【作者】 万青松；

【导师】 陈军宁； 谢常青；

【作者基本信息】 安徽大学 ， 微电子学与固体电子学， 2010， 硕士

【摘要】 微机电系统是伴随纳米加工技术发展起来的新型科技,在微纳米加工的这项新型的技术应用的过程中,利用激光的特点进行加工,会有很多的特点,为加工更小的微型器件,提供了新的方法。比如说在利用激光进行的利用掩膜版进行的光刻和利用激光的特点进行直写实验过程中,激光系统的能量输入掩模面,在输出面上能量分布均匀是否,这都将影响到输出面上的光的能量的分布,这样在加工的过程中,能量的均匀分布的特性,就会影响加工制作元件的质量。因为激光光束的振幅在横向上呈高斯分布,能量并非均匀分布这个原因,这就需要把高斯光束整形为能量均匀分布的平顶光束,因此曝光系统中光能分布均匀性是很重要的。本文在分析现在常用的几种激光整形的方法后,针对实验室内的脉冲半导体固体激光器的特点和实际用途,,提出以二元光学理论为基础,利用实验室微纳米器件的加工技术,设计并且制作了脉冲半导体固体激光的波面整形的阵列位相环匀光片。论文首先从理论上证明了二元光学元件的衍射效率,在此基础上,说明对激光波面的整形作用设计的关键就是利用相位恢复进行设计的问题。在此思想基础上,利用GS算法,对设计进行分析和优化,在设计的初期,首先利用MATLAB软件进行模拟实验,模拟入射场和出射光场的光的分布情况,从而给出了二元光学元件的位相分布。从模拟结果看出,出射光场呈平顶化的分布,实现了波面整形。利用模拟的实验就可以得到,如果设计的器件是纯相位的元件,那么这种器件会对激光具有一定的整形作用。然后,在二元光学的特有的加工设计理论基础之上,利用角谱衍射理论作为模拟匀光器光路的理论基础,设计阵列结构的位相环,所设计的每个单元的结构是3环2值位相环,其中每个单元最外环半径由实际的光路给出,本文的设计是应用355nm固体激光,则根据激光设计最外环直径为0.3mm,中间环直径0.108mm,最小环直径是0.027mm,利用纳米器件加工工艺,在3英寸的JGS2石英基材料上制作出两台阶的170*170个结构的微浮雕衍射微光学元件,并利用MATLAB对高斯光对设计的阵列结构的位相环进行模拟仿真,证明了设计的机构可以实现对激光能量的均匀化,在此基础上还可以提高光能利用率。在制作阵列位相环元件的过程中,首先根据计算设计的数据,使用专业软件LEDIT绘制了两块掩模版的图形并制作完成。为了保证在第一版掩膜版和第二版在套刻曝光的时候,能够精准的吻合进行套刻,并降低误差对结果的影响。在设计掩模板的时候两侧分别加入了相应的对准标记。接着通过试验摸索,首先对石英进行测试和抛光,其次在对石英涂胶过程中,使用增粘剂解决了石英材料的亲水性所带来的无法粘合光刻胶的问题。在利用等离子体刻蚀,蒸金属和剥离等技术基础上,最终把掩模上的图形转移到石英基片上,关键是研究等离子体刻蚀的参数的设定上,例如在离子刻蚀过程中的流量,功率和时间的选择和设定。主要是根据以往刻蚀的经验,并结合本次实验刻蚀的深度,进过大致的实验测试,最终确定了刻蚀加工的时间。最终确定加工的参数：1)光刻阶段实验室内的温度：20℃；使用的增粘剂型号：六甲基二硅胺烷；增粘剂涂胶时的转速：5000r/min；光刻胶型号：9920型,光刻胶涂胶时的速率：3000r/min；前烘的温度：85℃,前烘的时间：4min；光刻机的曝光时间：13s；光刻胶的显影时间：60s；光刻胶的定影时间：30s；2)刻蚀阶段实验的温度：20℃；本底真空(低真空)：1.4×10-2Pa,刻蚀机的压强：15Pa,通入刻蚀机气体的压强：5-8Pa,刻蚀机的偏转电压：300V,使用时的刻蚀的压强P=400W；通入刻蚀机的气体：CHF3:180sccm, SF6:60sccm;刻蚀时间：T=4分50秒(因为时间不好控制,大致为整数)；刻蚀速率：V=70nm/min。制作完成后,对阵列位相环进行了试验检验,利用显微镜对石英进行观察,检查其制作后的效果图。在此基础上,并对整形效果进行了测试,对比阵列菲涅耳波带片的整形效果,对结果进行了可能存在的问题进行分析,为下一阶段的制作工艺,制作出良好的元件提出了一些建议。并利用整形技术测试直写曝光的试验,得到了一些比较好的曝光结果。由于二元光学的原理和传统光学的不甚相同,所以元件的稳定性等还需要进一步考察。更多还原

