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Home , Cavity magnetron, Geoffrey Dummer, Russell Ohl

Feature by Dr Bruce Taylor HB9ANY

l E-mail: [email protected]

t Christmas 1938, working in their small rented garage in Palo Alto, California, two The enterprising young men calledA Bill Hewlett and Dave Packard finished designing a novel wide-range Wien bridge VFO. They took pictures of the instrument sitting on the mantelpiece Revolution (Part 1) in their house, made 25 sales brochures and sent them to potential customers. Thus began the company Dr Bruce Taylor HB9ANY describes the invention of the that by 1995 employed over 100,000 people worldwide and generated annual tiny device that changed the course of radio history. sales of $31 billion. The oscillator used fve thermionic valves, the active devices that had been the mainstay of communications for over 25 years. But less than a decade after HP’s frst product went on sale, two engineers working on the other side of the continent at Murray Hill, New Jersey, made an invention that was destined to eclipse the valve and change wireless and electronics forever. On Decem- ber 23rd 1947, John Bardeen and Walter Brattain at Bell Telephone Laboratories (the research arm of AT&T) succeeded in making the device that set in motion a technological revolution beyond their wildest dreams. It consisted of two gold contacts pressed on a pinhead of semi-conductive material on a metallic base. The regular News of Radio item in the 1948 New York Times was far from being a blockbuster column. Relegated to page 46, a short article in the edition of July 1st reported that CBS would be starting two new shows for the summer season, “Mr Tutt” and “Our Miss Brooks”, and that “Waltz Time” would be broadcast for a full hour on three successive Fridays. But right at the end, after another unexciting story about the broadcasting of road traffc reports, the article mentioned that had dem- onstrated a small metal cylinder that could “create and send radio waves” but contained “no , grid, plate, or glass envelope to keep the air away”. It could amplify and The point contacts of the frst transistor were created by a razorblade slit in gold foil wrapped around the oscillate and had been named a “Transistor”. edge of a triangular plastic wedge. (Bell Labs) The name had been chosen by internal ballot among Bell Labs executives and germanium transistor, which he called a Origins research staff. and Transitron, while working for CFS Westing- The roots of the invention were much Surface States Triode were considered fairly house near Paris. By mid-1949 many of older. The rectifying properties of crystals good but unwieldy, and Transistor came out them were in use as amplifers in the French had been discovered by Karl Braun in well ahead of Crystal Triode, Solid Triode and telephone system. At this time European 1874, before wireless existed, and the Iotatron. Little did the apathetic NYT reporter industry was still recovering from the devas- cat’s whisker detectors that became popu- realise that he had witnessed the frst public tation of war but research at UK companies lar in the early 1900s were semiconductor demonstration of an invention that would such as BTH, GEC and STC was not far in all but the name. Nor was the spawn a world-changing technology. behind the US and their frst products were concept of a three-electrode solid-state Quite independently, Herbert Mataré in named Crystal Valve and Germanium Triode amplifer a new one. As far back as 1926, June 1948 also invented the point-contact as well as Crystal Triode. the German-American engineer Julius

