DIY Semiconductor Patterning

[@BreakingTaps]

🚨 *Addendum* 🚨 - "Why not fix the laser and just move the stage under the laser?" It's a good question! Speed mostly, it's generally a lot slower to draw the pattern with a mechanical stage, particularly if you need a lot of "flood fill" regions. And in theory a galvo can give very small resolution even if the laser spot is relatively large. I.e. you could position a 2 micron line (due to 2um spot size) 200nm away from another line. Depends on the quality of a stage, but precise movements of a large stage are a lot harder than precise rotations of a lightweight mirror, especially considering backlash and such on the stage. But it's a totally viable technique, and I might try it if I can't make the galvo behave. 🙂 - "Why direct-write laser instead of DLP chip?" No particular reason (my first attempt years ago was with a pico projector actually), I just wanted to try the direct-laser approach. There are some pros/cons to each. With DLP you run into limitations with pixel size quickly, which means you need correspondingly better optics to continue reducing feature size. Direct write laser can "scale" in that aspect a lot cheaper: a good clean beam passed through a 60x objective could theoretically hit sub-micron features. OTOH, you have to deal with issues like the galvo linearity/stability. So different trade offs. You can find commercial devices of both varieties competing in the same space for example :)

[@fgbhrl4907]

Hah, thanks for answering that. What about a stage that is based on one of those flexure designs? That would allow tiny movements.

[@sublucid]

Thank you for the considered answer! Have you also thought about using a Wicked Lasers LaserCube? Its blue diode is 1300mW at 445nm, which is within the range (350nm-450nm) specified by Microposit's datasheet.

[@evilcanofdrpepper]

Is there any way you can see how far off the laser is coming out of the galvo and just use the stage to correct it? You could try to make the lines straighter and maybe even see if for some reason it's repeatably off mark the same amounts in when doing similar things? Kind of like how the Shaper Origin handheld cnc router uses a small but accurate cnc to improve the positioning you do by hand.

[@ExtantFrodo2]

Like fgbhrl suggested flexure xyz stages can be very precise, zero backlash, readily characterized and driven by very standard gcode. Any speed lost due to greater inertial mass may be offset by running many parallel beams at once. You could even make mirror images cut at the same time that would register perfectly with their counterparts - which may be useful somehow in the construction of MEMS devices. Another argument for using a mechanical stage is that your beams (and thus the walls of your resist) could be made to be exclusively perpendicular to the substrate rather than all converging at the microscope lens.

[@Beregorn88]

I mean, you already have a sub-micron stepping stage, you just had to make a spatial filter for your laser and half a decent focusing optics to get better results with less effort... Also, is your laser polarized, and was the dichroic designed to work at 45°? Most of the off-the-shelf dichroic are designed to work at normal incidence and suffer big degradation in performance at high angle, especially if the laser is polarized in the wrong direction

[@AppliedScience]

I was going to click the like button, then realized I had already clicked! Really nice project.

[@BreakingTaps]

Thanks Ben! Glad you enjoyed it ♥

[@_spartan11796]

@@BreakingTapsI’m a big fan of both of you. You guys do amazing work!

[@nathanieljames7462]

Between the 2 of you I would expect to learn how to like a video twice

[@klausbrinck2137]

Beginner mistake, no worries, it´ll go away... By "Breaking Taps" u click "like" always before starting the video, everyone knows... ;-)

[@MrTweetyhack]

I see a colab in the future

[@HuygensOptics]

Nice project Zach! I've got a remark: given the resolution of your patterns, your resist layer thickness is at least several microns. Generally, you don't need that kind of thickness if you want to do subsequent etching. Using a resist layer thickness of less than 300nm will improve your image definition dramatically, because fully exposing a thick layer of photoresist in a very short time all the way to the bottom is very difficult. This is because of the optical density at the laser wavelength and the fact that photobleaching of the photosensitive component isn't instantaneous.

[@AG-pm3tc]

That is amazing to see so many wizards in one comment section!

[@BreakingTaps]

Thanks for the tips, that's great to know! I wasn't really sure what thickness to be aiming for, so just chose an arbitrary speed near from the datasheet (3500RPM) and left it constant so there was one less variable to think about. Good news is that it seems pretty consistent, around 1.7-2um each time. I'll try increasing the speed and get a thinner layer for my next tests, thanks!

[@HuygensOptics]

@@BreakingTaps if 2um is your thickness at 3500rpm, then increasing RPMs is probably not going to give you a significantly thinner layer. Adding a little solvent is a better strategy. Or alternatively you could use a resist like az1505.

