwhich was too thin, the mask got penetrated in spots14:30
ashaware you at uni?14:31
Action: azonenberg is a phd student in computer science at RPI14:31
azonenbergno formal training in ee/nanotech whatsoever14:31
azonenbergits just a hobby for me14:31
ashawI am a 1sy uear undergrad in B. Eng (Elec)/ B. Sci. (CS/Math)14:31
azonenbergIn terms of bonding, i was thinking FCBGA14:31
azonenbergstick solder balls on top metal14:32
azonenbergflip over and heat gun to the PCB14:32
azonenbergno messing around with wire bonding14:32
azonenbergMost hobbyists are scared of BGA lol14:32
ashawyou need a thick top layer14:32
azonenbergBut the funny thing is, on a home asic its the easiest way of doing stuff :p14:32
azonenbergi have successfully soldered to ~1000nm evaporated Cu over ~10nm Cr14:32
azonenbergYou have to be careful but its possible14:32
azonenbergbut i have dies with 30ga wire coming off them that i soldered to14:33
ashawI have been designing a compond vaccum chamber14:33
azonenbergjust as a PoC, no lithography on that sample14:33
azonenbergand very nice14:33
azonenbergi'm not very far on that14:33
ashawfor doing all this work14:33
azonenbergwould have been ,except for the local cops14:33
ashawwhat about them?14:33
azonenbergfriend of mine got raided last november when his neighbor called 911 on him14:33
azonenbergthought his vacuum chamber was a bomb14:33
azonenbergthe court case finally ended last week14:33
azonenberghe got all of his equipment back (chemicals had been destroyed) and paid a small fine14:34
ashawwhat was the fine for?14:34
azonenbergsomething about attempted obstruction of justice (which is not a crime in this state)14:34
azonenbergbasically he wasnt polite enough to the responding officer14:34
azonenbergThey needed a conviction, even if just a paper victory14:34
azonenbergto make sure he wouldnt sue for malicious prosecution14:35
azonenbergIn any case that resulted in me not having vacuum gear for a year14:35
azonenbergor i'd probably have a DC sputtering rig in the living room now14:35
ashawWhat is he using for his vaccum chamber?14:35
azonenbergit was a giant varian 18x18x24" stainless steel box14:35
azonenbergthat he got for $1k on ebay14:35
azonenberghe was using it for some consulting work too14:36
ashawI have got a salvage order out at the metal yards here14:36
ashawlooking for 200mm stainless steel pipe14:36
azonenbergIn any case, in the interim i've been doing evaporation on campus14:36
azonenbergthey have one in the mat sci department that i cna use whenever i want for free14:36
ashawthat is cool14:37
azonenbergcheap and has a few occasional film defects but good enough for my design rules14:37
azonenbergthats how i did all of the metalization for my processes14:37
ashawI want to use spin foating14:37
azonenbergmy spin coater14:37
ashawoh sorry, missunderstoodf you14:37
azonenbergthe cardboard thing in the middle is the spatter shield14:38
azonenbergthen a 2x4 frame, an electric drill14:38
ashawit is 1.40 am here14:38
azonenbergand a sanding wheel with some masking tape on it14:38
azonenbergi see, where you at?14:38
azonenbergits ten in the morning14:38
azonenbergthat would do it14:38
azonenbergHave you used subversion?14:38
ashawbut prefer mecurial14:39
ashawor git14:39
ashawbut not for any of this stuff.14:39
ashawall on paper14:39
azonenbergwell the project is on svn now, switching to git in the longer term is a possibility but svn was what most of the folks working on it preferred14:39
azonenbergi'd love if you could set up a wiki page with some of your work to date14:40
azonenbergjust so we know where work is14:40
azonenbergwho's gotten how far on what14:40
ashawyeah, mabee in a few weeks, I will put somehting up.14:40
azonenberghttp://code.google.com/p/homecmos/source/browse/trunk/lithography-tests/labnotes/azonenberg_labnotes.txt summarizes my work14:40
ashawIt is a lot of planninf14:40
ashawbut not much prac14:41
azonenbergsend me your google code email address  and i'll add you to the project14:41
ashawI think that a simple atom beam setup can be made14:42
azonenbergI want a SEM/FIB at some point14:42
azonenbergthats further out14:43
azonenbergin case you havent guessed my dream home includes a class 1000 cleanroom :p14:43
ashawmine an ISO class 3 room14:44
azonenbergwhats that in the powers-of-ten scale?14:44
azonenbergoh, nice14:45
azonenbergMy school has a class 10014:45
azonenbergbut i dont think i need that good for 1um design rules on prototype scale fab14:45
azonenberggotta keep costs down :p14:45
ashawmy final goal is to have a 350nm process at home14:45
azonenbergMine too :)14:46
