16:52 <berndj> with the recent paranoia about NSA-infected random number generators, how hard would it be to decap some chips and put them under the microscope to check if their built-in RNGs really do what it says on the tin?

16:53 <nats`> the biggest problem in my opinion would be to reconstruct the RNG circuit and see if it's a real one

16:54 <nats`> + other part of the chip could come and manipulate some value like Vgate etc...

16:54 <nats`> I'm not sure it's better than a statistic analysis of the output

17:00 <soul-d> http://people.umass.edu/gbecker/BeckerChes13.pdf

17:00 <soul-d> it explains a few facets your intrested in and also have a conclusion you'r not gonna like

17:31 <azonenberg> soul-d: actually i'm collaborating with the folks behind that paper

17:31 <azonenberg> There's a few things they didn't think of

17:35 <soul-d> :)

17:35 <azonenberg> I'm just gonna stick this in here http://colossus.cs.rpi.edu/pictures/2013/November/11-25-2013%20-%20xc2c32a%20SEM/jpegs/xc2c32a_dash_27_se_4500x_10kv_12mm_annotated.jpg

17:36 <soul-d> mmm what you break ?

19:36 <berndj> i still struggle to read those micrographs

20:01 <Sync_> the problem is that looking at them with a microscope is not really enough

20:08 <berndj> is there any way to tell n-type from p-type just by looking at the scan?

20:08 <berndj> from what i've seen you can at least see boundaries between (some?) types of doped areas

20:09 <berndj> is that due to the doping or due to different oxide/nitride layer thicknesses?

20:09 <nmz787> looks like there's height diffs too in addition to brightness

20:09 <nmz787> brightness could be due to shifts in composition, but height would do it too, so hard to tell

20:12 <nmz787> azonenberg: I was wondering what you think of achieving 1 micron features relatively close together with a DLP projection system, and maybe a microsope. Currently I can get the focus of the projector down to about 1024 pixels across 1cm, so that's ~25.4 microns per pixel, but I dunno how much diffusion will occur. I have some PCB resist and some old (expired) SU-8 that IDK if would still work

20:13 <azonenberg> berndj: In general you cannot tell doping from a micrograph

20:13 <azonenberg> That image is after a selective stain process to highlight P doping

20:13 <azonenberg> i grew oxide over P-type implants with dash etch

20:14 <azonenberg> nmz787: Not sure

20:14 <azonenberg> I've been away from this project for a while due to lack of time and funding

20:14 <azonenberg> once i have a real job and am out of grad school i plan to get back to it

20:14 <nmz787> azonenberg: lemme know if you move to Oregon :P

20:14 <nmz787> azonenberg: intel is building tons of new fabs

20:15 <nmz787> azonenberg: what about theorhetically, off the top of your head?

20:15 <nmz787> any ideas?

20:15 <nmz787> I have been talking with a resist company TOK and they've given me some simulation stuff in response to some of my questions/desires

20:15 <azonenberg> I'd say you definitely want additional optics

20:16 <azonenberg> there was a paper on doing DLP for MEMS

20:16 <nmz787> yeah i may have it

20:16 <azonenberg> i am more inclined to do 405nm laser direct write

20:16 <nmz787> well, dunno for mems, but it was a relatively DIY paper

20:17 <nmz787> yeah but with direct write you then need interferometers for feedback, which makes everything super vibration noise prone

20:18 <nmz787> you might get around it with a DVD player like optical voice coil focus, but write time would be slow

20:18 <nmz787> and a camera for inspection

20:19 <azonenberg> You dont necessarily need interferometers

20:19 <azonenberg> I was thinking of doing optical stages with rotary encoders

20:19 <azonenberg> That would get me down to a few microns i think

20:20 <azonenberg> as in, assume the leadscrew is precise and just measure angular position

20:20 <azonenberg> i have some for example that are 250 microns per turn

20:20 <azonenberg> a 256-tick encoder gives me slightly submicron positioning

20:30 <nmz787> i'm interested in microfluidics, and need to have straight walls and curves reproduced correctly, so leadscrew assumption is hard for me to get over

20:31 <nmz787> i figure TI has done the hard work for me re: precision, as long as any optics don't distort the image too much

20:46 <Sync_> nmz787: leadscrews will do your trick nicely

20:46 <Sync_> c3 precision and everything is pretty easy

20:50 <nmz787> c3 precision?

20:51 <Sync_> yes

20:51 <nmz787> googling

20:51 <Sync_> it basically tells you the integrated deviation over 300mm

20:51 <Sync_> in µ

20:52 <Sync_> so with c3 you get 8µ in 100mm

20:52 <Sync_> mostly it is less

20:53 <Sync_> I got some c3 ones in my microstages and I'm hitting +-1µ over 50mm

20:53 <nmz787> how much would a set cost?

20:53 <nmz787> is there a c4 grade?

20:54 <nmz787> :D

20:54 <Sync_> there is

20:54 <nmz787> i am working on microstepping now with arduino

20:54 <Sync_> well that depends on the pitch and diameter

20:54 <Sync_> but my 1mm lead 10mm diameter ones are about 1k for 130mm long ones

20:55 <Sync_> the length is not the issue with cost but the nut

20:56 <nmz787> hmm, well my DLP was $30 on ebay in decent enough shape (no bulb). I can shine a laser in that and get a decent image

20:57 <Sync_> I have some of those cheap dell DLPs here

20:58 <Sync_> I messed around with the a bit but in the end microstages are easier and more reliable imho

20:58 <nmz787> for a large effective surface I'd still need a stage though

20:58 <nmz787> microstepping and/or moving the image around the DLP area could help with fine alignment of sections

21:02 <Sync_> stages are also cheap