<azonenberg>
i'm just writing up a lab manual for my lab that describes some of the more common processes
<B0101>
the SQUID problem is not fixed yet
<B0101>
I might try QDs soon but not untill SQUIDS are done
<azonenberg>
i see
<B0101>
omg...
<azonenberg>
B0101: ?
<azonenberg>
swkhan: if you are still interested in SiO2 stuff i can mail you a 4" <100> single-side-polish wafer this weekend
<azonenberg>
PM me the address
<azonenberg>
Do what you want with it, all i ask is that i get at least half of it back
<azonenberg>
preferably with thermal oxide on it
<B0101>
azonenberg: i found that my silicon is being destroyed slowly by an unknown substance
<azonenberg>
Destroyed slowly
<azonenberg>
as in, you have a contaminant on it?
<azonenberg>
I cant say i'm surprised
<azonenberg>
There are only really two ways for a semiconductor device to fail
<azonenberg>
either something that belongs is in the wrong place (design error, electromigration, etc)
<azonenberg>
or something that doesnt belong is there
<azonenberg>
Have you made any progress in isolating the contamination?
<B0101>
hmm, not yet i believe is something from the fab process
<B0101>
*its
<B0101>
ok it looks like the silicon can no longer conduct, at all
<B0101>
i don't know if you know what may cause that to happen
<azonenberg>
Oxide growth?
<azonenberg>
surface contamination?
<azonenberg>
Post details of your fab process and i can take a look at it
<azonenberg>
stick it in your wiki page
<B0101>
ok
<B0101>
i will do it asap
<azonenberg>
if you are not already, you should be keeping lab notes
<azonenberg>
makes it much easier to go back and look at what processing was applied to a given sample
<B0101>
i do keep lab notes, all of them are in my notebook
<azonenberg>
i see
<azonenberg>
Well, if you dont mind sharing please do
<azonenberg>
i understand if you dont want to publish everything just yet
<B0101>
not everything but just important stuff
<azonenberg>
i see
<azonenberg>
Well again, post what you have on the process and i'll take a look
<azonenberg>
i dont know much about SQUIDs though
<B0101>
out of topic: have you ever thought of silicon based nuclear reactors?
<azonenberg>
radioactive silicon?
<B0101>
idk, but i have heard that the US is researching solid state nuclear reactor s
<B0101>
idk if that may happen but heard that details are confidential
<swkhan>
azonenberg: 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)
<swkhan>
azonenberg: i can PM you by the end of tonight =)
<swkhan>
azonenberg: any special precautions you would advocate?
<azonenberg>
swkhan: back
<swkhan>
yay
<azonenberg>
and from what i understand, dry oxidation is pretty simple
<azonenberg>
Stick in furnace, heat
<azonenberg>
The hotter it is, the faster it grows
<swkhan>
there's a guy in my lab who built an ozone generator
<azonenberg>
800-1200C is the usual range
<azonenberg>
The thicker the oxide is, the slower it grows
<swkhan>
and he has compressed oxygen go through a filter
<azonenberg>
because you get diffusion limited
<swkhan>
er compressed air go through an oxygen filter
<azonenberg>
based on the native oxide thickness, the temp, crystal orientation, and wet or dry conditions
<azonenberg>
dry=air, wet=water vapor
<azonenberg>
I havent used the process myself but i understand the theory
<B0101>
brb
<swkhan>
i wish the temperature could have been lower. i think the furnace can go up to 1100 C
<azonenberg>
well, do the math for whatever thickness you want to grow
<azonenberg>
i suggest trying for 100-200nm
<swkhan>
whatever thickness _you_ want me to grow for you =)
<azonenberg>
Lol, i assume you want to use it for something too
<azonenberg>
let's see, dry oxidation at 1000C on <100>
<swkhan>
well 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.
