Factors influencing the gas bubble evolution and the cristobalite formation in quartz glass Cz crucibles for Czochralski growth of silicon crystals

Hirsch A, Schulze M, Sturm F, Trempa M, Reimann C, Friedrich J (2021)


Publication Type: Journal article

Publication year: 2021

Journal

Book Volume: 570

DOI: 10.1016/j.jcrysgro.2021.126231

Abstract

Long-term Czochralski (Cz) silicon crystallization processes like multi-pulling demand high qualities and performances of fused quartz crucibles. Crucial issues are the gas bubble evolution and cristobalite (Crs) formation within the bulk and on the inner crucible surfaces. Here, crucibles by four suppliers were investigated using vacuum bake-out tests (VBT), for which crucible samples are heat-treated under vacuum at 1450 degrees C for different holding times with and without direct Si contact. An improved data analysis showed that the bubbles in all crucibles grow with process time; however, the expansion is more pronounced in the bulk material than in the critical surface-near region. Further, we observed that the final bubble size is higher in natural than in synthetic SiO2 material. Crs formation could be observed at all crucibles' surfaces, distinguishable into brownish Crs at sites with Si contact and white Crs without Si contact. The resulting Crs layer thickness and the surface covering increased with longer holding times; however, too thick layers could cause chipping. Further, the observed Crs growth rate is different for all crucible types. Finally, the crucibles were evaluated for their highest application potential for long-term Cz experiments.

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APA:

Hirsch, A., Schulze, M., Sturm, F., Trempa, M., Reimann, C., & Friedrich, J. (2021). Factors influencing the gas bubble evolution and the cristobalite formation in quartz glass Cz crucibles for Czochralski growth of silicon crystals. Journal of Crystal Growth, 570. https://dx.doi.org/10.1016/j.jcrysgro.2021.126231

MLA:

Hirsch, Antje, et al. "Factors influencing the gas bubble evolution and the cristobalite formation in quartz glass Cz crucibles for Czochralski growth of silicon crystals." Journal of Crystal Growth 570 (2021).

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