Doping Silicon with Lasers

[@SamZeloof]

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

[@SamZeloof]

Can also check your junction by shining a bright light on it and measuring the voltage cross the diode, like a solar cell, should be able to get 100mV

[@Mwwwwwwwwe]

Dang dude! Is that your experience from hobby building😲

[@BreakingTaps]

Thanks Sam, appreciate the tips! Good to know about Al/Cu contacts, I'll look around for a sputter target. Did you make your own target, or something that can be bought commercially (or maybe layer thin Cu first then thick Al)? Yeah, I was irritated at my shoddy mask alignment there 😭 The wafers did have a reasonably thick thermal oxide (500nm-1um, just based on time/temp) protecting the other regions. But the laser might be churning up the edge and could be unprotected. I'll try again with smaller contacts! Will check with a flashlight too. Not sure why I didn't think about that 🙃 Appreciate all the help!

[@Alexander_Sannikov]

@@Mwwwwwwwwe that dude is actually insane, definitely check out his channel if you haven't already. he's on another level.

[@Mwwwwwwwwe]

@@Alexander_Sannikov DUH🤦‍♂️ didn't see that he had a YT chanel... thanks will check it out😁

[@B0Boman]

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?

[@LanceThumping]

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.

[@michaelandersen7535]

Think of how much more accessible cutting edge research would be, for undergrad courses or whatever, if the researchers who knew their own work the best did the marginal extra work to create a "minimized" version of their procedures. It would be fantastic!!

[@excitedbox5705]

@@michaelandersen7535 lol "marginal". There are many things that are so sensitive and complex that simplifying it is more work than the original research. Getting something ready for production is mostly that simplification, and it is much harder and is the reason that it takes so long for new inventions to be brought to market. Not to mention that researchers are almost always under funded, limited on time, and under huge pressure to publish more papers, and fill out grant/funding proposals.

[@Willr7theSquid]

I can assure you this exists, but it lives behind NDAs and the privacy of industrial semiconductor fab methods. Makes one wonder how fast this research would advance if it weren't all hidden and competitive in this manner.

[@storminmormin14]

That’s called KZbin.

[@NJ-sx5hn]

We could call it the Foundation.

[@kenjinks5465]

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.

[@BreakingTaps]

Interesting, I'll look into that! Is that what the curve tracer is doing? I have a cheap "octopus tracer" which I was using to generate the curves, but not entirely sure the circuit or if it would function differently (there aren't really any controls, so I can't change the AC freq for example). Thanks!

[@BillDemos]

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!!!!

[@ytcomments8524]

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.

[@Robert_McGarry_Poems]

Good idea.

[@BreakingTaps]

Noted, thanks! Will look into constructing a four probe setup, that's a good idea with pogo pins too. Would be a lot simpler and less fiddly :) Cheers for the tips!

[@jfieqj]

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.

[@Robert_McGarry_Poems]

And then lasts twenty minutes! Short,😉

[@izzieb]

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

[@bsgconsulting]

You stole my dumb joke.

[@izzieb]

@@bsgconsulting Ohm my!

[@zagmongor]

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.

[@0xTJ]

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

[@GermanMythbuster]

YEAH! It's amazing! Also people can help out if they know something, instead of researching everything your self. Some times small pieces of information can save you hours.

[@Streetsy]

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. 😄

[@eulemitbeule5426]

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?

[@eid0eid0]

that would be incredible, but I once read it's nor known how to double frequency with fiber lasers as is done with yag. Do you have useful information about this?

[@BreakingTaps]

Yeah, definitely investigating some kind of flow chamber to keep the phosphoric moving across the surface and clear bubbles. In some cases you can see where the bubbles have disrupted the underlying laser path, which we'd want to avoid for precision paths. SHG is on the potential todo list! I'd love to have a pulsed green laser, would open up a few projects. I don't _think_ it would be too hard to put a crystal in the optical path but haven't looked too closely yet.

[@VincentGroenewold]

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. :)

[@ARVash]

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

[@E3SniperspreeE3]

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.

[@shawnm8232]

What degree were you studying where you got to do this ?

[@E3SniperspreeE3]

@@shawnm8232 Electrical engineering with a focus on nano device physics. I had a difficult time getting a job after college though. Awesome subject, didn't end up paying my bills though. Software is soooo much cheaper and faster.

[@drewc5576]

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.

[@takoslvt]

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

[@sooocheesy]

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.

