Patent ID: 9273411
Filing Date: 2016-03-01
CPC Classification: C30B,Y10T

Claim Text:
1. A method of producing a crystalline material comprising the steps of: i) providing a crystal growth apparatus comprising a chamber and a hot zone within the chamber, the hot zone comprising at least one heating system, at least one heat removal system, and a crucible containing at least solid feedstock; ii) heating the solid feedstock in the crucible with the heating system to form a liquid feedstock melt; iii) removing heat from the hot zone with the heat removal system to form a partially solidified melt comprising solidified crystalline material submerged in remaining liquid feedstock; iv) determining an amount of solidified crystalline material in the partially solidified melt with at least one laser positioned at a height above the crucible by measuring a surface height of the remaining liquid feedstock with the laser, calculating a density of the partially solidified melt from the measured surface height, and comparing the density of the partially solidified melt to a density of the liquid feedstock, a density of the solidified crystalline material, or both; and v) further solidifying the partially solidified melt to form the crystalline material.