azonenbergGood to see somebody who actually is interested in doing lab work, a lot of the folks here are bouncing off ideas but not really doing much14:46
azonenbergthe main people doing hands-on work are me, B0101, and swkhan14:46
ashawI just do not have a garrage atm14:46
azonenbergswkhan is mostly doign thin film work at nasa ames, not as much microfab14:47
ashawI am at college14:47
azonenbergdorm? small apartment?14:47
Action: azonenberg is a grad student14:47
ashawsingle room14:47
azonenbergi'm sharing a large apartment with four undergrads14:47
azonenbergnice big common/living room14:47
azonenbergthat's turned into a pretty well equipped lab14:47
azonenbergThe last tenants, the landlord tells me, had a stripper pole in that corner14:48
azonenbergright about in the same spot i have a 4-inch wafer probing station14:48
ashawI am thinking of renting some industrial spacew14:48
ashawas soon as I have got my set of test gear14:49
azonenbergIf you can afford it, i highly recommend it14:49
azonenbergwill help keep neighbors off your back14:49
CIA-67homecmos r144 | wiki/CurrentStatus.wiki | Edited wiki page CurrentStatus through web user interface.14:49
azonenbergDid you see this pic btw? http://homecmos.googlecode.com/svn/wiki/images/S7301603_fullres.jpg14:50
ashawwhat sort of imaging are you doing14:50
azonenbergI was using a companion cube earlier as a test mask14:50
azonenbergbut then realized the puns about nyanotechnology were too good to pass up lol14:50
azonenbergAnd you mean, for looking at test dies?:14:50
azonenbergMostly my amscope metallurgical microscope14:50
azonenbergi borrow a few hours on SEMs on campus every month or two14:51
ashaware you using a 405nm bluray laser for imaging?14:51
ashawor something else?14:51
azonenbergOh, for exposure14:51
azonenbergI'm actually using two wideband sources14:51
azonenbergdepending on the application14:51
azonenbergfor large scale contact litho (mostly PCB fab) i have some quartz-tube mercury vapor lamps14:51
azonenbergnot filtered for any specific wavelength14:52
azonenbergand for projection i use a halogen :p14:52
ashawthat may actually be your imagin problem14:52
azonenbergNo, the problem is focus14:53
azonenbergnot chromatic aberration14:53
azonenbergi can see it blurry in the eyepieces14:53
azonenbergalso, more importantly, drift in my stage14:53
azonenbergit moves during the exposure14:53
azonenbergbeen meaning to buy an aftermarket stage14:53
ashawwhat are you using for the stage?14:53
azonenbergthe amscope is a cheap scope ($800ish)14:53
azonenbergshould probably just invest in an olympus/nikon or osmething14:54
ashawWhy not get a pyrex blank and mill out a wafer holder14:54
ashawand a dichronic mirror14:55
ashawas a viewer14:55
ashawI'll be studying machining next year14:57
bart416azonenberg, you have access to web of knowledge eh?15:03
bart416(or anybody else for that matter)15:03
bart416I can't get Author(s): Sunaga, H (Sunaga, H); Hoshiai, T (Hoshiai, T); Kamei, S (Kamei, S); Kimura, S (Kimura, S)15:06
bart416Source: IEICE TRANSACTIONS ON COMMUNICATIONS  Volume: E87B   Issue: 10   Pages: 2831-2846   Published: OCT 200415:06
bart416 for some reason :(15:06
azonenbergashaw: back in a bit, have ppl over for a project15:33
ashawgog anyway15:45
Action: azonenberg waits patiently for tuesday when new batch of wafers arrives17:09
ashawin your work, what type of wafer is best, 100, 110 or 111 and why?17:13
azonenberg<100> is more commonly used for CMOS17:14
azonenbergin MEMS a KOH/TMAH etch will produce 4-sided pyramidal holes that are 30 degrees from the surface plane17:14
azonenbergand aligned to the <111> planes17:14
azonenberg<110> etches vertically in KOH/TMAH17:14
azonenbergthe <111> planes are parallel and i think 70 degrees to the wafer flat17:15
azonenbergin <100> wafers the <111> planes are parallel and perpendicular17:15
ashawoh cool17:16
ashawWhat size wafer do you want to use?17:16
azonenbergUusally 2 inch17:16
azonenbergI dont ever work with full wafers though17:16
azonenbergBecause i never need to make that many devices at once17:17
azonenbergi usually work with ~3mm dies17:17
azonenbergSo i buy a 2-inch wafer, evaporate metal over the entire surface, then cleave into small samples and do litho on each one separately17:18
azonenbergoften using a different mask for each test17:18
ashawwhat devices have you made?17:18
azonenbergSuccessfully? None17:18
azonenbergSo far i've mostly been doing test patterns to improve lithography resolution17:18
azonenbergi've done parallel lines at 20um half-pitch17:18
ashawusing your microscope17:18
ashawyeah, I've seen that17:19
