*Article* **Study on Deposition Conditions in Coupled Polysilicon CVD Furnaces by Simulations**

**Shengtao Zhang 1, Hao Fu 1, Guofeng Fan 2, Tie Li 3, Jindou Han <sup>1</sup> and Lili Zhao 1,\***


**Abstract:** Electronic-grade polysilicon is the cornerstone of the information industry. Considering the demand for this material in the semiconductor industry, any technological improvement has great potential benefits. Due to the quality requirements of electronic polysilicon, its preparation process is characterized by low raw material utilization and high cost. Simply increasing the deposition rate by increasing the chemical reaction rate will easily lead to a reduction in the proportion of dense materials. For the first time, a coupled furnace scheme is proposed to improve the utilization of raw materials while maintaining the same deposition quality. The deposition conditions on the surface of silicon rods with different base plate designs were modeled and analyzed using the software PolySim, and a design characterized by a high flow rate and the use of 9 mm and 15 mm nozzles was selected for the coupling scheme. In coupling mode, the simulation results show that the utilization of raw materials is increased by 17.5%, and the deposition rate is increased by 44.9%, while the deposition quality and uniformity remain approximately unchanged. The results show that the coupling scheme with high feed flow is beneficial for significantly improving the deposition conditions and the utilization rate of raw materials, which also provides guidance for material preparation processes with similar principles.

**Keywords:** electronic polysilicon; flow field; temperature field; boundary layer; coupled furnaces
