#homecmos IRC log for Tuesday, 2011-08-16

azonenbergNote to self - my denatured alcohol has some sort of contaminant in it03:28
azonenbergTotally destroyed film quality03:28
azonenbergwhen i used undiluted solution it worked03:28
bart416heh azonenberg05:18
CIA-67homecmos r113 | trunk/lithography-tests/labnotes/azonenberg_labnotes.txt | Today's lab notes05:43
azonenberggaah, it didnt work on the other side06:08
azonenbergThe cause of the problem is now unknown again06:08
azonenbergThe back side of the wafer is pretty screwed up but the front is good enough i can definitely do testing on it06:08
azonenbergthough a full working comb drive may prove a little difficult06:08
azonenbergI'm taking that one (2 inch double-side-polish <110>) and another one (2 inch single-side-polish <110>) up to campus tuesday morning for copper/chrome plating06:09
azonenbergand hopefully that night i can start lithography tests06:09
azonenbergalso, a quick dip in HF is very effective at removing residue from failed tantalumfilm coating runs06:10
azonenbergtakes the native oxide off, as well as whatever is sitting on top06:10
azonenberga full rca clean is overkill but the hf step works beautifully06:10
azonenbergStill getting some pinholes in the film, not sure where the contaminant is coming from06:11
azonenbergThe tantalum oxide step is by far the lowest yield i have on any of my processes06:11
azonenbergeven though photoresist is applied on the exact same tool it's been far more cooperative06:12
azonenbergmakes me wonder if perhaps i should consider buying some emulsitone glass forming solution instead06:12
azonenbergor using an alternate metal hardmask06:13
azonenbergsay, gold over chrome06:13
azonenberghttp://mail.mems-exchange.org/pipermail/mems-talk/2009-April/243146.html suggests that it will work well06:15
azonenbergGold can be etched, afaik, in HCl : H2O2 solution06:16
azonenbergthe obvious problem is that its expensive06:17
azonenbergnickel also looks good except its hard to etch06:17
azonenbergOr depsoit, for that matter06:19
azonenbergThe paper i'm reading suggests that koh may not attack copper/chrome much though06:20
azonenbergso i want to explore using a CuCr stack as a hardmask without using any ta2o5 under it06:20
azonenbergBack from campus with two freshly CrCu plated 2-inch <110> wafers20:46
azonenbergShould make for a fun evening20:46
azonenbergadhesion seems way better than i got before with just Cu20:49
azonenbergthoguh we wont know for sure until i test20:49
bart416Well, we shall see eh :D20:50
nathan7azonenberg: sweet21:34
azonenbergOne is double side polished with Ta2O5 over the surface, the other is single side polished and bare21:34
azonenbergboth were plated on the polished side(s) with 5-10nm Cr and around 1000nm Cu21:35
--- Wed Aug 17 201100:00

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