I am planning to give away most of my accumulated stuff, lots of Toshiba FET's and other stuff. I can't be bothered with asking for postage so now I can give away a few unobtainium FET's and stuff the box with other junk. I could take it to the dump at $60 a ton but I can't see that much waste.
Well when travel restrictions are reduced i can get an extra 35kg X2 on my luggage allowance with spare air miles
I'd be surprised if you couldn't take it to any of the 10,000 top-notch universities, including your alma mater. At least of the passives/actives -- some of those precision parts would be a godsend for making preamps for a few of the more finicky, low noise systems. But a lot of work, too, versus buying instruments.
The big old parts are more hobby stuff, to be honest. And maybe everything. I don't have time at work to rebuild and get some of our older microscopes up and running, although there's some renewed interest in automating some of our work, where they might serve as great basis to bolt the entire optical manufacturer's catalog to. We'll have to either tear apart a new microscope or an old one.
Otherwise, it's easier to buy the zeros of precision/accuracy than make older stuff work, which is a bit of a shame, because it's absolutely amazing what folks accomplished on limited (by today's standards!) processes. I've been nerding out on ruling engines for making optomechanical parts (see: all things lithography!) and how to make parts more accurate/precise than the machines that makes it. So many shoulders to stand on.
Last edited:
Accepting EUV with immersion lithography on some of the more emergent nodes, the repetitive pattern of a ruling engine means you need to hit 10 nm over a full reticle; I'm not sure how you'd stitch effectively. And you have to do quad patterning?
I'll stick with more reading/being fascinated by prewar efforts, starting from the likes of Fraunhofer.
Re Holographic 3D imaging
Early 80ies, I met the magic at the Museum of Holography, NY city.
Museum of Holography in SoHo Closes, Citing Finances - The New York Times
Now things have progressed a lot
Maria Callas | Base Hologram
George
Early 80ies, I met the magic at the Museum of Holography, NY city.
Museum of Holography in SoHo Closes, Citing Finances - The New York Times
Now things have progressed a lot
Maria Callas | Base Hologram
George
Semi lithography (courtesy Canon).
Canon : Canon Technology | Canon Science Lab | Semiconductor Lithography Equipment
Canon : Canon Technology | Canon Science Lab | Semiconductor Lithography Equipment
To make a ruler all you need to do is make an interference pattern. It is not an IC mask which has details. Even if you were using a long wavelength source off say 600 nm (orange) getting the interference pattern at every 600 nm you could place the resulting lines with a position seperation resolution of at least 10 nm.
A line spacing of 2400 nm would still be too small to be useful. The useful limit would be about five times that.
It is actually in the realm of practical to measure distances of less than 10 nm with optical equipment. Completely not the same issues as IC masks.
That method uses a phase locking loop and with even a red light source resolution of 5 nm should not be hard.
A line spacing of 2400 nm would still be too small to be useful. The useful limit would be about five times that.
It is actually in the realm of practical to measure distances of less than 10 nm with optical equipment. Completely not the same issues as IC masks.
That method uses a phase locking loop and with even a red light source resolution of 5 nm should not be hard.
Last edited:
What you are saying doesn’t make any sense. Position (measured e.g. by the interference pattern shift) and optical resolution are two completely different things. No idea where 2400nm comes from. You were talking about printing in photoresist now you are talking about measuring distances.
I give up.
I give up.
Seems 193 and 248 nm is the highest f light sources currently in use EUV is being investigated.
"Next-generation Semiconductor Lithography Technology
Because photolithographic optical apparati project very detailed circuit patterns onto wafers, they need to use very short wavelength light sources. Current devices use 248 nm KrF (krypton fluoride) or 193 nm ArF (argon fluoride) excimer lasers as light sources, which are capable of creating circuit patterns of a width of about 100 nanometers. Various other light sources are currently being studied to get this size down to the 50 nanometers that will be required in the future. In addition to fluoride dimer excimer lasers with wavelengths of 157 nm and X-ray lasers, EUV (Extreme Ultra-Violet) light sources are attracting keen attention.
