passivating effect on a silicon surface. Jean Hoerni attended the same meeting, and was intrigued by Atalla's presentation. Hoerni came up with a "planar idea" one morning while thinking about Atalla's device. Taking advantage of silicon dioxide's passivating effect on the silicon surface, Hoerni proposed to make transistors that were protected by a layer of silicon dioxide. The planar process was developed by Jean Hoerni while working at Fairchild Semiconductor, with a first patent issued in 1959. The planar process used to make these transistors made mass-produced monolithic silicon integrated circuits possible. MOSFET In 1959, the MOSFET was introduced and in 2020 it was still the dominant transistor type in use, with an estimated total of 13sextillion () MOSFETs manufactured between 1960 and 2018. The key advantages of a MOSFET transistors over BJTs are that they consume no current except when switching states and they have faster switching speed (ideal for digital signals). Early commercialization The world's first commercial transistor production line was at the Western Electric plant on Union Boulevard in Allentown, Pennsylvania. Production began on Oct. 1, 1951 with the point contact germanium transistor. The first commercial application of transistors in telecommunication was in the Fall of 1952 in tone generators for multifrequency signaling of the No. 5 Crossbar switching system in the Englewood, NJ installation, used for the first field trial of direct distance dialing (DDD). By 1953, the transistor was being used in some products, such as hearing aids and telephone exchanges, but there were still significant issues preventing its broader application, such as sensitivity to moisture and the fragility of the wires attached to germanium crystals. Donald G. Fink, Philco's director of research, summarized the status of the transistor's commercial potential with an analogy: "Is it a pimpled adolescent, now awkward, but promising future vigor? Or has it arrived at maturity, full of languor, surrounded by disappointments?" Semiconductor companies initially focused on junction transistors in the early years of the semiconductor industry. However, the junction transistor was a relatively bulky device that was difficult to manufacture on a mass-production basis, which limited it to a number of specialised applications. Transistor radios Prototypes of all-transistor AM radio receivers were demonstrated, but were really only laboratory curiosities. However, in 1950 Shockley developed a radically different type of solid-state amplifier which became known as the bipolar junction transistor, which works on a completely different principle than the point-contact