azonenbergThen etched them into <110> Si using a Cr hardmask17:19
azonenbergWhich was not thick enough so the pattern wasnt as sharp as it should have been17:19
azonenbergareas that werent supposed to be etched got attacked17:19
azonenbergthe sum total of my work to date17:20
ashawwhat is the grid pattern?17:23
azonenbergsticky gel tray for holding the dies17:23
azonenbergso they dont shake around17:23
ashawah cool17:24
ashawdo you do cmp?17:25
azonenbergDo i have the facilities for it? Have i attempted it? Have i been successful?17:25
azonenbergI have abrasives ranging from sandpaper to 6um diamond to 250nm diamond to 60nm colloidal silica17:26
azonenberghavent had the time to do much process development yet17:26
ashawall three17:27
azonenbergso yes, yes, no :p17:27
ashawhave you got a precision turn table?17:27
azonenbergi wish17:28
azonenbergyou know what my spin coater is?17:28
azonenbergA drill17:28
azonenbergand a sanding wheel :p17:28
azonenbergThe stuff i have now will not scale to submicron17:28
azonenbergi have no illusions about that17:28
azonenbergBut i want to get everything working at a large scale before shrinking17:28
ashawCool, I understand that.17:30
ashawI was just asking17:30
azonenbergDefinitely on the roadmap17:30
ashawperhaps share the design of the CMP spindle and the spin coater?17:30
azonenbergmy cmp is done with finger pressure on the back of the die17:31
azonenbergagainst a microscope slide lol17:31
azonenbergand the spin coater i havent documented much because i plan to do a second revision in the near future17:31
azonenbergthat one will be fully open17:31
azonenbergthis one i dont have any deisgn documents etc for17:31
ashawhave you tried using a CPU fan?17:31
azonenbergTried, no17:31
azonenbergconsidered, yes17:31
azonenbergproblem is the air movement and the poor speed control17:31
azonenbergi want to get a similar motor, probably from an rc aircraft17:32
azonenbergbut use a better speed controller so i can do engine braking etc17:32
azonenbergand do closed loop feedback control with a nice process controller that lets me specify multiple steps17:32
azonenbergfor example, go up to 60 rpm17:32
azonenbergwait 1 minute while i apply resist17:32
azonenbergthen go up to 500 to spread for 30 sec17:33
azonenberg3000 to thin for 60 sec17:33
azonenbergthen stop over the course of 10 sec17:33
ashawI have been thinking about how to hold the wafer.17:34
azonenbergi use masking tape17:34
azonenbergsticky side up17:34
ashawthat works17:34
azonenbergthen tape the end of the tape down with a second piece17:34
azonenbergi want a vacuum chuck17:35
ashawAs I said before, I am looking forward to doing a precision machining course next year17:35
azonenbergi took the intro shop class here but never did anything beyond 0.005 inch tolerance17:36
azonenbergwhich is huge17:36
ashawwhat 0.15mm?17:37
ashawyeah that is woute big17:37
azonenbergsomething like that17:37
ashawSo are you thinking of useing somthing like LOCOS?17:39
azonenbergNot sure yet, i havent though much about the cmos side of things17:40
azonenbergmy process for the comb drive is relatively straightforward17:40
azonenbergEvaporate 1000nm Cr over both sides of <110> 2-side-polished wafer17:40
azonenbergApply photoresist to both sides17:41
azonenbergsorry, i cleave into dies first17:41
azonenbergthen apply PR17:41
azonenberg(have to figure out how to hold it to the coater without damaging the resist)17:41
azonenbergExpose backside etch mask (a big square cutout in the middle of the die), develop, etch in HCl17:42
azonenbergI also forgot to mention that without breaking vacuum i'll do maybe 50nm Cu over the Cr17:42
azonenbergsince Cu's native oxide is etchable but Cr's is hard to remove17:42
azonenbergSo then i wet etch the die in 30% KOH at ~85C until i've gone down around 400 microns17:42
azonenbergthen i apply resist to both sides again, expose the comb drive mask17:43
azonenbergetch hardmask, etch Si17:43
azonenbergthe KOH etch will start going down from the top, while continuing to go up from the bottom17:43
azonenbergthey meet ~50um from the top of the wafer17:43
azonenbergleaving me with my comb drive fingers 50um thick, ~20um across17:43
azonenbergand a 500um thick carrier ring around the whole thing17:44
azonenbergThen i strip the Cr hardmask17:44
azonenberggrow thermal oxide over the entire die to prevent shorts17:44
azonenbergevaporate metal 117:44
azonenberglithography of metal 1 mask17:44
azonenbergboom done17:44
azonenbergI have not yet perfected the through-wafer etch process but the rest shoudl not be too hard17:44
ashawyeah, quite a simple process17:44
