Integrated gate bipolar transistors

There are two major types of power switches used today the bipolar power transistor (BJT) and the power MOSFET. The IGBT (integrated gate bipolar transistor) is used in the higher power industrial applications, such as 1 kW power supplies and electronic motor drives. The IBGT has a slower turn-off than does the MOSFET, so it is typically used for switching frequencies of less than 20 kHz. 

PolycrystaUine Si (poly-Si) thin films are used in integrated circuits as gate electrodes, emitters in bipolar transistors, load resistors and interconnection connectors. SiH is generally used as the precursor, where it undergoes pyrolysis at reduced pressure (typically -133 Pa) in the presence of H, He or N to deposit poly-Si at temperatures between 610 and 630°C [2, 3]. Epitaxial Si films are deposited using... 

Field-effect transistors (FETs) have dominated the semiconductor industry, largely displacing the earlier bipolar junction transistor (BJT) because of its negligible gate current and convenience in the design of integrated circuits. Figure 29 sketches how an FET works. 

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