Tootfinder

For some reason the combination of 160K and my Mitutoyo 100x/0.90 objective means that as the last bits of ILD begin to etch away, substrate features become *less* visible.
I expected to see strong contrast at edges of substrate features when the ILD was etched away despite poly, STI trenches, and diffusion areas all being the same material (silicon).
But that's not what I'm seeing.
Going back to my archives, though, most of my good full die 100x shots are with the …

Fine-grained dark matter substructure and axion haloscopes
Ciaran A. J. O'Hare, Giovanni Pierobon
https://arxiv.org/abs/2509.14874 https://arxiv.org/pd…

Fine-grained dark matter substructure and axion haloscopes
The velocity distribution of cold dark matter within galaxies is expected to exhibit ultra-fine-grained substructure as a result of the many foldings of an initially smooth phase-space sheet under gravity. The innumerable folds of this sheet in the inner regions of a galactic halo would appear on solar-system scales like an extremely large number of spatially overlapping streams of dark matter particles. Some of these streams may also receive amplified densities if dark matter undergoes enhance…

Proposal of cavity quantum acoustodynamics platform based on Lithium Niobate-on-Sapphire chip
Xin-Biao Xu, Lintao Xiao, Bo Zhang, Weiting Wang, Jia-Qi Wang, Yu Zeng, Yuan-Hao Yang, Bao-Zhen Wang, Xiaoxuan Pan, Guang-Can Guo, Luyan Sun, Chang-Ling Zou
https://arxiv.org/abs/2509.14728

Proposal of cavity quantum acoustodynamics platform based on Lithium Niobate-on-Sapphire chip
A scalable hybrid cavity quantum acoustodynamics (QAD) platform is proposed. The architecture integrates superconducting transmon qubits with phononic integrated circuits on a single chip made by lithium niobate-on-sapphire substrate. The platform supports tightly confined and guided phononic modes in unsuspended waveguides and microring structures, while the superconducting qubits reside on the sapphire substrate. Efficient piezoelectric coupling between the phononic modes and transmon qubits …

PIC12F683 just has a few traces of dielectric and a few vias left before it's fully stripped to substrate.
Surprisingly, poly still seems fully intact. I'm not sure if any of my cleaning steps at the end will remove it, but it's quite firmly stuck down and I haven't seen *any* of it floating free yet. Some of the tungsten contacts have come off, which doesn't surprise me at all.
Now that all the oxide over the poly is gone the poly images are even sharper, alt…

Zero-energy resonances in ultracold hydrogen sticking to liquid helium films of finite thickness
R. Karahanyan, A. Voronin, V. Nesvizhevsky, A. Semakin, S. Vasiliev
https://arxiv.org/abs/2509.14652

Zero-energy resonances in ultracold hydrogen sticking to liquid helium films of finite thickness
We investigated quantum states of ultracold hydrogen atoms in a combined potential comprising the H-He film interaction in the presence of a substrate and the Earth gravitational field. We show that the shift and width of the gravitational quantum states are determined by the complex scattering length for the H-He film-substrate potential. We demonstrate that for specific helium film thicknesses above a substrate, zero-energy resonances occur if the combined potential supports a bound state exa…

PIC12F683 poly/substrate with some residual contacts (some floated away, some sitting at random positions, some still firmly attached) but almost all oxide etched.
Doing the whole die at this state, then will probably do a clean to get all the loose contacts and debris off, another imaging pass.
Then I'm not sure if it's worth the effort to try for a clean substrate image given the poor contrast I'm seeing, vs just calling this the final form. We'll see what happe…

And now that I'm below poly, I think it's time to give my microscope a well-deserved break from the near-constant imaging it's been doing the past few weeks.
369963 photos totaling 203.4 GB. Over a hundred hours of imaging time averaging around 3000 photos an hour. 27 etch cycles, 72 imaging runs.
I'll start shooting some analysis video later today talking about the device floorplan and such. But as a teaser, here's the final image just after stripping poly bu…

Multiplicity Distributions and the Frontier between Soft and Hard Physics
H. R. Martins-Fontes, F. S. Navarra
https://arxiv.org/abs/2509.15056 https://arxi…

Multiplicity Distributions and the Frontier between Soft and Hard Physics
The multiplicity distributions measured in proton proton collisions at the LHC exhibit interesting new features. One of them is the appearance of substructures, such as the so-called "shoulder" at large multiplicities. The most natural interpretation of this behavior is the existence of two production mechanisms. The final result is then a superposition of two distributions. In a previous publication we assumed that the two production mechanisms are soft and semihard partonics scatterings. In t…

Gluon Polarimetry with Energy-Energy Correlators
Yu-Kun Song, Shu-Yi Wei, Lei Yang, Jian Zhou
https://arxiv.org/abs/2509.14960 https://arxiv.org/pdf/2509.1…

Gluon Polarimetry with Energy-Energy Correlators
We propose a novel method to probe gluon linear polarization via energy correlations in hard scattering processes. This approach exploits the characteristic $\cos 2ϕ$ azimuthal modulation in single- and two-point energy correlations within jets initiated by polarized gluons. In contrast to conventional techniques that rely on $k_t$ resummation or intricate jet substructure observables, our method offers a theoretically robust and experimentally accessible avenue for gluon polarimetry. We perfo…

And another couple of etch cycles on the PIC12F683 done.
On the home stretch, I've almost got the last of the dielectric off. But I don't want to be too aggressive because ideally I'd get a beauty shot of intact poly across the whole die first, *then* undercut the poly and get a substrate image.
So I'm still doing my usual 2 minutes etch, then image routine. It'll take as long as it takes.