Evaluating cooling tube effects on defect formation and distribution in Czochralski crystal growth

The quality of silicon ingots is paramount in semiconductor manufacturing as defects profoundly influence the crystal integrity and device performance. This study investigates the impact of cooling-tube configurations on defect formation during the Czochralski process. Comprehensive modeling and simulation elucidated the intricate relationship between the presence of a cooling tube and the evaluation of point defects within silicon ingots. The results show that cooling tubes augment the axial temperature gradient and shift the point-defect behavior from vacancy-rich to interstitial-dominated regions with an increase in the axial temperature gradient of up to 1.6 times. Additionally, cooling tubes impede the formation of agglomerated defects by reducing point-defect mobility and propagation time, resulting in a reduction of the agglomerated defect count by up to 30% compared to processes without cooling tubes. Experiments validated the simulation findings, demonstrating a notable decrease in agglomerated defect counts. These insights underscore the potential of optimized cooling-tube designs for enhancing semiconductor device performance and manufacturing yield, thereby driving progress in electronics and beyond.