Dawon Kahng: Architect of the Silicon Age
Dawon Kahng, a name that echoes in the hallowed halls of solid-state electronics, was a Korean-American engineer and inventor whose contributions fundamentally reshaped the landscape of modern technology. Born in Keijō, Keiki-dō, Korea, Rep of, on May 4, 1931, he navigated a world on the cusp of immense change, ultimately becoming a pivotal figure in the semiconductor device fabrication revolution. His life, though tragically cut short on May 13, 1992, in New Brunswick, New Jersey, U.S., left an indelible mark, particularly through his groundbreaking invention of the MOSFET (metal–oxide–semiconductor field-effect transistor), often referred to simply as the MOS transistor.
The Architect's Early Blueprint
In the Korean name system, the family name precedes the given name, a detail that anchors Kahng's identity to his heritage. His given name, Hangul 강대원, transliterated as Gang Daewon under the RR system and Kang Taewŏn using the MR system, speaks of a lineage rooted in the Hanja character 姜 (meaning ginger, but often used as a surname). His birth in Keijō, then a part of Korea, Empire of Japan, now known as Seoul, South Korea, placed him at the nexus of cultural and political shifts that would inevitably influence his trajectory.
Kahng's academic journey began at Seoul National University, where he immersed himself in the principles of physics. The allure of advanced research beckoned him to the United States in 1955, leading him to Ohio State University. It was within the rigorous academic environment of Ohio State that he honed his expertise, culminating in a doctorate in electrical engineering in 1959. This period of intense study, particularly his doctoral thesis on "Phosphorus diffusion into silicon through an oxide layer" at Ohio State University, laid the theoretical groundwork for the practical innovations that would soon follow.
A Partnership Forged in Innovation
The year 1959 marked a watershed moment in electronics history. At Bell Telephone Laboratories in Murray Hill, New Jersey, Dawon Kahng, alongside his brilliant colleague Mohamed Atalla, achieved a monumental feat: the invention of the MOSFET. This wasn't merely an incremental improvement; it was a paradigm shift. The MOSFET, a transistor that uses an electric field to control the conductivity of a channel, became the cornerstone of virtually all modern electronic equipment. Kahng and Atalla's ingenuity extended to the development of both the PMOS and NMOS processes, essential for the fabrication of these revolutionary devices. Their initial fabrication efforts utilized a 20 micrometre process, a testament to the cutting-edge technology of the era.
Their collaboration didn't cease with the MOSFET. Building upon this success, Kahng and Atalla ventured into the realm of hot carrier devices, exploring what would later be recognized as the Schottky barrier. While the concept of the Schottky diode, or Schottky-barrier diode, had been theorized, it was Kahng and Atalla who, between 1960 and 1961, brought it into practical realization. Their 1962 publication detailing a novel "hot electron" triode structure with a semiconductor-metal emitter solidified their pioneering status in this field. The Schottky diode, with its swift switching capabilities, would go on to become indispensable in mixer applications, and their subsequent research delved deeper into high-frequency Schottky diodes, though that particular line of inquiry remains unadorned with specific citations.
Expanding the Frontiers of Semiconductor Technology
The relentless pursuit of innovation led Kahng and Atalla to further groundbreaking work. In 1962, they conceptualized and demonstrated an early metal nanolayer-base transistor. This intricate device featured a metallic layer of nanometric thickness strategically sandwiched between two semiconducting layers, with the metal acting as the base and the semiconductors serving as the emitter and collector. The inherent advantage of this design lay in its reduced resistance and fleeting transit times within the ultrathin metallic nanolayer, enabling operational frequency capabilities far exceeding those of conventional bipolar transistors. Their experimental work involved depositing gold (Au) thin films, meticulously controlled to a thickness of 10 nanometres, onto n-type germanium (n-Ge) substrates. The emitter was fashioned from a crystalline semiconductor, specifically n-type silicon (n-Si), making contact through a point contact. This was not just theoretical musing; it was tangible engineering, pushing the boundaries of material science and device design.
The late 1960s saw Kahng embark on another transformative invention. In 1967, alongside his colleague Simon Min Sze, he invented the floating-gate MOSFET (FGMOS). This innovation led directly to the conceptualization of the floating-gate memory cell, a fundamental building block for numerous semiconductor memory devices. Kahng's vision was profound: he proposed that the floating gate within an MOS semiconductor device could serve as the core component of a reprogrammable read-only memory (ROM). This prescient idea became the bedrock upon which technologies like EPROM (erasable programmable ROM), EEPROM (electrically erasable programmable ROM), and the ubiquitous flash memory were built. His research interests also extended to ferroelectric semiconductors and luminous materials, contributing significantly to the field of electroluminescence, though the specifics of this work remain elusive, marked only by a placeholder for further citation.
A Legacy Etched in Silicon
Following his distinguished tenure at Bell Laboratories, Kahng assumed the role of the founding president of the NEC Research Institute in New Jersey, a testament to his leadership and continued commitment to technological advancement. His professional accolades were numerous and well-deserved. He held the esteemed titles of fellow of the IEEE and fellow of Bell Laboratories. The Franklin Institute recognized his monumental contributions by awarding him the Stuart Ballantine Medal, and Ohio State University honored him with the Distinguished Alumnus Award from its College of Engineering.
The impact of his work was further cemented by posthumous recognitions. In 2009, Dawon Kahng was inducted into the prestigious National Inventors Hall of Fame. Then, in 2014, the invention of the MOSFET, his most impactful creation, was officially recognized as an IEEE milestone, a distinction reserved for seminal achievements in electronics.
His life was tragically cut short by complications arising from emergency surgery for a ruptured aortic aneurysm in 1992, but the silicon etched with his genius continues to power the world. Dawon Kahng, a name synonymous with innovation, remains a towering figure in the history of technology, his legacy woven into the very fabric of our digital existence.