【Abstract】 Micro-electromechanical systems is developed with nano-processing technology That is new science and technology. In the process of using MEMS technology, laser micro processing technology has many advantages, so it provides a new processing method of micro-devices. In the use of laser mask lithography and direct writing experiments, Lighting system image plane (mask) of the light will directly affect the distribution of light energy distribution, which determines the quality of the production of components, However, the amplitude of the laser beam is Gaussian distribution, the energy is not uniform, which requires the energy of the Gaussian beam shaping for the uniform distribution of flat-topped beams Therefore, in the light exposure system uniformity is importantBased on the analysis of several lasers are commonly used shaping method, for the laser characteristics and practical use, We propose a binary optical theory, using laboratory micro-nano device fabrication technology, design and produce the array uniform structure of phase-ring.The paper is proved that the diffraction efficiency of binary optical elements, and explain that the problem of phase retrieval is the key to the design of laser shaping. Based on this idea, we use the GS algorithm optimization, and use MATLAB software to simulate the incident and outgoing light field, which gives the phase distribution of binary optical elements. From the results we see that the outgoing light field of the distribution was flattened, so it confirmed the pure phase element can be achieved for laser shaping.Furthermore, according to the binary optics, we design the energy homogenizer, and simulate the optical absorption of optical devices is the use of angular spectrum diffraction theory。We designed the phase ring array, each element is the value of phase 3, Central 2, one of the most outer radius of the actual diameter of optical.The most outer diameter of 0.3mm, the middle diameter of 0.108mm, the smallest diameter of 0.027mm, Our design is the application 355nm laser, using nano-device processing technology, producing two-level structure of micro-relief diffractive optical elements in JGS2 quartz material, Production structure is 170* 170 in the 3-inch quartz chip and simulated Gaussian beam through the device in MATLAB, The results proved to achieve uniformity of laser energy, and increase the rate of light diffraction.In the production process, First of all, according to calculations, using professional software LEDIT to draw the two mask graphics and produced. In order to ensure the mask in the first edition and second edition in exposure time, to coincide precisely and reduce errors. So we plus the alignment marks on both sides of the graphics board in the mask. We explored through experiments. First, we tested and polished quartz Second, in the process of coating quartz, Quartz material was easy to swap plastic problems solved using the Hexamethyl disilylamine.Using plasma etching, steam metal and lift-off technology, The graphics in the mask eventually transferred to the quartz substrates, Plasma etching technology was used to transfer the mask graphics to the quartz substrate eventually. The parameters of plasma etching were researched, such as the etching rate and etching time. According to the requirements of component’s structure, the depth of etching was determined, and further the etching time was defined.Final experiment parameters:(1)Lithography stageTemperature:20℃; Tackifier:Hexamethyl disilylamine. Whirl coating rate: 5000turn/min; Photosensitive resist:9920; Whirl coating rate:3000turn/min; Before baking:85℃4 min; Exposure time:13 seconds; Development time:60 seconds; Fixing time:30 seconds;(2) Etching stageTemperature:20℃; Vacuum at the end (low vacuum):1.4×10-2Pa, Working pressure:15 Pa, Ventilating pressure:5～8 Pa, Auto bias pressure:300 V, etching pressure:P=200/400W, Gas and intensity:CHF3:180sccm, SF6:60sccm; Etching time:T=4min50sec; Etching rate:V=70nm/min.Production is completed, we conducted a test on the array, using the microscope on quartz were observed to check the effect after its production plans. On this basis, testing the effects of quartz shaping, contrast Array Fresnel zone plate shaping effect, Results in the problems analyzed, for the next stage of the production process, making a good device to present a number of recommendations, We use the uniformity of laser and test the direct writing of laser, got some good exposure results, Since the principle of binary optics and traditional optics are different, so the stability of such devices need to be further investigated.更多还原