| 摘要 |
A production apparatus for producing a crystal includes a crucible divided into a plurality of stages, each stage containing a crystal precursor material, and a heater arranged to heat the crucible. The crucible has formed therein a degassing hole in a side wall portion thereof for discharging an impurity gas produced when refining the crystal precursor material by adding a scavenger thereto, and a lower portion of a first stage of the plurality of stages is positioned to cover an upper edge of a wall portion of a second stage of the plurality of stages. The overall height of the plurality of stages is 10 mm to 50 mm, the degassing hole has a diameter of 1 mm to 5 mm, and a fluoride crystal is formed from the crystal precursor material. |