[@BreakingTaps]

Hm yeah, the datasheet maxes out with 500nm @ 7000 RPM. My coater should be able to hit that, I'll give it a shot and see. Good idea about adding some solvent. Will look into AZ1505! I've been wanting to get some SU8 as well, just because it looks very useful for "structural" applications where the resist is left in place.

[@faxezu]

@@BreakingTaps Be careful with exposed SU8! This stuff is ridiculously hard to remove, nearly had to scrap several fully structured 8" MEMS wafer because someone was curious about my stuff and opened the box outside the yellow light area... (partially my fault because I stored the box outside the litho area, but the stepper was down and all shelfs were full). The thickness of 150µm wasn't helping this either. Warm acetone or NMP over several hours followed by plasma ashing in a O2/Ar plasma somewhat removed it (I also read that warm Piranha solution makes quick process of the SU8 but would have definitely destroyed my wafer) . At least some devices survived.

[@trulyinfamous]

I find this channel to be a great compliment to Applied Science. Both channels are doing really complicated things in a home shop, things that you would think would stay in the lab environment.

[@kirbyjoe7484]

This guy is doing some crazy work I would never have dreamed could be approached in a DIY setup. The other channel I have seen that blew my mind in this regard is Thought Emporium.

[@AlphaPhoenixChannel]

Neato! I'm impressed with the quality you were able to get out of an old 3d printer mirror box. What kind of setup are you hoping to replace it with? some "better" COTS part, or a homebrew with a mirror bolted to a few piezos or something? Hmmm... are piezos too small for this? it looked like your angular range was actually pretty big. Actually I guess that scaling is a separate question - when you had the "demo raster" running while you walked through the beam path, the lateral displacement of the beam was on the order of mm. How many microns across the surface was that once sent through the rest of the optics and microscope objective and whatnot?

[@BreakingTaps]

Thanks! I'm not sure what v2 will look like to be honest. The deflections are pretty big (+/- 20degrees? something like that), but that could be changed... I was trying to maximize the full range of the galvos because I figured they would not have much accuracy if trying to make very small deviations. If the a piezo galvo or whatever had very small range, we can tweak the focal distances in the relay system to make it work, probably just with much longer focal distances. I have a few options that I'm thinking about: - Getting a better galvo, the "digital" ones designed for etching should be tuned better. - Some kind of tip/tilt flexure mechanism, actuated by voice coils or high TPI threads or something. I don't _technically_ need all the speed of the galvo, so we can use a slightly slower mechanism too - a few different more "mechanical" designs (coupling a ballscrew to a rotary mechanism), so we can take advantage of high resolution in the ballscrew mechanism - A sorta silly idea someone mentioned on Discord which is growing on me: a CoreXY style 3d printer mechanism that "rasters" above the tube lens in the system, replacing the galvo entirely. Similar to how CO2 laser cutters have a traveling mirror, but coupled into a microscope objective. Still mulling that one over. - Or just admitting defeat and using the wafer stepper for all motions. Would be very slow though. The "demo raster" was an "X" shape and just about filled the entire field of view (I used it to help align various components). It depends where you look, but on the first lens it travels a few mm, on the second lens it's traveling a centimeter or two. And ultimately the FOV is either 2x2mm (20x objective) or 500x500um (40x objective).

[@1xBublex1]

I suggest looking either for proper galvos (like for actually your purpose) or to keep in mind that the mirror surface of your galvos has optical quality. I assume the galvos you used don't actually have the needed surface quality and that this might create the "wobbly" structure of your trial structures. Just a suggestion from my side - I hope I'm not too late 😅

[@alesksander]

@@1xBublex1 theoretically if error is repeatable u could calibrate wobble into "control system". But yeah if there is huge variation and bad repeatability is another case.

[@Parkskiingftw]

Wow once again I am blown away. I am fresh out of EE, and watching your videos has got me inspired to work on my own laser scanning microscope.

[@martingallagher9074]

Do you know if commercial LSMs have enough power to bleach the photoresist?

[@laststand6420]

This is some serious DIY. The fact that you are creating the beginnings of an Integrated Circuit with off the shelf hardware and 3d printed parts is seriously impressive.

[@ONRIPRESENCE]

You've got to look into green lithography technology. I covered some in my quantum hardware lecture series on QuantumGrad. Basically, egg whites diluted with water can function as a polymer photoresist and even e-beam resist. This means that egg whites can serve as resist material for both micron and nano scale features. Plus, it's non-toxic : D

[@bungalowjuice7225]

We live in interesting times. It's such a pleasure to see highly intelligent people do what they excel at.