24 Practical Wireless October 2018 physicist who had been engaged on anti- submarine warfare research during WW2. When he learned of Ohl’s discovery, Shock- ley immediately postulated that it might be possible to make a solid-state amplif er by applying an electric f eld across a p-n junc- tion but, initially, all attempts to vary the con- ductivity with the control f eld failed. Without any tools to see what was happening inside the crystals at the subatomic level, progress was dependent on intuition and trial-and- error. By January 1946 the group admitted that they were “groping in the dark”. However, the failures led Bardeen to postulate a theory of surface states in semi- To the chagrin of Walter Brattain (right) and John conductors and to continue experimenta- Bardeen (glasses), Bill Shockley insisted on sitting tion. By late 1947, Bardeen and Brattain had at their workplace for this posed Bell Labs publicity switched from to n-type germanium Research Director Ralph Bown introduces the f rst photo. (Bell Labs) and felt that they were getting close to suc- point-contact transistor to the press. (Bell Labs) cess. Then Brattain tried a conf guration in old pipe-cleaner knife and these detectors which a pair of very closely spaced point Lilienfeld, who patented a forerunner to famously outperformed those that were not contacts were created by using a razor blade the modern electrolytic , f led optimised in this way. He refused to allow to cut a minute gap in the gold foil wrapped a patent for an FET-like device that was anyone to clean the dirty knife, which had around the edges of a small triangle of plas- granted in 1930. Since materials of the pu- acquired “exactly the right momentum for tic. The contacts were pressed into the sur- rity required weren’t available at the time, the job”! face of the germanium by a spring fashioned it is unlikely that Lilienfeld succeeded in This war effort also gave rise to the next from a paper clip. By December 16th the making a working transistor but his claim important breakthrough. While working on team had achieved signif cant power gain was strong enough to prevent Bell Labs detectors in 1940, Bell Labs chemist and on December 23rd they demonstrated from patenting the f eld-effect approach Russell Ohl made the fortuitous discovery speech amplif cation to Bell Labs manage- 18 years later. of a rectifying junction at a defect in a bar of ment. An “entirely new thing in the world” The theoretical foundations for tran- silicon and noted its photovoltaic behaviour. had been created. sistor operation were laid in 1931, when Ohl had been bitten by the radio bug when Cambridge University mathematician Alan using spark on 150m during Patenting Wilson formulated the quantum mechanical WW1 and had built a superhet as early as Everyone at Bell Labs was familiar with the theory of conduction in . He 1921. He coined the terms n-type, for mate- legend that their company originated be- correctly attributed their properties to the rial containing some atoms of phosphorus, cause Alexander Bell had beaten Elisha presence of impurity atoms in the crystals, antimony or arsenic (in which conduction Gray in a race to the patent off ce. So, the opening the way for less empirical work on is by ), and p-type, for material transistor invention was classif ed as Bell solid-state devices. During WW2, Wilson containing some atoms of boron, aluminium Labs Conf dential until it was better un- worked on radio communications for the or gallium (in which conduction is by holes), derstood and patent protection had been secret Special Operations Executive (the and the p-n junction was born. Initially this applied for. But in whose name? Shockley ‘Ministry of Ungentlemanly Warfare’) and discovery wasn’t disclosed outside Bell was Bardeen and Brattain’s supervisor, later on the UK project to develop the atomic Labs, and Ohl was instructed to cut any and was disgruntled that his subordinates bomb. He was knighted in 1961. chance p-n junctions out of silicon that was had made the breakthrough without his With the development of the high-power sent to his British counterparts. active participation. Bell Labs’ lawyers 10cm cavity magnetron by advised that Shockley’s own work was and at University, Bell Labs overshadowed by that of Lilienfeld, and high resolution radar became Work on semiconductors at Bell Labs had that Bardeen and Brattain were the actual feasible if a reliable detector could be found. begun before the war, and energetic boss inventors. Consequently, they refused to After Bell Labs were unsuccessful in devel- initiated a new unif ed solid- put his name on the patent for the point- oping thermionic valves for this very short state programme in June 1945, as soon contact transistor. , attention was turned once again as the men who had been assigned to Professional jealousy and bruised ego to cat’s whisker crystal diodes. In Britain, the military work began to return to the lab’s spurred Shockley into a frenzy of independ- Telecommunications Research Establish- new ‘Idea Factory’ at Murray Hill. The aim ent work, which he initially kept secret from ment (TRE) developed an aluminium-doped was specif cally to devise an alternative to the rest of the group, thus starting to alienate silicon cartridge that was manufactured by thermionic valve telephone amplif ers and them. By the end of January 1948 he had BTH and GEC. While at TRE, the eccentric the initial funding of $417,000 was billed come up with a theoretical transistor design Bristol physicist Herbert Skinner improvised to AT&T. that worked quite differently from that of a technique for f nding a sweet spot for As manager of the programme, Kelly ap- Bardeen and Brattain, being composed of a the contact by tapping the crystals with an pointed William Shockley, a -born sandwich of p-type germanium between two

