水冷系统对直拉法生长大直径硅单晶拉速的影响  

Effect of Water-Cooled System on Pulling Rate of Large-Diameter Silicon Single Crystals Grown by Czochralski

作　　者：李明智 Li Mingzhi(The 46^(th)Research Institute,CETC,Tianjin 300220,China)

机构地区：[1]中国电子科技集团公司第四十六研究所,天津300220

出　　处：《半导体技术》2021年第4期305-309,共5页Semiconductor Technology

摘　　要：在直拉法生长大直径硅单晶过程中,单晶炉内的温度梯度直接影响单晶生长的质量。分析了炉体内添加水冷板后循环水流速对系统固相温度梯度的影响。研究发现在不影响单晶炉内固液界面处熔体表面温度的前提下,增大固液界面处固相温度梯度可有效提高晶体生长速率。但若冷却水流速过大,熔体可能生成新的不规则结晶核,凝固在晶体界面导致晶变。当单晶炉体内放置水冷板时,改变水冷板水流速大小可调整系统的温度梯度。通过仿真得出当循环水温度为296.15 K时,生长14英寸(1英寸=2.54 cm)硅单晶最适水流速约为55 L/min。经过对比实验得出,在晶体生长的过程中,炉体内加水冷板后的晶体生长速率逐渐高于未加水冷板的,最大生长增速约为9%。In the process of growing large-diameter silicon single crystals by the Czochralski method,the temperature gradient in the single crystal furnace directly affects the quality of single crystal growth.The influence of the circulating water flow rate on the solid phase temperature gradient of the system after adding a water-cooled plate in the furnace body was analyzed.It is found that increasing the solid phase temperature gradient at the solid-liquid interface can increase the growth rate of crystal without affecting the surface temperature of melt at the solid-liquid interface in the single crystal furnace.However,if the cooling water flow rate is too high,the melt may generate new irregular crystalline nuclei,which will solidify at the crystal interface and then lead to crystal pattern transition.When a water-cooled plate is placed in the single crystal furnace body,the temperature gradient of the system can be effectively adjusted by changing the water flow rate of the water-cooled plate.Through simulation,it is shown that when the circulating water temperature is 296.15 K,the optimum water flow rate for the growth of14 inches(1 inch=2.54 cm)silicon single crystal is about 55 L/min.Through comparative experiments,it is concluded that in the process of crystal growth,the crystal growth rate after adding the water-cooled plate in the furnace is gradually higher than that without the water-cooling plate,and the maximum increased growth rate is about 9%.

关 键 词：硅单晶生长 水冷系统 固液界面 晶体生长 温度梯度 

分 类 号：TN304.053[电子电信—物理电子学]