azonenberg changed the topic of #homecmos to: Homebrew CMOS and MEMS foundry design | Wiki: http://homecmos.drawersteak.com/wiki/Main_Page | Repository: http://code.google.com/p/homecmos/ | Logs: http://en.qi-hardware.com/homecmos-logs/
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<nmz787> well having poor vacuum will definitely reduce the performance of the spectrometer
<nmz787> 'backpack' diff pumps exist, though they'll be pricey
<nmz787> i.e. like this one uses http://www.mymochii.com/
<nmz787> (this SEM)
<nmz787> I guess you're referring to the sentence "However, since the sensitivity obtained using atmospheric pressure ionization is limited by the amount of gas and entrained ions that can be drawn into vacuum, the limits of detection must reflect their small size."
<nmz787> ?
<nmz787> Noxz: perhaps my FIB can be of some use once I get it uncrated and running
<SpeedEvil> For some things, you can swap out a turbopump for a sublimation pump
<SpeedEvil> Nice clean titanium films suck
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<pie_> suck it good
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<Noxz> took another step in my head towards the turbo pump
<pie_> \o/
<Noxz> the expense is justifiable.. just my entire lab is in boxes so :/
<Noxz> and likely can not have the lab shack I was thinking about, and will have to use a bedroom
<pie_> aw why no shack
<Noxz> too many scientific instruments
<pie_> shack too small? xD
<Noxz> a SEM and MS arent exactly small
<Noxz> yeah, my actual property lines suck
<Noxz> llike under 100sq ft max of a shack
<pie_> wait you have a sem for your own personal use? D:
<Noxz> I want to make one
<pie_> :D
<Noxz> personal = for my future career
<Noxz> horology/watchmaking
<pie_> then again i guess if someone has a job and some decent income its not impossible
<Noxz> I do alright
<Noxz> Applied Science guy litterly made one from scratch
<SpeedEvil> Noxz: does it say what the max height of the shack is?
<Noxz> right now I am actually looking up papers on using GaAs + Green laser to make free electrons instead of a Tungsten filament
<Noxz> SpeedEvil, around here, 10ft
<Noxz> which is MUCH better than the headroom I have in the bedroom
<SpeedEvil> Noxz: can you have a basement?
<Noxz> especially since my fumehood exhaust fan take up a bit of that room
<pie_> lol sunk shed
<Noxz> that is the 'basement' grade
<Noxz> it's right near a small creek, so on an ECA, Environmentally Critical Area
<Noxz> Creek + Steep slope to it
<Noxz> and naything I want to do outside will need a surveyer to come out
<Noxz> right now it looks like I will just rebuild the deck
<Noxz> I really wanted more headroom for the fumehood, too
<Noxz> :/
<SpeedEvil> I have idly wondered about this as an inspiration for a shed.
<SpeedEvil> Add robot legs.
<Noxz> hehe
<SpeedEvil> (more for shuffling though)
<SpeedEvil> But in some legislations might work as a get-out from size rules.
<pie_> :D
<SpeedEvil> ^jurisdictions
<pie_> build it on treads
<pie_> its not a shed its a car!
<SpeedEvil> yeah - treads are boring though, when you can have at-at shed.
<pie_> i need to stop being so practical
<SpeedEvil> :)
<SpeedEvil> Also, in the UK, it is not illegal to drive on roads something only a madman would drive on roads as it's so dangerous.
<pie_> hey, if nasa can build a rocket platform on wheels, i can build a shet
<pie_> shed
<SpeedEvil> I was amused to find that the shuttle transporter (for the shuttle alone, not the stack) was bought by SpaceX and is being reused as a rocket stage transporter
<Noxz> "parking spaces" are regulated on properties too
<Noxz> based on size of house and junk
<SpeedEvil> Noxz: But if it keeps moving, it's not parked.
<pie_> why do they regulate that
<Noxz> pie_, much of it seems like HOA sort of thing
<Noxz> city wide
<pie_> so much house related stuff is regulated that jut seems dumb and idk why
<pie_> HOA?
<Noxz> home owners aswsociation
<pie_> 0.o
<Noxz> they tell you what color of paint you can use on your house, what kind of grass and how long it can be
<Noxz> etc
<pie_> meh i guess
<Noxz> it keeps things "standard"
<pie_> i was thinking more actual building code stuff though i thik
<Noxz> so you dont have a weirdo sore thumb in your neighborhood
<SpeedEvil> pie_: yeah - this isn't about safety
<Noxz> there is almost nothing that regards to safety and number of cars allowed on your property
<Noxz> unles syou can think of something
<SpeedEvil> fire risk
<pie_> something strange looking might give uptight entitled white people a heart attack? :D
<Noxz> anyways.. might change my placs some to actually have a lab
<Noxz> if I was able to park my electric project car on the slanted driveway I would be set in the garage, but the driveway isnt long enough
<Noxz> there's just some BS regarding my property lines
<Noxz> and required setbacks from streetss and such
<SpeedEvil> are you required to park your car along the driveway, not across?
