thanks for sharing! I loved seeing the process and SEM pics. This is def promising for home chip fab. If the resistance goes down then the doping is working! For a while all my PN junction curves looked like that too, fixed it by using Al with a few % Cu mixed in for both P and N contacts and annealing at 450c. Pure aluminum tends to alloy with the silicon and forms spikes that go deep into the wafer and shorts your junction to the undoped silicon below. Not sure if this is a problem with Ti/Al. Also, your sputtered metal electrodes overhang the doped regions. Is there thick oxide on the non-overlapped regions? If the doped regions are 1x1mm, maybe try sputtering metal only on the center 0.5x0.5mm of each to be safe

Ion Implant process engineer here. Your description of my process was spot on! I'm impressed how you succinctly and thoroughly explained what I do in just over a minute and might have to steal your explanation when people ask me what I do! You also mention that ion implant will probably never be feasible in a home fab setup, and that's probably true under one condition... if you are concerned with purity of the energies and species being implanted. If you are OK just implanting everything in your source gas, it may be feasible for someone to setup a "shotgun" implanter, which is basically a plasma chamber fed by some dopant-containing gas over the wafer with an acceleration grid in between that sends all the positive ions into the wafer, dopant included. This was actually the first type of implanter ever used in industry. One issue with this design may be uniformity, not sure how this was solved in industrial applications. Another issue is that you still have to anneal the silicon to "activate" the dopant... speaking of, have you considered sending your laser doped wafers through an anneal furnace to "wash out" some of the nonuniformities?

This makes me think that there should be a sub-section of each scientific field (similar to this one at least) that focuses exclusively on the minimization/simplification of all techniques, tools, etc. needed to do certain experiments or create certain devices. It would be interesting to see a scientific group that actually worked to figure out the minimal setup needed to create usable chips and to shrink those needs.

If you input an AC wave into the wafer while using x/y deflection on the scope, you can apply the the AC signal to the x probe, while reading the output with the y probe. You will get a hysteresis curve telling the function of the pn junction at that AC frequency. The freq to use will depend on the capacitance of the junction.

5:08 I am in tears. What a wonderful image. Edit: Just saw that you were trying to make a diode. Well, the contacts are of paramount importance. Who on earth did tell you to use Al as a p contact???!!! Generally, you need high Workfunction (Φ) if you need an ohmic contact to a p-type semiconductor. You can think of it like this: the n-type semiconductor has a high fermi level and generally likes to give electrons, so you match it with a metal that likes to give electrons, such as: Cesium, Na, K, Aluminium. On the other hand, you match a p-type semiconductor with a metal that likes to retain its electrons, such as: Platinum, Selenium, Copper, Gold. Platinum and Selenium are kings with a work-function Φm being 6.35eV!!!!

This channel is amazing and deserves a lot more followers. If a video starts with "Hey folks, short video today talking about doping silicon with phosphoric acid and lasers" it's guaranteed to be good.

I love seeing work-in-progress content! It's really cool to watch projects evolve

This is dope! No, really - it's doping silicon. Will you be making a video about transistors with this technique?

You dig into such interesting projects, love your channel, thanks

Multi-layer contacts can be done using, for example, one or more of Mo/W/Ti/Cr as a Shottky or Ohmic contact, depending on your application and diffusion layer doping. Consider making a four probe resistance measurement setup (linear or square) for example with tiny pogo pins. You could also make the opposite side of the wafer back side electrode and measure your diode structures (e.g. pnn or even pin with more pure silicon) through the wafer.

This was really great. Thank you for sharing it with us. I can't wait to see more.

So glad I found your channel! Very interesting stuff!!

Definitely appreciate the updates along the way on projects!

Awesome content. Nice micrographs too. I never know what to expect when you post a new video, but I'm always glad you did. It's so fascinating to watch you work through the issues and figure out what your data is telling you.

The fact I can follow what you’re saying for the most part, shows how good you are at these educational videos. Thanks for sharing. 😄

If you want to play around with it.. I have a 600W (1 joule/pulse x 600hz) 308nm XeCl laser used for surface annealing flat panel displays in OLED production.

