| azonenberg | So... current priorities | 04:30 |
|---|---|---|
| azonenberg | building process control modules | 04:31 |
| azonenberg | for BGA reflow (unrelated project) and my spin coater | 04:31 |
| azonenberg | As well as probe tip etching | 04:31 |
| azonenberg | I want to think if its possible to combine them all onto a single generic "industrial control module" | 04:31 |
| azonenberg | with a unified API so i can tlak to them all with similar code | 04:31 |
| B0101 | Hi Azonenberg | 06:22 |
| azonenberg | hi | 06:22 |
| azonenberg | Any progress? | 06:22 |
| B0101 | nope | 06:22 |
| B0101 | I was sick | 06:22 |
| B0101 | didn't do any experiments | 06:22 |
| azonenberg | A legitimate excuse lol | 06:22 |
| azonenberg | Btw, look up the paper "Etch rates for micromachining processes, part II" | 06:23 |
| B0101 | ok | 06:23 |
| azonenberg | Actually, why dont you set up a wiki page for "recommended reading" | 06:23 |
| azonenberg | that paper is not one that you will read once and go "oh, cool idea" | 06:23 |
| B0101 | sure | 06:23 |
| azonenberg | its mostly tables of numbers | 06:23 |
| azonenberg | and discussion of results | 06:23 |
| azonenberg | Edtremely useful reference | 06:23 |
| azonenberg | extremely* | 06:23 |
| azonenberg | the de facto "etch bible" | 06:23 |
| azonenberg | covers both wet and plasma on like 90 different materials | 06:24 |
| B0101 | wow | 06:25 |
| azonenberg | I have both a PDF and a hard copy, the hard copy is pinned up to my bulletin board above my desk | 06:25 |
| azonenberg | i use it all the time | 06:25 |
| azonenberg | other good references - "Tantalum oxide thin films as protective coatings for sensors" if you're using Ta2O5 | 06:28 |
| azonenberg | "Fabrication of very smooth walls and bottoms of silicon microchannels for heat dissipation of semiconductor devices" for KOH etching | 06:28 |
| azonenberg | "Reproducible Electrochemical Etching of Tungsten Probe Tips" for making microprobes | 06:28 |
| CIA-67 | homecmos r145 | wiki/Recommendedreading.wiki | Created wiki page through web user interface. | 06:31 |
| B0101 | Gimme a few links to put up on the new page | 06:32 |
| azonenberg | Those papers are very useful | 06:33 |
| azonenberg | let me try to find donwload links that are public | 06:33 |
| azonenberg | silly subscriptions | 06:33 |
| azonenberg | "Etch rates for micromachining processing, part II" http://microlab.berkeley.edu/labmanual/chap1/JMEMSEtchRates2(2003).pdf | 06:33 |
| azonenberg | 255 citations | 06:33 |
| azonenberg | "Tantalum oxide thin films as protective coatings for sensors", http://orbit.dtu.dk/getResource?recordId=266688&objectId=1&versionId=1 | 06:34 |
| azonenberg | "Fabrication of very smooth walls and bottoms of silicon microchannels for heat dissipation of semiconductor devices" - http://linkinghub.elsevier.com/retrieve/pii/S002626920000015X | 06:36 |
| azonenberg | unfortunately that isnt a public link | 06:36 |
| azonenberg | "Reproducible Electrochemical Etching of Tungsten Probe Tips", https://apmc.zyvex.com/literature/apmc-literature-surveys/stm-tip-fabrication/stm-tip-review/Reproducible%20Electrochemical%20Etching%20of%20Tungsten%20Probe%20Tips.pdf | 06:36 |
| CIA-67 | homecmos r146 | wiki/Recommendedreading.wiki | Edited wiki page Recommendedreading through web user interface. | 06:39 |
| B0101 | sorry, i gtg, see you tommorrow | 06:40 |
| azonenberg | k | 06:40 |
| bart416 | azonenberg, I might be able to get my hands on one of these: http://www.tequipment.net/LecroyWaveJet352.html | 07:16 |
| azonenberg | Shiny | 07:17 |
| azonenberg | 500 MHz? | 07:17 |
| bart416 | Yah | 07:18 |
| bart416 | Main issue is logistics | 07:19 |
| bart416 | I can't go and pick it up myself | 07:19 |
| bart416 | Too long of a distance | 07:19 |
| bart416 | So might have to pass on it | 07:19 |
| bart416 | But 150 euro for that thing... | 07:19 |
| azonenberg | Used, i assume? | 07:19 |