ashawfor cmos, it seems that some CVD will be a nescesity17:45
azonenbergWhy do you say that17:45
azonenberggate oxide can be sol-gel Ta2O517:46
azonenbergas an added benefit that's high-K17:46
azonenberg(but its a PITA to etch)17:46
azonenbergCan be deposited by spin coating though17:46
azonenberghttps://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc6/246731_2099114599044_1280772249_2517084_4941952_n.jpg is the first draft of my comb drive top etch mask btw17:46
ashawwhat about inter transistor isolation17:47
azonenbergLOCOS and/or SOI are options17:47
azonenberglike i said mems has been my focus so far17:47
ashawLOCOS requires CVD of SiN17:47
azonenbergIt requires a diffusion mask17:47
azonenbergWhich is usually Si3N417:48
azonenbergBut does not have t obe17:48
ashawwhat would you use?17:48
azonenbergTa2O5 is a possibility17:48
azonenbergI might also consider reactive sputtering in a nitrogen atmosphere17:48
azonenbergThe main problem with cvd of si3n4 is that it involves dealing with silanes17:49
azonenbergnot fun17:49
azonenbergreactive sputtering might be worth considering17:49
azonenbergof say a silicon target in argon with a little N217:49
ashawyeah that might work, and then deposit the cover oxide later?17:50
azonenbergyou can replace CVD SiO2 by sol-gel or possibly reactive sputtering of Si with some O217:50
azonenbergnot sure if that last process would work17:50
azonenbergbut spin-on glass is a known material17:50
ashawOh, I just thought of a problem.17:50
ashawyou need the SiO2 in order to protect the silicon when removing the Si3N417:51
azonenbergThe more the merrier17:51
azonenbergHow do you strip nitride?17:51
azonenbergHF or phosphoric?17:51
Action: azonenberg digs out wet etch table17:51
azonenbergPECVD nitride, low refractive index - near zero in KOH and 10:1 HF, 60nm/min in BHF17:52
azonenbergphosphoric + sulfuirc works but the table doesnt have an etch rate listed17:53
azonenbergpure phosphoric works too17:53
azonenbergAnd what would the nitride be deposited over17:53
azonenbergthermal oxide?17:54
azonenbergPhosphoric doesnt bother that very much17:54
azonenbergThe biggest goal in the process, to make it safe and hobbyist-friendly, is to not require flammable, explosive, or toxic gases17:55
azonenbergSmall volumes of inert gases like N2 or Ar for sputtering etc are ok17:55
ashawLooking at some documentation here you cannot deposit the Si3N4 directly over Si17:55
azonenbergThe papers i've read suggest thermal oxide17:55
ashawit must be over the protective layer.17:55
azonenbergso grow dry oxide 50nm or so17:55
azonenbergthen reactive sputter a Si target17:56
azonenbergwith some N217:56
ashawyou have a layer of siO2 not Si17:56
ashawyou are reactive sputtering with SiO217:57
azonenbergI am saying, sputter Si onto the SiO218:01
azonenbergin a mixed Ar + N2 atmosphere18:01
azonenbergThey didnt even use any argon, pure nitrogren gave a better mix18:02
azonenberg"Silicon nitride films (from 500 to 7500Å in thickness) have been deposited on silicon and silicon dioxide by reactive sputtering of a silicon cathode in a N2 glow discharge"18:02
azonenberg"Argon and nitrogen gas mixtures resulted in excess silicon incorporation in the deposited nitride films. "18:02
azonenbergso you use pure N2 for stoichometric nitride and add argon if you want to be Si rich18:03
azonenbergam i missing something here? if so, please tell me18:04
ashawOh, cool18:04
ashawso you sputter rather than CVD the Si3N418:04
azonenbergYes, thats the whole point18:06
azonenbergno need for silanes or other nasty gases18:07
azonenbergjust a little N2 and optionally some argon18:07
azonenbergYou can also sputter SiO2 but i forget if its usually a SiO2 target or reactive of Si + O218:07
azonenbergEvaporation is preferred as no gases are required at all18:07
azonenbergFor materials we cant evaporate, or need step coverage, sputter18:08
azonenbergBut CVD is top of the no-no list18:08
azonenbergwith spin coating obviously as the first choice18:08
ashawno, there is one worse18:08
azonenbergWhen swkhan comes back let her vent for a while18:08
azonenbergshe's been battling ALD of ZnO for weeks now18:08
azonenbergatomic layer deposition18:09
azonenbergits a form of epitaxial CVD18:09
azonenbergapply one precursor, form a monolayer on your targert18:09
azonenbergpurge chamber18:09
azonenbergapply other precursor, let it react, purge18:09
azonenbergit lets you control thickness extremely accurately, and if you are on the right substrate produce a monocrystalline epitaxial film18:10
azonenbergBut its also a pain to get working apparently lol18:10
