A cost-effective approach for transitioning to larger wafer production by small Czochralski pullers

Abstract

As the semiconductor industry continues to evolve, the demand for larger silicon wafers has grown significantly. However, transitioning from traditional 4 and 6-inch wafers to larger sizes poses numerous challenges, especially for smaller semiconductor companies with limited financial resources. This article explores a cost- effective approach to address this transition by modifying a small Czochralski (CZ) puller to grow a larger silicon wafer. The study employed a simulation-based method using 3D transient finite element analysis to evaluate the effects of modifying the CZ puller's B-chamber and thermal shield and applying a cooling jacket. The results show that these modifications can enhance the temperature gradient during crystal growth and improve stability when growing an 8-inch silicon ingot. Practical experiments also highlight the complexities involved in achieving a successful transition to 8-inch wafers, including the need for precise adjustments in gap distances and argon gas volume.