<azonenberg> nathan7: ping
<azonenberg> I ran a test of parallel lines on the 5um process
<azonenberg> Not entirely successful, my exposure lamp burned out halfway through the run so it underexposed :P
<azonenberg> but i decided to develop and etch anyway to see what i got
<azonenberg> Nowhere near all of the pattern came out but i did demonstrate optical resolution adequate to clearly separate the lins
<azonenberg> lines*
<azonenberg> pic following in a bit
<CIA-67> homecmos r116 | trunk/lithography-tests/labnotes/azonenberg_labnotes.txt | Today's lab notes
<azonenberg> Latest test on the 5um process
<azonenberg> Not exactly successful, these are supposed to be unbroken lines
<azonenberg> But it demonstrates i have the optical resolution to hit 5um
<azonenberg> i just need to improve the develop/etch process
<azonenberg> A lot :P
<azonenberg> swkhan: check out the link above
<azonenberg> this is what i'm working on in my living room fab
<azonenberg> the 5um process is under active development but isnt yet feasible, the 20 gives reasonably good results but i still have some glitches in my exposure system
<nathan7> azonenberg: pong
<azonenberg> today's test run
<nathan7> mhm
<azonenberg> overetched and underexposed but does demonstrate adequate resolution
<nathan7> :)
<azonenberg> the 5um process is clearly not ready for prime time though lol
<azonenberg> these are, even so, the smallest structures i've made to date
<azonenberg> note the scale bar
<azonenberg> nominally 5.29 micron half pitch
<azonenberg> they were theoretically 5.29 lines and 5.29 trenches but as you can see i overetched
<azonenberg> so the trenches got bigger and the lines got destroyed
<nathan7> mhm
<nathan7> It's a start
<nathan7> ..don't you have this "wait, whoa, I can _MAKE_ _FIVE_ _MICROMETER_ _STRUCTURES_"
<nathan7> every once in a while?
<nathan7> I have that with 3D printers
<nathan7> every once in a while, I go like "wait, WHOA, I can _PRINT_ _OBJECTS_"
<nathan7> azonenberg: :D
<azonenberg> and lol, i have that sometimes with all kinds of projects
<nathan7> (=
<azonenberg> This gives you a better idea of the devastation caused by the underexposure http://colossus.cs.rpi.edu/~azonenberg/images/homecmos/2011-08-26/5h10_002_annotated.jpg
<azonenberg> the entire circular field should have had grating in it :P
<azonenberg> that's the FOV of my system
<azonenberg> Another potential problem is that i am testing on a decently thick copper layer
<nathan7> mh-hrm
<azonenberg> You normally dont think of a micron as being thick :P
<nathan7> hehe
<azonenberg> But when you're trying to do 5um features in it
<azonenberg> using a *wet etch*
<azonenberg> rather than RIE
<azonenberg> it becomes problematic
<azonenberg> this is comparable to doing around a 150um PCB trace in 30um copper
<azonenberg> Doable, but requires careful process control
<azonenberg> the shiny areas are the only part of the lins that weren't at least somewhat attacked
<azonenberg> lines*
<azonenberg> again, severe overetch
<azonenberg> http://colossus.cs.rpi.edu/~azonenberg/images/homecmos/2011-08-26/5h10_008_annotated.jpg is the side of the exposure field showing the edge of the etched area
<azonenberg> the copper doesnt quite go all the way to the edge because some of it chipped off when i cleaved the die off the wafer (coating was done before separation of dies)
<azonenberg> That last pic is cool because it's showing submicron features lol
<azonenberg> not created by me, but present on the edges nonetheless
<nathan7> :o
<azonenberg> i've been looking at some of the rough bumps along the edge and it looks like i'm able to clearly resolve points around 600nm apart
<azonenberg> i'm looking to see if there are any smaller features i can find
<azonenberg> to enahance resolution i turned off the red/blue channels which eliminates any chromatic aberration
<azonenberg> hmm, one of the pinholes near the bottom left of the film looks to be around 350nm wide
<azonenberg> the crack on the middle left is around 400ish
<azonenberg> So do you know what that means?
<azonenberg> It means my optics are good enough for submicron resolution if i had a mask that was fine enough
<azonenberg> i could potentially hit say 500nm with these lenses if i had a fine enough mask
<nathan7> azonenberg: ..awesomesauce
<azonenberg> There are of course some downsides
<azonenberg> First off, it'd be immersion lithography
<azonenberg> Which would mean i'd have to clean oil off the die after exposure before developing
<azonenberg> without scratching anything
<azonenberg> so i'd need a solvent/surfactant that dissolves or emulsifies my immersion medium without harming photoresist etc
<azonenberg> second is that the FOV of my 100x objective is around 160 um :P
<azonenberg> so that'd be the maximum die size lol
<azonenberg> Realistically though, i do intend to attempt that soon
<azonenberg> i have a selection of immersion oils from Ted Pella inbound that i'm gonna play with and see which gives good results
<azonenberg> And lol, are any of you guys among the 8 fans of immersion litho on facebook other than myself?
<nathan7> I sould
<azonenberg> Most semiconductor people use water for immersion but i'd need a water immersion objective so for now i'll be using normal microscope immersion oil on my oil lens
<azonenberg> there are a lot of highly technical topics on fb that have zero or a handful of fans lol
<azonenberg> like Ta2O5
<Viper-7> lol