[@pox87]

Hey, confocal microscopy guy here! I'm super impressed with what you managed to do diy with a super low budget. Before blaming galvos, try to see if the unreliability is due to vibrations: they can be absolutely awful, especially in a setup suspended from the table, and with those long 3d printed parts holding heavy optics and metal parts. If you can, try to launch an etching experiment remotely from a pc in another room, consider doing it at night if you are close to a busy road/railway, and if you are not at the ground floor. If the result is much better, it's probably you whole setup wobbling about as you walk, talk, even breathe around it. Better yet, use your extra focusing optical path behind the dichroic to get a microscopy image of a sample on a camera with some decent frame rate (30 fps is enough), if you have vibrations, it will be extremely noticeable. Also, you can gain a lot of power (if you need it) by focusing the laser on the pinhole, instead of just placing the pinhole in the collimated beam path. As long as the resolution of the lens you use is worse than the size of the pinhole, you should still get a very clean beam out of it, it will just be more finnicky to align.

[@BreakingTaps]

Thanks for the tips, appreciate getting help from actual experts! Yeah I definitely think vibration is playing a role, although I might have underestimated how much. v2 will probably sit on a granite plate, and I might put some kind of air damper underneath to help with vibrations just to rule it out. That's a clever tip with the camera, will keep that in mind! And re: laser, I probably explained it poorly. The diode has an integral lens which is focused onto the pinhole, so the efficiency isn't as bad as it seems. But I have the pinhole intentionally misaligned because the aberration from a misaligned pinhole ended up giving better results than full intensity through the too-large-pinhole. That's why the ultimate spot ended up looking so dim. :)

[@miszcz310]

Omg... You are unbelievable.... What is your work ethic that you can finish such complex projects....

[@BreakingTaps]

Powered by project-ADHD 😂 I usually have 3-4 projects going at once, and when I get bored or burnt out I switch to a different one :) This project for example was 90% done in January but I just couldn't make myself finish, so went off to do other things until I got interested again :)

[@BRUXXUS]

Another awesome video and project! I have no doubt that you’ll get it all working flawlessly. Imagine making MEMS devices in a home shop…. Good grief. You and Applied Science are always pushing the limits, and I love it!

[@LesLaboratory]

Absolutely beautiful work, very, very nice! :-) Yeah, diode laser beam quality is beyond poor. If you want maximum available power and a nice clean beam, have you considered fiber coupling the diode? The beam focused into the end of a nice length of Silica SMA905 fiber, will yield a really nice Gaussian beam profile, plus you can run the fiber wherever you want it...

[@Alexander_Sannikov]

does the beam need to enter the fiber parallel or can it enter it focused to a point? what angular distribution does is have when it exits?

[@BreakingTaps]

Thanks Les, means a lot coming from an actual optical and laser expert! :) I haven't really looked into fiber coupling to be honest, and no real reason either, just didn't ocurr to me 🙂 Can you couple in multiple wavelengths to a fiber (so I can also include the red focusing laser)? I assume I'd need a single mode fiber instead of the bigger multi-mode stuff? Thanks for the help! My fiber-fu is pretty weak 😅

[@Jimmymcjimthejim]

@@BreakingTaps I've never done it but I believe so. You'll have to make sure that the fiber is rated for the range of wavelengths used. You also need a lens that optimally couples the free space laser to the single mode fiber. Newport has a good article on this if you search for "Fiber Optic Coupling".

[@dMb1790]

The stuff you manage to make in a home shop always blows my mind. You’re like a whole other level of Maker.

[@squa_81]

homemade slicon cpu when? you have tried silicon doping, you have the laser machine.... also your channel is awesome i guess i now have a project to follow on this channel for the forseable years to come

[@friskydingo5370]

Amazing you built a small copy of one of the most complicated machines on earth. 👍👏. ASML should hire you.

[@BreakingTaps]

You'll love the video that's scheduled for next week! Building a newer and better photolithography machine :)

[@friskydingo5370]

@BreakingTaps I can't wait 🙂 maby one day you can build layers and increase the number of transistors in short a true integrated circuit with 3d scaffolding. I recently came across this channel, and the few videos I have seen are extremely impressive. I look forward to supporting this channel any way I can. I'll be in suspense until your next video. Thank you 👍

[@robinbinder8658]

i struggle with a ikea shoe shelf and this man just diys himslef some lithography im truly stoopid

[@RiffZifnab]

This project wins a Golden Opossum award for showing us a really cool project made with less than stellar components. Can't wait to see V2. (:

[@mrstanlez]

in a past I replace galvos(rotation will be always limited by angle step) with XY positioning movement system. Similar to XY CNC light router/plasma cutter etc. The laser beam come to X mirror which you can make X movement and then to Y mirror. You need a bigger lens after XY positioning system, but resolution can go up to 100 nm. Have you tried ?

