On 22 Oct 1925, Julius Edgar Lilienfeld (a Polish1 professor in Germany) patented the field-effect transistor (FET).[LIL1] In 1928, he also patented the metal oxide semiconductor FET (MOSFET).[LIL2] Lilienfeld's designs worked.[ARN98][ROS95] The much later point-contact transistor (Bell Labs, 1948) was a dead end:[LIL4] today, almost all of the billions of trillions of transistors in our computers and smartphones are FETs of the Lilienfeld type.
Later Work on Transistors
In 1934, German engineer Oskar Heil patented another FET variant.[HEIL] Two decades after Lilienfeld, researchers at Bell Labs not only experimentally confirmed the field-effect described in Lilienfeld's patents[ARN98]—see the priority dispute Lilienfeld vs Bell Labs below—but also patented a point-contact transistor (PCT, patent filed on 26 February 1948 by William Shockley & John Bardeen & Walter Brattain).[BRA48] A few months later, the transistron (a junction field-effect transistor or JFET) was patented by German physicists Herbert F. Mataré and Heinrich Welker in France at Compagnie des Freins et Signaux Westinghouse (patent filed on 13 August 1948).[MAT48]
The PCT and the transistron were the first commercial transistors. In hindsight, however, the 1948 PCT—which was "never quite practical" and "merely a detour"[ARN98]—was a dead end, and today, almost all transistors are FETs of the Lilienfeld type, in particular, certain MOSFET[LIL2] variants patented by Egyptian engineer Mohamed M. Atalla and Korean engineer Dawon Kahng at Bell Labs in 1960.[ATA60]
The Priority Dispute: Lilienfeld (1925-28) vs Bell Labs (1948)
According to legal files (1948) examined by American physicist Robert G. Arns,[ARN98] William Shockley & Gerald Pearson at Bell Labs had confirmed the field-effect described in Lilienfeld's patents. Unfortunately, "published scientific, technical, and historical papers by these Bell scientists never mention either Lilienfeld’s or Heil’s prior work,"[ARN98] "not even a 1948 paper[SHO48] in which Shockley & Pearson demonstrated the field-effect experimentally."[ARN98]
In November 1948, various patent applications by Bell Labs were rejected for being too similar to Lilienfeld's (and Heil's) much earlier designs.[PAT48] (16 years later, in 1964, J. B. Johnson of Bell Labs claimed that some of Lilienfeld's FETs didn't work when he tested them, however, Arns points out[ARN98] that this statement "appears to have been deliberately misleading.") Later, some people claimed that Lilienfeld did not implement his ideas since "high-purity materials needed to make such devices work were decades away from being ready,"[CHLI] but the 1991 thesis by Bret Crawford offered evidence that "these claims are incorrect."[CRA91] Lilienfeld was an accomplished experimenter, and in 1995, Joel Ross[ROS95] "replicated the prescriptions of the same Lilienfeld patent. He was able to produce devices that remained stable for months."[ARN98] Also, in 1981, semiconductor physicist H. E. Stockman confirmed that "Lilienfeld demonstrated his remarkable tubeless radio receiver on many occasions".[EMM13]
Before the above issues became widely known, three Bell Labs researchers shared the Nobel Prize for the transistor, which should have been awarded to Lilienfeld. This was a major malfunction in the Nobel Prize selection process—and not the last one.[NOB] Bardeen, one of the 3 awardees, finally admitted in 1988 that Lilienfeld "had the basic concept of controlling the flow of current in a semiconductor to make an amplifying device,"[BAR88][ARN98] and that his own point-contact transistor "may have slowed the advancement of the transistor field because it diverted the semiconductor program from junction and field-effect transistors which subsequently proved to be far more useful commercially."[ARN98]
As of 2025, there is no reasonable doubt that the inventor of the transistor is Julius Edgar Lilienfeld.
1949: The Integrated Circuit
Since the invention of the transistor, computers have become much faster through integrated circuits (ICs) gathering many transistors on the same microchip.
In 1949, German engineer Werner Jacobi at Siemens filed the first patent for an IC semiconductor with several transistors on a common substrate (granted in 1952).[IC49-14]
In 1958, American engineer Jack Kilby demonstrated an IC with external wires. In 1959, Robert Noyce presented a monolithic IC.[IC14]
Since the 1970s, graphics processing units (GPUs) have been used to speed up computations through parallel processing. ICs/GPUs of today (2025) can contain hundreds of billions of transistors, almost all of them of Lilienfeld's 1925 FET type.[LIL1-2]
The Future
In 1941, the world's first general-purpose program-controlled computer (Konrad Zuse's Z3)[ZU36][RO98][ZUS21] could perform roughly one elementary operation (e.g., an addition) per second. Since then, every 5 years, compute has gotten roughly 10 times cheaper (note that his law is much older than Moore's Law which states that the number of transistors[LIL1-4] per chip doubles every 18 months). As of 2025, one human life after Z3, modern computers can execute about 100 million billion instructions per second for the same (inflation-adjusted) price. The naive extrapolation of this exponential trend predicts that the 21st century will see cheap computers with a thousand times the raw computational power of all human brains combined.[RAW]
Where are the physical limits? According to Bremermann (1982),[BRE] a computer of 1 kg of mass and 1 liter of volume can execute at most 1051 operations per second on at most 1032 bits. The trend above will hit the Bremermann limit roughly 25 decades after Z3, circa 2200. However, since there are only 2 x 1030 kg of mass in the solar system, the trend is bound to break within a few centuries, since the speed of light will greatly limit the acquisition of additional mass, e.g., in form of other solar systems, through a function ploynomial in time, as previously noted back in 2004.[OOPS2][ZUS21][DLH]