<SpeedEvil> Or, indeed, vertically on the bumper
<Noxz> along = on?
<Noxz> oh, you mean vertially vs horixontally
<SpeedEvil> yes
<Noxz> likely...
<Noxz> and horizontally would sorta intrude where the mailbox is
<Noxz> easy fix, but yeah
<Noxz> I was actually thinking about having a wench system so everytime I need to be in the lab garage, I would pull the car out and then have the space, and when done pull it back in
<Noxz> maybe make like a flase wall or something to the nose of the bumper and gain private space that way
<Noxz> (it faces the street)
<Noxz> I have 1-2 bedrooms I could use
<Noxz> and maybe a whole other living room space...
<Noxz> but, I wanted to keep nasty solvents out of the house
<Noxz> even with a fumehood, it was noticeable at my old place
<pie_> solvents gonna solv
<pie_> welll you could have a chemical storage shed separately?
<Noxz> I still dont want volatile things in the house all that much
<pie_> keep the SEM and stuff in the house
<Noxz> so, it is illegal to setup booby traps
<Noxz> because you are not the judge/jury, you are the victim of a break in.. you do not get to decide punishment for a crime
<Noxz> but, at the same time, you can shoot people who trespass, more or less
<nmz787> pie_: I have my own SEM for personal use :D
<pie_> :C
<pie_> nmz787, whats it cost to run it btw?
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<nmz787> pie_: not too much, the diffusion pump is 600W, so maybe another 500-1000W otherwise
<SpeedEvil> and filliment/... life?
<pie_> so just power?
<pie_> i dont really know what you need to run a sem
<pie_> (i should, but i dont)
<nmz787> filament is a consumable, I haven't had to seriously look into getting a new one yet
<pie_> thats the electron source?
<nmz787> there are at least a few shops around here that can supply them
<nmz787> yeah, tungsten
* pie_ is in the middle of nowhere (i.e. central europe :P)
<pie_> (well at least its not eastern europe i guess?)
<nmz787> hehe, idk some of the weird vacuum stuff seemed to have (historically at least) come out of that area
<pie_> though if i finally get my sh** sorted out and get around to studying properly maybe the uni will let me use theirs
<pie_> yeah im always surprised when people find all kinds of good shit here, i guess its not that it doesnt exist im just out of the loop :P
<nmz787> the more I learn, the simpler all this stuff seems to be
<pie_> well sure its not thaaaat complicated
<nmz787> of course I've been at this for years and years
<pie_> but you gonna go manufacture your own vacuum pump? :P
<pie_> though thats a neat idea
<nmz787> but eventually I guess many things are hard and then become straightforward once you become an expert
<pie_> not sure how viable
<pie_> ALL THE DEGASSING
<pie_> everything is hard until it becomes easy :D
<nmz787> yeah, maybe if they were planar pumps, able to be made with homecmos type fab
<pie_> nothing is hard you just have to study a lot
<pie_> > if you pay attention you will notice that i am cheating
<nmz787> :D
<nmz787> I got my SEM from a craigslist ad
<pie_> whats a planar pump
<nmz787> my FIB from ebay
<pie_> yeah we dont have craigslist
<pie_> also jesus fuck you have a fib
<nmz787> everywhere has craigslist!
<pie_> how much you get that for
<pie_> yeah people just arent throwing fibs out on every corner :(
<nmz787> $1500 plus twice that in my own shipping costs
<pie_> the uni is getting a fib this semester i thinl
<pie_> think
<pie_> thats pretty good no?
<pie_> how much for fib consumables?
<nmz787> (I drove to get it with a big truck and a trailer, rented forklift at both ends, built crates)
<nmz787> haha, a new ion source from the OEM is like $8k
<nmz787> from some local aftermarket place they want like $2k to refill it
<pie_> well at least its not 100
<pie_> 100k
<pie_> or 01k
<pie_> * 20k
<nmz787> and I think I might be able to get some nice isotopically pure gallium to try my own refill for under $100
<pie_> hwever much this stuff costs
<pie_> you in like some place near to big silicon manu?
<pie_> or something
<nmz787> you can see the scariest part of the FIB trip just a few moments after this time in this video https://www.youtube.com/watch?v=1huy6VH_zCw&t=1253
<nmz787> (when I dropped the FIB onto the trailer, due to the hydraulics lowering much faster than raising)
<Noxz> nmz787, I am interested in your SEM
<Noxz> ebay find or similar?
<nmz787> craigslist
<Noxz> ahhh
<nmz787> same model the Applied Science guy bought
<Noxz> decent?
<Noxz> seems kinda old
<nmz787> I need to add more pics https://www.takeitapart.com/guide/136
<nmz787> 10nm resolution seems "new" enough for me
<Noxz> also, what kind of ion source?
<nmz787> gallium
<Noxz> ion = electron gun?
<nmz787> no
<Noxz> no.. hrmm
<nmz787> the SEM uses electrons, the FIB uses ions
<Noxz> FIB? not familiar with what that is
<SpeedEvil> nmz787: Here doesn't have craigslist annoyingly.
