基于衍射效应的C-MEMS悬浮结构的仿真和制备.doc

  基于衍射效应的 C-MEMS 悬浮结构的仿真 和制备# 龙胡1,2，刘丹1,2，习爽1,2，徐亮亮1,2，汤自荣1,2** 5 10 15 20 25 30 35 40 （1. 华中科技大学机械学院，武汉 430074； 2. 武汉光电国家实验室，武汉 430074） 摘要：提出了一个制造三维 C-MEMS 的悬浮结构的制造体系。通过仔细分析三维 C-MEMS 的制 造过程，发现光刻中的曝光过程决定悬浮结构能否形成，而后续的处理如显影、烘烤将决定 悬浮结构能否保留下来。故而，分析曝光过程中光学的原理，建立了一个光学模型，该光学 模型主要是基于衍射效应，通过模拟光刻中曝光过程光的传播，得到曝光过程中光刻胶表面 光强的分布，从而解释曝光过程中悬浮结构的形成机理及各曝光参数对其的影响，并给实验 工艺指导。在曝光过程中，控制悬浮结构形成的要素主要有曝光模式、掩膜板至光刻胶之间 的距离、曝光时间、掩膜板图案。在后续的处理过程中，显影时间和烘烤时间决定悬浮结构 能否保留。通过对曝光和后续过程中各参数的控制，得到了一个可重复制备悬浮结构的制备 体系。 关键词：半导体技术；C-MEMS；悬浮结构；光刻；衍射效应 中图分类号：TN305.7 Simulation and fabrication of suspended C-MEMS structures based on the diffraction effects Long Hu1,2, Liu Dan1,2, Xi Shuang1,2, Xu Liangliang1,2, Tang Zirong1,2 (1. Huazhong university of science and technology, WuHan 430074; 2. Wuhan National Laboratory For Optoelectronics, WuHan 430074) Abstract: This paper proposes a fabrication system to create the suspended three-dimension(3D) carbon-micro-electro-mechanical systems(C-MEMS) structures. By analysing the fabrication process of C-MEMS structures, we find that proper control of exposure condition such as the air gap between the mask and photoresist and exposure time can help create suspended structures. We also find that the bake and development condition can consolidate or destroy suspended structure. We built a optical model based on diffraction effects by conbining the exposure process and optical theory. The optical model which simulates the transmission of light in lithography can predict the intensity distribution on the surface of the SU-8 photoresist. Using this optical model we can not only explain how the suspended structures appear but also present some manufacturing methods. In exposure process, the key elements in exposure process include the exposure mode, the air gap between the mask and photoresist, exposure time and the mask pattern. In the experiment, we find that bake time and development time have a great impact on the suspended structures which can consolidate or destroy suspe