Asianometry - 2024-06-16
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The FET, and especially the MOSFET, was a close equivalent to the way vacuum tubes work. This fact is often skipped in the history of transistors. In electronic design, the vacuum tube was an easily understood device. Put a voltage on the grid, stop current. Remove the grid voltage, current goes. On/off.
Yes, the MOSFET closely resembles the way the old vacuum tube works. In fact, tubes are more like JFETs than MOSFETs because to actually shut off a vacuum tube, you need to apply a negative voltage to the grid, just as you need to apply a negative voltage to a JFET's gate to shut it off.
You're talking about depletion mode vs enhancement mode. Depletion mode devices are on with no gate voltage and switch off when the gate is pulled 'negative'. Enhancement mode devices are off with no gate voltage and switch on when the gate is pulled 'positive'.
As far as I know, JFETs are always depletion mode devices. Most MOSFETs are enhancement mode devices but depletion mode MOSFETs exist.
Valves were very similar to depletion mode FETs. They definitely were not just on/off devices. Like transistors, they could be used in linear mode or as switches.
@@nicholasvinen I appreciate you explaining the errors in the original commenter's statements. I picked up on that also. I endorse your response in the context of this forum.
another correction might be that tubes were not used as switches in majority of their applications....
there was a lot of stuff happening right between on and off...ie most of it...
essentially, tubes are modulation devices....
What about a p-channel MOSFET. Put a voltage on the grid; there is no hole current. Remove the grid voltage, still no hole current?
One late night around 1975, my dad and I had a conversation. He designed satellites. In the conversation, he mentioned how everyone went with bipolar TTL but he was using RCA’s CMOS. It worked much better in the environment of space. I was in high school at the time. I built a stopwatch using RCA CMOS SSI chips. I still have the RCA books that he showed me that night.
CD4000 series, THE Classic!
@@ccshello1 I believe I was the first engineer to design-in CD4000 CMOS devices into a product in New Zealand - early 1970. It was so EASY to use this logic.
But one detail of my schematic for the impulse counter boards was overlooked by the draftsperson, and 20 PCB's were made and put into service. Oh my! About 3 months after commissioning the power-load-monitor for a large paper mill, the first card failed.
Reason?
They had all been operating perfectly well without a Vdd supply. And functioned just fine because of the input protection diodes on each chip pumping the supply rails from input signals only - until one card did not. Quickly fixed of course. Very red face over that, but it taught me to henceforth go deep on the physical performance of any design and thoroughly inspect the actual physical details around anything I subsequently designed. I was not quite 20 years old at the time.
Me Too. I have all the Motorola IC Design Books, heavily marked up.
I used to design with CMOS. Loved the technology. When run in the static regime it would draw next to no power. Made an alarm for my garden shed. It ran for about ten years on the same PP3 battery!
I like the use of a picture of a MOSBURGER store.
There's humor everywhere. The 1960s oven, for instance, with a vacuum fluorescent display and a matching microwave.
I'd like to add that one of my instructors, Robert W. Bower, made CMOS cost effective with his Self-Aligned Gate MOSFET,
U.S. Patent No. 3,472,712 . This resulted in the MASS production of MOSFETS.
Oh... but you see - he's no ASIAN, so it doesn't count.
Quick correction: it is the opposite: nMOS are n-channel MOSFETs, so p-doped wells, while pMOS have an n-well. Thank you for your great videos!
I presume you are referring to 11:15
He has been using this block diagram for quite some time that shows the Source and Drain in different colors, which imply they are different materials or are doped differently, when in fact the Source and Drain regions are, effectively, identical in construction, and what makes one a “source” and the other a “drain” really only has to do with how the transistors are hooked up and connected to the rest of the circuit.
I think it would behoove him to update his cartoon model to show the source and drain in the same color, indicating they are identical in construction and composition. The colors should be used to indicate whether the regions are n-type or p-type, and therefore the colors can be used for both “wells” (silicon substrate under the transistor) and “active areas” (source, drain)
Yup, to add, NMOS is named after the activated/inverted channel, the chemical doping is the opposite of the 'ON' channel. When gate is turned on, the p-doped Si inverts to form n-channel.
