高深宽比倾斜沟槽的深硅刻蚀技术

Deep Silicon Etching Technique for Slant Channel with High Aspect Ratio

针对微电子机械系统(MEMS)行业对3D加工日益增长的需求,提出了一种结合法拉第笼和倾斜衬底支架,利用改进的BOSCH工艺进行任意角度深硅刻蚀的创新工艺方案。首先通过仿真计算对法拉第笼的特征尺寸进行了优化,进一步采用法拉第笼和用于制备倾角的衬底支架,对BOSCH工艺参数进行了调整,最终获得了倾角为30°、深度超过25μm、深宽比高达7.9∶1的倾斜沟槽。结果表明利用法拉第笼和倾斜衬底支架,采用深硅刻蚀工艺可以制备高深宽比的倾斜沟槽,而且沟槽角度可以通过加工不同倾角的支架实现。结合法拉第笼和倾斜衬底支架进行等离子体刻蚀可为其他倾斜结构的制备工艺提供参考。

For the growing demand of 3D machining in micro-electromechanical system(MEMS)industry,a novel process scheme using the improved BOSCH process was proposed with the combination of the Faraday cage and slant substrate support to carry out the deep silicon etch at any angle.The characteristic size of the Faraday cage was optimized by simulation and calculation,and further the BOSCH process parameters were adjusted by using the optimized Faraday cage and the substrate support for preparing slant angle.Finally,the slant channels were achieved with the slant angle of 15°and 30°respectively,the depth more than 25μm,and the aspect ratio up to 7.9∶1.The results show that by using the Faraday cage and slant substrate support,slant channels with high aspect ratio can be obtained by deep silicon etching process,and the angle of the slant channel can be realized by fabricating the slant support with different slant angles.Plasma etching carried out by the combination of the Faraday cage and slant sub strate support can provide a reference for the processes of other slant structures.