Yes, Yes. I know. Because of that I said 'something similar'. Yokogawa/Minimal.fab themselves say different things for different chips, up to one week, but also one day.

That depends on the used substrate, they don't only have the ones which are in common use. They also don't need masks for anything, and their wafers are small. It's all a little hard to get, and the most current information is their Japanese site, with translation.

Have you looked deeper at theirs, or 'similar' stuff? I think it's misleading trying to extrapolate from an ancient process to this, 'or similar', because the roads taken by the mainstream(machinery and processing) do not necessarily apply to other roads, which others may have taken. And I don't mean by circumventing physics. Just applying them differently. For different volumes and scales.

> They also don't need masks for anything

To skip the use of masks, there exists only 2 possibilities.

For low resolutions, down to around the 1 micrometer claimed in the linked site, it is possible to use a small and low cost laser projector, which is also quite fast.

For higher resolutions, an electron-beam machine is needed, which works in a vacuum chamber, and which is big, expensive and slow (the slowness is not actually due to the electron beam, but to the fact that a chip that must be made with high resolution lithography would have many more components in the same area than a chip that can be made with low resolution lithography).

An electron-machine would be bigger by itself than what Yokogawa shows as being a "Minimal Fab", so I assume that Yokogawa uses a laser projector.

I could not find any statement about which is their best achievable resolution, but they give an example of a circuit made with 4 micrometer gate length, so I assume that their best resolution might be around 1 micrometer, which is compatible with a laser projector.

Yokogawa gives their processing time at one week, for a fabrication process with 98 steps, which is very close to what I have estimated in another posting here.

Actually, I think that the company whose site is linked in this thread might have just bought some equipment from Yokogawa, as that could match their claims.

Nonetheless, a one-day processing remains compatible only with semi-custom chips, where the customer just interconnects the pre-existing components, not with a fully custom chip.

Moreover, the Yokogawa equipment uses tiny wafers, where the maximum die size is limited to about 8 by 8 millimeters, and at that size you would get 1 die per wafer, with great chances that it may be a bad one, or if you make small 2 by 2 mm dies, you get just 16 per wafer, from which a dozen might be good, and so on.

So you must need only a small number of dies, otherwise the fabrication could take forever. Nonetheless, even such a small number of dies could be good enough for prototypes or for the needs of small businesses or individuals.

I certainly would like to order such integrated circuits, but for this the vendor would have first to publish the technical documentation with the characterization of the semiconductor devices that can be made with their fabrication process, to enable the customer to do simulations of their designs, before submitting one for fabrication.

A one-micron resolution is intermediate between that used for the Intel 80386 processors and Intel 80486 processors, but closer to the latter.

So it would certainly be good enough to make various custom circuits, which could substitute the standard microcontrollers or FPGAs together with any needed auxiliary ICs, where MCUs and FPGAs typically must include at least an order of magnitude more internal resources than are used in any single project, in order to enable their use in any of those projects, so a dedicated chip can be made much simpler and more energy-efficient.