Your projects are always inspiring! Love your presentation style. Ah and your old cap is epic, don't stop wearing it!

Duude, nothing short of amazing. BTW Happy new year 🎉🎉

This is very exciting! Please keep going

Thank you for taking the time to inform me on such an understandable manner i had not heard of any of this despite my interest in electronics and diy hobbies

As someone who binge watches youtube videos on whatever subject I'm interested in that day, I very much appreciate your meticulously planned and edited videos. As I am usually searching for explanations of certain phenomenon, or in the case of many of your videos, diy versions of expensive processes or simply exposure to those processes I wouldn't normally get to see, I personally don't care so much that you put out videos on a strict schedule. I watch your videos because of how detailed you get and seeing what results you can achieve (and issues you had to resolve) once you've dialed everything in. Needless to say it's still fun to see everything you get to play with.

glad i found ur channel, great content.

Bro. Keep up the good work. See something like this in a home lab gives me mad hope for the future.

very interesting video. I learned a lot from it. Thank you!

Kind sir, you are making beautiful and highly engaging videos. As a videographer I really appreciate the great looking floating head setup you got going - great looking grading! Keep doing what you’re doing!

hey, you making exceptionally great content! keep on going!

Nah, you've done it! looks great and it's so cool your having a go and showing us, I worked as final test for Applied Materials their Implant division and know what you have is great and you should keep going ...wow ! just as writing this you showed your hat and yeah keep going ! my two favourite subjects Mass Spec and semiconductor stuff, oh yeah and microscopy ! can we have a lab tour soon please ? have a great holiday and I can't wait for more, blistering hot channel by the way....cheers.

Whoever does the lighting/set design is a genius. It's absolutely beautiful.

this is so awesome please keep us updated :D

Enjoying your channel. Merry Christmas! Oh, nice hat. The old one rocks, too.

Enjoying your content! I always chuckle when you say "There are a lot of better explanations on the internet about this topic, but..." quickly followed by the best explanation of said topic on the internet, lol.

The algorithm brought me here because the intricacies of all this is all way over my head but the general gist of it absolutely fascinating. Thanks.

Oh yeah, work-in-progress is always awesome to me! I mean, with a fully perfected video, while very nice, it does feel a bit like magic. Seeing work-in-progress and sometimes simply failures, makes it real, makes me feel like maybe I can do it as well. So I'm all for it! :) I'll become a Patreon as well in the new year as I finally will have a bit more to spend again. :)

Great Christmas morning watching this vid!

Awesome video!

this is really dope!

Really cool effort towards individual / garage scale integrated circuits. Me and friends have dreamed about simplified processes to make this possible for many years. BTW I've watched a whole bunch of your videos and never even noted your hat :)

Nice work, Cant wait to see the first garage-semiconductor CMOS chip-collab

"short video" - 18 minutes.... Mmmmmmm. Yummy science content

Found your channel just now and you immediately received a sub and bell turned on, Great content and presentation.

This was a great video

Work in progress stuff is important. It's a big reason why I think the internet is even useful at all.

color me surprised and highly interested to try this on my own, thanks a lot for the great content as always!

This is really interesting. I wouldn't have thought something like this could remotely work in a home shop at all. I do love that you're talking about it even though it's not quite there yet, I really hope that some other more knowledgeable people help you figure it out. I like these sorts of "work in progress" videos.

Amazing work.

Wow! I bet this kind of thing would really help for small scale retro chip production.

18:09 The laughter at the end, was the best part!

Great content as always, and sweet hat!

Oh my, this video is a gem ! I've been interested by the Silicon world for more than 2 decades and yet never heard about this technique :-O

Kick ass work! I love watching people smarter then me, it pushes me to advance to new levels. There was a time this would have been like listening to people having a conversation in Mandarin, but now I actually understand what you're talking about. I hope one day I will be doing these experiments on my own in my own homemade lab. The way I view things is if an apocalypse happened I'm not smart enough to rebuild our world with what I know now and I want to have those skills even though that won't ever happen it's better to know as much as you can about everything you don't already understand.

I always find that it's amazing that you can make garage-semiconductor

My parents always told me doping was bad but this seems pretty cool

I don't have any idea about this niche of computing, however the lasers are cool. Subscribed, hopefully I can learn more!

