Editing Power semiconductor device (section)

===Improvement of structures===

The IGBT design is still under development and can be expected to provide increases in operating voltages. At the high-power end of the range, the MOS-controlled thyristor is a promising device. Achieving a major improvement over the conventional MOSFET structure by employing the super junction charge-balance principle: essentially, it allows the thick drift region of a power MOSFET to be heavily doped, thereby reducing the electrical resistance to electron flow without compromising the breakdown voltage. This is juxtaposed with a region that is similarly doped with the opposite carrier polarity (''holes''); these two similar, but oppositely doped regions effectively cancel out their mobile charge and develop a 'depleted region' that supports the high voltage during the off-state. On the other hand, during the on-state, the higher doping of the drift region allows for the easy flow of carriers, thereby reducing on-resistance. Commercial devices, based on this super junction principle, have been developed by companies like [[Infineon]] (CoolMOS products) and [[International Rectifier]] (IR).