<swkhan>
azonenberg: you're still working on the copper stuff? =)
<swkhan>
ever figure out why chromium works?
<swkhan>
or why titanium is used as an adhesion layer for platinum, etc.?
<bart416>
swkhan, learn some basic chemistry
<swkhan>
bart416: ouch =( i read a book on chemistry, i still don't understand. transitional metals are weird
<bart416>
You need to look at the oxidation states in specific
<bart416>
That's the easy guideline
<bart416>
On the other hand, you need to look at the potential differences for the redox reaction
<bart416>
And the molecular orbitals
<bart416>
But to show it easy: Platinum has two common oxidation states 4 and 2 and uncommonly 6 and 3, while Titanium has 4, 3, 2; chrome has 6, 4, 3, 2
<bart416>
azonenberg, about that railgun design
<bart416>
We did some more math
<bart416>
We figured out if we actually built it like we originally intended to it would have fired
<bart416>
Once
<bart416>
It'd rip itself apart (in a cloud of shrapnell I think)
<azonenberg_work>
hi mrdata
<bart416>
I heard captain picard was still looking for you!
<mrdata>
yes, ever since that incident on romulus
<mrdata>
but, he'll have to wait
<azonenberg_work>
lol
<bart416>
Strictly speaking the incident wasn't on romulus
<bart416>
But related to romulans, your memory banks are flawed!
<mrdata>
an unfortunate consequence of the explosion
<bart416>
I blame listening to trekies whining about irc trolls for knowing such things :|
<azonenberg_work>
lol
<mrdata>
and now to business. so this is the first ive heard of #homecmos
<mrdata>
what goes on, around here?
<azonenberg_work>
mrdata: we've been around for a while but are still small
<azonenberg_work>
As of now i'm the main one doing lab work but am getting good input from others
<azonenberg_work>
B010101 isnt here right now
<azonenberg_work>
but is setting up a lab as well
<azonenberg_work>
she's planning to do work on Josephson junction stuff from what i hear
<azonenberg_work>
i'm focusing on MEMS
<mrdata>
nice
<azonenberg_work>
and am the main one backing the project
<azonenberg_work>
mrdata: Once i get a working comb drive
<azonenberg_work>
a mems accelerometer is within reach
<azonenberg_work>
the control stuff will obviously be an external microcontroller and not a stacked-die design like modern ones are
<azonenberg_work>
And bonding is still an unsolved problem
<bart416>
mrdata, you building an icbm?
<azonenberg_work>
right now i am focusing on fab, and i have a probing station suitable for testing a couple of points
<azonenberg_work>
three probes is enough to do a single transistor
<azonenberg_work>
will need four or five to test gates, unless i hard-wire inputs to Vdd or Vss
<mrdata>
bart416, not building, no; i am curious about what-if scenarios, for global disaster and collapse
<azonenberg_work>
mrdata: a lot of people are
<azonenberg_work>
One thing none of us have touched on is the materials
<mrdata>
so it would be nice to have, let's see.. homebrew hall effect sensor, temperature sensor,...
<bart416>
After I'm done there'll be no globe left for a global disaster
<azonenberg_work>
photoresist, for example, i have no idea how to make
<mrdata>
silicon purification
<azonenberg_work>
i know the theory behind crystal growth but have no idea how to refine the materials
<azonenberg_work>
Its not something i'd attempt with the setup i have now
<mrdata>
has read up on solar grade silicon purification techniques
<mrdata>
but i havent done any
<azonenberg_work>
Having a Czochralski rig in my basement would be cool
<azonenberg_work>
Make my own 4-inch boules lol
<azonenberg_work>
But i'm not nearly that advanced yet
<azonenberg_work>
bart416: oh, good news
<mrdata>
would like to have a x-ray photovoltaic cell
<azonenberg_work>
a guy i was doing consulting with a while ago needs a sample tested under vacuum
<azonenberg_work>
and is buying me a bell jar and mechanical pump
<mrdata>
nice
<azonenberg_work>
the chamber has feedthroguhs rated to 30A
<azonenberg_work>
Which means that if i can get myself a diffusion or turbopump, setting up a sputtering or filament evaporation system is well within the realm of feasibility
<mrdata>
what pressure will the bell jar reach?
<azonenberg_work>
Its rated to high vacuum iirc
<mrdata>
1 torr?
<azonenberg_work>
i dont have full details
<mrdata>
less?
<azonenberg_work>
His tests dont need to go too deep
<azonenberg_work>
Personally, i'd like to hit 1E-6
<azonenberg_work>
which would let me do evaporation
<azonenberg_work>
sputterin i could do at around 1E-1 or -2
<azonenberg_work>
DC sputtering*
<azonenberg_work>
I wont know for sure until itry pumping it down
<azonenberg_work>
Also, tonight i am going to try running some polishing experimnents
<azonenberg_work>
see if i can take a rough chunk of some material (silicon? metal plate?) and get it to an optical polish or better
<mrdata>
yes
<azonenberg_work>
1500 grit sandpaper, 6-3-1 um diamond paste
<azonenberg_work>
50-250nm diamond paste
<azonenberg_work>
then 60nm colloidal silica CMP
<mrdata>
if you had to start from nothing, in the woods, with 18th century equipment, what could you do
<azonenberg_work>
It'd take a while, i dont have the chemistry background
<mrdata>
you'd have to know metallurgy
<azonenberg_work>
One of the first things to do would be to build electric motors (not that hard) for a spin coater and polishing machine
<azonenberg_work>
and a vacuum pump
<azonenberg_work>
which would be necessary for most of the remaining work
<mrdata>
ok, so we'll say you have copper wire (otherwise you have to refine the copper forom ores)
<azonenberg_work>
this assumes you have 1700s era metallurgy available (reasonably pure copper wire)
<azonenberg_work>
and basic steam powered machine tools
<azonenberg_work>
if you dont have the second, get it first
<mrdata>
yes. but you can use your knowledge of modern methods and equipment, to make those
<azonenberg_work>
Correct
<azonenberg_work>
Given the knowledge, they arent that difficult to make
<azonenberg_work>
a few years to get decently working ones at most
<azonenberg_work>
probably less given a good team
<azonenberg_work>
The next step is to start building up stocks of raw materials
<mrdata>
many metals can be made pure by electroforming
<azonenberg_work>
refining pure metals etc
<azonenberg_work>
as well as synthesizing solvents and such
<azonenberg_work>
This is not my area of expertise
<mrdata>
yes. i need catalysts
<mrdata>
platinum, palladium, rare earths,...