A separate FET device is the TFT with metal S/D where n-type channel gets accumulation and becomes even more conductive, no need for inversion.
Source/Drain doping determines the transistor type. If the doping is n-type, it's NMOS. If the doping is p-type, it's PMOS.
There could be only one well in a more straightforward process or two wells in a more advanced process.
When your content dropped, it was the perfect end to my father's day. Thanks lad.
TWO NOBEL PRIZES? Well ok then, that's a very short list of people (5)
Asianometry, you never fail to deliver. I never knew that surface oxide growth was primarily developed as passivation. It’s so simple of a concept but not one I learned, and I spent 2 years working on preventing damage to the si/sio2 interface causing dangling bonds, creating traps and causing parametric shifts as device ‘on’ time increased.
Federico Faggin while at Fairchild worked on the self-aligned Si gate MOS technology. He then went on to design the 4004 CPU at Intel using the same technology.
Cf his autobiography.
this is only 25 mins but seemed that Faggin was noticeably absent
The comments under your videos are just as amazing as the videos itself!
6:50 Dr. I. M. Ross. In between 1962 and 1973, per US Government request, few hand-picked Bell Labs researchers and engineers were transferred out to a newly formed company: Bellcomm Inc. in Washington DC. The firm's task is to serve System Engineering role and coordinate with many NASA contractors to make Lunar landing possible. Yes, that's Apollo program and later Skylab. After they completed the tour of duty, they returned back to BTL. Many of them soon got promoted to senior leadership positions: Ian (Bell Labs president), Day (BL Chief Architecture SVP), Martersteck (BL Switching Systems SVP), and many others.
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BTW, 3N99 is a depletion mode MOSFET, a not-so-common semiconductor component.
During the brief hey-day of NMOS, depletion mode transistors were VERY common thanks to ion implantation, which allowed manufacturers to place ions under the gate, "pre-inverting" the surface. Aside from that, you are correct that finding a discrete N-channel depletion-mode device was like trying to find Big Foot.
Applause for the day I never missed your video 😁😁 ,thanks for your detailed information once again 👏
In the description op MOSfets, you made some mistakes. Firstly, an nMOS transitor is in a p subtrate or well and a pMOS is in an n well or substrate. The n refers to the carriers after the channel is inverted (ie, when the fet starts to conduct). Also, when applying a positive voltage to the gate, electrons are attracted into the channel and with negative voltage holes are. Opposite charges attract and equal charges repel.
Every time I watch your videos I think I am a little bit closer to understanding the struggles had too get us where we are today.
You make learning fun with dry humor. Hehe.
11:49 I'm glad you had as much trouble explaining exactly how transistors work as I did trying to understand them.
I love your deep dive into the early days videos... unfortunately for viewers man I'm going to assume those are also the ones that take the most time to research.
"since we are in the caveman days before the British commercialised ion implantation..." a video on the Rise and fall of Lintott (later Applied Material Implant Division) would be cool. I worked there in the late 90s...
I find your videos a very good background and deeply reserched, into the subject being viewed.
Most of them were being developed whilst I was at school and into the electronics industry I joined.
Namely , English Electric, Marconi Insruments, and I feel the best Ferranti Defence Systems and the semiconductor system.
They were developing a silicone on saphire F200L version of their F100L whilst I worked for them, and well missed in 😊these times, we could do with an̈ updated version of the Ferranti Bloodhound, to protect us in the UK.
You glanced over Telydynes Fetron, high voltage fet's swap into valve replacement for several common US and European valves. It made it brief inroads mainly in the Britidh Post Office, long-distance telephone links, but was quickly overtaken by conventional semiconductor products.
Thanks for the video's.
I worked at a Philips chip factory in the Netherlands in the late 80's, and we did have Ion cannons there, but most of the processes were still done with ovens that would get 1300ºc hot and the wafers would be in there for about 13 hours so we never would handle the wafers we had put ourselves in the oven.
We were creating the one chip TV from Phiips. The good old times when Philips was still a big big player in the world market.
It's not that bad. We have 2 electric toothbrushes and one airfryer from Philips. I bet those toothbrushes are good cash cows.