ashawI mean why does whe want to do it?18:11
azonenbergNo idea, its apparently part of a larger project at the lab18:11
azonenbergwhich i know very little about18:12
ashawOh cool.18:13
ashawIt does look like if we can get CMP worked out, It will make a lot of other things easier18:13
azonenbergIncluding polishing of cross section samples18:14
azonenbergOne problem i'm having for cross sections is that my photoresist is soluble in some component of ted pella diamond paste lol18:14
azonenbergi dont know what it is, the msds says "proprietary nonhazardous water-based formula"18:14
azonenbergBut it takes my resist right off18:14
azonenbergfast enouhg that there is definitely chemical action as well as mechanical going on18:14
azonenbergi wanted to measure undercut in a TEM image18:15
ashawwhy not sputter over the mask18:16
azonenbergI have a couple of ideas18:16
azonenbergThe point is, that was one of several problems i had polishing18:16
azonenberganother is contamination18:16
azonenbergLarge polishing compound gets stuck on the surface18:16
azonenbergand causes deep scratches when i try a fine polish18:16
azonenbergi think i need to sonicate to get it off18:16
ashawwhat is your finest polish?18:17
azonenberg60nm colloidal silica is the smallest18:17
azonenbergnext up is 250, 500nm diamond18:17
ashawyeah, that is probably too big18:18
ashawneed finer18:18
azonenbergToo big?18:19
azonenbergFor what18:19
azonenbergYou can always get smaller CMP slurry18:19
azonenberggoes down to 20nm18:20
azonenbergbear in midn these are spherical particles too18:23
azonenbergSo 20nm will not give you a 20nm surface finish, it'll go smaller18:23
ashawoh yeah.18:23
azonenbergthe diamond is rough, i think18:23
azonenbergmight be crystalline chunks18:23
ashawcolloids can be rought too18:23
azonenbergthe silica is round in most cases specificlaly though18:24
azonenbergits made for that purpose18:24
berndjazonenberg, i'm really glad you guys got your vacuum chamber back (albeit sans chemicals), but also bummed about both the primary and secondary miscarriages of justice18:31
berndjby secondary i mean the "obstruction of justice" thing18:32
azonenbergIt was pretty ridiculous18:32
azonenbergEspecially taking a whole year18:32
azonenbergthe raid was last november18:32
azonenbergIt drove him out of school, he had to take a full time job to pay legal fees18:32
azonenbergall this because the local cops wanted to save face rather than admitting "sorry, we misunderstood"18:33
berndjmalicious prosecution would be exactly right!18:33
azonenbergYeah, but the deal prevents him from suing18:33
berndja DEAL?18:33
azonenbergthe alternative would have been going to trial18:33
berndjoh that.  yes, that's another major flaw with justice systems18:34
azonenbergwhich would have been an acceptable risk in normal cases18:34
azonenbergBut one in which it's you vs a police department that doesnt want to screw up publicly...18:34
azonenbergDoesnt usually go well for the defendant18:34
berndjso the deal was, "here, we'll convict you of obstruction of justice, and in return you promise not to sue us"18:34
azonenbergwell, more precisely by accepting the deal its considered a conviction so he loses the right to sue18:35
berndji imagine you guys just want it all to be over18:35
azonenbergits the equivalent of a guilty plea18:35
berndjbut i'd be cooking up revenge fantasies getting hold of ACLU etc18:35
berndjthat's just so broken!18:35
azonenbergIt is18:35
azonenbergI've been busy over the last year trying to make sure nobody will ever be able to do the same to me18:36
azonenbergreading up on the fire code, zoning ordnances18:36
azonenberghazmat disposal policies18:36
azonenbergmsds book and documented lab policy in a visible place18:36
azonenbergrunning by the book even more than some labs on capmus18:36
berndjgood thing obstruction of justice isn't a criminal offence though - i'm surprised though, did i get that right?18:36
azonenbergNot exactly18:36
azonenbergObstruction is a misdemeanor18:37
azonenberghe pled to *attempted* obstruction18:37
berndjbut not a felony?18:37
azonenbergwhich is some kind of hypothetical offense that is not actually illegal18:37
berndjomg, it's even weirder than i thought18:37
azonenbergso basically he has no crimes on his record but by virtue of being a paper conviction (and paying a token fine to drive the point home)18:37
azonenberghe cant sue18:37
azonenbergAnd he cant come out and say he was innocent afterwards18:39
azonenbergSince i was not a defendant, i can :P18:39
berndjspam your senator or something!18:39
azonenberghe tried, no response18:40