| azonenberg | And o_O | 07:19 |
| bart416 | Yes | 07:19 |
| azonenberg | i have no idea what that is in USD but its cheap :p | 07:20 |
| bart416 | Used, but in good condition | 07:20 |
| bart416 | Roughly 200 USD | 07:20 |
| azonenberg | i paid close to 1K USD for mine | 07:20 |
| bart416 | Normally you'd pay over a tenfold of that for a new one | 07:20 |
| azonenberg | And that looks way better per channel | 07:20 |
| azonenberg | Mine has the 16ch LA which is nice, but deep memory would help greatly | 07:20 |
| azonenberg | for some applications | 07:21 |
| bart416 | Well, logic analyzer you can build | 07:33 |
| bart416 | Scope is a lot harder | 07:33 |
| bart416 | An FPGA, USB chip, and some buffers and you have a LA | 07:33 |
| azonenberg | Yeah | 07:36 |
| azonenberg | I plan to do that soon actually | 07:36 |
| azonenberg | make one with really deep memory | 07:36 |
| bart416 | Heh, I got to play with one of those newer NAs this week | 07:36 |
| azonenberg | Why do cheap scopes not have deep memory? | 07:38 |
| azonenberg | its not like ddr2 is expensive | 07:38 |
| azonenberg | you could throw a hundred megabytes on there for $10 | 07:38 |
| bart416 | most scopes use static ram as far as I know though azonenberg | 08:34 |
| bart416 | well at least all the ones I've had to open up do so | 08:34 |
| swkhan | azonenberg_work: still no wafer. what did dhl/fedex say? | 23:02 |
| azonenberg | swkhan: it was us post office | 23:03 |
| azonenberg | and they say it was signed for | 23:03 |
| azonenberg | and delivered | 23:03 |
| azonenberg | you're saying it got lost? :( | 23:03 |
| swkhan | oh! okay, i'll check at the post office on monday then | 23:03 |
| azonenberg | you have the tracking #, right? | 23:03 |
| swkhan | i don't remember it. can you pm it to me? | 23:04 |
| azonenberg | sent | 23:05 |
| swkhan | they said it was delivered ~1 week ago?! | 23:06 |
| azonenberg | Yes | 23:07 |
| azonenberg | So somebody has it, apparnetly lol | 23:07 |
| swkhan | they did make a mistake recently. they gave us some highly flammable substance that "donna ...?" owns | 23:11 |
| swkhan | something dodecaethylthiol or something | 23:11 |
| swkhan | we haven't tried to contact donna because we're apathetic / lazy i guess =\ | 23:11 |
| azonenberg | lol | 23:11 |
| swkhan | grr | 23:17 |
| swkhan | do you have much experience with a semiconductor parameter analyzer? | 23:17 |
| azonenberg | whats that? :P | 23:17 |
| swkhan | or a 4 point probe even? | 23:17 |
| azonenberg | I know the idea of a 4-point probe but i havent used thm | 23:17 |
| swkhan | it's a really fancy set of voltage sources and current sources and voltage monitors and current monitors | 23:17 |
| azonenberg | My sheet resistance measurements to date have been no more sophisticated than "is there something conductive on top of this insulating film or not? | 23:18 |
| swkhan | all i really need is an easy way to probe a really small metal insulator metal capacitor | 23:18 |
| swkhan | so i have it like a crossbar + | 23:18 |
| azonenberg | So you have two layers of metal with dielectric between them | 23:19 |
| azonenberg | Define small | 23:19 |
| azonenberg | 50nm? 200um? | 23:19 |
| swkhan | larger =p | 23:19 |
| azonenberg | >200um? | 23:19 |
| swkhan | like maybe 500 um to 1 mm | 23:19 |
| azonenberg | oh | 23:19 |
| azonenberg | thats like, hand solderable | 23:19 |
| azonenberg | lol | 23:19 |
| swkhan | not with my hands :\ | 23:19 |
| azonenberg | What do the pads look like? | 23:19 |
| swkhan | i don't have bond pads | 23:19 |
| azonenberg | how do you connect to the layers? | 23:19 |
| azonenberg | You dont have bond pads | 23:20 |
| azonenberg | so for the top layer you just probe the metal | 23:20 |
| swkhan | you type faster than i think | 23:20 |
| azonenberg | Is the bottom layer bigger? | 23:20 |
| swkhan | yes | 23:20 |
