Design And Research Of Array Phase-Ring Based On Binary Optical Theory

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.