I wanted to make sure the SEM was still happily chugging away so picked up some cheap wafer fragments on eBay and did some imaging. Truth be told, I think I just enjoy throwing things in the SEM and seeing what they look like. If you have something you’d like imaged drop me a line (particularly if you’re from the hacker or maker community) and we can arrange to have it imaged. Currently samples need to be conductive as we don’t have a sputtering machine up and running here yet.
Anyway… on to the images! Here’s a shot at the lowest magnification:
Honestly, it would probably just be better to use an optical microscope here. And in fact, the features on this chip are relatively big. But I do love the fact that with a SEM you can go all the way from 30x to 20000x.
Here’s a random shot of part of the matrix, I’d guess this is something like a 1 micron process? Maybe sub-micron but not double digit nanometer. Pretty old stuff:
After taking that image I zoomed out a bit. Thing about SEMs is that they’re often somewhat destructive. You can see that the die has been scared in that area. After that shot I lowered the acceleration voltage a bit…
I’m guessing there’s a reason these wafers found their way onto eBay and not into a product.I assume this marking was produced by test jig to mark dies as faulty:
Some more random shots showing the bonding pads, you can see there’s a bunch of (I guess addressing) logic around the pads and next to the ROM matrix:
The corner where 4 dies meet, I just thought it looked kind of neat:
Track right, enhance 224 to 176:
I wanted to focus in on one feature, even if it was just random junk on the die and see what kind of resolution I could get.
Enhance 34 to 46:
Following images look further at the structures to the far right of the image.
57,19. Things look so messy up close:
Hmm not very interesting:
I picked this random blob and zoomed in further. I assume these is just a random fabrication defect:
15 to 24 Give me a hard copy right there:
That’s a big/small blob of something! But at least we’re at the nanometer scale now. Anyway there we go. Suggestions on things to throw in the SEM? let me know!