October 2018 Practical Wireless 25 The Transistor Revolution

n-type regions. After it was discovered that minority carriers could indeed traverse the bulk semiconductor, the concept appeared feasible and he successfully patented this bipolar ‘junction transistor’ in his own name. It would eventually supersede the point- contact type but at the time no-one knew how such a device could be fabricated and it was dubbed a ‘persistor’ because it seemed that much persistence would be required to make it. Meanwhile, with patent protection secured and after Naval Research Labora- tory staff had withdrawn a claim that they had already made the same thing, Bell Labs William Pfann (left) with an early zone refning Shockley describes the concept of the npn junction announced the invention of the point-contact furnace. (Bell Labs) transistor. (Bell Labs) transistor at a press conference on June 30th 1948. Research Director Ralph Bown applications, including CV versions for to displace a small molten region slowly illustrated the structure of the new device military use. Mullard’s Reference Manual of along its length. This causes the impurities with a giant cutaway model. The attendees Transistor Circuits provided a useful starting to be swept to the end of the crystal, which were given headphones to hear the device guide for many amateur designers but high is eventually cut off. For silicon crystals, a amplify and oscillate and to listen to a broad- frequency were still rare and the variation of this technique called foat zone- cast received on a radio set that used tran- only described was a 5-transistor refning was devised in which contamina- sistors instead of valves. After the unveiling, unit for the emergency frequency of 500kHz. tion is avoided by maintaining the molten the public showed only lukewarm interest portion in place by surface tension, without but Bell Labs was besieged by requests for Crystals a containment vessel. A similar process was sample devices from the electronics industry While the frst point-contact transistors also developed independently by Siemens in and the armed forces. By the summer of used polycrystalline germanium, the key West . 1949 the lab had fabricated 4000 working to the manufacture of junction transistors To produce the npn or pnp sandwich germanium transistors. is the production of extremely pure single of Shockley’s junction transistor, Morgan Also in that year, the US Justice Depart- crystals that can be doped very precisely Sparks invented a double-doping method of ment fled a new antitrust suit against the with p-type and n-type impurities. Chance changing the relative impurity concentrations Bell System. In view of this, as soon as the often plays a vital role in discovery. In while the crystal was being drawn from the military agreed in late 1951 that transistor 1915, the Polish chemist Jan Czochralski melt, producing the frst grown-junction ger- technology need not be classifed, AT&T absent-mindedly dipped his pen into a manium transistor in April 1950. After further made manufacturing licences available crucible of molten tin instead of his ink- refnement, Bell Labs announced this inven- without restriction to interested companies in well. When he lifted the pen, he found that tion in July 1951. Meanwhile, the trio that NATO countries and Japan for the relatively it drew out a flament of tin that proved to had made the initial invention had broken up. modest fee of $25,000 (about $260,000 in be a single crystal. Frustrated by Shockley’s management style, today’s money). Licensees, government Bell Labs chemical engineer Gordon Brattain refused to work with him again, labs and university researchers were given Teal advocated developing this technique while Bardeen left Bell Labs altogether. This sample transistors. They were also invited for growing large single crystals by draw- was a foretaste of the problems that would to a technology symposium and a two-day ing a seed slowly from a crucible of molten later lead to the downfall of Shockley’s busi- transistor manufacturing plant tour at West- germanium but he received no support ness enterprise. ern Electric that was attended by 100 rep- from Shockley or management for this resentatives from 40 companies, including work. Working evenings and weekends, he Silicon BTH, Ericsson, GEC, , Siemens and pursued the idea unoffcially, shutting his ap- For transistor manufacture, silicon has Telefunken from Europe. When published in paratus away in storage during the day since inherent advantages over germanium book form, a revised edition of the symposi- there was no room for it in the metallurgy because of its greater abundance, lower um proceedings called Transistor Technology lab. By late 1949 he was able to make very leakage current and higher operating tem- was soon dubbed Ma Bell’s Cookbook. In pure single germanium crystals and the huge perature range. But the material is more 1955 AT&T relinquished its original transis- improvement compared with polycrystal- diffcult to purify and process and, owing tor patents to stave off forced divestiture, line material became evident to all. For the to the lower charge carrier mobility, a sili- although hung on to those production of wafers for modern VLSI micro- con transistor must have a much narrower covering key manufacturing processes. circuits, the Czochralski/Teal process is still base region for operation. In the UK, Mullard started production the basis of the principal method of growing It wasn’t until 1961 that, with gold dop- of the point-contact OC50 and OC51 in silicon boules, which today may be up to 2m ing and epitaxy, a silicon transistor (the 1952, before launching a range of junction long and 450mm in diameter. 2N709) exceeded germanium speed. transistors the following year. Subsequently, At the same time, William Pfann invented During WW2 great strides had been made over ten British manufacturers produced the zone-refning method of purifying a in the art of purifying the material, and by hundreds of transistor types for different crystal ingot by using induction heating coils 1945 silicon of 99.999% purity was available.

