Worthwhile to note that an alternative magnetic microscopy technique called MFM (Magnetic Force Microscopy) has been around for at least a few decades now, with resolutions down to 10 nm.
This new technique is done in a scanning electron microscope, which has some advantages - I’d expect you could get better temporal resolution since this scans an electron beam vs scanning a solid probe tip for magnetic force microscopy, and it would be easier to do multimodal analysis with other SEM techniques (standard SEM, energy dispersive spectroscopy for measuring composition, etc)
Edit: after skimming the paper, two interesting things stand out to me - it seems like the resolution is limited by the detector, maybe that can be systematically improved. And the lit review doesn’t actually discuss MFM, but does discuss electron holography (which I didn’t know about but is cool) and a couple other recent SEM based techniques that have more specialized hardware requirements
I really hope I can one day afford a microscope like a TEM so I can do cool imaging of chip dies.
From a security perspective I would feel like it might help us find more flaws in the silicon that create these security nightmares.
From a purely honest perspective..... I'm amazed at how complex modern chips and the packaging have become. It feels like black magic, but I don't want to call it that cuz it feels like I'm overlooking the insane talent and labor that goes into making these things feasible
I haven't worked with STEMs before, but with Two photon and confocal setups. My bet is everything around the microscope is probably going to cost as much as, possibly even more the microscope itself. E.g., a good optics bench will set you back several thousand, and they are extremely heavy. STEMs also typically operate in a vacuum at very low temperatures approaching absolute zero, so you will some liquid nitro handy to cool your sample as well as a way to pump all the air out.
There are also techniques for the TEM (transmission electron microscope) to visualize and measure magnetic fields such as electron holography.
Esentially by splitting the electron beam in two, passing half through vacuum and half through a magnetic sample, then recombining the beams, you can extract magnetic information from the interference pattern of the two beams with some Fourier analysis magic.
The preprint is freely available, thre are nice pictures where you can see mm/cm-size magnet near the electron beam, over a "G-grid detector" that act like a test pattern in the background.
Worthwhile to note that an alternative magnetic microscopy technique called MFM (Magnetic Force Microscopy) has been around for at least a few decades now, with resolutions down to 10 nm.
https://en.m.wikipedia.org/wiki/Magnetic_force_microscope
This new technique is done in a scanning electron microscope, which has some advantages - I’d expect you could get better temporal resolution since this scans an electron beam vs scanning a solid probe tip for magnetic force microscopy, and it would be easier to do multimodal analysis with other SEM techniques (standard SEM, energy dispersive spectroscopy for measuring composition, etc)
Edit: after skimming the paper, two interesting things stand out to me - it seems like the resolution is limited by the detector, maybe that can be systematically improved. And the lit review doesn’t actually discuss MFM, but does discuss electron holography (which I didn’t know about but is cool) and a couple other recent SEM based techniques that have more specialized hardware requirements
https://en.m.wikipedia.org/wiki/Electron_holography
I really hope I can one day afford a microscope like a TEM so I can do cool imaging of chip dies.
From a security perspective I would feel like it might help us find more flaws in the silicon that create these security nightmares.
From a purely honest perspective..... I'm amazed at how complex modern chips and the packaging have become. It feels like black magic, but I don't want to call it that cuz it feels like I'm overlooking the insane talent and labor that goes into making these things feasible
I haven't worked with STEMs before, but with Two photon and confocal setups. My bet is everything around the microscope is probably going to cost as much as, possibly even more the microscope itself. E.g., a good optics bench will set you back several thousand, and they are extremely heavy. STEMs also typically operate in a vacuum at very low temperatures approaching absolute zero, so you will some liquid nitro handy to cool your sample as well as a way to pump all the air out.
While it's a bit involved, BreakingTaps has a process to build a homemade scanning laser microscope.
https://youtu.be/9TYlQ4urcg8?si=Tq2XIXrxVZ5FcUNi
Very cool!
There are also techniques for the TEM (transmission electron microscope) to visualize and measure magnetic fields such as electron holography.
Esentially by splitting the electron beam in two, passing half through vacuum and half through a magnetic sample, then recombining the beams, you can extract magnetic information from the interference pattern of the two beams with some Fourier analysis magic.
I have a writeup with examples from a project i did years ago on my blog, if anyone is interested: https://longcreek.me/blog/2021/holography-intro
Walkthrough of calculations using Python: https://longcreek.me/blog/2021/holography-code
> The magnitude of the studied fields is from 0.001 T to 2 T.
Is that T for Tesla? Two Tesla, in a SEM sample? Wouldn't that tear most SEMs apart?
And what kind of SEM sample can generate a field like that? Surely not any microscopic sample?
The preprint is freely available, thre are nice pictures where you can see mm/cm-size magnet near the electron beam, over a "G-grid detector" that act like a test pattern in the background.
Can't find the original paper in russian :(
For anyone interested the author (Mikhail Gribkov) loves macro photography in general: https://rtraveler.ru/nature/rossijskij-fotograf-izobrel-unik...
Anyone link to paper? Page link didn’t work required sign up
"Download this paper" works fine for me (without signing up). Here you go anyway: https://pdfupload.io/docs/782c5e5f
Thank you!
> sees magnetic field
Which color it is ? /s