SiHCl_3-H_2体系多晶硅化学气相沉积的传递-动力学模型

Transport-kinetic model of polysilicon chemical vapor deposition in SiHCl_3-H_2 system

提出SiHCl_3-H_2体系多晶硅化学气相沉积的传递-动力学模型(TKM),同时考虑传递过程和表面化学反应动力学对硅沉积速率的影响。研究硅沉积过程受表面化学反应速率限制和传递速率限制的边界条件,并且研究表面化学反应速率受氢气浓度限制或SiHCl_3(TCS)浓度限制的边界条件,提出同时受氢气浓度限制和TCS浓度限制的边界条件。为了验证TKM的有效性,应用该模型计算硅棒长度为2 m、硅棒直径为10 cm、气流速度为0.67 m/s、硅棒表面温度为1 398 K、常压(0.1 MPa)条件下,不同H_2/SiHCl_3配比下的硅沉积速率。研究结果表明:通过TKM的计算结果与Habuka所测得的实验数据比较,相对误差为3.6%(小于10%),表明该模型准确可靠。

The transport-kinetic model （TKM） of polysilicon chemical vapor deposition （Poly-Si CVD） in a SiHCl3-H2 system was developed. The both aspects of surface reaction kinetics and transport phenomena on silicon deposition rate were taken into account in the TKM. The limiting conditions of transport rate and surface chemical reaction rate were studied. Furthermore, the conditions of hydrogen concentration limitation or SiHCl3（TCS） concentration limitation were investigated by TKM and the conditions of both limitation by hydrogen concentration and TCS concentration were also developed in TKM. In order to verify the TKM valid, the silicon deposition rate in different ratios of H2 to TCS were studied by TKM under the conditions of silicon length of 2 m, silicon radium of 10 cm, gas flow rate of 0.67 m/s, surface temperature of 1 398 K and pressure of 0.1 MPa. The results show that by comparing calculated results with the experimental data measured by Habuka in the open literature. The relative error is 3.6%, which confirms the validity of TKM since the relative error is within 10%.