26 Practical Wireless October 2018 were initially reluctant to change over from thermionic valves, which were cheaper than transistors at the time. So, in October 1954 Texas Instruments and Industrial Development Engineering Associates (IDEA) in Indianapolis teamed up to launch the famous $49.95 Regency TR-1. This pocket- sized MW AM set used four npn germanium junction transistors in a superhet circuit with one /mixer, two 262kHz IF stages and one audio amplif er. (The low Gordon Teal (left) and Morgan Sparks developed the IF was chosen to increase the gain). Before crystal growing and doping technologies that made teenagers adopted it as a personal music the junction transistor possible. (Bell Labs) player, the radio was marketed as a ‘security item’ since the USSR was now an atomic power. In spite of its somewhat mediocre performance, the radio was a success and almost 100,000 sets were sold in the f rst 12 months. But having underestimated the cost of making the radio, TI hardly broke even on the venture and after that the company concentrated on making semiconductors for In 1954 the 4-transistor Regency TR-1 was the other manufacturers to incorporate in their world’s f rst commercial transistor radio. Over products. 100,000 sets were made. (Joe Haupt) One of the enterprises that emulated the TR-1 was a small Japanese company called TI then dominated the market for silicon Tokyo Tsushin Kogyo (Totsuko). With little transistors for several years. The little more information than a Bell Lab’s licence company was suddenly in the big league. and Ma Bell’s Cookbook, they started In the UK, the TRE electronics engineer manufacturing point-contact and then Geoffrey Dummer, a specialist in radar junction transistors, obtaining a reasonable synthetic trainers, presented a fundamental yield of about 5%. After a false start with paper in 1952 describing the concept of the a portable radio whose plastic case was The f rst germanium junction transistor was . But British semiconductor found to come apart in the summer heat, fabricated by Morgan Sparks in 1950. (Bell Labs) manufacturers were unwilling to take the they launched their TR-55 model in August risk of investing in the idea and it would be 1955. This 5-transistor set was Japan’s f rst Further improvements by DuPont allowed six years before radio engineer transistor radio and it spearheaded the entire the f rst grown-junction silicon transistor to (W9GTY) of TI was awarded a patent for Japanese consumer electronics industry. be fabricated at Bell Labs in January 1954 the f rst crude IC. He demonstrated that For the product launch, Totsuko’s owners but in spite of this success the development transistors, diodes, and changed their tongue-twisting brand name wasn’t followed up commercially by Western could be fabricated in a single chip, although to one that could more easily be pronounced Electric, the manufacturing side of AT&T. his hybrid design required them to be in the West. They called it Sony. The name Meanwhile Teal had left Bell Labs to join interconnected by f ying bonding . Bell became well known outside Japan after a f edgling start-up company that would Labs researchers also missed the integrated discerning thieves who broke into a New become called Texas Instruments. After circuit and Western Electric had to enter York warehouse ignored other makes to steal telling Teal repeatedly “This business is cross-licensing agreements to make them. only the 4000 Sony radios stored there. not for you. We don’t think you can do it”, In 1953 Philco developed electrolytically Bell Labs f nally agreed to accord a licence Consumer Radio machined surface-barrier germanium to TI in 1952. But instead of making only In addition to hearing aids, it seemed transistors that could operate up to 60MHz germanium transistors Teal established a natural that portable radio receivers would and manufacturing licences were granted group to work on grown-junction silicon be among the f rst commercially made to other companies including Sprague transistors and 150 good ones had been consumer products to employ transistors. and a division of Plessey. In 1955 these made by the time of the IRE National Demonstration sets were shown at the transistors were used in the f rst commercial Conference in May 1954. At the conference, 1952 Components Exhibition in Paris transistor car radio and in 1958 improved speaker after speaker reported that the and at the 1953 Dusseldorf Radio Fair, versions were orbited in the 108MHz beacon development of the silicon transistor would where the Intermetall Corporation that transmitter carried by Explorer 1, the f rst US take several years so that Teal created a had been founded by Mataré on his return satellite. sensation when he revealed that he had to Germany demonstrated a prototype Next month I will conclude by describing a handful of them in his pocket and that receiver that used four hand-assembled the f rst uses of transistors in amateur radio commercial production at TI was beginning point-contact transistors. and more recent developments in transistor immediately. With no effective competition, But the established radio manufacturers technology.

