高深宽比微结构深度测量技术的研究进展

Research progress of depth measurements of high aspect ratio microstructures

高深宽比孔/槽微结构现广泛应用于微机电系统(MEMS)与三维集成电路(3D-IC)等领域,是微纳器件的基础性工艺结构。随着器件微型化与功能化的发展需求,孔/槽微结构的深宽比不断提升。深度作为重要参数对器件加工工艺、器件性能有直接影响,微孔/槽结构深度的精确测量具有重要意义,但测量方法面临巨大挑战,成为测量领域的难题之一。针对这一问题,按照非光学和光学测量方式将测量方法分为两大类,介绍了扫描电子显微镜、扫描探针术、白光显微干涉技术、共焦显微技术和反射光谱技术等测量方法的工作原理,在微孔/槽深度测量方面的研究现状,尝试从中总结每种测量方法的优缺点,最后,讨论了未来高深宽比微结构深度测量发展趋势以及研究重点,为之后高深宽比微结构深度的测量技术研究提供帮助。

High aspect ratio hole/slot microstructures are now widely used in the fields of micro-electro-mechanical systems(MEMS) and three-dimensional integrated circuits(3D-IC), and are fundamental process structures for micro and nano devices. With the development need for miniaturization and functionalization of devices, the depth-to-width ratio of hole/slot microstructures is constantly increasing. As an important parameter, depth has a direct impact on the device processing and device performance. The accurate measurement of the depth of micro-hole/slot structure is of great significance, but the measurement method faces great challenges and has become one of the difficult problems in the field of measurement. To address this issue, the measurement methods are divided into two major categories according to the non-optical and optical measurement methods, and the working principles of measurement methods such as scanning electron microscopy, scanning probe technique, white light microscopic interferometry, confocal microscopy and reflection spectroscopy are introduced. The research status of the depth measurements of micro hole/slot is introduced, and the advantages and disadvantages of each measurement method are summarized. Finally, the future development trend and research focus of high aspect ratio microstructure depth measurement are discussed to help the future research of high aspect ratio microstructure depth measurements.