EUV sources have wavelengths of just 13 nanometers, and so should be well able to create patterns of under 50 nanometers. However, because almost all materials absorb EUV, refractive optical elements cannot be used to control the EUV path, and special mirrors, known as multilayer coating mirrors because their surfaces are coated with multilayer thin-film coatings, are being developed. The coatings consist of a large number of alternating layers of materials having slightly different refractive indices to provide a resonant reflectivity to EUV. The manufacture of multilayer reflectors, in turn, requires very high precision coating technologies to deposit coatings with atomic-level thicknesses."
Seems EUV is not in common use just yet and there is no discussion of 'interference pattern' lithography.
"Next-generation Semiconductor Lithography Technology
Because photolithographic optical apparati project very detailed circuit patterns onto wafers, they need to use very short wavelength light sources. Current devices use 248 nm KrF (krypton fluoride) or 193 nm ArF (argon fluoride) excimer lasers as light sources, which are capable of creating circuit patterns of a width of about 100 nanometers. Various other light sources are currently being studied to get this size down to the 50 nanometers that will be required in the future. In addition to fluoride dimer excimer lasers with wavelengths of 157 nm and X-ray lasers, EUV (Extreme Ultra-Violet) light sources are attracting keen attention.
EUV sources have wavelengths of just 13 nanometers, and so should be well able to create patterns of under 50 nanometers. However, because almost all materials absorb EUV, refractive optical elements cannot be used to control the EUV path, and special mirrors, known as multilayer coating mirrors because their surfaces are coated with multilayer thin-film coatings, are being developed. The coatings consist of a large number of alternating layers of materials having slightly different refractive indices to provide a resonant reflectivity to EUV. The manufacture of multilayer reflectors, in turn, requires very high precision coating technologies to deposit coatings with atomic-level thicknesses."
Seems EUV is not in common use just yet and there is no discussion of 'interference pattern' lithography.
To produce a ruler requires lines spaced a know distance apart. It does not require any other shape. Thus we are not talking about the limitations of lithography.
If you ever used a ripple tank in high school you would have made interference patterns.
That is all that is required to make a ruler, equally spaced lines. A simple diffraction grating can do this along with a beam spreader lens. The other method would be a dual slit source, but it is easier to do a holographic simulation of a diffraction grating. Cyberphysics - Diffraction Gratings
You must have a light source that is both monochromatic and coherent. The limit on resolution would actually be the photo resist and uniformity of application.
Outside of the photography realm where you are trying to print images there are other uses of optical physics.
The other method to make a ruler is to use a screw to position the tool making your marks. As there are some limits to the accuracy of a screw you can put a position sensor on it. That position can be determined by pulsing a light at it and determining the delay in the reflection. Now trying to compare the start time to the return time isn't practical for short distances aka Michelson & Morley. However if you use a beam splitter and compare the coherent light source to the returned light you can determine the phase diffferences. That is actually a technique used to make very precise screws. (Yes well over simplified but in RF wavelengths that is how speed radar works.)
If you ever used a ripple tank in high school you would have made interference patterns.
That is all that is required to make a ruler, equally spaced lines. A simple diffraction grating can do this along with a beam spreader lens. The other method would be a dual slit source, but it is easier to do a holographic simulation of a diffraction grating. Cyberphysics - Diffraction Gratings
You must have a light source that is both monochromatic and coherent. The limit on resolution would actually be the photo resist and uniformity of application.
Outside of the photography realm where you are trying to print images there are other uses of optical physics.
The other method to make a ruler is to use a screw to position the tool making your marks. As there are some limits to the accuracy of a screw you can put a position sensor on it. That position can be determined by pulsing a light at it and determining the delay in the reflection. Now trying to compare the start time to the return time isn't practical for short distances aka Michelson & Morley. However if you use a beam splitter and compare the coherent light source to the returned light you can determine the phase diffferences. That is actually a technique used to make very precise screws. (Yes well over simplified but in RF wavelengths that is how speed radar works.)
