Precursor to Germanium transistor development - crystallography!

[Al (astral highway)]

How a chemist working in crystallography set the scene for Teal's later (1948)development of the Germanium transistor.

https://www.chemistryworld.com/opini...680.article://

[Trevor]

Sorry link not working for me
Trev

[Dave Moll]

Nor me - returns an error from Chemistry World saying that the page was not found.

[Al (astral highway)]

https://www.chemistryworld.com/opini...008680.article

This should work but it seems readers have to sign up to the Royal Society of Chem website as it's premium content...

I'll try this edit, replicating the most relevant (to us) parts under the Fair Use for comment guidelines.

------------
Author: Andrea Sella

"...There’s an old joke that you can spot crystallographers by their beards and sandals – the facial hair provides a rich source of heterogeneous nucleation necessary to grow the gem-like crystals required. It’s a reminder of just how weird the process of crystallisation is, and the complexity that underpins an issue at once evocative and fundamental.

...Czochralski (1885–1953) was a Polish Chemist and Inventor of the Czochralski technique for creating single crystals


...Czochralski never obtained a formal degree because his Polish school qualifications were never recognised; instead, he worked full-time at AEG, where he began to conduct detailed crystallographic studies of metals. ...

Legend has it that while waiting for a crucible of molten tin to solidify on his desk, Czochralski absent-mindedly dipped the nib of his pen into the metal rather than the ink-pot. As he removed his pen he drew out a thin strand of metal. Czochralski immediately realised he had found a new method to measure the rate of crystallisation: rather than follow the speed of the front, he would draw a filament out of the melt and measure the maximum rate above which the filament would snap. After a series of trials, Czochralski found the best method was to suspend a capillary by a silk thread above a crucible containing a metal only a few degrees above its melting point. The string ran over a pulley and then across to a motor. On lowering the capillary into the melt, the liquid would be drawn up the tube, crystallising almost immediately and acting as a seed from which the filament could grow.

With this device Czochralski was able to make filaments over a meter long. Each was a single crystal. This represented a huge advance over the previous ‘Plitsch’ method, which involved pressing metal powder with a binder into a rod. Heating the rod progressively along its length would recrystallise the grains into a single, crystalline rod...


The technique would finally come into its own in 1948, when Gordon Teal at Bell Labs grew single crystals of germanium. Using a graphite crucible filled with the semiconductor heated to between 935–980˚C by an induction furnace, Teal introduced a seed crystal into the melt and very slowly pulled it upwards. At pulling at rates below 0.003 inches per second, a cylindrical single crystal emerged with unheard of levels of purity– a gleaming silvery ‘boule’ of germanium. The crystals would allow Bell Labs to commercialise the first germanium-based solid-state transistors.

But Teal, a native of Texas, was lured away by a competitor, Texas Instruments, for whom he developed a similar process to grow crystals of the more desirable silicon. At a conference in 1954, Teal ostentatiously showed off new silicon transistors, playing music by Artie Shaw on a gramophone record player. In contrast to their germanium counterparts, silicon transistor amplifiers kept the music playing even when dipped into a beaker of hot oil. The solid state revolution had arrived.

Today, the Czochralski method is used for optics, electronics and even jewellery, and we can understand why having a beard could help one as a crystallographer (understanding nucleation remains one of the fundamental challenges of chemistry). The sandals, on the other hand, remain a mystery…"

[Bazz4CQJ]

I had no problem with the link and I'm not registered...but then, I am a chemist . By my time (at Plessey, Caswell), the challenge was pulling boules of GaAs. We bought ready-cut wafers from a company called MCP somewhere near Cambridge and I once saw their boule-pulling equipment, which was very impressive. IIRC, the big problem at that time with GaAs was that wafers were not adequately flat, so the photolithography was poor and yields were low.

Am I right in believing that all the effort with GaAs that went on the UK (Caswell, Malvern), eventually went down the toilet?

[Dave Moll]

Originally Posted by astral highway

https://www.chemistryworld.com/opini...008680.article

This should work but it seems readers have to sign up to the Royal Society of Chem website as it's premium content...

This reader, who didn't take chemistry beyond the first year of "A" levels at the turn of the 1970s, didn't need to sign up to anything to read it. Thank you for the link - though I'm not so sure about the beards and sandals .