I don't come close to understanding all the details in even this video, which is a tiny, tiny piece of the whole understanding of microelectronics technology. What I do appreciate is the astounding scale of the big picture. What a long, strange trip it's been, from those early cat whiskers to an IC with feature sizes of a few nanometers, and many trillions of devices fabricated on one wafer. If this doesn't blow your mind, you must not have a mind to be blown.
And we're not finished yet. Far from it.
When I started in IC design, the first chip had a metal gate process. I sure don't miss that mess! :D Neither do I miss processes with only one metal layer.
I was around when dual-layer metal was being attempted. It was not uncommon back then to get zero yields due to "pin holes" in the insulating SiO2 insulator between the two layers that shorted the two metal layers. Thankfully, they figured it out over time!
@@demef758 I suppose the only thing to miss about single metal is how easdy it was to reverse engineer the chips. For a while, I had a side hustle doing that for some Intel chips and the NEC floppy disk controller.
Lots of good chips were designed with a single layer of aluminum.
@@allanflippin2453 You cannot tell anyone, but our company also used to de-cap chips, and reverse engineer them.
Not tired of this diagram yet. Used all of this for so long in industry. In hobby. And as a child, marveled at using the same. Happy to watch this and to watch this again. Important history for so many reasons. So many layers. Pun intended
To the Digital Age is an awesome book. And to think in not too soon a time we're going to have precision tunable analog "transistors" working together with digital that can do things digital transistors cannot do efficiently. Mostly in the fields of research for the time being but I'm sure people will come up with multitudes of uses for such nearly invariant analog signals.
Wizards inscribe secret runes upon thin sheets of metal and then harness the power of lightning through it to force the metal to think, and you still think magic isn't real?
Look at it through the eyes of the Scientific Method …. Electrons flow through traces of a electro conducting metal embedded in a di-electric material …..
"Magic is any technology so advanced that it's working principles are completely incomprehensible to the observer". Most things are magic to most people. There was a time when producing fire from something not already on fire was magic.
Oh that's not right at all. Silicon is considered a metalloid, not a metal. The part about wizards and secret runes, though? Spot on.
that image at 24:14 alone justifies all your videos !
Wow incredible content, never heard about passivation before, never thought the oxide layer was that important!
Amazing how long the planar transistor technology has dominated the industry. I wonder which technological break throughs enabled the transition to vertical gates and the current FinFET transistors.
Thank you for this well researched piece which was delivered by you in the usual concise manner. I really like your presentation style. Thank you.
it's incredible hearing stories about people from all over the world beating the odds and moving to america to try their best in the highest areas of competitiveness. we should celebrate that kind of thing more
It’s worth noting that William Shockley was an avowed racist and eugenist.
It shouldn’t be, it’s a brain drain on other nations.
My Sunday evenings consist of coding javascript, and learning about the history of transistors; thank you again.
Sorry about the JavaScript 😅
@@fensoxx It's a blast, actually; like ATARI player-missile graphics on crack
There are support groups for people struggling with JavaScript related cognitive impairment. And remember: Anything is better than suicide :P
@@fensoxx I'm currently 'trying' to learn javascript, what do you mean?
Actually vacuum tubes or valves as the British call them are field effect devices made well before MOSFET devices. Tubes were the first devices to use field effect.
I could listen to your essays on semiconductor technology for hours on end......cheers !!
They really improved mosfet transistors in the last decade or so in every possible way. They make nitride and carbide mosfets that can operate at hundreds of watts of RF power and at temperatures that would cook silicon. On the other extreme they have the ones on microprocessor chips that have nearly zero leakage when off and can switch on at insane speed.
24:19 LOL @ MOSBurgers!!!!! 😅😅😅😅😅
It's now 4 in the morning in southern Europe.
Me: 👀🍿 new asiometry video.
I can’t seem to find your electron microscope link on YouTube. Can you post it? I’d love to see it!
Two months ago??? What?!
@@TheLegendaryHacker for the same reason, early access tier on Patreon! I’m part of a tier that gets some videos early but not all. My Patreon bill is also so high lol. The scanning microscope one got released eventually.
I think your technology series are great, but could you draw the source and drain in the same color? They're interchangeable on a mosfet, just both n or p regions.