| swkhan | well they are at like a T junction | 23:20 |
| azonenberg | So you have two metal bars crossing at a T | 23:20 |
| swkhan | so i have the bottom electrode shadow mask patterned horizontally | 23:20 |
| azonenberg | the capacitor is where they overlap | 23:20 |
| swkhan | yes | 23:20 |
| azonenberg | And the 0.5mm figure is what exactly? | 23:21 |
| azonenberg | the width of one bar? | 23:21 |
| swkhan | the planar distance from where the bottom electrode is probed to where the top electrode is probed | 23:21 |
| azonenberg | Ok | 23:21 |
| azonenberg | So standard multimeter probes are a little big | 23:22 |
| azonenberg | You dont have proper micropositioners i take it? | 23:22 |
| azonenberg | If you did this'd be a solved problem | 23:22 |
| swkhan | we have some sort of positioners but either they don't work perfectly or i stink at using them or both | 23:22 |
| swkhan | we have tungsten probe tips that say 45 degree angle and 12 um which i assume is the tip width | 23:23 |
| swkhan | or tip radius or tip diameter | 23:23 |
| azonenberg | Ok | 23:23 |
| azonenberg | 12um is plenty for this size | 23:23 |
| azonenberg | i've done large IC components with 25um probes | 23:23 |
| swkhan | well smaller is better. 0.5 mm is pathetic | 23:23 |
| azonenberg | lol | 23:23 |
| swkhan | but more important than all of that is some reproducible measurement | 23:23 |
| azonenberg | well I've hit 20um targets with homebrewed submicron probes | 23:24 |
| swkhan | the manipulators kind of bobble a bit when i lower or raise them | 23:24 |
| swkhan | wow! | 23:24 |
| azonenberg | and cheap micromanipulator 110 positioners | 23:24 |
| swkhan | 110 dollars? | 23:24 |
| azonenberg | no, thats the model number | 23:24 |
| azonenberg | 110 and 210 | 23:24 |
| swkhan | oh | 23:24 |
| azonenberg | They were around $100 each on ebay though lol | 23:24 |
| swkhan | because ours were about 1000 each | 23:24 |
| swkhan | maybe 100 | 23:24 |
| azonenberg | The $1K ones are overkill | 23:24 |
| swkhan | i just remember they weren't worth whatever we paid for them | 23:24 |
| azonenberg | most of them are good to submicron | 23:24 |
| azonenberg | http://colossus.cs.rpi.edu/pictures/2011/June/6-24-2011%20-%20lab/S7300939_sm.jpg | 23:24 |
| azonenberg | This is me hitting a bond pad on a 350nm 3-metal microcontroller (PIC12F683) | 23:25 |
| azonenberg | with a homemade submicron tungsten tip | 23:25 |
| swkhan | wow =) | 23:25 |
| azonenberg | magnification is in the 60-120x range | 23:25 |
| swkhan | grr i'm really frustrated | 23:25 |
| azonenberg | http://colossus.cs.rpi.edu/pictures/2011/June/6-24-2011%20-%20lab/S7300935.JPG is the rig i have | 23:25 |
| azonenberg | i assume yours is similiar? | 23:25 |
| swkhan | i thought i had a good research idea and i'm being derailed by equipment | 23:25 |
| azonenberg | I got a fiber optic illuminator since taking this pic, huge help :P | 23:26 |
| swkhan | ours is way uglier, smaller, and way less incapable | 23:26 |
| azonenberg | Lol, my probing station was bought used on ebay | 23:26 |
| azonenberg | You're saying your gear isnt as nice? | 23:26 |
| swkhan | yes | 23:26 |
| azonenberg | o_O | 23:26 |
| azonenberg | sorry | 23:26 |
| swkhan | well, i'm more irritated that the girl who set this up is totally incompetent | 23:27 |
| Action: azonenberg wonders at the feasibility of making capacitors on his process now | 23:27 | |
| swkhan | and told me that she knew this machine worked | 23:27 |
| swkhan | =\ | 23:27 |
| swkhan | i'm going to get scooped | 23:27 |
| swkhan | i just want one paper, then i can be happy again | 23:27 |
| azonenberg | 20um capacitors made of evaporated copper on Ta2O5 high-K dielectric | 23:27 |
| azonenberg | maybe 50 for starters | 23:27 |
| azonenberg | i think are entirely feasible | 23:28 |
| azonenberg | And my probe tips were made in this apparatus http://colossus.cs.rpi.edu/pictures/2011/June/6-22-2011%20-%20lab%20work/S7300912.JPG | 23:28 |