<azonenberg>
will take just over three hours
<azonenberg>
for 100nm
<azonenberg>
and 8 hours for 200nm
<azonenberg>
100nm is a dark red-violet and 200 is a pale yellowish
<swkhan>
there's a really sweet guy in my lab who cleaned a quartz tube for you just in case =)
<azonenberg>
i tried using it for Ta2O5 but it was hard to guess because i didnt have the refractive index of the film too accurately
<azonenberg>
1250A would be first order blue
<azonenberg>
nice and easy to see when i test HF etch rates on it
<azonenberg>
just over four hours by dry oxidation at 1000C
<azonenberg>
oh, wow
<azonenberg>
at 1100 its waaay faster
<azonenberg>
only an hour and a half for 1250A
<azonenberg>
four hours would get up to 2750
<azonenberg>
tbh i am not currently to the point that i need any specific thickness that accurately
<swkhan>
we have a 3k tube furnace hooked up to a wet pump
<azonenberg>
i just want >100nm
<swkhan>
okay =)
<azonenberg>
wet pump, meaning you can do steam?
<swkhan>
i just want you to be happy =0
<swkhan>
not steam, a wet pump meaning it uses oil
<azonenberg>
oh
<azonenberg>
you mean a vacuum furnace?
<swkhan>
yes
<azonenberg>
Can it run at atmospheric pressure?
<swkhan>
yes
<azonenberg>
ok, well trying to oxidize something by heat in vacuum doesnt usually go well :p
<swkhan>
we have leaks =\
<azonenberg>
Oh, i see
<swkhan>
so might as well be atmosphere
<swkhan>
i'll keep the vacuum pump off though
<swkhan>
it works so-so though no research coming from it anyway
<azonenberg>
I see lol
<swkhan>
my professor gave the go ahead =D
<swkhan>
i'll send you the address
<azonenberg>
Well, 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 fab
<azonenberg>
the wafer is a 4-inch so you'll have to scribe it up
<azonenberg>
if you cant fit all of the pieces in the tube at once, and have time for more than one run
<azonenberg>
two or three thicknesses might be nice
<azonenberg>
MTI is my current wafer supplier of choice as most others wont touch you unless you want to buy by the boat
<azonenberg>
The prices are a bit higher per unit but i dont have to buy 25
<swkhan>
we have extra wafers lying around
<swkhan>
i can do that for free for you
<swkhan>
i wasn't sure what you had
<swkhan>
(i just checked with my professor, i didn't want to offer until i knew i could)
<azonenberg>
If you have extras you can afford to get rid of, i'm not gonna turn down free silicon :)
<azonenberg>
i just dont want to be a drain on anyone's resources if they're helping me for free
<swkhan>
well i was basically asking you to pay me $20!
<swkhan>
you've helped me so much. i've been a drain on your resources =p
<azonenberg>
Lol, i would never pay anyone $20! - i cant afford that much
<azonenberg>
2.4E18 dollars?
<swkhan>
well if i kept half of that wafer that's like $20
<azonenberg>
thats more than even bill gates could afford
<azonenberg>
by a couple orders of magnitude :p
<swkhan>
what?
<swkhan>
oh lol!
<azonenberg>
20 factorial dollars lol
<swkhan>
i seriously initially thought you were that poor
<swkhan>
poor guy... can't afford a few pizzas
<azonenberg>
Well, i am indeed running this lab on a grad student's salary
<azonenberg>
But its one of my few expenses other than food and rent
<azonenberg>
and i use such tiny amounts of supplies that stuff lasts me a long time
<azonenberg>
i buy one or two wafers, do a film deposition on campus
<azonenberg>
and use the result of that for several months of work
<azonenberg>
right 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 Ta2O5
<azonenberg>
The one thing i dont have is oxide
<azonenberg>
And to be perfectly honest you're welcome to that half of a wafer - i dont need it
<swkhan>
o_O
<azonenberg>
my entire work to date has been using four 2-inch wafers, most of which are no more than half consumed
<azonenberg>
i have no clue what i'd ever do with a whole 4-incher lol
<azonenberg>
buying it was a mistake, since then i've been getting 2s
<swkhan>
well it's a different resistivity than what we use (we use very highly doped wafers)
<azonenberg>
Higher than this?