Morgan Sparks and Gordon Teal. Image in the video is correct, but you mish mashed the names in the audio.
Thanks, Jon. as always a great video!
ck in the 60's I remember having 8 transisters on a board that gave us 8 inverters. Double th transisters and we had an amplifier. Put these in a main frame with "AND", "ORs" & "Flip Flops" with other items and you had a "DATA PROCESSOR". Those were the days. New inventions every day.
your diagram is the other way around at 12:13,
NMOS has p-type bulk. the structure of the device becomes NPN. if you have p bulk (NMOS), you need to apply positive voltage NOT negative voltage to create electron channel.
on the other hand PMOS has n-type bulk. the structure of the device becomes PNP. if you have n-type bulk, you need to apply negative voltage to create channel.
the diagram shows NMOS (NPN) with the operation voltage of a PMOS which does not make sense
negative voltage does not attract electron which has negative charge, and push holes which has positive charges, positive voltage does.
Great video, a very interesting historical guide to the field effect transistor. Thank you.
2:30 that is why he is called Shockley
And don't forget Schottky. His diodes were better.
Ahh, positive gate voltage turns on NMOS device…
In the (more common) case of an enhancement type MOSFET yes, but a depletion type MOSFET also exists and takes a negative voltage to turn off. Both existed early on, though the enhancement type version was the first one to be made
The MOSFET was indeed a game-changer, revolutionizing the semiconductor industry. Stellar video.
Amazing video as always sir. Thank you.
The amazon 1 click patent diss though 😂😂😂
20:00 Wow, that reference lol
As a Certified Geek, I took an electronics voc-tec class in the early 1960's. I still perfectly understand how vacuum tubes work. But solid state electronics still baffles me. What? How does a "hole" travel?
Anyway, the MOSFET works just like an old triode vacuum tube. Meaning that a charge in the grid or gate controls the flow of the electrons trying to move from filament to plate or source to drain.
A hole, event though is has "mobility" and a speed, does not actually travel, since it is a "vacancy" or essentially a "missing" part of the bulk. What travels is the energy wave around the hole, which translates as an evanescent wave through the structure, where the outer electrons are essentially a protective wall, around the vacancy. This electron bubble continues to move toward some potential, until it is absorbed in some Fermi band, or hits some kind of interference, such as a defect within the structure, where that energy shell is disrupted in random directions, and then the hole collapses into the thermal zone. The hole "per se" contains no energy, but the shell does. A crude analog might be a tornado, or an eddy current. The "vacancy" inside those also can contain no significant mass or other obvious energy, and it can be a vacuum, but the shell can suck up whole houses.
I suppose it would be a bit of a tangent, but I'm very interested to know why some solid-state transistors - like FETs in general? - are able to simulate effects of vacuum tubes, in technologies where that might be desirable (e.g. audio amplification), while others don't appear to have that ability. It's a quality which is probably not very helpful in some applications, but quite desirable in others.
Vacuum tubes and FETs use the same process - electron flow control via electric fields.
It's mainly to do with the transfer curve. Valves and FETs are both transconductance devices, ie, use voltage to control a current. But they have different curves of input voltage vs output current. They also saturate differently. It is possible, but not easy, to make a JFET have a curve very much like a signal valve. It requires careful biasing and usually adjustment of every device built.
@brunonikodemski2420 - 2024-06-17
Our team of 3 built our first alloy transistor, at MSU, as part of a class project, and it had a gain of 4. We were third best, with another group getting a gain of 8, and number two getting a gain of 6. The rest of the class all got gains below 1. We got an A-grade, while numbers one and two got an A+plus. I complained to our TA, and he told me to suck it up, since the rest of the class got C's. Academic Life was harsh back then. So later I became an IC designers, with several ASICs under my belt.
@demef758 - 2024-06-17
What, no safe space to retreat to?
@kayakMike1000 - 2024-06-17
@@demef758 back in those days, we called that the bench, and people there were called bench warmers.
@L3uX - 2024-06-17
Given the spread, A grade was very sensible. I wonder why you complained and if your academic life was harsh back then is sarcasm or not.
@jfv65 - 2024-06-17
Meritocracy in practice!
@chinaman1 - 2024-06-17
Bravo