[@sosaysthecaptain5580]

Nice project! I built the DLP version of this a few years ago, using a UV light engine and a wafer inspection microscope, rigged to step and repeat. Pretty good results at comparable resolution, although with some imperfections on the tiling.

[@13ryman]

It looks like the waves are mostly due to the galvo controller. My light Show laser (unity elite pro3) was wavy similar to yours until I aligned it using the potentiometers on controller board. Basically projecting a grid test pattern with pangolin quickshow software and adjusted the controllers until the corners are as close to square as possible. I'm fairly new to pro lasers but these adjustments solved my wavy problems

[@Tarex_]

Took me weeks to align the mirrors on my K40 crapbox, i am in awe of a setup like this, yes different worlds, i know

[@ladronsiman1471]

Fantastic ..I worked on optics back in the day .I get surprise about all kinds of new solutions ,that are already available this days .20 year ago something like you have put together will be very ,very expensive ..And only corporations or universities will be able to afford .To see you doing this type of research is a great accomplishment !!

[@peepopalaber]

I am everyday fascinated how far we have come. We can do that stuff now AT HOME. Great job!

[@mordoc333]

I was attempting DIY PCB lithography at the time this video dropped. What a nice coincidence

[@kevinb.8649]

This is the type and level of diy we need to future proof agents SHTF! The more that know this stuff the better off and safer we are.

[@andrewharmon9839]

Excellent explanation of the optics between the galvos and microscope objective!

[@dingdongdaddy589]

Pretty cool. I’ve been in semiconductors for over 20 years, servicing mask aligners. 😆

[@Robertkopp84]

You guys are just awesome. One of you will eventually come up with something that can spit out usable chips within the next 5 years.

[@malachilandis9542]

Have you seen Robin Renzetti on KZbin? He mostly does very precise machining, stuff like machine spindles. He also machines his own surface plates and measures them for flatness with an autocollimator. To do this, he made custom mirror mounts, and I think you'd like his kinematic mounts. He made a custom differential screw to get better resolution when adjusting the mirrors. Maybe something there would help you out? Very nice videos, keep them up!

[@BreakingTaps]

I love Robin! That man has so much knowledge packed into his head it's amazing. Not sure I saw the custom mirror mounts though, will go dig through his videos to find it. Thanks for the tip!

[@shortbystudio]

Thanks I had selected the same project for pbysics and now with your contribution I can do it

[@Skeptical_Numbat]

Utterly impressive that this can be made as a DIY system.

[@Mr1Spring]

Really nicely done. I use SU-8 spinned on a Si wafer in combination with a 365nm Led and a pattern printed on a transparancy (outsourced to a specialized printing company cost around €20 for an A4). Placed the transparancy on the wafer with a thick piece of UV tranparant glass. Expose and develop. Very high aspect ratio's possible with a spatial resolution down to 3-5 micrometers.

[@arguetav]

Dr Nick, can you share the company that you used to print the masks?

[@Mr1Spring]

@@arguetav ProArt BV in Groningen, The Netherlands. Ask for film with high density in black/white. Transparant for UV and black silver blocks UV. Resolution in micrometers. Just give them a call and discuss your needs.

[@joycekurita3037]

I love your honesty and comments on plastic parrs..good work!

[@electrobification]

the pinnacle of scien for general public explained in a very clear way. yes this videos will start a revolution!

[@beautifulsmall]

Amazing work, subscribed. Reminds me of taking image stacks through the microscope, Driven by steppers it was move, wait for vibration to stop, open shutter, wait for vibration to stop,flash led light, close shutter. Had to move it from an attic to a cellar due to vibrations. The frame wasn't sturdy but with the right setup it worked very well, these vibrations are always there however big the machine. three phase FOC motors help enourmously with smooth control. Galvo, electrostatic, Henry at UMIST in 1990 built ascanning optical microscope with two 3" loudspeakers and two sweep generators, im feeling inspired.

[@UNVIRUSLETALE]

really well explained for something as magic as optics to my smooth brain

[@luke_fabis]

How about a Risley prism instead of a galvo? It might make for a much more robust and stable assembly.