[@Robert_McGarry_Poems]

Yeah, much better. It would take more passes but you could move faster... That would let you fine tune the surface texture while still getting a good deep implant structure. 👊

[@BreakingTaps]

Oh wow, that's quite a laser! Where'd you get that beauty? I might take you up on that offer at some point in the future. I'm in the middle of moving my shop to a new location at the moment, so I wouldn't be able to put it to use for a while. But perhaps in the future! I did recently find a 1W q-switched 355nm laser which I'm hoping to get commissioned soon, but unsure if the power will be high enough to do anything at that wavelength.

[@sooocheesy]

@@BreakingTaps Work - we repair lasers used in semiconductor photolithography, typically 193nm and 248nm systems that put out 10-40W. The 600W 308nm system is for flat panel displays. The only problem is the thing is a bit of a 'sledge hammer' compared to the 'scalpel' you're currently using.. It's just the light source and there's no beam steering/exposure tool attached. The raw beam is very large (~40mm x 25mm) so you would need some masking if you want to limit your exposure area.

[@Robert_McGarry_Poems]

@@sooocheesy Oh, that changes the equation... Gonna have to get in touch with Hoygans optics and see if a collaboration is in order.

[@RichardGreco]

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.

[@adfaklsdjf]

seems like twitter might be the way to reach out, since I don't think he can DM you via youtube anymore

[@BreakingTaps]

Oh wow, thanks for the offer! I'm on the road at the moment (holidays), but if you get a minute send me a note on twitter (@BreakingTaps) or email ([e-mail]) and we can go from there. Almost feels like cheating to have real equipment do the job haha. But could make for a really interesting video! Cheers!

[@ZURAD]

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

[@Ant0ine64]

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

[@aperturesignaturebandwidth]

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

[@eid0eid0]

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.

[@auxchar]

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.

[@troy3509]

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

[@voltronicsound1610]

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!

[@jerrywatson1958]

A video list that a high school STEM teacher can use for some courses would be great. Maybe put together a equipment list for a high school lab so we can propose a budget. How to make diodes, and such. I recommend for Jr. high school how to make capacitors (big ones) as a lab. Having to write reports on what they find interesting will help develop the other skills a person needs to succeed in life. My hope is for the next generation, as the current one has lost ground vs. what our grandparents did in the past.

[@andymouse]

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.

[@BreakingTaps]

Thanks! Lab tour in the future for sure! I'm moving to a new location (about 50% done at this point), so once the new space gets setup I want to do a tour and show it off :) Outgrew my garage and wanted a bit more space to work on projects :)

[@LongnoseRob]

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

[@Veptis]

Does the liquid or oxide layer impact the laser optically? Not quite sure how you focussed your beam - but I feel like that focussing through like 3mm of fluid could be rather difficult

[@jjones503]

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

[@DucBoy07]

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.

[@xxportalxx.]

I work in a wafer fab on ion implant, my guess would be that laser doping isn't used bc ion implantation gives better results with finer control, but if I remember I'll see if I can find someone who knows why we don't use laser diffusion.

[@Egg1456]

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

[@1.4142]

I like how 18 minutes counts as a short video

[@djredrover]

please let us see behind the scenes and the ones that you don't finish. This is where most of the learning is done!

[@------country-boy-------]

Another way to test junctions is by probing in the dark. Take millivolt / micro volt reading of a junction in the dark and then shine infrared light source at junction and measure the voltage generated. Even light emitting diodes behave like micro solar panels when put in sunlight and the voltage can be measured with a basic voltmeter. This is how photo-diodes and photo-transisters work. Well actually photo-diodes lower their resistance when illuminated by the correct wavelength (usually infrared). Theres no doubt in my mind that hobbyist will eventually produce customized semiconductors at home in the comming years.

[@ThomasAndersonbsf]

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.

[@treelineresearch3387]

The supporting tech tree needed to actually do this is probably too much for me to attempt myself, but it's amazing that garage-scale IC fab is becoming a reality. Who knows, in 10-20 years someone might have come up with a simple and cheap high vacuum solution that makes MSI fab on the scale of a small 5 axis CNC machine feasible.

[@kevorka3281]

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

[@BRUXXUS]

Definitely appreciate the updates along the way on projects!

[@blacklistnr1]

It's funny how some of the most interesting and insightful information comes from people who also say "I don't know"/'I'm not an expert"/"These are just my results"

[@Astronetics]

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

[@deefdragon]

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

[@WhenDoesTheVideoActuallyStart]

"It's not a documentary!"

[@BreakingTaps]

The struggle is real. I always start out thinking it'll be short, and end up cursing myself while editing 🙂

[@stevensexton5801]

@Breaking Taps, "Design of Experiments" may help you optimize your parameters.