Cool. Thanks for sharing.

This is so cool. Thank you.

Dope video bro!

Well done, keep it up

"I dont really know what I'm talking about" the honesty of that statement is underappreciated.

In college when we built mosefts, diodes, and capacitors we purged the chamber with nitrogen at the end of annealing. I think the final aneal had some hydrogen to get rid of dangling bonds. Been years since I have done it tho. I look forward to your content and my own lab once I can afford to set up my own lab.

Best Christmas present

That's Dope bro.

How in the hell have I never seen your content? SUBBED!

I've been interested I making integrated circuits at home lately, this tech is good to know about!

This is unbelievable , thanks for your effort. These are perhaps the first stones for free as freedom semiconductors technology for humanity. The same as Linus did for software. We are far far away from industry but this is a start. Fiber pulsed lasers are great and cheap, now we need more frequency, it would be a god send if we could double or triple the frequency with crystals.

Man this stuff is cool!

On the chalkboard in the background: "Photo litho nano particles Potato" Yes...potato!

Amazing stuff.

Awesome new hat, with dope science content

I dont know how I got here, but this is very cool. Love the explanation and details.

Tips from Jeri??? That's awesome!

Glad for the shift, as seeing what does not work well or work at all, is a good way to document paths in the road with "warning" signs, though with caveats that someone might go "well that is excellent that is what I needed" and not just "ah that does not work ok let me try this other direction, since I don't have a good *this works for sure* path". I really wish more people would do this documentation of everything including what does not work and what it actually did as far as they can tell. Thanks a bunch, one of these days I will have some money I can spare to throw your way, and this is why you and others doing this will get first crack at that extra money :) Hopefully I will soon have my lab and workshop moved too so I can offer trade of skill and tool set with people since I really need an electron microscope, but access to one might be even better as it would add the validity of the person doing the scanning to the already valuable view of what is accomplished (or not accomplished) to make up for the pestering others and then having to wait for shipping and the like (and trusting the shipper to not damage or alter the item being scanned or something LOL) That bit if the person has good reputation for just showing the work and not trying to alter it's results for any particular reason, well makes up for the negatives I would say.

I like the worn out hats! It gives them character and a story to tell!

as a patron, i can't care any less about any perks. the only benefit i want from supporting you is you continuing to make good videos.

If you have a 1064 nm fibre laser you could just use SHG to generate 532 nm pulses. Should work if you only need like 40 % max power at 1064 nm. And you should probably get a system to remove those white clouds when you're doping, maybe immerse the wafer in phosphoric acid and use a small pump to circulate the fluid?

Loved seeing WIP

Wish you had taught my semi conductor physics class, because this video was 100x more interesting than any of my professor's lectures.

Thanks!

This is fascinating! Please do more semiconductor stuff!

Merry xmas, this must be one of the best presents :)

I'll say it if nobody else will. This is pretty dope.

dope video :D

Love for both hats. :)

This video is dope

Love & Subcribed 👍

This is soooooooooooo cool! Would be really neat to get a basic IC made.

I like how 18 minutes counts as a short video

For your resistance measurements, you should really be using a 4 wire measurement

this video is dope

That's dope.

Christmas came early!

I can help you with some ion implantations. We have a 1.7MV NEC tandem accelerator, we don't get the very high currents like a implanter would. But we can go deep and do direct write without the lithography.

Very interesting.

I am excited to see Jeri featured in your video :D

Thanks.

I like the old hat. But the new one is fantastic. Also the doping stuff is dope. Love your projects and vids about them regardless the outcome.

I love your old hat :) The new one looks good too. But the best thing is your personality, it looks really good on you

Great video, and I do like to see the in-progress state of things. The content is very well presented. Is a grown Silicon Dioxide layer transparent to your laser because of the thinness? I thought SiO2 was not very transmissive to long IR (>10um) like C02 lasers, but that's probably gigantic compared to the layer thickness.

DIY transistors. Hell yeah! Fastest path to rebuilding a civilization after we do ourselves in.

Thanks

I just started a job as a technician for marking lasers... found a fun experiment to do :D