[@BreakingTaps]

Oh! Interesting! I wasn't aware of these devices, looks super cool. Will do some more reading, cheers for the tip!

[@jamessmith84240]

Well done mate. It just goes to show how complicated this process is. How Intel and AMD do the things they do blows my mind.

[@funkalicious2002]

You continually make some of the most interesting stuff I’ve ever seen on the internet. Thanks for all of it.

[@mystamo]

Criminally cool. The combo of the work your doing now with the etching is incredible.

[@RecursionIs]

Great explanation with animations at 9:30. I'd be interested to see a version with Huygen's spheres overlayed onto the video

[@adamvalt6609]

yep, that was amazing

[@Alexander_Sannikov]

huygens spheres are problematic with singular rays that can't actually exist. as in, they only exist because the beam is much thicker than the wavelength but its wave structure is inconvenient to visualize and it also causes inevitable diversion over distance.

[@EMAHGERD]

You beat me to my dream project. Absolutely stellar job, so great to see that hobbyists can do this!

[@5eZa]

cool prototype. looks like it could benefit from a solid steel structure and an enclosure so you can temperature control it and eliminate air currents and so forth

[@moritzalbert3314]

What could help you to get steeper walls in your etched layer would be to use a microscope optic with a longer focal length so the cone of light that hits your substrate is allot thinner/sharper and doesn't spread out as much towards the top. Also planning on building something like this but instead of galvos I'll use glass cube prisms that displace the beam when rotated. Will adapt your solution of using a microscope lens for the final focusing though, very smart.

[@jimzielinski946]

Great project, thank you! I'm thankful there are folks like you around. If society ever collapses, you're the kind of guy who will help build everything back. (Sorry if I have a depressing opinion of our world and where it's going, but you at least give me hope.)

[@byronwatkins2565]

Spinning mirrors are always moving so your spot cannot dwell to increase exposure time. Only repeated frames or higher intensity can do that. Repeatable frames will demand that the mirrors rotate synchronously. At some point you will also face reflections from the back glass surface being out of focus and exposing your resist from behind...

[@RedShiftedDollar]

One thing that might give you a major improvement in power is to adjust how you are doing the beam quality enhancing aperature. Running the wide beam through the aperature is blocking a lot of light. If you use two lenses to focus the beam and then return it to parallel, placing the aperature near the focal point might enhance quality while also enabling more light to pass through.

[@MCGeorgeMallory]

The feature size of the defects caused by the aberrations is pretty impressive. I wonder if at some point real photolithography machines will be based on the aberrations we made along the way.

[@BreakingTaps]

Oh you'll love this: sub-resolution assist features. Not quite the same, but these are features that are added to masks which help compensate for diffraction effects. What's neat is that they are smaller than the minimum feature size that can be made with the mask, but due to diffraction they still "add" to the feature and help fix problems or adjust the final shape. Super neat stuff!

[@joelevi9823]

Amazing stuff.. if long plastic parts are creeping i can suggest mounting them with a long screw going through the long axis and pressing the part to the extrusion.. maybe it will provide a better stiffness.

[@AllThingsComplex]

With the laser traveling all the distance, getting reduced, the atmosphere affecting it, and not to mention there's always particles floating around like (hair, dear skin cells, dust, etc), that can get in the way of the laser. Putting it a vacuum will improve the laser and not degrade it.

[@rotten-Z]

Mirrors can be moved linearly rather than rotated. This will also give a raster

[@2smoker64]

Years ago I had a set of piezoelectric galvos for very fine deflection.

[@eideticex]

Could try sitting it on a paver and dense foam for isolation to rule out at least some of the vibration. Surprising such a hodgepodge setup even works, let alone with results that are kind of promising.

[@stephenthomas2311]

Fascinating project. Like that it is 3Dp parts ebay/amazon parts. Very cool. Also, happy to see you are wearing the 'favorite' ball cap.

[@4n2earth22]

Way fun and interesting! It is super nice to experience new ideas and principals from a source that elucidates these concepts so understandingly in both general idea and detail. Seriously, well done.

[@BrendaEM]

Cool stuff! Often in DPSS lasers they use a pair of wedge prisms to make the beam with less anisotropism before the rest of the crystals. Perhaps if you such things before your spatial filter, you might get even more a more a Gaussian profile--with a little more power.