<azonenberg_work>
Given somewhat pure materials, you can use float-zone crystallization to make them purer
<azonenberg_work>
among other techniques
<mrdata>
yes that works for silicon
<azonenberg_work>
Photoresist, i have no clue
<azonenberg_work>
the active ingredient in the stuff i use is some long complicated diazo compound abbreviated DNQ
<azonenberg_work>
in a novolac-epoxy resin
<mrdata>
starting from metallurgical grade silicon, (~99% pure), make silicon solar cells
<mrdata>
must purify the silicon to 99.999
<azonenberg_work>
Ok
<azonenberg_work>
Float zone might work for that
<azonenberg_work>
Repeat a couple of times
<azonenberg_work>
then you can do doping of boron and phosphorus compounds by diffusion
<azonenberg_work>
spin-coat a solution of an alcohol-baseed dopant and heat in air to drive in
<azonenberg_work>
if anyone tries it i'd love to hear the results
<azonenberg_work>
if success, great
<azonenberg_work>
if fail, let us know what you tried and how it failed
<azonenberg_work>
so we wont make the same mistake
<bart416>
You'd need a SEM to analyse the mistake though :(
<azonenberg_work>
Depends on how small it was
<azonenberg_work>
most of my stuff i can do at least some failure analysis under optical microscopy
<azonenberg_work>
And i want to build a sem at some point
<azonenberg_work>
you have no idea :P
<azonenberg_work>
But knowing the mat sci department's microscopy lab manager has its perks for the short term lol
<azonenberg_work>
i'm last priority in scheduling since i'm not paying, but i can get my analysis done eventually
<mrdata>
microscopy is a critical technology
<azonenberg_work>
mrdata: agreeed
<azonenberg_work>
Optical comes first
<azonenberg_work>
you need to get basic electronics (including single silicon transistors at macroscale) working before you try doing too much of a shrink
<mrdata>
really?
<mrdata>
the scanning/tunneling microscope was a breakthrough
<azonenberg_work>
mrdata: Do optical first
<mrdata>
definitely
<azonenberg_work>
Quick inspection of large samples in full color
<azonenberg_work>
STMs shouldnt be too hard to build
<azonenberg_work>
i actually want to make an STM or AFM some time soon
<azonenberg_work>
then a SEM later on
<mrdata>
if your fab lab is in your living room, how do you handle dust?
<mrdata>
finger prints?
<mrdata>
etc
<azonenberg_work>
mrdata: hair net, lab coat, and rubber gloves
<azonenberg_work>
pretty much eliminates particulates from me
<azonenberg_work>
the ambent levels are low enough that i can live with them given frequent cleaning (right before a film deposition etc)
<mrdata>
so, maybe a dust remover?
<azonenberg_work>
I have not had any issues with dust in air
<azonenberg_work>
when you try shrinking to micron scale or doing mass production cleanroom capability will be nice
<mrdata>
imagines an eavesdropper watching thru the window, and getting very confused and worried
<azonenberg_work>
for research scale on tens-of-microns features?
<azonenberg_work>
not a problem
<azonenberg_work>
mrdata: a friend of mine actually got raided by local cops and some federal folks
<azonenberg_work>
neighbor saw vacuum equipment in his basement and called 911 reporting a bomb
<azonenberg_work>
people are idiots... but he still hasnt gotten his stuff back and the court case isnt over yet
<azonenberg_work>
a year later
<azonenberg_work>
so i've been very paranoid in terms of making sure i'm up front with the landlord etc about whats going on
<azonenberg_work>
msds book in plain view, full fire sprinkler coverage
<azonenberg_work>
proper and documented waste disposal
<mrdata>
residential zoning might forbid some stuff
<azonenberg_work>
lives in Highway Commercial zone ;)
<mrdata>
good
<azonenberg_work>
permits light industrial work including "laboratories for commercial and academic research and development"
<mrdata>
good
<azonenberg_work>
i looked that uup a while ago
<azonenberg_work>
and after a year and a half of living here my ex-cop landlord (retired chief of police actually) hasnt turned me in
<mrdata>
irf the authorities think youre operating a clandestine lab, they'll shut you down. doesnt matter what you make
<azonenberg_work>
so my best guess is he doesnt think i'm doing anything illegal
<mrdata>
so it's good to make sure you dont try to hide
<azonenberg_work>
Yeah
<azonenberg_work>
I dont work outside on the sidewalk to avoid freakng out the neighbors, obviously
<azonenberg_work>
But i also dont make any attempt to hide
<azonenberg_work>
makes mental note to add latest purchase of polishing compound to MSDS binder