The MEMSNAS process: Microloading effect for micromachining 3-D structures of nearly all shapes
The MEMSNAS process: Microloading effect for micromachining 3-D structures of nearly all shapes
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DOI：
10.1109/jmems.2003.823219
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发表时间：
2004-04-01
影响因子：
2.7
通讯作者：
Fujita, H
中科院分区：
文献类型：
--
作者：
Bourouina, T;Masuzawa, T;Fujita, H
我们提出了一种几乎所有形状的三维（3-D）结构的微加工工艺。这是一种使用设备的单掩模工艺，在微电子实验室和工业中广泛使用。主要思想是利用反应离子蚀刻（RIE）的微加载效应，在不同直径的微孔阵列中获得多个高度。由于蚀刻的各向同性性质，邻近微孔的重叠产生了三维轮廓。在去除掩模材料和第二次各向同性RIE步骤后，获得最终的连续和光滑的三维结构。该制造工艺通过实现各种三维结构（包括微透镜）进行了验证，这些结构蚀刻在30微米深的腔中，半径为375微米，高度（凹陷）为10微米。所得结构的粗糙度低至25纳米。定量实验研究导致了三种不同工艺的校准和经验理论模型，可以作为进一步制造三维微结构的设计规则的基础。
We propose a technological process for microfabrication of three-dimensional (3-D) structures with nearly all shapes. This is a one-mask process that uses equipment, widespread in the microelectronics laboratories and industry. The main idea is to take advantage from the microloading effect of reactive ion etching (RIE) in order to obtain multiple levels of heights in an array of microholes of different diameters. A 3-D profile results from an overlap of the neighboring microholes due to the isotropic nature of the etching. The final continuous and smooth 3-D structure is obtained after removal of the mask material and a second isotropic RIE step. This fabrication process was validated with the realization of various 3-D structures including microlenses, etched in a 30 mum deep cavity, with 375 mum in radius and 10 mum in height (sag). The resulting structures have shown a roughness down to 25 nm. A quantitative experimental study led to the calibration of three different processes and to an empirical theoretical model, which can serve as a basis of design rules for further fabrication of 3-D microstructures.