Wide-bandgap semiconductorsWide-bandgap semiconductors, such as SiC and Group-III nitrides, are advanced materials widely used in high-power, high-frequency, high-temperature electronics and optoelectronics. The progress in the wide-bandgap semiconductor technology is hindered by the lack of homoepitaxial substrates suitable for the epitaxy of multi-layered high-quality device structures. Further reduction in the dislocation density and complete elimination of micropipes is strongly desirable for SiC wafers.
Conventional methods of bulk crystal growth, like Czochralski growth from the melt, are inapplicable for the fabrication of the wide-bandgap materials. So an alternative, sublimation (Physical Vapor Transport) technique, is world-wide spread for growing these semiconductors.
STR Activity in the Market of Wide Bandgap SemiconductorsIn our everyday work, we develop and apply for the industrial facilities the advanced models of SiC, AlN and GaN bulk crystal growth by PVT with the focus on specific features of the growth technique. Comprehensive analysis is performed in a wide range of the problems arising in long-term growth, from evaluation of the growth system design to prediction of the crystal quality.
Use of Numerical ModelingTo get a better insight into the growth process, as well as to optimize the growth system design and operating conditions, numerical modeling is extensively used. The larger is the size of a crystal of a required quality, the more stringent are requirements on the choice and control of the operating conditions. Additionally, the cost of an individual growth run rises significantly with the crystal size. All this makes growth modeling an important tool applicable to every stage of the technology, from the growth system design to the optimization of the growth conditions, including the materials utilization efficiency and other economical factors.