Anyone have video of memory silicon visably changing state? - Page 1
Forum section: electronics / general

author: jnz
author_rank: Frequent Contributor
timestamp: October 02, 2017, 04:19:05 pm
content: So, probably most of you guys know whatflashmemory looks like under a microscope, how you can see 0 and 1 states. Does anyone have a video of change state happening? I realized I have no idea what it would look like and now I kinda want to see it.EDITED TO REMOVE "FLASH"

author: westfw
author_rank: Super Contributor
timestamp: October 02, 2017, 07:16:50 pm
content: QuoteReally? I had no idea. Do you have a link to a site with relevant photomicrographs?Aren't flash cells among the smallest features made with semiconductor materials? I thought that by the time you were able to resolve individual cells, you were usually looking at electron microscope pictures, or at least deep UV illuminated photos that had been artifically colored...

author: jnz
author_rank: Frequent Contributor
timestamp: October 02, 2017, 07:35:16 pm
content: I just saw some color photos of 0-1 gates and the guy posted a link to software to OCR them back into data.I'll try and find the link.

author: Yansi
author_rank: Super Contributor
timestamp: October 02, 2017, 07:43:01 pm
content: I don't think so you can see anything, unless it is a mask rom memory.

author: sasa
author_rank: Regular Contributor
timestamp: October 02, 2017, 08:00:58 pm
content: Modern flash memory devices use floating gate transistors, which can hold charge very long time: 1 for no charge, 0 - charge. In that case, no visible change under the microscope.Quote from: jnz on October 02, 2017, 07:35:16 pmROM is another story. I believe you refer on Piter Monta's page about physically reading memory from memory cans in HP-35:http://www.pmonta.com/calculators/hp-35/

author: jnz
author_rank: Frequent Contributor
timestamp: October 02, 2017, 09:09:31 pm
content: Quote from: sasa on October 02, 2017, 08:00:58 pmIt definitely wasn't that. It was some English guy boiling acid to decap.Ok, my bad, it must have been ROM and not flash. OK. I'll see if I can edit. So, I can definitely expect no video of ROM changing state, maybe writing EEPROM though?

author: hamster_nz
author_rank: Super Contributor
timestamp: October 02, 2017, 09:38:04 pm
content: Maybe this will help... I don't have access to the actual paper, but the keywords might lead to something.http://iopscience.iop.org/article/10.1088/0957-4484/17/7/S14/meta"Visualization of charges stored in the floating gate of flash memory by scanning nonlinear dielectric microscopy"

author: helius
author_rank: Super Contributor
timestamp: October 02, 2017, 10:27:28 pm
content: You can see TTL gates changing state with a SEM—a scanning electron microscope—ifthey are connected to bond wires. The bond wires are large enough that they can be visualized by the amount of deflection they cause to the electron beam. The gates themselves are not easily visualized this way, but a more sensitive instrument (an AFM or atomic force microscope) can sense very small electric fields on a chip. Of course with a SEM you have the problem of disrupting the chip itself with the electron beam.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 03, 2017, 03:44:45 am
content: This might be the closest thing out there:This is reading out the memory electronically, so it's not visible in the sense of a microscope watching the die.You can't photograph that which has no image: Flash, EPROM, DRAM and SRAM shouldn't have any visible change whatsoever, and are off the list. Possibly, FeRAM is visible, because of the special material used in its construction; the same may be true for any memory made with ferromagnetic or phase-change materials.You also can't use an electron microscope, for the problems highlighted above: electron bombardment easily flips states, corrupting the data. A low energy (< 10 eV?) electron microscope (I'm not sure which types can do this?) might sense the electric field at the surface, which would be an excellent way to tell. Or likewise, an atomic force microscope with a charged probe.Tim

author: chicken
author_rank: Frequent Contributor
timestamp: October 03, 2017, 04:23:42 am
content: With the SHARP memory LCDs, the traces visibly change from light to dark with charge. Though, that may be a side effect of the chip-on-glass process.https://youtu.be/zmsshlkiYkU

author: jnz
author_rank: Frequent Contributor
timestamp: October 03, 2017, 03:40:40 pm
content: Those are helpful. Thanks everyone, that was more or less what I was looking for.I wish I had the giant rom image (visable by a microscope) I was looking for from a PIC, but that's fine.

author: HwAoRrDk
author_rank: Super Contributor
timestamp: October 04, 2017, 10:14:54 am
content: Quote from: jnz on October 02, 2017, 09:09:31 pmWere you thinking of Ken Shirriff? His website is atwww.righto.com.I think I recall reading something he wrote about recovering data from a ROM by visually examining the die under a microscope (or rather, from many stitched together hi-magnification photos of the entire die).

author: sasa
author_rank: Regular Contributor
timestamp: October 04, 2017, 11:30:05 am
content: Quote from: jnz on October 03, 2017, 03:40:40 pmIf that is interesting for you, on Piter Monta's page you have quite large complete die image one of the ROM for HP-35:http://www.pmonta.com/calculators/hp-35/chips/index.html

author: medical-nerd
author_rank: Regular Contributor
timestamp: October 04, 2017, 09:41:21 pm
content: HiyaOld tech I know, but I've always found bubble memory fascinating - here's a very short video showing the magnetic bubbles moving through the chip (they are 'serial' devices).Cheers

author: chicken
author_rank: Frequent Contributor
timestamp: October 05, 2017, 07:27:03 pm
content: This one may also be of interest: Photonic Emissions Analysishttps://youtu.be/Gt6VyuLZBww?t=1824

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 06, 2017, 05:06:55 am
content: What about OTPROMs? They work using microscopic fuses so it should be possible to visibly see the writing process.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: October 07, 2017, 12:50:41 am
content: For anyone versed in German: Optisches Testen von ICs (optical testing of integrated circuits)see attached filealso covers capacitive coupled measurement and stimulation.At least the references should be usable for anyone else.If someone is interested, I could post it in several zip parts (5M total)

author: Gyro
author_rank: Super Contributor
timestamp: October 07, 2017, 09:55:56 am
content: Quote from: NiHaoMike on October 06, 2017, 05:06:55 amAren't most OTPROMs just EPROMs in an opaque epoxy package? I don't think there are many parts (mayble old PLDs or Bipolar ROMs) that actually zap anything.