azonenberghe was being branded a terrorist in the media18:40
azonenbergended up changing his name and moving halfway across the country18:40
azonenbergi am not kidding18:40
azonenbergthey basically did their best to ruin his life so they wouldnt have to admit they made a mistake18:40
berndji keep tellin ya, you're in the wrong country18:41
ashawberndj, where are you?18:41
berndjsouth africa18:41
azonenbergyou suggest we move to a police state like the UK or a communist dictatorship like NK?18:41
azonenbergIt's not a good situation but i think its not quite as bad18:42
berndjno, i suggest you move to a quasi third-world country18:42
azonenbergIf i did that i'd probably end up designing weaponry for some warlord18:42
berndjwe're actually more like a quantum superposition of a first and third world country18:42
azonenbergnot doing useful research18:42
ashawyeah I get that18:43
berndjwith coefficients 0.1 and 0.9, respectively18:43
ashawoh and btw, we beat you in the tri nations18:43
berndjyeah, we always choke and leave thing up to the tailenders18:44
Action: berndj doesn't follow sport, hence doesn't care18:44
Action: ashaw doesn't either, just wanted to try to make conversation18:45
berndjthe dirty little secret most south africans don't know is that australia regularly nukes us in rugby, one of our first-tier sports, whereas in australia i gather it's just something you play if no other team picks you18:46
berndjreally quite a minority sport.  could be wrong of course18:46
ashawyeah union is minority18:47
ashawbut still big enough18:47
berndjwhich end are you? west? east?18:47
azonenbergenough about sports :p18:47
berndjashaw, is it easy(ish) to get high-tech supplies in sydney?18:49
ashawof what kind?18:49
berndjSi wafers, for argument's sake. or semi devices that aren't a 2N305518:50
ashawI can get a lot of ICs and stuff, element14 has an office here.18:50
ashawbut silicon wafers not so much18:51
ashawand like everyone PCBs go to china18:51
berndji can get common stuff here, but it seems like anything more than that, and it's order from overseas time18:51
berndjwe do still have pcb houses though.  probably even 4-layer18:52
ashawwe have them here, but sooo expensive18:52
berndjazonenberg, what sort of chemicals did you guys not get back?18:53
azonenbergberndj: common solvents, drain cleaner (why?), fluorescent dye, and some concentrated HNO318:54
ashawso like stuff you can buy at a hardware store18:54
azonenbergthe hno3 was ACS grade18:54
azonenbergBut stuff like acetone and denatured alcohol18:55
ashawso a hardware store and a drug store18:55
azonenbergThey considered it dangerous18:55
berndjclaim that the chemicals were yours and sue them for that18:55
azonenbergThey claimed that they were destroyed "because they were dangerous"18:55
berndjlol. are these people even human?18:56
ashawhave you got propper chamical storage atm?18:56
azonenbergHis response to the judge on hearing that was "Better send hazmat over to the hardware store. I heard they're stockpiling the stuff"18:56
azonenbergashaw: Relatively, yes18:56
ashawup to code?18:56
azonenbergFor home use, certainly18:56
ashawso double containered18:56
azonenbergsolvents / acids / flammables separated by significant distance18:56
ashawso double containered18:56
azonenbergI have trays under most18:56
azonenbergworking on getting everything18:56
berndjwaitaminute... this all got as far as being in front of a judge, who didn't then dismiss the case??18:56
ashawtrays made of?18:56
azonenbergashaw: glass18:57
azonenbergberndj: yes18:57
azonenberghe did not18:57
azonenberghe dismissed some charges but not all18:57
ashawwhich ones were not dismissed?18:57
azonenbergthe obstruction, which was related to him refusing to leave his home when ordered to do so by an officer who had entered it illegally (without a warrant) and with no obvious reason18:58
ashawwhat were they affraid of?18:59
azonenbergWhy were they there? why did they ask him to leave?18:59
berndjashaw, i was in aus a few times and i got the impression something like this could easily happen in aus too.  comment?18:59
azonenbergwhy didnt they drop charges whe nthey realized he was harmless?18:59
berndjseemed like a pretty police and rules-centric country18:59
ashawyeah, I'm trying to set up a lab here.18:59
ashawbut getting arround the regs is hard19:00
azonenbergashaw: re trays, i know i am not up to osha codes because i dont have an eyewash (though i do have a shower in the bathroom a 10 sec run away19:00
ashawwill have to rent commercial spave19:00
azonenbergBut its not a workplace19:00
azonenbergso osha doesnt have jurisdiction19:00
