Power MOSFET

A power MOSFET is a specific type of MOSFET (metal-oxide-semiconductor field-effect transistor) designed to handle significant power levels. A power MOSFET is a specific type of MOSFET (metal-oxide-semiconductor field-effect transistor) designed to handle significant power levels. Compared to the other power semiconductor devices, for example an insulated-gate bipolar transistor (IGBT) or a thyristor, its main advantages are high switching speed and good efficiency at low voltages. It shares with the IGBT an isolated gate that makes it easy to drive. They can be subject to low gain, sometimes to a degree that the gate voltage needs to be higher than the voltage under control. The design of power MOSFETs was made possible by the evolution of MOSFET and CMOS technology, developed for manufacturing integrated circuits in the 1960s. The power MOSFET shares its operating principle with its low-power counterpart, the lateral MOSFET. The power MOSFET, which is commonly used in power electronics, was adapted from the standard MOSFET and commercially introduced in the 1970s. The power MOSFET is the most common power device in the world, due to its low gate drive power, fast switching speed, easy advanced paralleling capability, wide bandwidth, ruggedness, easy drive, simple biasing, ease of application, and ease of repair. In particular, it is the most widely used low-voltage (that is, less than 200 V) switch. It can be found in most power supplies, DC to DC converters, and low voltage motor controllers. It has a wide range of power electronic applications, such as portable information appliances, power integrated circuits, cell phones, notebook computers, and the communications infrastructure that enables the internet. The invention of the MOSFET by Mohamed Atalla and Dawon Kahng at Bell Labs in 1959 was a breakthrough in power electronics. Generations of MOSFETs enabled power designers to achieve performance and density levels not possible with bipolar transistors. In 1969, Hitachi introduced the first vertical power MOSFET, which would later be known as the VMOS (V-groove MOSFET). In 1974, Jun-ichi Nishizawa at Tohoku University invented a power MOSFET for audio, which was soon manufactured by Yamaha for their hi-fi audio amplifiers. JVC, Pioneer Corporation, Sony and Toshiba also began manufacturing amplifiers with power MOSFETs in 1974. Siliconix commercially introduced a VMOS in 1975. In the late 1970s, the VMOS developed into what became known as the DMOS (double-diffused MOSFET) or VDMOS (vertical DMOS). John Moll's research team at HP Labs fabricated DMOS prototypes in 1977, and demonstrated advantages over the VMOS, including lower on-resistance and higher breakdown voltage. The same year, Hitachi introduced the LDMOS (lateral DMOS), a planar type of DMOS. Hitachi was the only LDMOS manufacturer between 1977 and 1983, during which time LDMOS was used in audio power amplifiers from manufacturers such as HH Electronics (V-series) and Ashly Audio, and were used for music and public address systems. Alex Lidow co-invented the HexFET, a hexoganal type of Power MOSFET, at Stanford University in 1977, along with Tom Herman. The HexFET was commercialized by International Rectifier in 1978. The insulated-gate bipolar transistor (IGBT), which combines elements of both the power MOSFET and the bipolar transistor, was developed by B. Jayant Baliga at General Electric between 1977 and 1979. Several structures had been explored in the 1970s, when the first commercial power MOSFETs were introduced. However, most of them have been abandoned (at least until recently) in favour of the Vertical Diffused MOS (VDMOS) structure (also called Double-Diffused MOS or simply DMOS).