SiC DioMOS with precisely controlled epitaxial channel
- PDF / 905,848 Bytes
- 6 Pages / 585 x 783 pts Page_size
- 66 Downloads / 170 Views
Introduction Conservation of the environment has become a critical issue for sustaining the well-being of humankind. One factor that threatens the environment is the soaring demand for electric power from fields, including transportation, information, and telecommunications. The established infrastructure for electric power distribution already represents a powerful network and is ready to grow toward smart grid implementation. However, an inexhaustible supply of electric power from nuclear power plants is now viewed as unrealistic, especially after the meltdown of the Fukushima nuclear power plant in Japan. As a result, drastic reduction of electric power loss during power distribution is necessary. Power electronics systems manage alternating currentdirect current (AC-DC) and DC-DC conversions between each stage of electric power distribution. Fundamental circuits (inverters and converters) for the power electronics systems consist of energy-storage components (inductors and capacitors) and switching components (semiconductor diodes and transistors), which alternate the conduction between the ON- and OFF-states. The efficiency of these power conversions is constantly being improved by limiting power losses in the components within power electronics systems.
Figure 1 shows the unit structure of a typical vertical power metal oxide semiconductor field-effect transistor (MOSFET), which contains a planar MOSFET on the surface with a voltage-blocking drift layer under the MOSFET. Thousands of such units are typically integrated into powerdevice chips to manage large currents. Semiconductor power devices must withstand large voltages during the OFF-state by using a thick drift layer, which in turn causes conduction loss because of the large ON-state resistance (RON). Additional power losses result from the switching period of these power devices, typically on the order of a few to hundreds of kHz. Conventional Si power devices with blocking voltages (BVs) >400 V take advantage of bipolar conductivity modulation (both majority carriers and minority carriers support the current conduction) to reduce the conduction loss of RON from the thick drift layer. The Si insulated gate bipolar transistor (IGBT) with this bipolar conductivity modulation has become a more favorable solution compared to the unipolar Si MOSFET. On the other hand, bipolar conductivity modulation inevitably leads to slower turn-off switching due to excess minority carriers and larger switching losses. Si power devices cannot be easily applied to modern applications requiring higher voltages, higher currents, lower
Makoto Kitabatake, Panasonic Corporation, Japan; [email protected] Atsushi Ohoka, Panasonic Corporation, Japan; [email protected] DOI: 10.1557/mrs.2015.91
© 2015 Materials Research Society
MRS BULLETIN • VOLUME 40 • MAY 2015 • www.mrs.org/bulletin
425
SIC DIOMOS WITH PRECISELY CONTROLLED EPITAXIAL CHANNEL
SiC epitaxial growth General developments
Figure 1. Schematic cross-section of a vertical SiC power metal oxide semi
Data Loading...
