| azonenberg | Which means I have until then to prepare samples | 00:25 |
|---|---|---|
| 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) | 00:25 |
| azonenberg | And another one gone all the way | 00:26 |
| azonenberg | iow, a full hardmask-liftoff-etch-strip sequence | 00:26 |
| azonenberg | Here goes... gonna try doing a full process on a die soon | 02:16 |
| azonenberg_lab | So I'll be doing this die using the same method I did last night | 02:33 |
| azonenberg_lab | Except that time I stopped pre-etch so i'd have a nice specimen to image | 02:33 |
| azonenberg_lab | This time i'll take it to completion and see... | 02:33 |
| azonenberg_lab | WOOT | 04:37 |
| azonenberg_lab | I see a pattern on this die... | 04:38 |
| azonenberg_lab | Gotta etch another minute, then strip | 04:38 |
| azonenberg_lab | But this might be my first (messy but very real) success at the process | 04:38 |
| azonenberg_lab | Hmm, the hardmask cracked | 04:52 |
| azonenberg_lab | wonder whats up with that | 04:53 |
| azonenberg_lab | But the next one looks quite nice | 05:11 |
| CIA-67 | homecmos r96 | trunk/lithography-tests/labnotes/azonenberg_labnotes.txt | Today's lab notes | 05:39 |
| azonenberg_lab | http://i.imgur.com/0PwSX.jpg | 05:49 |
| azonenberg_lab | First semi-successful KOH etch | 05:49 |
| azonenberg | Well, looks like i still have some stuff to do | 06:33 |
| azonenberg | and no time to do any more processing between now and the SEM session on thursday | 06:33 |
| azonenberg | Next to-do, if the SEM images confirm my theory, is to prepare 10-20 dies, spin coat them all in resist | 06:33 |
| azonenberg | soft bake, expose them all one at a time (no multi-exposure capability yet), develop them all, and rinse | 06:33 |
| azonenberg | then one at a time try coating experiments | 06:34 |
| azonenberg | lekernel: http://i.imgur.com/0PwSX.jpg | 16:41 |
| lekernel | that's engraved silicon? | 16:41 |
| 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 | 16:41 |
| azonenberg | into <100> Si | 16:41 |
| lekernel | hehe, cool! | 16:42 |
| azonenberg | this is at 100x magnification, the thinnest lines are about 20 um | 16:42 |
| azonenberg | The process should scale further (to 5um) but i'm doing process development at a larger scale for now | 16:42 |
| azonenberg | Another few days and hopefully i'll have these bugs ironed out | 16:43 |
| kristianpaul | i can barelly read the 20 um in the botton, but, yeah !! | 16:44 |
| kristianpaul | :-) | 16:44 |
| azonenberg | kristianpaul: That was at the edge of the FOV | 16:44 |
| azonenberg | Didnt expose all the way | 16:44 |
| azonenberg | I need a better light source still | 16:44 |
| azonenberg | Rough guess the entire cube is 1mm across | 16:45 |
| azonenberg | This camera isnt calibrated so i cant be too sure | 16:45 |
| bart416 | Ok, this is a weird question, I think I'm reading it wrong | 16:53 |
| 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 ... . | 16:53 |
| bart416 | What the hell are they asking there? :S | 16:54 |
| azonenberg | Integral as in integer-valued result? Or as in calculus | 16:54 |
| bart416 | no clue | 16:55 |
| azonenberg | Since it looks like algebra to me | 16:55 |
| bart416 | yeah does so to me as well | 16:55 |
| bart416 | But the way the question is asked makes it weird | 16:55 |
| bart416 | answers are -4 and -1 btw | 16:55 |
| bart416 | azonenberg, so what the hell are they asking there? | 16:59 |
| bart416 | Cause I don't get it | 16:59 |
| bart416 | Cause what I think they're asking makes no sense at all | 16:59 |
| azonenberg | bart416: no idea, kinda busy atm | 17:00 |
| azonenberg | Hmm... so it looks like some of my problems are caused by photoresist contaminating th ehardmask | 18:04 |
| azonenberg | need to figure out how to remove it | 18:04 |
| R0b0t1 | A tiny scrubby brush | 18:50 |
| azonenberg | R0b0t1: Lol | 18:51 |
| azonenberg | Seriously, i'm not sure | 18:51 |
| 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) | 18:52 |
| azonenberg | That wouldn't solve my real problem | 18:52 |
| azonenberg | Which is that the photoresist seems to be dissolving into the hardmask | 18:52 |
| R0b0t1 | Ouch. | 18:52 |
| R0b0t1 | hmmm | 18:52 |
| azonenberg | Resulting in a complex that's less resistant to prolonged etches but also difficult to strip :P | 18:52 |
| azonenberg | http://colossus.cs.rpi.edu/~azonenberg/images/homecmos/2011-06-29/S7301011.JPG | 18:52 |
| azonenberg | Brown background is PR covered in hardmask before liftoff | 18:53 |
| azonenberg | the low-lying areas are hardmask on silicon | 18:53 |
| azonenberg | the brown spots in the middle of those areas are my unknown contaminant or whatever | 18:53 |
| azonenberg | It looks a lot like photoresist, except there was no resist there earlier | 18:53 |
| azonenberg | So i think its dissolving into the hardmask, then depositing there as the solvent evaporates | 18:53 |
| azonenberg | This image is at 400x | 18:54 |
| azonenberg | FOV is around 400um | 18:54 |
| R0b0t1 | Is there a way to change solvent or use much less? | 18:59 |
| azonenberg | R0b0t1: The solvent is in the solution, i got it as a liquid | 19:01 |
| bart416 | azonenberg, the entire issue with the question was the At should be a For :P | 19:11 |
| bart416 | + P is a function | 19:11 |
| azonenberg | Oh lol | 19:11 |
| --- Thu Jun 30 2011 | 00:00 | |
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