October 2018 Practical Wireless 27 Feature by Dr Bruce Taylor HB9ANY

l E-mail: [email protected]

ireless World first reported the inven- tion of the transistor in October 1948. The Transistor Using little more than Wa microscope, an Avometer and a pulse source for point-contact forming, enter- prising amateurs were soon making their own transistors by replacing the single Revolution (Part 2) cat’s whisker of selected germanium diodes by two. By 1950 enthusiasts in the UK were building simple receivers using Dr Bruce Taylor HB9ANY concludes his look at the history commercially-available Raytheon point- contact transistors that were primarily of the transistor, relating how the invention impacted made for hearing aids. amateur radio and moving on to modern developments Radio amateurs also started ex- perimenting with transmitters as soon as in integrated circuitry and microprocessors. suitable transistors became available at accessible prices. The February 1953 is- sue of QST described how RCA manager K2AH even made a 146MHz CW QSO with W2UK over 25 miles with a power input of 24mW to a single selected experimental point-contact germanium T165/6 transistor. In the UK, a miniature 3.5MHz transistor transmitter by G5CV aroused great inter- est when operated at the 1953 Amateur Radio Exhibition. A simple receiver using two GEC point-contact transistors was described in the January 1954 issue of Wireless World, while a topband (160m) transmitter by G3IEE using a Mullard OC50 featured in the RSGB Bulletin for March. At this time manufacturers such as Philips made ‘experimental transistors’ available to amateurs at low prices. These were devices that failed to meet the full profes- sional specifcations and would otherwise have been scrap. In mid-1956 IDEA launched the Regency ATC-1, a simple two-transistor mobile converter that tuned the fve HF amateur bands. One germanium npn tran- sistor acted as oscillator/mixer, with output at 1230kHz for a broadcast receiver, and The 1956 Regency ATC-1 HF band converter was one of the frst commercial transistor products for radio a second pnp one as Q-multiplier/BFO. It amateurs. (W8ZR) was sold for $79.50. In September of that year W1OGU, a 10-transistor kit set used three Mullard IT-2232 was phased out in 1990. technician with Raytheon, achieved the germanium AF115s as RF amplifer, local It took several years for many of the tra- frst transatlantic QSO with a transistor oscillator and mixer, with four OC45s for ditional shortwave receiver manufacturers transmitter, working OZ7BO in Copenha- the BFO and three IF amplifers coupled by to change from valve to transistor designs gen and G3AAM in Birmingham on 14MHz. 455kHz piezoelectric ‘transflters’. After re- and not all did so successfully. Eddystone’s His crystal-controlled rig used one 2N113 placing the audio output stage by a higher frst solid-state communications receiver germanium alloy junction transistor as power amplifer, I used the compact set was the S960; virtually a model S940 7MHz oscillator, driving a second as dou- as a mobile receiver for several years but with 12 transistors in place of valves. Its bler/output stage with 78mW input. its performance didn’t match that of good performance was inferior to its parent and One of the frst shortwave transis- valve receivers of that period. Starting with it was dropped two years later. The more tor receivers for radio amateurs to be the Model IM-30 in 1961, Heathkit also compact EC10 that was introduced in 1963 made in the UK was the Heathkit GC-1U produced a series of rudimentary transistor was more successful and over 6,000 were Mohican, which was sold in 1961 for £38 testers and curve tracers that evolved with made, followed by around 10,000 of the 15/- (around £800 in today’s money). The the device technology until the fnal Model Mk2 version with an S-meter and fne-

