Study on the crystallization of quartz glass crucibles for preparation of single crystal silicon

In order to avoid un-uniform crystallization on the surface of a quartz glass crucible that is known to affect the production yield of the single crystal silicon, Ba (barium) was selected as a crystallization promotor and the inner surface of the crucible was coated using Ba (barium hydroxide octahydrate)-solution by the spray pyrolysis method. For un-coated crucible, it was found that the crystallization of its surface started at 1350 degrees C, and at 1450 degrees C the surface was uniformly crystallized with beta-cristobalite phase. It was found that the crucible coated with Ba began to be crystallized from 1000 degrees C and was uniformly crystallized on the crucible surface at 1300 degrees C. In this case, alpha-cristobalite and needle-shaped BaSi2O5 phase were created and disappeared as a crystal phase, and the beta-cristobalite phase was eventually evenly distributed over the Ba-coated crucible surface.