Last edited:
The feature size typically measures the gate width on a mos transistor - its not the actual distance between connections like conductors going from one part of the circuit to another - these are much larger. See here for example.
1.1.2 Shrinking Features
1.1.2 Shrinking Features
Last edited:
Ed, were talking about semiconductor fabs. They make stuff ya know! Pretty easy to google this and see how they do it!
Peace
**** talking comedian... - YouTube
Peace
**** talking comedian... - YouTube
Bonny,
Derfy was talking about making ruling engines. That was what I was addressing. He seemed to imply he was following lithographic methods, my point was there are other ways. Micro lithography is a different issue. The optical effects are also used in audio! Ever seen one of the JBL diffraction lenses used to increase the high frequency coverage?
In audio scaling down is actually mostly about voice coil glues and diaphragm motion limits. But the physics remain the same.
The other neat issue is how to determine wavelength/frequency with dispersion and a ratiometer.
Derfy was talking about making ruling engines. That was what I was addressing. He seemed to imply he was following lithographic methods, my point was there are other ways. Micro lithography is a different issue. The optical effects are also used in audio! Ever seen one of the JBL diffraction lenses used to increase the high frequency coverage?
In audio scaling down is actually mostly about voice coil glues and diaphragm motion limits. But the physics remain the same.
The other neat issue is how to determine wavelength/frequency with dispersion and a ratiometer.
Last edited:
Man, I did not want to stir up any controversy! I was being sentimental about old precision instruments.
I had been reading up on some of the beautifully precise lead screws historically made, and the subsequent bootstrapping of using one lead screw to make an even more precise (thread pitch regularity being more important than the actual pitch) lead screw. Hopefully needless to say, but getting a perfectly regular interference pattern over a large area to make a, well, incredible regular is a hard problem!
Ed -- yes, the most precise rulers are made using holography (aka multi-patterning) and you mentioned 10nm, which is WAY BELOW the groove pitch presently being sold. Therefore, you'd have to do said efforts in a DUV stepper (EUV more likely since you need that resolution over a full reticle).
Diffraction Grating Physics
Andrew/Bonasai: EUV is in risk production and DUV is in ramp at TSMC for 7nm node size. Think your sources are a little old? But, yes, minimum feature sizes are now divorced from "node size". Also worth noting there are a huge number of design rules around how closely you can pack gates given multipatterning and power density (among so many other things), so the actual amount of a chip that is truly at the limits of lithography is very small. Gratings would be over a whole reticle so provides a different challenge.
I had been reading up on some of the beautifully precise lead screws historically made, and the subsequent bootstrapping of using one lead screw to make an even more precise (thread pitch regularity being more important than the actual pitch) lead screw. Hopefully needless to say, but getting a perfectly regular interference pattern over a large area to make a, well, incredible regular is a hard problem!
Ed -- yes, the most precise rulers are made using holography (aka multi-patterning) and you mentioned 10nm, which is WAY BELOW the groove pitch presently being sold. Therefore, you'd have to do said efforts in a DUV stepper (EUV more likely since you need that resolution over a full reticle).
Diffraction Grating Physics
Andrew/Bonasai: EUV is in risk production and DUV is in ramp at TSMC for 7nm node size. Think your sources are a little old? But, yes, minimum feature sizes are now divorced from "node size". Also worth noting there are a huge number of design rules around how closely you can pack gates given multipatterning and power density (among so many other things), so the actual amount of a chip that is truly at the limits of lithography is very small. Gratings would be over a whole reticle so provides a different challenge.
I was addressing the misconception that ‘10 nm feature size’ means stuff is 10 nano meters apart. It’s not. It refers to a very specific measurement on a chip - the gate width. AFAIK this remains the definition.
Ed
Yes, ok.
Regards
Andrew (aka Bonsai because I lived in Japan when I joined diyAdio. Some folks call me Banzai! Totally different thing)
Ed
Yes, ok.
Regards
Andrew (aka Bonsai because I lived in Japan when I joined diyAdio. Some folks call me Banzai! Totally different thing)