While semiconductors like the CPU and the LSI are used for computing and memory, power devices are used for electricity control and conversion. Semiconductors tend to be associated with ICs. But power devices are semiconductors that can operate under large current and high voltage, in contrast to ICs. For example, the power circuit called an inverter that controls the electric power for running a train is embedded with power devices called a gate turn-off thyristor (GTO) and an insulated gate bipolar transistor (IGBT). These power devices turn the power on/off several hundred times to several tens of thousands times per second. In addition, these power devices can handle high voltage of several thousand volts, enabling the operation of the Shinkansen bullet train.

Inverters embedded with the efficient IGBT and other power devices are used in home appliances such as air conditioners, refrigerators, microwaves, rice cookers and LCD televisions, which are indispensable in our everyday live. They are also used in hybrid cars, fuel cells, solar cells and wind power generation, which are essential for taking measures against global warming.

MEMS are ultra-compact systems composed of micro-mechanical components such as sensors, actuators and electronic circuits on a silicon wafer using the microfabrication technology of the LSI (semiconductor) manufacturing technology. MEMS contribute to the ultra-miniaturization of various products, for example digital micro-displays (DMD) of projectors, nozzles inside the heads of ink-jet printers and a variety of sensors such as gyroscopes, pressure sensors, acceleration sensors and flow rate sensors. They are also used in the blood test chips and catheters of medical devices.
The most distinctive feature of MEMS is that mechanical devices as well as electrical functions can be created on a wafer in a large quantity stacked three-dimensionally using laminating technology, as opposed to the integrated electronic circuits of the conventional LSI, which is created on a plane. This enables the enhancement of the high performance and large capacity of the LSI. In the future, MEMS will miniaturize sensors and other devices even further and make them even more efficient in terms of power consumption.