[Al (astral highway)]

Originally Posted by Bazz4CQJ

..,. By my time (at Plessey, Caswell), the challenge was pulling boules of GaAs. We bought ready-cut wafers from a company called MCP somewhere near Cambridge and I once saw their boule-pulling equipment, which was very impressive...

Am I right in believing that all the effort with GaAs that went on the UK (Caswell, Malvern), eventually went down the toilet?

That’s an interesting first-hand recollection and impression, thank you 😊

If the UK went down the toilet afterwards , wasn’t that precisely because Teal was and his silicon advances were stateside?

I wonder how long AEG stayed in the forefront, as early adopters?

[David Simpson]

Al, best bet is to look up Andrew Wylie's site www.wylie.org.uk for in-depth info on early "Crystal Valves" &/or "Crystal Triodes". Cant provide a picture as its "All Rights Reserved".
I've a couple of early GET1'a & STC3X/302N's
I've attached a picture, plus some GEC info, and Wikipedia info.
Seemingly, these early devices were just a dollop of Germanium with two big pins of phosphor Bronze wolloped into it.

Regards, David

[Craig Sawyers]

Documentary about the invention of the transistor at Bell labs. I hadn't realised that the first thing they spent a lot of time on was a field effect transistor. And it was only when that failed that they moved on to what became the point contact junction transistor. Interview with Moore (founder of Intel, and Moore's Law). A lot of tension between Shockley, Brattain and Bardeen.

https://www.youtube.com/watch?v=U4XknGqr3Bo

[G6Tanuki]

Historically, there was quite a bit of experimentation into negative-resistance devices as amplifiers: tin and zinc showed some promise as oscillators

http://www.sparkbangbuzz.com/els/zincosc-el.htm

These are essentially a low-tech precursor to the Gunn-Diode oscillator/amplifier.

[Craig Sawyers]

Back in the day (1977) I was looking for work post degree. I had an interview at RSRE. My supervisor said "If you meet Cyril Hilsum, don't whatever you do mention the Gunn diode". Apparently Hilsum and coworkers did the theory, but Gunn applied the theory and managed to build a working device.

Hilsum refused to describe the device as a Gunn diode when he addressed a conference, calling it a "negative resistance microwave diode".

It is even enshrined in Wikipedia https://en.wikipedia.org/wiki/Ridley...3Hilsum_theory

Hilsum is still alive, aged 93.

[G6Tanuki]

Fascinating.... Theory and publications-in/citations-of academic journals are all very well, but reality more remembers those who got the patents and/or turned their theories into profitable products.

"Give me Patents; Patents are what pay our bills!" as a distant relative who worked for Bell-Canada was alleged to have drilled into to the labs he managed.

[Bazz4CQJ]

Originally Posted by astral highway

If the UK went down the toilet afterwards , wasn’t that precisely because Teal was and his silicon advances were stateside?

I was only involved with semiconductor materials for a fairly brief time in the late 70’s and I’m sure there are other people on the forum who were more closely involved and could add more to this. But at that time, the Americans were quite dominant in using silicon. The British did have some capability in silicon R&D, and production, within Plessey (at Caswell and Swindon). Looking at potentially faster materials, however, Plessey, working closely with the Government labs at Malvern, were actively investigating GaAs and InP, and particularly the area of microwave GaAs FET’s. There was a feeling around that they might be ahead of the Americans in that area. Plessey had commercial contracts to supply GaAs FETs when I was there. I think it was also true that some people thought that GaAs IC’s might get in to computers. At some point, somebody must have pulled the plug on all of this work and I don’t think there’s anything much going on anywhere in the in the UK now?

Sadly, places like Caswell, Swindon and Malvern (not to mention GEC Hirst at Wembley) are now largely historical references, as are company names like Plessey, GEC and Ferranti .

[Al (astral highway)]

Originally Posted by Bazz4CQJ

I was only involved with semiconductor materials for a fairly brief time in the late 70’s and I’m sure there are other people on the forum who were more closely involved and could add more to this. But at that time, the Americans were quite dominant in using silicon...

Sadly, places like Caswell, Swindon and Malvern (not to mention GEC Hirst at Wembley) are now largely historical references, as are company names like Plessey, GEC and Ferranti .

Thank you, that’s a really interesting post. My partner’s father worked as a research scientist at Ferranti and also designed weapons guidance systems (user interfaces by the sound of it). He died tragically young, way before I met her ,however so I can’t ask him about his experiences.

I always had a fondness for Ferranti products and have a lovely old gas discharge tube in the original packaging.