62 Practical Wireless November 2018

Transistors.indd 62 20/09/2018 09:24 tuning control. In 1971 you could choose between the valved Model 830 receiver and the transistorised 1830 version with slightly better performance. The 830 was Eddystone’s last valve receiver and contin- ued in production until January 1973. National HRO receivers had been a long-time favourite with radio amateurs, and around 10,000 sets were used by the Y-Station service that supplied intercepted enemy wireless messages to Bletch- ley Park during WW2. In 1964 National The UK version of the 10-transistor Heathkit introduced a transistor version of the Mohican receiver was launched in 1961. (GM3NZI) receiver that retained the classic ‘PW’ gear drive but no longer had plug-in coils. This transitional set had 37 germanium transis- tors in sockets connected by conventional W1OGU achieved the f rst transatlantic QSO with a point-to-point wiring, just like its valve 78mW transistor transmitter in September 1952. predecessors.

Diffusion The f rst successful method of making a junction transistor involved creating the base layer by dropping a tiny p-type pellet into the n-type melt while drawing the crystal, and then converting it back to The IM-30 was the f rst of a series of simple n-type. With this double-doping process, transistor testers that could measure DC gain and and also the improved rate-grown variant, leakage current. (Heathkit) it was diff cult to accurately produce and connect to the very narrow base region W1OGU’s historic 14MHz transatlantic transmitter required for high frequency performance. used two germanium 2N113 transistors. (Raytheon) Problems also arose with the alternative alloy junction process developed by GE the printing industry had already been and RCA, since precise control of the used for the production of printed circuit alloying temperature and the thickness of boards, using a photosensitive resist that the base layer was diff cult. In a batch of was exposed through an optical mask. 100 transistors, the gain could vary from The technology was readily adapted to 20 to 50dB. chemically etch precisely-dimensioned Once again, chance played an essential windows in the oxide layer covering the role in the development of a hugely impor- silicon wafer, through which the n and tant new technology. While doping by gas p-type impurities could be diffused to diffusion had been used to introduce the make a double-diffused transistor and this Early transistor receiver technology. The glass- donor impurities into germanium crystals, important invention was announced by Bell encapsulated Mullard germanium transistors attempts to use the process at the very Labs in June 1955. With the Cold War in are mounted on solder sockets like little valves. high temperatures required for processing full swing, ample military funds were avail- (GM3NZI) silicon were initially unsuccessful because able to develop these new transistors that of damage to the wafer surface. But could operate at high temperature and high that he had no right to know. while Bell Labs chemist Carl Frosch was frequency. All three men attended a celebration experimenting with diffusion, the hydrogen dinner in New York but the Bardeen and carrying the dopant impurities accidentally Nobel Brattain families travelled to Stockholm caught f re, causing water to be produced It had been expected for several years separately from the Shockleys and only in his diffusion chamber. Frosch discovered that the invention of the transistor merited shared the formal ceremonies there. For all that the f ne green silicon dioxide layer that a Nobel Prize, so it was no real surprise three Laureates, it was the pinnacle of their this formed on the surface of the wafer when Bardeen and Brattain were chosen careers. For Shockley, it was the prelude to sealed it and protected it from damage. to receive the 1956 award for Physics. It his demise. Unlike germanium oxides, silica is strong, was less certain that Shockley would also inert and an excellent insulator. Initially share the coveted prize but in the end his Silicon Valley considered a problem, the oxide turned out name was included although the vote was In view of his abrasive management style, to be a key element of reliable solid-state not unanimous. Shockley tried to f nd out Shockley was repeatedly passed over for electronics. from the Swedish Royal Academy of Sci- promotion at Bell Labs. So, during 1955 he Photolithography techniques from ences who had opposed him but was told left to launch his own enterprise and, with

