> On Oct 25, 2025, at 2:53 PM, dwight via cctalk <[email protected]> wrote:
>
> So much has changed since then. First was the doped gemanium junctions.
> Silicon waited until photo and surface defusion started happening. The
> opening of PMOS and NMOS was when we truly moved from the descrite devices to
> the complex circuits. The combining of P and N doping brought in CMOS. It was
> slow but great for low power application. Then the mask creation of self
> aligned gates brought the speed always waiting in CMOS. The art of making
> mask that understand the wave nature of light, do the optical corrections
> need for even tinier dementions. Now UV light is pushing the size of the
> tiniest transistors.
"UV" indeed. In particular, what's called "Extreme UV" -- 13 nm, almost in
what is typically considered X-ray wavelengths. That is the territory of ASML
lithography machines, a world where no other company has gone. The details are
quite mindboggling. The entire optical path has to be in vacuum, and the
optical elements are mirrors. The precision involved is vastly greater than
anything else in history. For example, mirrors accurate to a few nanometers
(vs. 100 nm or so for typical telescope mirrors). Positioning accuracy of the
wafer X/Y carriage to 10 nm, with movement in a fraction of a second from one
die position to the next. Temperature control to insanely small values. And
so on. I spent a bit of time reading their technical descriptions; I know just
enough about precision mechanical engineering and optics to get my mind
severely blown from seeing what these people do.
I remember at one time IBM was building a synchrotron so they could generate
coherent X-rays for lithography. That never went anywhere as far as I know.
ASML doesn't do that, they use exotic laser technology instead.
paul