[@BreakingTaps]

Will take a look, thanks!

[@MasterThief117]

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

[@Robert_McGarry_Poems]

The one thing we can all agree with.

[@adfaklsdjf]

I saw the potato as well

[@BreakingTaps]

🥔

[@sto2779]

5:51 - whoa that is cool. This means means this is a valid alternative for precision wafer sensitizations which today uses ion implantation. This means the laser method is much more affordable and doable. I wonder why big companies haven’t done this before…

[@Alexander_Sannikov]

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.

[@BreakingTaps]

♥♥♥♥

[@Richard-Freeman]

FINE! I'LL WATCH THIS VIDEO! Just a heads up, youtube has been pushing this video for days.

[@BreakingTaps]

The Algo moves in mysterious ways 🙂 Cheers for stopping by!

[@lugiarboy]

As mentioned by other guys, be careful of your aluminium lest it diffuses through the Titanium layer and form unwanted silicates on the silicon layers below although i do not expect it to be serious as you are dealing with lasers. And 4 point probe is your friend for measuring/calculating resistances at these scales

[@mborowski2010]

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.

[@jbrownson]

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

[@themeek351]

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

[@BryantCutler]

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

[@goatmeal5779]

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

[@Alexander_Sannikov]

if you have only a good n-type contact, you can make an n-p-n transistor(maybe even a field transistor) to test if that works!

[@Mwwwwwwwwe]

Would love to see you try making Ruby with a laser...I've got a 60watt blue 450nm laser which can melt stones( including white ones... sure it could fuse alumina

[@Dr_stef]

I have done my first tests with laser doping and my results where around 10-25 ohm per sequare centimeter with a xtool f1 ir laser. and i have been able to do this multiple times in a row. also trough 360 nm termal oxide. Also the hot probe test works well

[@MeepMu]

Christmas came early!

[@brute_force_and_ignorance]

The amount of thermal damage as evidenced by the ripples, etc., would seem to be counter to the process of making "good" diodes, since the junction is no longer particularly single crystal, so is likely to have leakage and soft breakdown characteristics. It may be possible that lower power for longer durations could allow the dopant to gradually get incorporated into the wafer. You only need around 900C local temperature for boron doping as I vaguely recall from the process used a job from over 40 years ago. Ditto phosphorous, I think, although that might have needed a higher temperature, say closer to 1000C local temp. But otherwise, that was the approach, we coated the wafers with dopant and popped them into the furnace for an hour or so. However, I also vaguely recall that our diffusion process resulted in growing kind of a doped oxide layer, possibly, which then had to be removed.

[@MCWaffles2003-1]

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

[@fizzyplazmuh9024]

Operating under pressurized fluid should get you much more progress but I am sure you are already familiar with the required pressures and whether you can achieve them with your resources. Using a higher boiling point phosphor source you may be able to have your target preheated by a few hundred degrees to ease the stresses on the doped points during firing.

[@materializa852]

I have just arrived here because I was looking and thinking of the same..... I do have a 50W Fiber Laser... 1064nm also...! But still frequency vs power.. I guess..! I'll give it a try thou!

[@davidstocker2278]

I work at Intel in a module that uses thermal diffusion to do the nmos and pmos wells. It's the main way the big boys dopent into processors

[@leyasep5919]

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

[@SpikeTheSpiker]

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

[@supergiantbubbles]

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.

[@whifflingtove]

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 :)

[@Alexander_Sannikov]

1:00 what a pretty shot, wow

[@jimurrata6785]

Tips from Jeri??? That's awesome!

[@nonsquid]

This seems like a great way to create a radiation detector by flashing an array of PN diodes that can be used to measure a "picture" of radiation, from the field, by using a shielded lead box around your array and a lens of aluminum to focus the gammas onto the array like an old box camera. The resolution would be set by the pixel size of your diodes and inversely proportional to the distance rule. BTW -have you tried your diodes under intense light to see if they are photovoltaic?

[@petermgruhn]

[precious] I hear you. But I think you're making the right decision.

[@AlphaNerd132]

question.. you seem to just be setting a pool of fluid on top of your silicone. that is a HUGE variance. Why not put a layer on with a q-tip, then add a slide of glass? the surface tension will give you a pretty repeatable thickness of fluid.

