Floating-zone growth of surface-coated silicon under microgravity

Abstract A phosphorus-doped silicon crystal has been recrystallized under microgravity (μg) by float-zoning aboard a sounding rocket at a rate of 5 mm/min. The crystal was coated with SiO 2 to suppress Marangoni convection. It grew free of microstriations. During its travel, the molten zone was counterdoped with boron, released from a point-shaped source. Analysis of the B distribution in the solidified melt showed that under microgravity the dopant propagation is purely diffusive. The distribution found in a terrestrial sample suggests the presence of an additional, gravity driven, steady convective flow.