Twinning during Czochralski Growth of Heavily doped, dislocation-free single crystal Silicon (NASA Funded)


Advanced, low voltage power control electronics are needed to enable low power consumption computers, telecommunications and automotive devices.  Lower voltage power electronics are made from dislocation-free silicon heavily doped with arsenic or antimony to provide extremely small electrical resistivity. As crystal resistivities have been lowered to attempt to achieve lower power losses, twinning of the crystal has unexpectedly occurred during growth, so that the crystal no longer possesses the required crystallographic orientation for device function. The purpose of this project is to determine the mechanism of twin formation, so that crystal growth process conditions can be designed to eliminate this defect and allow lower resistivity crystals to be grown reliably.