[@AlphaPhoenixChannel]

"Very cool micrographs but not necessarily good devices"... gradschool flashbacks

[@BreakingTaps]

😂 I should probably put a PhD PTSD trigger warning at the beginning :)

[@fizzyplazmuh9024]

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

[@tobiastho9639]

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

[@ToadyEN]

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

[@GlyphZero]

so welding but not. how about some grind/wash with your acid and then dope with your wash?

[@Robert_McGarry_Poems]

Interesting idea. Start textured... Etch, anneal, implant...

[@lukes6578]

So cool!! To combat your SiO2 problem may I suggest creating a nitrogen filled environment to prepare your wafer in? I'm imagining something like a sandblasting box (I know it's a lot of volume, hopefully N2 isn't that expensive) so you can work in it without introducing oxygen. Then you would be able to chemically remove the SiO2 layer (HF acid perhaps) and then cover your wafer with the phosphoric acid and you should be able to remove it from the environment and zap it with your lazer and not have to worry about messing up the surface! :)

[@Jeremy-fl2xt]

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.

[@BreakingTaps]

Thanks! The SiO2 is pretty thin, even the "thick" thermal oxide that I grew was about 1 micron. But the laser I'm using is 1064nm, which is _juuuuust_ barely infrared and SiO2 is still pretty transparent to it because it's almost visible. You're right though, if this was a CO2 laser it wouldn't be a problem at all, and would ablate away the glass easily :)

[@HomelessDeamon]

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

[@bewarako]

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

[@omsingharjit]

i am not related this field but...... 5:21 and 14 : 40 i have seen your dopent materials was not uniformly layer on top of the wafer before laser scanning . i suggest you .. to place your wafer on BLDC motor for centrifugal distribution of dopent very evenly but you have to Aline your wafer with laser in circular position you can mark on disk for that . Then you place your doped wafer in oven to distribute it evenly .

[@xanokothe]

This is awesome! Are you trying to do something similar to electron-beam lithography?

[@skuzlebut82]

This is absolutely fascinating. Nothing against you but I'd like to see Ben from Applied Science to give this a shot. He's got all sorts of sophisticated equipment and could probably do a lot with what you've done here.

[@youruniquehandle2]

Just an idea, maybe you could start a second channel for in progress projects. That way you can have a channel of only highly polished, finished projects and another for in progress, rough around the edges stuff. The second channel could also be used for more in depth breakdowns of the science and tech while the main channel can be a little more superficial for the common KZbin viewer.

[@c0d3w4rri0r]

This is really fascinating work but what I really want to know is how are you proposing to link the different components together. After all it’s not really an integrated circuit until you start making circuits on the chip.

[@programorprogrammed]

This was a great video

[@chrisvanalstine8136]

I have an old beat up hat also that I love. Hats like that are earned I have only ever worn a hat to the point of destruction twice and it sucks switching to a new hat. The new one never feels right.

[@xushenxin]

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

[@yeetmcmeat]

instead of using an acid could you sputter the dopant onto the silicon? possibly even after removing the oxide if that's an option. I feel like that could make the amount that ends up in the silicon more reliable.

[@elchippe]

You need to anneal the doped wafer to activate the doping part.

[@Tater1004]

Whoa, where did you even start on this? I’d love to read some research papers to wrap my head around the process.

[@nicktohzyu]

One thing i've always wondered is how schottkey diode packages are made. In the final product, it's effectively wire - ? silicon ? - wire, so how is it manufactured such that one junction has schottkey behavior while the other is an ohmic contact?

[@BreakingTaps]

I'm not sure to be honest! Maybe I'll tear one open to check.

[@lugiarboy]

Its the doping gradient of the silicon, one edge of the silicon is heavily doped to form an Ohmic contact when it touches one wire. Then the rest of the lightly doped silicon naturally forms the schottky diode at the region of contact with the other wire. (The information on the wikipedia page Schottky Diode is correct but without a guide to doping ratio, about 1000 times more dopants is a rough guide) Note that the work function of the metal wires used are a part of the equation which will affect the diode formed

[@postvideo97]

As this method would be very good for low cost/low volume fabrication and would scale fairly well for a medium volume fab. Maybe one day the first self-sustaining colony on Mars will be using this method to make semiconductors.

[@askquestionstrythings]

Awesome new hat, with dope science content

[@traviskeller7706]

You should try some tests with some of the multiple 405nm "compressed spot" focused beam. Looks to possibly be a inexpensive home shop method

[@ukpoetry]

Thank-you. The one time I am thankful for the creepy web tracking. I was searching for this.

[@quinntalley1681]

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

[@hardwareful]

Laser doping might still be good enough for back contact doping? At least after copious amount of annealing, perhaps.