直边衍射场沉积铬原子三维特性分析

发布时间：2019-03-29 17:37

【摘要】：原子光刻是通过激光驻波场会聚原子沉积光栅得到具有周期性的纳米量级条纹的技术。由于沉积基片的存在,会在激光驻波场内产生衍射现象,影响激光驻波场内光强分布,导致沉积纳米光栅结构发生变化。因此,探讨激光驻波场会聚原子过程中沉积基片的衍射影响具有重要意义。本文基于半经典模型分析了直边衍射扰动下激光驻波场沉积铬原子三维运动轨迹及沉积特性,并从半高宽与对比度入手对沉积光栅进行研究。通过探讨不同衍射模型确定基片产生衍射为直边衍射,并对直边衍射场进行分析,建立了直边衍射扰动下激光驻波场模型,通过四阶Runge-Kutta算法,对直边衍射扰动下铬原子在驻波场中的三维运动轨迹及沉积效果进行仿真。考虑到激光参数的影响,本文分析了激光功率与失谐量变化时,铬原子在直边衍射场中运动轨迹和沉积效果。从半高宽和对比度两方面入手,对铬原子沉积光栅结构进行数值分析。结果表明:当激光功率为3.93mW,失谐量为200MHz时,原子沉积光栅的半高宽为6.04nm,对比度为0.863。此时,原子沉积光栅的质量最佳。本文考虑了激光驻波场中因沉积基片的存在而引起的直边衍射现象的影响,对铬原子三维运动轨迹及沉积效果进行仿真,仿真结果更接近实际,对实验具有理论指导意义。
[Abstract]:Atomic photolithography is a technique to obtain periodic nanoscale fringes by laser standing wave field converging atomic deposition gratings. Because of the existence of the substrate, the diffraction phenomenon will occur in the laser standing wave field, which will affect the intensity distribution in the laser standing wave field and lead to the change of the structure of the deposited nano-grating. Therefore, it is of great significance to investigate the diffraction effect of substrate deposition in the process of laser standing wave field converging atoms. Based on the semiclassical model, the three-dimensional motion trajectory and deposition characteristics of chromium atoms deposited in laser standing wave field under the perturbation of straight-edge diffraction are analyzed in this paper. The deposition grating is studied from the aspect of half-width and contrast. By discussing different diffraction models, the diffraction of substrate is determined to be straight diffraction, and the diffraction field of straight edge is analyzed. The standing wave field model of laser under the perturbation of straight side diffraction is established, and the fourth order Runge-Kutta algorithm is used. The three-dimensional motion trajectory and deposition effect of chromium atom in standing wave field under the perturbation of straight-edge diffraction are simulated. Considering the influence of laser parameters, the movement trajectory and deposition effect of chromium atom in the straight diffraction field are analyzed when the laser power and detuning are changed. The structure of chromium atomic deposition grating is analyzed numerically from the aspect of half-width and contrast. The results show that when the laser power is 3.93mW and the detuning is 200MHz, the half-width and contrast of atomic deposition grating are 6.04 nm and 0.863, respectively. At this point, the quality of atomic deposition grating is the best. In this paper, the effect of vertical diffraction caused by the existence of substrate in laser standing wave field is considered, and the three-dimensional motion trajectory and deposition effect of chromium atom are simulated. The simulation results are closer to the reality, which is of theoretical significance to the experiment.
【学位授予单位】：桂林电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN24

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