November 2018 Practical Wireless 63

Transistors.indd 63 20/09/2018 09:24 The Transistor Revolution

National launched the solid-state HRO 500 in 1964. It was built like a traditional valve receiver but used 37 (right) addresses the other seven germanium transistors and 20 diodes. (Merate Chronometer Center) members of the ‘traitorous eight’. (Fairchild)

the f nancial backing of Beckman Indus- pany had fallen apart. Shockley did almost tries, Shockley Semiconductor Laboratory no further work of scientif c value and went started up in April 1956. The facility was on to pursue a racist dysgenics agenda, located in a new industrial park that was lecturing about the inferiority of African- being set up in the Santa Clara Valley on Americans and advocating the sterilisation land owned by Stanford University. It was of people with an IQ under 100. He died the start of silicon in Silicon Valley, the in 1989 without fortune but knowing that The 33-transistor Eddystone 1830 had a JFET/ extraordinary zone of innovation and tech- he had been the intellectual driving force MOSFET cascode RF amplif er and dual-gate nology that now accounts for one-third of behind a technological revolution and the MOSFET f rst mixer. (Eddystone UG) all the venture capital investment in the catalyst of an industry that turned a quiet US. Shockley planned that his company Californian valley into the most concen- would “set the world on fi re”. Indeed, it trated source of wealth on the planet. did, but not at all as he envisaged. None of Shockley’s Bell Labs col- Planar Technology leagues wanted to join him. But because The ‘traitorous eight’ that defected en of his reputation as a scientif c genius, he masse from Shockley Lab went on to had no diff culty recruiting very talented found Fairchild Semiconductor with a staff, including the chemist Gordon Moore $1.38 million loan from Sherman Fairchild, (of Moore’s Law), Swiss physicist Jean a New York playboy-inventor who was the Hoerni and Robert Noyce, who was largest shareholder in IBM. Each of the employed at that time by the radio and eight had to make an initial investment of TV manufacturer Philco but was seeking $500 to purchase 100 of the company’s research-oriented work. In the UK, Ferranti shares, a sum that Noyce had to borrow began producing bipolar silicon diffused from his grandmother since neither he nor This 432MHz converter was typical of the transistors in 1954. Shockley could also his parents had any savings. He had no homebrew UHF art in 1965. It uses three TI have directed his new team to ramp up diff culty repaying her with interest, for less germanium pnp transistors in the UHF stages and production of silicon transistors to prof t than two years later his stock was worth three Mullard OC171s for the frequency multiplier from a rapidly expanding US market. But $300,000 and his personal fortune was and 28MHz IF amplif er. (GM3NZI) instead, he insisted that they devote their eventually to grow to over $3 billion. efforts to developing a special four-layer The timing was fortuitous. Alarmed by pnpn that was diff cult to fabricate the surprise launch of Sputnik 1 in October reliably and of limited application. As a 1957, the US Military suddenly had major result, Shockley Semiconductor Lab never requirements for lightweight miniature turned a prof t. solid-state components for its catch-up Shockley proved an even worse man- programme and total annual purchases ager in his own company than at Bell Labs. soon exceeded $100 million. Fairchild’s He constantly feuded with subordinates, f rst contract was to manufacture silicon insulted his staff and refused to listen to mesa transistors for IBM’s navigational their advice. He became paranoid about for the XB-70 Valkyrie bomber. trivial incidents, recorded all phone calls, To make arrays of transistors, they cobbled and at one point even ordered all his em- together a step-and-repeat camera using ployees to take a lie-detector test. Genius ordinary 16mm movie camera lenses. The Noyce made the f rst monolithic silicon IC in 1961. without ethics wasn’t a winning formula yield was reasonable but reliability proved This basic fl ip-fl op had four transistors and two and by September 1958, after a mutiny of an issue and technicians had to ‘tap test’ resistors. (Fairchild) eight dissidents lead by Noyce, the com- the transistors with pencil erasers to check