<Noxz> focused ion beam
<SpeedEvil> nmz787: or technically it does, but there are like 4 things for sale in a half a million population area
<nmz787> electrons are lighter and less ballistically damaging, ions are like shooting bullets and will mill the sample
<nmz787> SpeedEvil: yeah I've been to some places where the craigslist site was for like a whole country
<Noxz> yeah, I was reaing into ion etching a bit more today
<Noxz> not on purpose
<nmz787> Noxz: FIB == focused ion beam
<Noxz> came across it in a paper
<Noxz> nmz787, yeah, I found that
<Noxz> so, I am trying to look into AlGaAs + photons -> electron (gun) for SEM
<nmz787> whoops, now I see you said that already
<Noxz> I also see you said where you got the SEM from, craigslist
<Noxz> it was near the tldr section
<Noxz> ;)
<Noxz> nmz787, do you vote that I buy this guys turbomolecular pump (plus gaguges, all the fittings, and the edwards rv12 double vane roughing pump that will be used for other uses beyond roughing) ?
<Noxz> I am certainly leaning towards doing it
<nmz787> depends how much $
<Noxz> $2100 shipped
<nmz787> hmm, seems high enough that you should be guaranteed that it is in great condition
<Noxz> pfeiffer TMH 260 turbo w/ TCP120 controller
<Noxz> yeah, he has photos of the gauges on everything showing great vacuum
<Noxz> which was the main reason I was looking at his double vane pumps
<Noxz> effusion is vapor deposition from a source metal?
<Noxz> looking at thin layer of Mg for negative electron affinity
<Noxz> if I am understanding some of these concept correctly
<nmz787> Noxz: you can also get great vacuum from oil diffusion pumps, they're cheaper, have no moving parts, and the repair is usually just stainless steel wool (to clean the internal jets/baffles) and fresh oil which is like $150 for a bottle... maybe a new gasket or a new heater coil
<Noxz> oil diffusion doesnt work for making a Mass Spectrometer
<Noxz> little oil particles back up into the chamber
<Noxz> may be fine for SEM
<Noxz> but not MS
<Noxz> which is the other thing I want UHV for
<nmz787> well, idk, seems like you could just subtract the oil from the signal using calibration
<nmz787> but yeah makes sense
<nmz787> even for SEM it can get nasty if you mess something up
<Noxz> heh
<nmz787> oil ends up all over your sample
<Noxz> hazy picture or similar?
<Noxz> ah
<nmz787> or the oil get's flash-burned and tars up
<Noxz> well, anything I put into the SEM I wouldnt really expect to get back out, imho ;)
<nmz787> I guess if someone was doing EDX (xray analysis) on the SEM then they'd essentially have the same problem an MS would have
<Noxz> I would be characterizing MEMS style mini gears
<Noxz> more or less
<Noxz> but yeah, currently today I have been interested in non-tungsten sources of electrons
<nmz787> but sometimes the lack of vibration with a diff pump makes for better images
<nmz787> any particular reason? just no easily avail tungsten?
<Noxz> it's not that.. more likely it burns out after 40-100hrs
<Noxz> and just.. the idea is cool
<Noxz> laser + photodiode = electricity
<Noxz> dope it with NEA of some sort and those electrons shoot off
<nmz787> NEA?
<Noxz> Negative Electron Affinity
<nmz787> ah
<Noxz> Cesium + Oxygen was used in the paper I read
<Noxz> buut, I just finished reading doping Diamond w/ Mg to obtain a negative
<Noxz> and, well, I have Mg...
<Noxz> you dont even need to sputter it.. you could likely just put the sample you wotn in the same chamber as some Mg under vacuum and melt/boil tthe Mg
<Noxz> boom, Mg vapor
<pie_> <Noxz> it's not that.. more likely it burns out after 40-100hrs
<pie_> oh damn thats not a lot...
<pie_> for 8k apiece...
<Noxz> no, you can get a box for like $20
<pie_> oh that was something else the
<Noxz> that is an ion source, from Gallium, he said
<pie_> then
<pie_> ah
<Noxz> this is an electron source
<pie_> ok right
<pie_> whew xD
<Noxz> actually.. looks more like $40 ea?
<Noxz> the Applied Science guy likely got it for super cheap
<Noxz> maybe he has some to give away
<Noxz> ;)
<nmz787> he is also really really smart... like he started his own business when he was in high school
<nmz787> as in some tech business
<Noxz> I was just smoking pot in high school
<Noxz> lol
<Noxz> more or less
<Noxz> I guess I was in AP Calc, but still
<nmz787> haha, I still smoke, right next to the FIB
<Noxz> I havent smoked in like 7 years
<nmz787> study high, test high, get high scores
<Noxz> I got piss tested when hired at Chemical Abtsracts Services and havent done it since, for fear of random tests
<Noxz> though, I no longer work for them, in fact I work at home now, but still
<nmz787> it's legal here :P
<Noxz> here too