azonenbergand secondary containment, while advisable, is not required for private homes19:00
azonenbergI have it on most of the stuff19:00
azonenbergnot the large cans of hardware store solvents19:01
berndji hope that besides lab managers, you also count lawyers among your friends, azonenberg !19:01
azonenbergwhen they run out i'll be replacing them with much smaller volumes of higher purity19:01
ashawand what about disposal?19:01
ashawhow are you dealing with that?19:01
azonenbergashaw: stored in properly labeled containers and then disposed of depending on the material19:01
azonenbergAcid and base waste with no toxic stuff like heavy metals is neutralized to pH 7 +/- 0.519:02
azonenbergdiluted 10:1 with water and drain disposed19:02
ashawI would prefer that PTFE trays were used instead of glass19:02
azonenbergeverything else is taken to an official dipsosal site19:02
azonenbergand i dont have ptft atm but i will be getting it for the HF19:02
ashawall really complicated and annoying.19:02
azonenbergbear in mind that my local grocery store stores the hf on metal shelving19:02
ashawAt least they did not see the analytic glass and say he was running a drug lab19:03
azonenbergashaw: they tried19:03
azonenbergtested samples of everythign he had19:03
azonenbergbut he was smart enough to not keep any drug precursors around19:03
azonenbergnot even in tiny amounts19:03
azonenbergso they had no basis19:03
azonenbergi do the same here19:03
ashawI mean it is so hard to have an analytic chemistry lab without being able to do that stuff19:04
azonenbergThe other thing in my favor is that my landlord is a retired police chief19:05
ashawand when you get to precursers of percursers19:05
azonenbergWho knows full well what i am doing19:05
azonenbergand is completely fine with it19:05
ashawYeah, political help19:05
azonenbergi even showed him the MSDS book a few times to be 100% up front and make it clear i was hiding nothing19:05
azonenbergOne of his problems is that he was less open about what he was doing19:06
azonenbergi want it to be clear from the start i have nothing to hide19:06
berndjomg i have atoms in my house! i can make drugs!19:06
azonenbergwhich a drug lab would never do19:06
ashawit is a bit more than that berndj19:06
ashawhe would have volumetric glassware19:06
ashawand analytic balances19:06
cheaterwho are you guys talking about19:07
azonenbergcheater: friend of mine who got himself raided last year19:07
azonenbergbecause the neighbor saw vacuum gear and called the police on him19:07
cheaterwas he actually making any drugs19:07
azonenbergcheater: no, he was doing semiconductor research lol19:07
azonenbergThey never actually officially claimed they thought he was a drug lab as they had no evidence19:08
berndjso what DID they claim???19:08
azonenbergfirst, that his 100ml of HNO3 was a life-threatening danger to everyone on the block :p19:08
cheaterwas it?19:08
azonenbergthen that it could have reacted badly with the solvents stored 20 feet away19:08
azonenbergthen finally started grasping at straws19:09
azonenbergand said that when the officer told him to leave the buliding he hadnt done so19:09
berndjdid they propose an actual reaction that could have led to, say, HCN?19:09
azonenbergthey alleged they could have "produced an exothermic reaction"19:09
ashawwhat like aluminium19:09
ashawthat his windows were made of19:09
berndjthey should have just convicted him of BEING an exothermic reaction19:10
ashawand rust19:10
azonenbergthe theory was that if the hno3, drain cleaner (poor quality h2so4) and acetone had mixed19:10
azonenbergit had maybe a 10% chance of causing a small fire19:10
azonenbergStored some distance apart, separate shelves, etc19:10
azonenbergwhen that claim fell apart they finally reduced their claims to the obstruction19:10
azonenbergwhich he couldnt defend against19:11
cheaterlol, damn cops.19:11
ashawand the risk that the iso got tooo hot was not higher19:11
azonenbergit was his word against the officer19:11
ashawdo yuo have video cameras up arround your house?19:11
azonenbergashaw: i have a bunch of webcams but nothign deployed atm19:11
azonenbergyou suggest i stream any such encounter to a secure offsite location?19:11
azonenbergThat was my plan as well actually19:12
cheaterbut make sure to have a lot of notification19:12
ashawI have a server in luxemburg where I could keep a 2 loop if you want19:12
cheaterplaques that inform about cameras19:12
azonenbergi have my own offsite backups etc19:12
cheaterotherwise in some places the recording might be illegal19:12
berndjcheater, do you need that though if it's on your own premises?19:12