64 Practical Wireless November 2018

Transistors.indd 64 20/09/2018 09:24 The 1976 Ferranti F100L was the frst 16-bit microprocessor designed and manufactured in Inexpensive SDR dongles spawned a new generation of Europe. It used an enhanced rad-hard bipolar technology with 3.5 micron features. (Ferranti) communications receivers. (HB9ANY)

whether tiny loose particles trapped in the integrated electronics. In the UK, Plessey because of its high power consumption. hermetic package could contaminate the was involved in integrated circuit develop- Two years later Intel introduced the com- exposed p-n junctions. ment at an early date but the frst ICs to be mercial 16-bit 3-micron 8086 microproces- To solve this problem, Hoerni built on produced commercially in Europe were the sor and the x86 family architecture rapidly the earlier work of Frosch to invent the Micronor devices introduced by Ferranti became ubiquitous in desktop PCs and ground-breaking planar technology that from 1962. These ICs had a wired OR func- laptops. In due course this led to the next protected the sensitive junctions with oxide tion and were used mainly in iteration in wireless technology. Although and allowed all the contacts to be made on developed by Marconi for the Admiralty. the concept was much older, in 1995 Ste- one side of the silicon wafer. This passiva- The second generation of this family used phen Blust coined the term Software De- tion process reduced leakage currents and an enhanced DTL technology that was fned Radio and soon SDR hardware and the confguration automatically created faster but less dense than TI 74 series TTL, software allowed any PC to be turned into graded bases that reduce the charge car- which emerged as the most popular logic a high-performance transceiver capable of rier transit time, as in drift transistors. It confguration after it appeared in 1966. handling a wide range of communications also supported the aluminium-over-oxide Micronor II ICs powered the Argus 400 modes. interconnection scheme that was used by computers that were used in many indus- Today there are 19 silicon Noyce to make the frst commercial mono- trial control applications, such as nuclear manufacturing facilities in the UK. A lithic silicon integrated circuits in 1960, power stations and the Jodrell Bank radio single modern FPGA can have as many after the problem of aligning successive telescope. In 1966, Plessey started the as 50 billion microscopic transistors and photolithographic masks had been solved. frst European production of MOS ICs at (including memory) a high-end smartphone Patent litigation between Fairchild and TI Swindon. contains a total of around one trillion, over the invention of the IC lasted many or ten times more than the number of years but out of court the two companies Evolution neurons in the human brain. To visualise entered a cross-licensing agreement with a In 1968 Moore and Noyce left Fairchild to the total number of transistors that have net payment to Fairchild. found Integrated Electronics Corp, a name been manufactured, we can take as a The individual components in the they abridged to the snappier Intel. In- metric the number of cells in the human production versions of these ICs were spired by HP, they practised a non-hierar- body – about 100 trillion. Then a Fermi isolated by reverse-biased p-n junctions, a chical management style that encouraged estimate of the total number of transistors technique that had been patented by Kurt the exchange of ideas and innovation and made since 1947 exceeds the number Lehovec while at Sprague Electric, who in 1971 their four-bit 10-micron 4004 CPU of human cells in the entire population of paid him only $1 for the rights to this key chip with 2300 MOS transistors launched the UK and within a few years the number invention. (A common practice at the time). the microcomputer age. At that time of transistors produced may equal the Until it was overtaken by TI in 1967, Fair- few people envisaged the wide-ranging number of human cells on the planet. Even child became the undisputed leader of the consequence of the synergy of micropro- visionaries like Bill Hewlett and Dave semiconductor industry and in due course, cessors and wireless, and in the same Packard would have been astounded. spin-off ‘Fairchildren’ spawned the creation year a marketing study commissioned by In the years immediately following its of dozens of successful companies in Sili- AT&T reported that “there is no market for invention, the transistor was conceived con Valley, such as AMD, Intersil, National mobile phones at any price”! as a replacement for the thermionic valve. Semiconductor, Signetics and Teledyne. The frst European 16-bit microproces- Indeed, it was, and a very good one but The silicon dioxide layer also proved sor was the Ferranti 3.5-micron F100L, it also triggered revolutionary growth in the key to neutralising the troublesome introduced in 1976. This mil-spec rad-hard communications technology and created surface states that had thwarted attempts chip, designed in Bracknell and fabricated a world that has become interconnected to make an insulated-gate feld-effect in Manchester, had about 7000 compo- as never before. Apart from wireless itself, transistor. John Atalla fnally succeeded nents and 2m of aluminium track intercon- perhaps no other modern invention has in making a working FET at Bell Labs in nects. It was orbited in OSCAR-9, although had a greater infuence on almost every 1959, paving the way for modern MOSFET it wasn’t frequently enabled in that satellite aspect of our daily lives.

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