Power Semiconductor device types

ipTEST’s MOSTRAK systems can test the following device types:

Hand test fixture

  • MOSFET

  • IGBT

  • Bipolar transistor

  • Diode, rectifiers

  • Thyristor (SCR), Triac

  • Linear voltage regulator (VReg)

  • Transient voltage suppressor (TVS)

Silicon carbide (SiC)

Semiconductors provide advantages for fast, high-temperature and high-voltage devices. Initial problems with the interface of SiC with silicon dioxide have hampered the development of SiC-based power MOSFETs and insulated-gate bipolar transistors. In recent years nitridation has dramatically reduced the defects causing the interface problems. SiC MOSFETs are now widely available.

Gallium Nitride (GaN)

Enhancement-mode transistors became generally available became commercially available in 2010. These devices were designed to replace power MOSFETs in applications where switching speed or power conversion efficiency is critical. These transistors, also called eGaN FETs, are built by growing a thin layer of GaN on top of a standard silicon wafer. This allows the eGaN FETs to maintain costs similar to silicon power MOSFETs but with the superior electrical performance of GaN.

Metal Oxide Semiconductor Field-Effect Transistor (MOSFET)

MOSFET’s are designed to handle significant power levels. Compared to the other power semiconductor devices, 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 CMOS technology, developed for manufacturing integrated circuits in the late 1970s. Te power MOSFET 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.

Insulated-Gate Bipolar Transistor (IGBT)

IGBT’s are a three-terminal power semiconductor device primarily used as an electronic switch which, as it was developed, came to combine high efficiency and fast switching. It consists of four alternating layers (P-N-P-N) that are controlled by a metal-oxide-semiconductor (MOS) gate structure without regenerative action. Although the structure of the IGBT is topologically the same as a thyristor with a 'MOS' gate (MOS gate thyristor), the thyristor action is completely suppressed and only the transistor action is permitted in the entire device operation range. It is used in switching power supplies in high power applications: variable-frequency drives (VFDs), electric cars, trains, variable speed refrigerators, lamp ballasts, and air-conditioners. Since it is designed to turn on and off rapidly, the IGBT can synthesize complex waveforms with pulse-width modulation and low-pass filters, so it is also used in switching amplifiers in sound systems and industrial control systems. In switching applications modern devices feature pulse repetition rates well into the ultrasonic range—frequencies which are at least ten times the highest audio frequency handled by the device when used as an analog audio amplifier.

Diode

The Schottky diode (named after the German physicist Walter H. Schottky), also known as Schottky barrier diode or hot-carrier diode, is a semiconductor diode formed by the junction of a semiconductor with a metal. It has a low forward voltage drop and a very fast switching action. The cat's-whisker detectors used in the early days of wireless and metal rectifiers used in early power applications can be considered primitive Schottky diodes. When sufficient forward voltage is applied, a current flows in the forward direction. A silicon diode has a typical forward voltage of 600–700 mV, while the Schottky's forward voltage is 150–450 mV. This lower forward voltage requirement allows higher switching speeds and better system efficiency.

Bipolar Junction Transistor (bipolar transistor or BJT)

BJT’s are a type of transistor that uses both electrons and holes as charge carriers. Unipolar transistors, such as field-effect transistors, only use one kind of charge carrier. BJTs use two junctions between two semiconductor types, n-type and p-type. BJTs are manufactured in two types: NPN and PNP, and are available as individual components, or fabricated in integrated circuits, often in large numbers. BJTs can be used as amplifiers or switches. This ability gives them many applications in electronic equipment such as computers, televisions, mobile phones, audio amplifiers, industrial control, and radio transmitters.