azonenbergAnd in NY its legal given the consent of one party19:12
cheateryou do19:13
cheaterin germany you do, at least19:13
berndjnot like he'd be filming the street19:13
cheatersince i moved here i was surprised by a few laws19:13
cheaterdoesn't matter berndj19:13
berndjyeah but germany is a bit meschugge sometimes :)19:13
cheaterlaw is law19:13
ashawSighneage is good though19:13
Action: berndj is german19:13
cheaterso check with your local laws19:13
cheateryou mean signage?19:13
ashaw"warning CCTV in use"19:14
berndjgood idea either way, i agree19:14
cheaterresolves any ambiguous legal situation19:14
ashawOnly has to be a couple stickers on windows19:14
berndjcould even prevent overzealous cops from going too far in the first place - might make them think a bit harder about what they do19:14
berndjbut watch out for evidenciary rules19:15
berndjgermany for example might not permit footage stored in another country!19:15
berndj(just guessing)19:15
azonenbergi have in-country servers that are pretty hard to find19:15
ashawkeep a buffer on site in case they pull the phone line19:16
azonenbergashaw: I do not expect a full on response like that, we arent talkign a hostage situation here19:16
ashawand have a backup mobile connection19:16
ashawyou never know with the USA19:16
azonenbergFor that matter, now that its been a year since his raid i think the odds of anyone bothering me are low19:17
berndjjust reading about all this, i have to conclude that america is fscked19:17
cheaterit is19:17
berndjit is, for all kinds of reasons, but this is another one that mainstream media don't cover19:18
berndji spy with my little eye a fixed rubik cube in azonenberg's lab19:20
berndjcan't say i'm surprised19:21
azonenbergWas never actually that good at them19:21
berndji geeked out on them when i was a kid19:21
berndjused to be able to do it semi-consistently <60s19:21
berndjwhat is that thing that looks like an electric drill, but has a flexible tube running from the chuck into a cardboard box???19:22
ashawthe spin coater.19:23
ashawit is an electric drill19:23
azonenbergthe cardboard is a spatter shiedl19:24
berndjah! and a flexible coupling hose type thing?19:25
cheaterwhere do i see the pic?19:28
cheaterberndj :)19:32
berndjcheater: http://imgur.com/a/Bnwst - third-last pic19:34
flyback-i'd be an asshole to my neighbor after that19:48
cheateris he a19:49
flyback-people are such idiots19:49
flyback-I seen commerials telling people to snitch stuff out19:50
flyback-i've decided I rather let the country burn19:50
flyback-i'm so fed up with the way some law enforcement behaves19:51
flyback-hell with it all19:51
flyback-but I think the video is a good idea19:52
flyback-have it stream to multiple other locations19:52
cheater yup19:53
flyback-the terrorists can have the country as far as I am concerned anymore19:56
flyback-between the way the tsa, etc acts and a bunch of other bullshit19:56
cheaterthere's nothing terrorists can do  to america that the american's haven't19:57
flyback-i've pretty much given up on anything20:01
flyback-i've given up on bein able to ever invent anything20:04
flyback-thx to patent trolls20:04
flyback-wish I was wrong20:08
azonenbergoh, you can invent stuff20:13
azonenbergYou just cant market it without getting sued :p20:13
flyback-i've give up on society, etc20:17
flyback-I can't wait to die20:17
berndjmaybe it's all an anarchist deep cover operation - propaganda of the deed20:34
berndjto get normal people so upset with government they'd rather have anarchy20:34
berndjazonenberg, do you grok patents? i've always wondered if you're allowed to use a patented invention sans licence even at home20:35
azonenbergNot very much, no20:35
cheaterwhy not20:43
azonenberggaah, finally making some progress21:11
azonenbergThe bug i've been fighting with (that only occurred on hardware and not in simulation)21:12
azonenbergnow occurs in simulation too :p21:12
azonenbergRe patents, the de facto rule is the same as copyrights21:13
azonenbergIf you draw their attention they'll come after you21:13
azonenbergBut if you arent worth the money, they'll probably leave you alone21:13
ashawactually patent infringement in research is allowed, or so I had read21:20
azonenbergResearch they have exemptions for but i dont know the full details21:25
flyback-http://boingboing.net/2011/10/08/wipo-boss-the-web-would-have-been-better-if-it-was-patented-and-its-users-had-to-pay-license-fees.html <-- idiot21:29
berndjnot an idiot - just the enemy21:59
--- Mon Oct 10 201100:00

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