<azonenberg> Which means I have until then to prepare samples
<azonenberg> I have two more on the to-do list - a die with hardmask lifted off and baked, then etched in KOH (but not stripped, so i can observe undercut)
<azonenberg> And another one gone all the way
<azonenberg> iow, a full hardmask-liftoff-etch-strip sequence
<azonenberg> Here goes... gonna try doing a full process on a die soon
<azonenberg_lab> So I'll be doing this die using the same method I did last night
<azonenberg_lab> Except that time I stopped pre-etch so i'd have a nice specimen to image
<azonenberg_lab> This time i'll take it to completion and see...
<azonenberg_lab> WOOT
<azonenberg_lab> I see a pattern on this die...
<azonenberg_lab> Gotta etch another minute, then strip
<azonenberg_lab> But this might be my first (messy but very real) success at the process
<azonenberg_lab> Hmm, the hardmask cracked
<azonenberg_lab> wonder whats up with that
<azonenberg_lab> But the next one looks quite nice
<CIA-67> homecmos r96 | trunk/lithography-tests/labnotes/azonenberg_labnotes.txt | Today's lab notes
<azonenberg_lab> First semi-successful KOH etch
<azonenberg> Well, looks like i still have some stuff to do
<azonenberg> and no time to do any more processing between now and the SEM session on thursday
<azonenberg> Next to-do, if the SEM images confirm my theory, is to prepare 10-20 dies, spin coat them all in resist
<azonenberg> soft bake, expose them all one at a time (no multi-exposure capability yet), develop them all, and rinse
<azonenberg> then one at a time try coating experiments
<azonenberg> lekernel: http://i.imgur.com/0PwSX.jpg
<lekernel> that's engraved silicon?
<azonenberg> Need to fix a few more issues with the hardmask (it didn't strip completely for some reason) but this is a mostly successful pattern etched down a couple microns with KOH
<azonenberg> into <100> Si
<lekernel> hehe, cool!
<azonenberg> this is at 100x magnification, the thinnest lines are about 20 um
<azonenberg> The process should scale further (to 5um) but i'm doing process development at a larger scale for now
<azonenberg> Another few days and hopefully i'll have these bugs ironed out
<kristianpaul> i can barelly read the 20 um in the botton, but, yeah !!
<kristianpaul> :-)
<azonenberg> kristianpaul: That was at the edge of the FOV
<azonenberg> Didnt expose all the way
<azonenberg> I need a better light source still
<azonenberg> Rough guess the entire cube is 1mm across
<azonenberg> This camera isnt calibrated so i cant be too sure
<bart416> Ok, this is a weird question, I think I'm reading it wrong
<bart416> Consider the integral expression in x: P = x^3+x^2+ax+1, where a is a rational number. At a = ... the value of P is a rational number for any x which satisfies the equation x^2+2x-2=0, and in this case the value of P is ... .
<bart416> What the hell are they asking there? :S
<azonenberg> Integral as in integer-valued result? Or as in calculus
<bart416> no clue
<azonenberg> Since it looks like algebra to me
<bart416> yeah does so to me as well
<bart416> But the way the question is asked makes it weird
<bart416> answers are -4 and -1 btw
<bart416> azonenberg, so what the hell are they asking there?
<bart416> Cause I don't get it
<bart416> Cause what I think they're asking makes no sense at all
<azonenberg> bart416: no idea, kinda busy atm
<azonenberg> Hmm... so it looks like some of my problems are caused by photoresist contaminating th ehardmask
<azonenberg> need to figure out how to remove it
<R0b0t1> A tiny scrubby brush
<azonenberg> R0b0t1: Lol
<azonenberg> Seriously, i'm not sure
<azonenberg> Somebody suggested an RCA clean before coating, which will help me confirm that it's not due to surface contamination (but i'm 99% sure its not)
<azonenberg> That wouldn't solve my real problem
<azonenberg> Which is that the photoresist seems to be dissolving into the hardmask
<R0b0t1> Ouch.
<R0b0t1> hmmm
<azonenberg> Resulting in a complex that's less resistant to prolonged etches but also difficult to strip :P
<azonenberg> Brown background is PR covered in hardmask before liftoff
<azonenberg> the low-lying areas are hardmask on silicon
<azonenberg> the brown spots in the middle of those areas are my unknown contaminant or whatever
<azonenberg> It looks a lot like photoresist, except there was no resist there earlier
<azonenberg> So i think its dissolving into the hardmask, then depositing there as the solvent evaporates
<azonenberg> This image is at 400x
<azonenberg> FOV is around 400um
<R0b0t1> Is there a  way to change solvent or use much less?
<azonenberg> R0b0t1: The solvent is in the solution, i got it as a liquid
<bart416> azonenberg, the entire issue with the question was the At should be a For :P
<bart416> + P is a function
<azonenberg> Oh lol