<swkhan>
so maybe stealing a bit of yours could be worthwhile =)
<swkhan>
yes like 0.0005 ohm * cm
<azonenberg>
holy cow lol
<azonenberg>
do they even sell those?
<swkhan>
maybe it's 0.005 ohm * cm
<azonenberg>
i thought this was about the highest doping you could get without doing implantation yourself
<swkhan>
but still very small
<azonenberg>
MTI offers the following ranges
<swkhan>
i don't actually get these myself
<swkhan>
my professor just gets them from some industry connections he has
<azonenberg>
as well as an afm and a couple of tems
<azonenberg>
and a dual beam sem/fib
<swkhan>
wow
<azonenberg>
the supra, fib, and afm are in the cleanroom
<swkhan>
i just got trained on the TEM... it's so coooool
<swkhan>
no cleanrooms here =(
<azonenberg>
both jeols and the TEMs are in the mat sci department's non-clean microscopy lab
<swkhan>
just one for photolithography
<azonenberg>
i linked you to rpi's cleanroom, right?
<swkhan>
FIB and DRIE soon
<azonenberg>
ooh, nice
<swkhan>
i think a while ago
<azonenberg>
wants to play on a fib
<azonenberg>
too bad they're so expensive lol
<swkhan>
i have a very good relationship with the lab manager here
<swkhan>
he lets me use my samples when he's calibrating a new machine
<azonenberg>
me too (mat sci at least, the cleanroom guys are a little less flexible)
<azonenberg>
and nice lol
<swkhan>
typically the machines are totally configured so i don't pay anything =)
<swkhan>
and get a professional to give me nice pictures
<swkhan>
plus i get to learn some physics and stuff
<azonenberg>
lol
<swkhan>
you know, you should seriously apply for an NSF fellowship if you haven't already won that
<swkhan>
you are so overqualified for it
<swkhan>
i know i would give you one if i could
<swkhan>
i would give you mine if i won one
<swkhan>
or at least half ;)
<azonenberg>
Right 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 year
<azonenberg>
i may be interning at lincoln labs this summer as well
<swkhan>
you know about NSF fellowships right?
<swkhan>
whoa lincoln =)
<azonenberg>
the recruiter is an alum who i know well and actually had as a student while TAing once
<azonenberg>
we played together in a wargame earlier today
<swkhan>
wargame?
<azonenberg>
he was visiting campus for the career fair and dropped in to pwn for a few minuts
<azonenberg>
is the sum total of my entire fab research to date lol
<swkhan>
omg pretty
<azonenberg>
F8-G1 are on a SEM pin mount kept elsewhere
<azonenberg>
J4-10 are open
<azonenberg>
this is box number 5 (1-4 are used for other stuff not related to fab work)
<azonenberg>
so once i make chip 5J10 i'll have to start using 3-part numbers
<azonenberg>
box, row, column
<azonenberg>
and go on to 6A1
<swkhan>
i'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 =(
<azonenberg>
i see
<azonenberg>
In 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 class
<azonenberg>
i have to do lithography after dark since i dont have a darkroom
<swkhan>
lol
<azonenberg>
(though i can do etching and depositions in daylight)
<swkhan>
that's so adorable
<azonenberg>
So basically all of my litho is done on evenings when i don't have homework due the next day
<azonenberg>
and the number of dies i do depends on how early my first class the next day is :p
<azonenberg>
adorable? what is lol
<swkhan>
that you do lithography at night
<azonenberg>
lol
<azonenberg>
what else am i going to do?
<azonenberg>
go out drinking with girls?
<azonenberg>
i'm about as interested in drinking ethanol as methanol or acetone