[@fluffy_tail4365]

wow incredible work, optics aren't easy! and yeah, the galvo-galvo system seems the weakpoint for now, managing to snag a better pair would make repeatabi;lity much better

[@Thefreakyfreek]

Probebly also a stiffer mount made from metal to house them in maby the bodys twist a bit in the plastic due to the acceleration

[@Veptis]

I am not familiar with the technologies, but it's a great opportunity to learn about it. And it also makes some of the stuff more accessible instead of it being a 160M EUV box nobody can buy, it's a neat little machine built out of somewhat available parts.... Without a cleanroom! My interest of microbolometers, which could count as mems devices.... So do you think it's possible with the resolution you have right now? Very few great KZbin channels like this exist. And you will always find them in the comments section on these videos!

[@TesserId]

Made me think that some crazy celebrity could have their autograph engraved on a length their hair, in quantities for their fans.

[@TesserId]

P.S. I'm not thinking in terms of a photo-resist for etching hair, I'm only wondering about direct laser ablation of hair.

[@timschafer2536]

What effect does sound vibrations etc have on the system? Is it isolated from outside vibrations so that they don’t interfere with the precision

[@BreakingTaps]

No vibration isolation at the moment, although that would definitely help improve reliability (and minimize the feature size). I know that commercial machines are often isolated, but I'm not sure at what point that becomes "required". I.e. is it 10um? 1um? 500nm? Not sure, but it would definitely help!

[@martylawson1638]

@@BreakingTaps Don't need anything fancy. Some tire inner-tubes under an optical bench will knock out everything above a 2-3 Hertz.

[@Snarkerd]

A source of wobble might be the aluminum extrusion. I worked on a machine that did micron scale automated bonding once. We tried extrusion for the frame first but even with the chonky profiles and structural plates you could bump the side of the thing and wobble it off course.

[@BreakingTaps]

Definitely possible! Between the extrusion and the generally unstable / cantilevered design, I wouldn't be surprised!

[@timobatana6705]

The only thing I really understand is lasers can instantly blind me so I'm glad people make videos like this so I can still enjoy it

[@DaCat2]

Great video, well done. Excellent results based on the components used. Perhaps have a look on eBay or similar for used CD/DVD mastering equipment. You could probably get the table and optics for a good price and it's a lot more sturdy. Most of that equipment is now obsolete.

[@asandax6]

Thanks to this video my decision is final. I am going to learn RISC-V.

[@TotesCray]

Another incredible video, as usual. Blows my mind what "home makers" are capable of, these days. Keep up the great work, looking forward to seeing more in the future!

[@ZeroToASICcourse]

Amazing you got such good results with 3d printed parts!

[@BreakingTaps]

I was pretty shocked to be honest, much better than I expected!

[@bastilux]

Great Project. You need definately get rid of the plastic parts, but not only the material is problematic but the design of the part. You want to avoid L shaped parts (and everything "hanging around" at all) beacause of vibratio issues. Also a more compact design with more mass will help with vibrations. Maybe you can get damped metal rods of ebay to replace the aluminium profiles?

[@MasterThief117]

This is absolutely fantastic work! I can't help but notice you're using 3d printed parts to hold optical components. I'm not sure what plastic you're using, and (I know you already know this) but plastics, especially PLA, have both a stress relaxation and a creep factor which will deform the parts over time. This won't really matter for macroscopic laser projects, but when you're dealing with microns, I would assume both of these variables can throw off alignment really quick. In fact, you could use this setup to measure this over time by firing the laser every hour or so over the course of a day onto a UV photosensitive film and plotting the points. I'm pretty curious what the results would be. Then again, I will admit I have absolutely no idea what I'm talking about when it comes to optics or if any of this drift even matters. The results seem to show none of the above variables matter much. EDIT: You mentioned all this toward the end of the video; I should have really watched the whole thing before commenting 🙃

[@BreakingTaps]

100% agree! Working on v2 which will feature a lot more metal components :)

[@logic0905]

It looks very cool! Maybe if you use thin wire to suspend the mirrors and a magnetic or electro-actuator, you'll get a much better result.

[@EdwardUnthank]

“Evolutionary design” is how I’m going to describe every “winged it” project from now on.

[@v1v3nd1]

Cant wait to see updates on this project. If you get it run properly someday, you could think about trying to mode-lock a diode laser for fs-pulses and go for two-photon-polymerization, basically enabling full 3d printing.

[@blindsniper35]

I've been meaning to take the next step in a similar project. Using the LCD for an sla 3-D printer to make pcbs. I've always been curious if I can get the features small and precise enough using a similar method with Optics. Thanks for getting me motivated to go back and experiment with that project/concept some more.

[@zouna007]

Awesome project. I don't know much about lasers, but could you use blu-ray laser with its lense from the blue-ray burner/reader to do the same as you did? I think the holes that they burn in to discs are about 130nm wide?

