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<azonenberg>
barrettfriedman: But the thing is, if you sputter over the resist
<azonenberg>
Odds are pretty good that the sidewalls will be somewhat conductive
<azonenberg>
may not be 100% covered to the same thickness as the tops, but there will be stuff there
<azonenberg>
And, furthermore, if you then dip it in solvent it may not separate cleanly or at all
<azonenberg>
on the other hand if you use evaporation i suppose it's possible to do what you want, but that's only if your design involves a single metal deposition step
<azonenberg>
also, what are you trying to deposit? Liftoff is generally only used for materials that are difficult or impossible to etch
<azonenberg>
because it can lead to high edge roughness as well as pretty much limiting your deposition method to evaporation
<azonenberg>
whereas conventional lithography can be used to pattern almost anything
<Sync>
interesting
<Sync>
neat little belljar azonenberg
<azonenberg>
Sync: ty
<azonenberg>
Not mine technically, was bought by a company i did consulting with last year
<azonenberg>
But they said i could hold onto it and use it for whatever i want
<azonenberg>
as long as they get to use it if they need it back in the future
<Sync>
but probably not up to spec for some high vacuum work
<azonenberg>
Sync: I was planning to turn it into a sputter coater
<azonenberg>
i can hit adequate vac for sputtering with the mechanical pump there
<Sync>
how low does it go?
<azonenberg>
I do need to redo some of the fittings, we totally disassembled it to find a leak
<azonenberg>
Of all the places to be leaking, the Pirani gauge :p
<azonenberg>
so i need a new one
<azonenberg>
We had it down to high tens of mtorr, maybe 60ish? The pump is rated for 40 but we had a slow leak
<Sync>
you can probably seal it with regular epoxy
<azonenberg>
That's easily deep enough for DC sputtering
<Sync>
well, I'm currently shopping for a vacuumchamber of my own
<azonenberg>
How far do you want to go?
<azonenberg>
I eventually would like to get deep enough for evaporation
<azonenberg>
The fittings on that chamber are def not good enough
<azonenberg>
But the jar and plate might be
<Sync>
well, I have a rubber sealed turbo, but can get metal gaskets for it
<azonenberg>
You have a turbomolecular pump? o_O
<Sync>
and four dual stage rotary vanes
<azonenberg>
Very nice
<Sync>
well okay, two, two are fubar
<azonenberg>
The pump i have is a dual stage rotary vane
<Sync>
I have a leybold d4b and a d8b working
<azonenberg>
My pump is a less fancy brand, i forget what
<Sync>
the others are ilmvac devices, used in chemical service and corroded to death
<azonenberg>
But it hit 40mtorr when we attached it straight to the pirani gauge
<azonenberg>
And we got the entire bell jar assembly down to below 100
<azonenberg>
before the leak got worse
<azonenberg>
When i have $1k ish to spare i want to rip it all out and put in KF16 or KF25 fittings
<Sync>
eh, that's only like 5^-2mbar ):
<azonenberg>
thats what we priced them out as
<azonenberg>
that would allow me to go nice and deep if i had a suitable pump
<Sync>
I spent less than that on my vacuum equipment
<azonenberg>
the base is a solid chunk of metal
<azonenberg>
Sync: that was for new
<Sync>
but the biggest problem will be the seal on the bottom
<azonenberg>
the albany valve and fitting company is like 10 mins from my apartment
<azonenberg>
You mean baseplate to jar?
