毫秒-纳秒组合脉冲激光对单晶硅的热力损伤机制研究

Monocrystalline silicon is widely used in the field of photovoltaic systems, and it is easy to cause thermal and mechanical damage when it is applied by laser, and the performance will change significantly. Previous studies have found that the morphology and size of the fractured area of monocrystalline silicon are difficult to control, and the depth of erosion and the radius of erosion are greatly affected by the laser pulse width. For the urgent needs of high-precision laser weapons and laser fine processing industry, this project proposes to monocrystalline silicon irradiated in the form of millisecond-nanosecond combined pulsed laser, study the process of combined pulsed laser action of monocrystalline silicon by theory, simulation and experiment. obtain the characteristics and laws of laser-acting monocrystalline silicon under various combined parameters, explore ways to enhance the effects of laser action, realizing monocrystalline silicon millisecond-nanosecond combined pulse laser breakage controllable, reveal the damage mechanism of thermal, stress strain and ablation of monocrystalline silicon by millisecond-nanosecond combined pulsed laser, and the coupling mechanism of various damage effects, establish thermal and mechanics damage database of millisecond-nanosecond combined pulsed laser on monocrystalline silicon. The development of this project can realize accurate and efficient laser action of monocrystalline silicon, provide scientific basis for anti-laser reinforcement measures of monocrystalline silicon and silicon based devices, and lay a theoretical and technical basis for the development, application and development of laser strike and protection systems. It has reference significance for the design and use of long-narrow combined pulsed laser systems.

单晶硅广泛应用于光电系统领域，在激光作用下易于造成热力损伤，性能将发生显著变化。前期研究发现单晶硅断裂损伤区域形貌和尺寸不易控制，熔蚀深度和熔蚀半径受激光脉宽影响大，针对高精激光武器和激光精细加工产业的迫切需求，本项目提出利用毫秒-纳秒组合脉冲激光的形式作用单晶硅。通过理论、仿真及实验的方式研究组合脉冲激光作用单晶硅的过程和效果，获取多种组合参数下激光作用单晶硅的特性和规律，探索增强激光作用效果的组合方式，实现单晶硅毫秒-纳秒组合脉冲激光断裂可控，揭示毫秒-纳秒组合脉冲激光对单晶硅的损伤机理，以及多种损伤效应的耦合机理，建立毫秒-纳秒组合脉冲激光对单晶硅的热力损伤数据库。该项目的开展，可实现精确、高效的激光作用单晶硅，对单晶硅及硅基器件抗激光加固措施提供科学依据，对长-窄组合脉冲激光系统的研制与使用具有指导意义。

基于毫秒、纳秒脉冲激光对硅晶体的辐照效应研究，开展毫秒-纳秒组合脉冲激光作用硅晶体的效果和机理分析。研究内容及主要成果包括：基于热传导理论及热-弹塑性理论，建立了毫秒-纳秒组合脉冲激光损伤硅晶体的热应力物理模型，得到硅晶体的温度场、应力场分布特性及演化规律；建立了组合脉冲激光辐照单晶硅的熔蚀喷溅物理模型，分析单晶硅的熔蚀形态随激光特性参数的变化关系。构建组合脉冲激光作用硅晶体的实验系统，实现了激光能量密度、光斑半径、延时、硅片厚度等各单一参数对硅晶体的损伤规律影响探究，阐明了毫秒-纳秒组合脉冲激光作用硅晶体的损伤机理。项目研究内容为长-窄组合脉冲激光系统的设计、研制与使用奠定理论基础，可为硅晶体的激光加工提供参考。