宽带隙半导体材料的纳飞秒双激光蚀除新技术基础研究

In this research, the femtosecond, nanosecond laser pulse will be combined together to realize the high efficiency and high quality removal of the wide bandgap semiconductor materials, the mechanism of which will be discussed by using the theory, simulation and experiment method. After comprehensive consideration of multiple laser absorption mechanisms, the transient thermodynamic and optical properties of the irradiated materials are investigated to reveal the laser energy coupling mechanism by using the plasma physics and quantum mechanics theory.The dynamic ablation process of the materials after the absorption of laser energy is researched to reveal the micro mechanism of phase transition by using molecular dynamics simulation method. Then, based on the above research findings, an ablation model is established. According to the ablation model, the effects of pulse interval and laser processing parameters on the processing efficiency, processing quality are investigated through experiments, and the model is further corrected by the experimental results. On the basis of the above investigation, the experimental device for realizing the method is researched and developed, and based on which the ablation process technology was thoroughly studied and optimized. The research will build a foundmental basis for the high efficiency, high quality ablation method for the wide band gap semiconductor materials. The research results of this project can further promote the application of such materials in the optical, microelectronics and other fields, and they are also significant in improving laser micro fabrication technology level of our country.

本课题将飞秒、纳秒脉冲激光的优点相结合，采用理论、仿真和试验研究相结合的方法对纳飞秒双激光作用下宽带隙半导体材料的高效精密蚀除机理展开研究。采用等离子体物理、量子力学的相关理论，综合考虑各种激光吸收机理，研究被加工材料对纳飞秒双激光的吸收过程及其瞬态热力学和光学特性,揭示其能量耦合机制;通过分子动力学模拟的方法，研究被加工体材料熔化、碎裂的动态过程，揭示其相变的微观机理,并以此为基础建立宽带隙半导体材料的纳飞秒双激光蚀除模型。以蚀除模型为指导，通过试验对脉冲延时、激光参数等对加工效率、加工质量的影响规律进行研究，并根据实验结果对模型进行修正。在此基础上完善实现该方法的实验装置，并对其工艺技术进行研究和优化，为最终形成一种新的针对宽带隙半导体材料的高效精密加工方法奠定基础。本项目的研究成果可进一步促进宽带隙半导体材料在光学、微电子等领域的应用，对提高我国激光微细加工技术水平具有重要的意义。

本课题将飞秒、纳秒脉冲激光的优点相结合，采用理论、仿真和试验研究相结合的方法对纳飞秒双激光作用下宽带隙半导体材料的高效精密蚀除机理展开研究。采用等离子体物理、量子力学的相关理论，综合考虑各种激光吸收机理，研究了被加工材料对纳飞秒双激光的吸收过程及其瞬态热力学和光学特性,揭示了其能量耦合机制; 通过分子动力学模拟的方法，研究了被加工体材料熔化、碎裂的动态过程，揭示了其相变的微观机理,并以此为基础建立了宽带隙半导体材料的纳飞秒双激光蚀除模型。以蚀除模型为指导，通过试验对脉冲延时、激光参数等对加工效率、加工质量的影响规律进行了研究，并根据实验结果对模型进行了修正。在此基础上完善了实现该方法的实验装置，并对其工艺技术进行了研究和优化，形成一种新的针对宽带隙半导体材料的高效精密加工方法。本项目的研究成果可进一步促进宽带隙半导体材料在光学、微电子等领域的应用，对提高我国激光微细加工技术水平具有重要的意义。