激光退火硅晶圆温度场分布的数值模拟研究

Numerical simulation of temperature field distribution induced by laser annealing in silicon wafer

目前,激光退火技术被广泛应用于半导体加工领域,但对如何选择激光条件进行相应的退火并没有系统清晰的准则可以参考,尤其是在硅的深注入杂质激活方面。本文通过对激光照射在硅晶圆上形成的温度场分布进行数值模拟研究,分析了激光波长和脉冲宽度对加热深度以及晶圆背面温度的影响。结果表明,延长激光波长或脉冲宽度,都有助于增加激光退火的加热深度。而对于特定的激活深度需求,存在着最优的激光波长和脉冲宽度组合,可以使退火所需要的激光脉冲能量最低,硅晶圆背面的温升最小。本文通过模拟仿真给出了激活深度在1~10μm范围内的最优波长和脉宽值,可为实现高效的深硅注入激光激活工艺提供重要的条件参考。

At present,laser annealing technology is widely used in the field of semiconductor processing,but there are no systematic and clear guidelines on how to select laser conditions for an annealing process,especially in the field of the activation of deeply implanted silicon.In this paper,the influence of laser wavelength and pulse width on the heating depth and the temperature on the backside of the silicon wafer are analyzed by simulating the temperature field in the silicon wafer irradiated by laser.The experimental results show that lengthening the laser wavelength or pulse width is helpful to increase the heating depth of laser annealing.For a specific activation depth,there is an optimal combination of laser wavelength and pulse width,which can minimize the laser pulse energy and the temperature rise on the backside of the silicon wafer.Also,the optimal wavelength and pulse width used in laser annealing process for the activation depth in the range of 1~10μm,which can provide an important reference for the realization of high efficiency laser annealing activation process for deeply implanted silicon.