[@tom95076]

great job. I can see you have spent a lot of time with this.. awesome..

[@poetac15]

Just listened to your within tolerance episode and I’m stoked to watch your backlog of videos again! Such good content.

[@gyrogearloose1345]

Astounding work! What you have achieved is very amazing, almost incredible. I'm looking forward to seeing how you will refine it further. Thanks for sharing!

[@h8shunlou]

This was great! The thought of materials science to the nanometer...at home!

[@derek2593]

Could you try exposure by passing the light beam through a small transparency picture of the desired etch, instead of using a galvo?

[@ThomasAndersonbsf]

Ok at (0:07) I took that as a maskless method, sorry I see now you mean the resin mask is made with out a photo positive mask, not that you are direct writing the deposited material by using Vapor Deposition with a laser assist so the vapor is not deposited where the laser is striking the surface. Still very forward thinking, love it, and I am guessing if a second laser frequency could be used on a material so one solidifies the material while the other diminishes the permanency of the material it would be even easier to do a direct lithography, like maybe causing it to turn to powder so it would be easy to extract with a static charge attraction. I think though direct write of the material is the way to go, I wish more people were working on this tech like you are, and we all had better way to get together and work on projects! This is the way, Replicator tech will lead to a federation future, while focusing on warp and phasers and photon torpedoes as the first focus leads to an empire dark mirror universe I believe (the tech are all just allagory for working on manufacturing tech first, and waiting to work on transportation, or destructive, tech till we have the most effective and decentralized ownership method. IE. it is micronized so anyone interested can own operate and house it in a garage, on a bench or even in the kitchen or home office, and even better if it is portable in say a trunk to be deployed anywhere,) and by manufacturing I mean the whole package, refining/recycling, power harvesting, assembly, so no supply line of any specialized materials are needed, though more concentrated materials acquisition could be done by mining dump sites for electronics and such, it's still possible if necessary to harvest from the wild like carbon from that lawn you mowed, or feeding in mineral rich rocks you found on a hike. Biggest advantage to it being shrunk and fully replication capable *with the assistance of someone putting the printed parts together, which avoids that whole fear of grey goo* the tech can propagate like a virus, ie if you hobknob with a friend who's house is infected, ie, they have one in their house, with replicator capable tech, you end up with your house infected with it by the fact they know how useful it is and offer to gift you a copy of theirs, which they make using theirs. and this cycle repeats when you find someone lacking one, where you copy yours with yours, and gift them one too, LOL, Before you know it the whole world will be able (even if they don't choose to) participate in a massive world wide opensource process of just about anything, even making killer floating nanobots that are powered by a wireless system at your house and destroying mold spores and viruses keeping your home clean, (and maybe even breaking down the toxins still persisting in our environment like fluorocarbons when they encounter them, as well as solvent evaporated gases like xylene and toulene from spray paint and such LOL)

[@henrik.norberg]

I still cannot believe that you don't have several million subscribers, it's a crime against humanity!

[@BreakingTaps]

♥

[@theecstatic9686]

Dude, you are changing my life over here....

[@harjoat]

You're fast becoming one of my favourite youtubers

[@PatrickHoodDaniel]

Excellent video!! Thank you so much for sharing.

[@hippie-io7225]

Brilliant! A couple of ideas: Use a chunk of machinists' granite mounted on shock mounts for your base. Consider LinuxCNC for g-code control. (lots of options)

[@sorry4all]

I envy his home lab/studio. I've always wanted such kinda nerdspace

[@wez50]

What power supply is driving the controller and galvo drives? Some of the wobble and repeatability issues could be from signal noise. In the past to prove or disprove I’ve used a battery to supply power… and get away from a noisy switch mode or ‘other’ noisy supply… also grounding with clean and dirty earths separated is important. Very interesting thanks 🙏🏻

[@lahma69]

Really neat stuff! While I certainly understand how this works on a macro level, I'm not quite sure how some of the different components are interacting together to give the final output. I think I need to re-watch your explanation a few more times. As always with your videos, the topic and application of your ideas to achieve some final outcome is infinitely interesting. Thanks for sharing all of your hard work with us!