<Sync>
yes
<azonenberg>
Or baseplate to pipe
<Sync>
baseplate to jar, you really want viton there
<azonenberg>
We have it
<azonenberg>
viton + dow corning high vacuum grease
<Sync>
yay, I got some pfpe grease for cheap
<azonenberg>
the limiting factor was the leak
<azonenberg>
and once i fix it, probably the pump
<azonenberg>
But again for dc sputtering i dont *need* to go that low
<azonenberg>
Not familiar enough with specs to know anything about that
<azonenberg>
My goals for tooling involve building a DC sputtering system (argon only at first, maybe add N2/O2 inlets for reactive sputtering later)
<azonenberg>
and a filament evaporator
<azonenberg>
Then in the long term maybe an electron microscope
<Sync>
I still bite my ass that I did not bid more on the varian scroll pumps here
<azonenberg>
But in the time it'd take to build one i'm thinking i could probably save up for a real one
<Sync>
maybe I can get one from work when it need overhaul
<Sync>
then I could run pure o2
<azonenberg>
I want a SEM
<azonenberg>
I have nowhere to put one in this apt but when i get a place of my own
<Sync>
I'd like to have the old ion implanter here that oxidizes at the university
<azonenberg>
lol, ion implanter? That would be convenient all right
<azonenberg>
homemade SIMOX?
<Sync>
well, I operate on as a job
<Sync>
+e
<azonenberg>
nice
<Sync>
or rather, I stand in front of it and scream at it that it does what I want from it
<azonenberg>
you a cleanroom technician or something?
<azonenberg>
process engineer?
<Sync>
no, first semester student with some contacts
<azonenberg>
oh lol
<azonenberg>
Lucky you, i didnt get into the cleanroom until i was a sophomore
<azonenberg>
And that was only because i was working with a third party company
<azonenberg>
that had me as a consultant, it wasnt for school
<Sync>
well, it's not like our process would need a clean room at all
<azonenberg>
Mine doesnt :p
<azonenberg>
I would use one if i had it
<Sync>
because we completely fail getting things right atm
<azonenberg>
And i plan to build one at home for when i shrink geometry to below 20um
<azonenberg>
but this is in my dream home / evil lair / $TERM_OF_CHOICE
<azonenberg>
Which is five to ten years out at best
<Sync>
a laminar flowbox should be enough
<Sync>
for most stuff
<azonenberg>
I want an entire room so i can have, for exmaple, a fume hood inside it
<azonenberg>
for spin coating and etching
<azonenberg>
and so i can have microscopes without dust covers :p
<Sync>
haha
<azonenberg>
plan is for that room to contain a hood/wet bench, my SEM, a metallurgical microscope, and whatever evap/sputtering rig i build
<azonenberg>
maybe 10-12 feet square?
<Sync>
but I really hate the ion implanter
<Sync>
you cannot get same results on different days because it decides that the same values on some valves produce different results
<Sync>
so you kinda have to get a feel for it
<azonenberg>
lol
<Sync>
yeah
<azonenberg>
Reminds me of the evaporator in the materials research center on campus
<azonenberg>
it's the only tool i use in my home fab processing that isnt actually at home
<azonenberg>
well besides the SEMs here and there
<azonenberg>
it's a 30-year-old CVC evaporator
<azonenberg>
full manual
<azonenberg>
actual valves you turn by hand
<azonenberg>
But it's so simple it almost never breaks down lol
<azonenberg>
Thoguh admittedly it is hard to get reproducible thicknesses
<Sync>
yes, this is the same problem here
<azonenberg>
But so far i havent needed to worry about exact thicknesses
<azonenberg>
a few percent variation is OK
<azonenberg>
My current short term goals are to improve lithography resolution to below 20um where it is onw
<azonenberg>
i have a roadmap down to 1.25um
<azonenberg>
but it will use commercially printed 8000DPI masks instead of the 600DPI laser pritner i use now
<azonenberg>
And if i could get the 40x objective to play nice i could theoretically hit ~350nm
<azonenberg>
more realistically i think 500-750 would be the limit
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<berndj>
azonenberg, re 8000dpi, maybe not quite that res but still significantly beyond 600dpi, can you get someone with an http://en.wikipedia.org/wiki/Imagesetter to do it a little more affordably than a full mask fab?
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<azonenberg>
berndj: they tend to not have the greatest results, can be noisy and have stray dots etc
<azonenberg>
since they usually arent fabbed in cleanrooms
<berndj>
drat
<azonenberg>
laserlab.com will make sub-$100 masks at 3.125um lambda and 12.5um minimum feature design rules
<azonenberg>
12x18 inches, 10x16 printable area
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