<glowplug>
Place sample. Rough alignment. Swing the optic unit over. Do your final alignment. Swing it back. Swing in LED panel. Hit blastoff. Swing it back. Take sample + enjoy. =)
<azonenberg>
oh and the rpi would have to also have GPIOs for the LEDs
<azonenberg>
and a timer
<azonenberg>
but thats trivial
<glowplug>
The mounts would be clamped to the rear of the desk with the sample clamped down to the front.
<glowplug>
What do you think?
<Sync_>
I think it is not time to think about that
<Sync_>
but it seems it is a good idea
<glowplug>
Holy shit sync_ thinks I had a good idea!
<glowplug>
And it was the damn stupid VESA mount one.
<glowplug>
Take what I can get...
<Sync_>
actually, I'm not here to diss your ideas ):
<glowplug>
I know. =)
<glowplug>
You were totally right about the projection litho.
<glowplug>
Thats for superhumans.
<glowplug>
And right about the furnace too. $1,000 is actually not a bad price.
<glowplug>
One thing I still think should be DIY is the optical encoder. I'm still going to give it a shot maybe I can save us ~$200.
<glowplug>
Depositing of silicon dioxide is done in the evap?
<azonenberg>
Normaly people do PECVD
<azonenberg>
we have a couple of opions
<Sync_>
you need to sputter that
<azonenberg>
options*
<azonenberg>
spin-on glass is one
<azonenberg>
RF sputtering of a glass target is another
<glowplug>
So thats the magnetron.
<azonenberg>
Reactive sputtering of Si with Ar + O2 plasma is another
<glowplug>
Alright just making sure I wasn't missing something important. Haha
<glowplug>
Wow manufacturer yields can typically be below 30%.
<glowplug>
This is a depressing business.
<azonenberg>
Yes, but thats for leading-edge stuff
<azonenberg>
they can be quite a bit higher for older-gen stuff
<azonenberg>
And these are for complex devices
<glowplug>
God point.
<azonenberg>
If we can make one NAND2 gate work on a 10um process from scratch i'll be really happy
<glowplug>
We are coming into the party at circa 1990 tech.
<azonenberg>
Yeah, if that
<azonenberg>
maybe 80s
<glowplug>
Haha. That is awesome.
<azonenberg>
I just want to make a board one day that has a custom flip-chip ASIC on it
<glowplug>
I knew about jeri but I haven't seen these videos yet.
<glowplug>
Have we asked if shes interested in helping?
<glowplug>
Spin coating with a CPU fan. Holy shit. Haha
<glowplug>
And it looks like she has a glass tube in the furnace.
<Sync_>
quartz
<Sync_>
they actually come like that
<glowplug>
Which appears to be a grill.
<glowplug>
Thats not a commercial furnace is it?
<Sync_>
I guess it is
<glowplug>
Hmm
<Sync_>
haha holy shit her diode is bad
<glowplug>
All the devices were pretty bad. But they were made without any litho.
<glowplug>
Extremely impressive.
<Sync_>
yeah well a mosfet is extremely easy to make
<Sync_>
because it just needs a channel
<Sync_>
and metal
<B0101>
hmmm, to make an electrical field, the potential difference between 2 charged plates is inversely proportional to the distance between my plates, am I right?
<azonenberg>
I've talked briefly with jeri
<azonenberg>
She was surprised that nobody had copied her setup yet
<glowplug>
I'm surprised too.
<azonenberg>
BTW, my guess is that one of the reasons for her trouble was the complete lack of attention paid to things like metal contamination
<glowplug>
We need to get our asses in gear.
<azonenberg>
i bet her stuff was loaded with sodium
<glowplug>
I'm sure she knows that too. But the fact is she has a working device.
<azonenberg>
Yeah
<azonenberg>
But an RCA clean isnt that hard to do
<glowplug>
I think she would be interested in collaborating if we can prove we are serious and get a working device as well.
<azonenberg>
Maybe
<azonenberg>
We can definitely try and pick her brain
<azonenberg>
I'll ping her on FB once we get some more serious progress
<glowplug>
Standard ungeared BLDC motor spinning at 10rpm constant.
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<glowplug>
If you combine the two you get .0016 r/s. With a .5 pitch leadscrew (standard micrometer) which is .5mm /r or .0008mm per second at the lowest speed. 800nm. =)
<glowplug>
This is of course assuming the slowest we can turn a BLDC motor is 10RPM. I can't find any examples of slower but it can probably be done.
<glowplug>
At any rate that makes the motor/gear assembly (not including leadscrew, nut, or encoder) about $15. The raw material for the acrylic cycloid gearbox and the cheap hobby outrunner.
<azonenberg>
Sync_: i'd use quartz for the actual wafer carrier
<azonenberg>
the question is whether alumina insulation on the furnace is dangerous
<Sync_>
yeah I think not
<Sync_>
if the carrier is quartz everything sould be fine
<azonenberg>
I wont even consider trying to clean my existing glassware
<azonenberg>
when i move to CMOS i'm buying all new fused quartz
<azonenberg>
and never handling it without gloves
<Sync_>
the mbe chamber shat itself again :/
<Sync_>
at first the thickness monitor died
<Sync_>
and now we have a short in the vacuum
<glowplug>
So I understand. The quartz carrier for the furnace is a cylinder correct?
<glowplug>
Ahh that is for doing multiple samples at once. Interesting.
<glowplug>
How much does that thing cost?
<Sync_>
they should be fairly cheap
<glowplug>
I have been researching closed loop control of steppers and finally realized that the Mesa SoftDMC can do it with quadrature encoder input.
<glowplug>
And it can do two at the same time.
<glowplug>
I was totally wrong about the parallel port latency being too high for th encoders also. It is a severe bottleneck for high rpm operation but at low rpm's it is completely acceptable.