[@thatoneguy99100]

FYI if you want to align a beam through an axis you need two kinematically mounted steering mirrors. This might be why you had trouble aligning your red and violet laser diodes to be coaxial. My current research involves aligning a pump and probe beam to be coaxial through a sample, and I achieved this by using two one-inch mirrors in a figure-4 configuration (though a Z or U shape works just as well) and then using a mirror in a one inch mount and the dichro as the second mirror for my probe beam. Four kinematic mounts total. I then align through a pair of irises, probe first and then pump. Maybe this could be helpful for you... Another thing that you're probably aware of is that you can achive a tigher focus with a larger diameter beam. The spot size is still going to be limited by your M^2 factor, so it still won't be great for a diode laser but proper spatial filtering to get a good gaussian profile goes a long way.

[@BreakingTaps]

Thanks for the tips, really appreciate it! Still learning the logistics of actually setting up optics, as opposed to the idealized plots you see in the textbooks :)

[@officialfanofrichiebricker8324]

Have you ever done any 3D holograms or is this a way different setup?

[@deltafire5058]

You need to set up extruder coast settings or clean your printer to fix your prints.

[@gslakes9481]

Seems like KZbin won't let me post links to the relevant research, but have you considered UV laser-induced graphene for direct writing circuitry? There's apparently also ways to change the induced conductive graphene to p-type or n-type reduced graphene oxide via multiple laser passes. Seemingly allowing direct writing of transistors. There's also some research with quantum optics which might allow sub-micron resolutions with direct writing. Alternatively, if you were happy to switch to a mask-based process, there's well-studied ways to use two-photon resins to get this sub-micron resolution using either SU-8 or the bio-based AESO resin. Hope this helps improve the accuracy of your process!

[@DEtchells]

It was nostalgic to see a bottle of Shipley photoresist again; that part of my life was about 40 years ago 😮 Back then, the bleeding edge of semiconductor fab was striving mightily to get to 1.25 um, so I’d say getting within an order of magnitude of that in a home shop is pretty amazing👍 (Of course, they were aiming for maximum-throughout/minimum-defect production, but still…) Most amazing to me was that the AFM could get down into such high-aspect ratio (high-slope, really) features. I knew that they had very high resolution both laterally and vertically, but didn’t realize that the probe tips were both thin and long enough to be able to track such steep slopes.

[@BreakingTaps]

Yeah AFM tips are really impressive these days! I'm using the DLC tips from ICSPI (www.icspicorp.com/tips). 20nm tip radius, 1 micron tip on a 3 micron post,

[@DEtchells]

@@BreakingTaps 🤯

[@otequileiro]

This video is perfect! thank you so much for sharing your knowledge!

[@68HC060]

Imprecision could also be due to bad quality mirrors (sometimes an overlooked cause).

[@weirdsciencetv4999]

You could make your own galvos that use flexure bearings. This should eliminate the stiction which is likely the source of your errors. You could also take position feedback directly from the back of the the mirror. I have made galvos as simple as a mirror cemented to a Nd magnet, centered in a helmholtz coil, supported by a wire torsion bearing. Since you’re not too concerned about blazing speed this could work for you. You could also make a two axis flexure for the mirror, along with two crossed helmholtz coil configuration. You could also buy a mems laser scanning mirror meant for laser projectors like the sony CL1

[@poco9964]

Looking forward to watching this evolve. Great work!

[@JohnDoe-uy9wg]

Another very interesting project! I am amazed by your project diversity. When I saw the issues you have with the galvos I wondered why not use a DLP (as others apparently did). After you mentioned you got the galvos from a 3D printer I first thought about the LCD printers. So this might be an option to increase reproducability. You could use a cheap chinese resin 3D printer (or the optical spare parts) and use 2 lenses to collect as much UV from the LCD as possible (you'd loose a lot but then again expose everything at the same time and I assume exposure time is not an issue compared to all the other prepping time). Probably those UV LEDs output way more UV power than the laser. First lens relays the picture of the LCD to a second lens (e.g. used 50 mm prime camera lens: cheap on ebay and the have smooth focusing mechanics) and second lens collimates for the microscope lens. Oh and another nice advantage of the LCD approach: you could use rather simple image manipulation algorithms for corrrect for light intensity falloff at the edges and even improve contrast on thin features/over etching in areas where two lines converge. Side note: Do you know about this software for doing (simple) optical design simulations clles WinLens by Qioptiq?

[@nekomakhea9440]

Can you use the optical litho to make better optical encoders for the galvos for better precision? Or use it to make MEMS electrostatically driven mirrors to replace the galvos? Maybe optical encoders for servos for the optical train elements to make it auto-calibrating in real time, instead of doing it manually every couple of days? A self-improving machine would be pretty big brain.

[@Sharklops]

Amazingly, my Recommended feed actually proved useful for once by suggesting this video which led me to discover (and subscribe to) your fantastic channel. Cheers!