| --- Tue Nov 1 2011 | 00:00 | |
| azonenberg | Yay, my Ni arrives tomorrow | 22:09 |
|---|---|---|
| azonenberg | now i can finally try KOH etching with a proper hardmask :) | 22:09 |
| bart416 | azonenberg, I did something far more useful! | 22:23 |
| azonenberg | ? | 22:25 |
| soul-d | nice , here ill need to use shed so probably won't do much during winter did find some vacuum stuff but those are called "vacuum excicator" there is a cheap 5 eur -> http://www.labstuff.nl/contents/media/1g.jpg wich is supposed to be a stolp kind of thing just looks like bottle to width is 3,1") | 22:38 |
| soul-d | the problem is not that the 5 euro might hurt but donno about actualy putting a vacume on it | 22:38 |
| soul-d | you have any ranges you typacily want to work at ? like specs of pump ? | 22:39 |
| soul-d | not to mention shipping it trough mail :) | 22:40 |
| azonenberg | My guess is that a dessicator will not go below, maybe, 1/10 atmosphere | 22:46 |
| azonenberg | but you need to hit the 1E-6 torr range to get good evaporation | 22:47 |
| azonenberg | So, let's see - my next wafer will be a 50mm <110> | 22:48 |
| azonenberg | One 8x8 block in the middle, thats 64 3x3mm dies | 22:48 |
| azonenberg | plus 12 more around it on each side | 22:48 |
| azonenberg | thats another 48 | 22:48 |
| azonenberg | 112 dies out of one wafer? That should work nicely | 22:49 |
| soul-d | k have any links of correct products | 22:49 |
| azonenberg | No, unfortunately | 22:49 |
| azonenberg | vacuum is on the list of things to explore | 22:49 |
| azonenberg | but i havent done much with it yet | 22:49 |
| soul-d | does it have to be glassware then ? or like like somthing with a porthole view type of construction although glass has it's advantage with it being inert to most stuff | 22:55 |
| azonenberg | Glass bell jar is what i plan to use | 22:56 |
| azonenberg | yes | 22:56 |
| soul-d | need to build a good safe haven first anyhow for stuff like that but just wondering would all metals be vapable ? like alu and silver just all the same ? since always wanted to make own telescope but never wanted to do the silver stuff with chemicals maybe lookup how they vapped up their mirrors (and maybe a area for you to look at ) ATM amature telescope making | 23:04 |
| azonenberg | All metals can be evaporated, given enough heat | 23:05 |
| azonenberg | i qualify that | 23:05 |
| azonenberg | For example, tungsten would be a little bit tricky ;) | 23:05 |
| azonenberg | It's used in fab often though, but deposited by sputtering | 23:05 |
| azonenberg | You can definitely evaporate aluminum | 23:06 |
| soul-d | only read the word in the books but process wasn;t explained | 23:06 |
| azonenberg | it's actually easier than sputtering it, you need a lot of power to sputter it because you need to break the native oxide off the target | 23:06 |
| azonenberg | and you dont know what sputtering is? | 23:06 |
| azonenberg | It's an alternative deposition process that runs at higher pressures than evaporation | 23:06 |
| azonenberg | When you evaporate, you usually run at the `1E-6 torr range | 23:06 |
| azonenberg | evaporation is much higher, more like 5E-2 torr | 23:07 |
| azonenberg | you fill the chamber with an inert gas, typically argon | 23:07 |
| azonenberg | and run high voltage through it | 23:07 |
| azonenberg | the resulting plasma ionizes the gas and causes the gas atoms to strike your target (the material being deposited) and knock atoms off by kinetic energy | 23:07 |
| soul-d | oh yeah i did read on it | 23:08 |
| azonenberg | note that you are mechanically knocking metal atoms off, so the bulk material is well below the boiling or even melting point | 23:08 |
| soul-d | somthing with dark regions of plasma ? | 23:08 |
| azonenberg | in fact, the target is usually cooled for long depositions specifically to keep it from heating too much | 23:08 |
| azonenberg | Since the pressure is so much higher, the deposition is usually pretty conformal | 23:08 |
| azonenberg | as opposed to evaporation which won't coat vertical structures (edges pointing straight toward the deposition source) well | 23:08 |
| azonenberg | Sometimes this is good and sometimes it's bad, but its a factor to consider | 23:09 |
| soul-d | probably hard to setup at home :P | 23:10 |
| azonenberg | Not really | 23:11 |
| azonenberg | i'm in contact with a prof at a SUNY school that is building one on the cheap as a demonstration | 23:11 |
| azonenberg | IN terms of homebrewing, sputtering needs a more complex apparatus and a means of feeding tiny amounts of inert gas into the chamber | 23:12 |
| azonenberg | evaporation needs much harder vacuum | 23:12 |
| azonenberg | you need a second stage pump | 23:12 |
| azonenberg | but sputtering level vacuum is within the reach of a mechanical pump | 23:12 |
| azonenberg | And the lack of deep vacuum is a nontrivial problem as turbopumps are expensive and diffusion pumps are slow | 23:14 |
| azonenberg | So sputtering is actually higher on my feasibility list | 23:14 |
| azonenberg | all i'd need is an argon canister from a welding supplier and a needle valve | 23:15 |
| soul-d | you do need to have nice buget for it all though | 23:17 |
| azonenberg | Yeah, its not a cheap hobby | 23:19 |
| azonenberg | but a few grand vs a few million? Huge improvement | 23:19 |
| --- Wed Nov 2 2011 | 00:00 | |
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