4 ms·

Short turnaround times does not mean a single day. Even an ancient 1 micron CMOS process requires something like one hundred process steps, many of which may n

Short turnaround times does not mean a single day. Even an ancient 1 micron CMOS process requires something like one hundred process steps, many of which may need up to a few hours in an oven. If completely automatized, it could be done in a week for small batches, but not in a day. One day could be achieved only for semi-custom integrated circuits, where the customer only specifies the interconnection of the components existing on the pre-processed chip. Decades ago, when unlike today, there were a very great number of integrated circuit producers, there were many who offered a set of IC dies from which to choose one, where each variant could have different sizes, while including various mixtures of digital gates and analog components like amplifiers, comparators, voltage references etc., and after choosing one of the available base dies the customer would specify only how to interconnect the components and how to bond the die to the package pads. With such semi-custom integrated circuits, it would be possible to complete their fabrication process in a day, by using direct exposure, instead of masks, for the final metal layers. At the 1 micron level, the photoresist can be patterned directly with a laser projector. There is no need for an electron-beam machine, like for nanometer-resolution lithography.

LargoLasskhyfv 1mo ago
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.
- adrian_b 1mo ago
  > 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.
- nfjesifb 19d ago
  minimal fab is dope they have done great work. Owning tools is complicated and expensive and I think there is a shot that api ifyig chip fab is a better direction to go than appliance ifying chip fab tools. they have made really cool stuff though >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. this^ is my shtick. almost none of what i am doing is new or cutting edge. all just reconfiguration of existing tools/infra/techniques to do a different business model.

LargoLasskhyfv 1mo ago

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.

adrian_b 1mo ago
> 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.
nfjesifb 19d ago
minimal fab is dope they have done great work. Owning tools is complicated and expensive and I think there is a shot that api ifyig chip fab is a better direction to go than appliance ifying chip fab tools. they have made really cool stuff though >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. this^ is my shtick. almost none of what i am doing is new or cutting edge. all just reconfiguration of existing tools/infra/techniques to do a different business model.