| azonenberg | lol | 23:28 |
| azonenberg | http://colossus.cs.rpi.edu/pictures/2011/June/6-22-2011%20-%20lab%20work/S7300921.JPG | 23:28 |
| azonenberg | standard electrolytic etching | 23:28 |
| swkhan | wow | 23:28 |
| azonenberg | seen closer, http://colossus.cs.rpi.edu/~azonenberg/images/homecmos/2011-07-05/probe1/probe1_008.jpg | 23:29 |
| swkhan | well how thick should a bond pad be by the way? how thick would your metal electrode (copper) be? | 23:29 |
| azonenberg | Hmm, depends on the bonding process | 23:29 |
| azonenberg | With copper its more annoying since you need a barrier layer | 23:29 |
| azonenberg | and adhesion | 23:29 |
| swkhan | i made mine ~100 nm each for top and electrode | 23:29 |
| azonenberg | 100nm is fine if you are probing | 23:29 |
| azonenberg | i think | 23:30 |
| swkhan | i had an adhesion layer too | 23:30 |
| azonenberg | Ta? Cr? | 23:30 |
| swkhan | cr | 23:30 |
| azonenberg | ti? | 23:30 |
| azonenberg | Yeha, Cr is the de facto standard | 23:30 |
| azonenberg | thats what i use too | 23:30 |
| azonenberg | though i hear sputtered Ta is catching on | 23:30 |
| swkhan | but it takes forever to sputter all this stuff | 23:30 |
| swkhan | i was just talking to a professor about this yesterday =) | 23:30 |
| azonenberg | I do evaporation, a nice thick film only takes a few minutes once you have decent vacuum | 23:30 |
| swkhan | i was reading a book on electrodeposition | 23:30 |
| swkhan | and they said that nb and v give better adhesion layers than cr or ti | 23:31 |
| azonenberg | And like i said, thickness depends on the proces | 23:31 |
| azonenberg | for example if you are soldering to it (flip chip bonding) you want a micron ish | 23:31 |
| azonenberg | or it'll just dissolve into the solder | 23:31 |
| azonenberg | and yes, i've read a little about Nb and V | 23:31 |
| azonenberg | But they're pretty exotic | 23:31 |
| azonenberg | and not used because while they may be better, its not by much | 23:31 |
| swkhan | chromium can form quadruple bonds | 23:32 |
| swkhan | my mind is still blown | 23:32 |
| swkhan | i need to relax | 23:32 |
| azonenberg | Thats why it sticks so well | 23:33 |
| azonenberg | and i have homework to do but i dont want to :( | 23:33 |
| swkhan | i'm going to a film festival with some friends. i need to take my mind off research that doesn't work | 23:33 |
| azonenberg | Lol | 23:33 |
| azonenberg | I think i'm going to try one of my alternative hardmasking ideas | 23:33 |
| swkhan | i'd invite you, but you'd have to take a plane... =p | 23:33 |
| azonenberg | One that i came up with a long time ago but never tried | 23:33 |
| azonenberg | i even have the coated wafer, just need to actually etch | 23:33 |
| azonenberg | and lol | 23:34 |
| azonenberg | Yeah, kinda on the wrong side of the continent :p | 23:34 |
| swkhan | the chromium mask? | 23:34 |
| azonenberg | no | 23:34 |
| azonenberg | The Cr mask has to wait until i get up to campus next week to do the thick Cr film | 23:34 |
| azonenberg | This one is older but i never actually tested | 23:34 |
| azonenberg | Ta2O5 plus Cu:Cr stack | 23:34 |
| azonenberg | use the metal as a mask for HF etch of the oxide | 23:34 |
| azonenberg | then use the oxide as a mask for KOH of the silicon | 23:34 |
| azonenberg | i have the three-film wafer sitting on a shelf but never actualy did anythign with it | 23:35 |
| swkhan | i'll talk to you later azonenberg. i'm going to ask my professor if he knows what happens to the wafer as well. i'll double check the office before i go | 23:36 |
| swkhan | honestly, if i don't find it in a week, i'm just going to use one our spares and thermally grow the oxide in atmosphere | 23:36 |
| azonenberg | Lol that works | 23:36 |
| swkhan | bye azonenberg =) | 23:37 |
| --- Sun Oct 16 2011 | 00:00 | |
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