UV-LIGA microfabrication process for sub-terahertz waveguides utilizing multiple layered SU-8 photoresist
UV-LIGA microfabrication process for sub-terahertz waveguides utilizing multiple layered SU-8 photoresist
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DOI：
10.1088/0960-1317/26/9/095010
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发表时间：
2016-09-01
影响因子：
2.3
通讯作者：
Paoloni, Claudio
中科院分区：
文献类型：
--
作者：
Malekabadi, Ali;Paoloni, Claudio
提出了一种基于UV LIGA（德语lithography，electroplating and molding）的微加工工艺，用于制作亚太赫兹（100-1000 GHz）宽高比的金属波导，作为亚太赫兹真空电子器件中的慢波结构。正确支持亚太赫兹范围内的频率所需的高精度和严格公差只能通过具有完全参数控制的稳定过程来实现。所提出的工艺，基于SU-8光刻胶，已开发，以满足金属亚太赫兹波导的高平面表面要求。它将被证明，对于一个给定的厚度，它是更有效的堆叠的SU-8层的数量与较低的厚度，而不是使用一个单一的厚层在较低的自旋速率。多层方法提供了接地平面或组装表面的电铸所需的平面性和表面质量，并确保波导的低欧姆损耗。提供了一个系统的程序来计算软和后烘烤时间，以产生高均匀性SU-8多层涂层作为非常高质量的金属波导的模具。设计制作了一种工作频率为0.3THz的真空电子器件用双波纹波导作为测试结构，基于UV LIGA的工艺可以低成本制作高精度的亚太赫兹3D波导。这是生产新一代负担得起的亚太赫兹真空电子器件的基础，以填补仍然阻止基于太赫兹辐射的众多应用广泛扩散的技术空白。
A microfabrication process based on UV LIGA (German acronym of lithography, electroplating and molding) is proposed for the fabrication of relatively high aspect ratio sub-terahertz (100-1000 GHz) metal waveguides, to be used as a slow wave structure in sub-THz vacuum electron devices. The high accuracy and tight tolerances required to properly support frequencies in the sub-THz range can be only achieved by a stable process with full parameter control. The proposed process, based on SU-8 photoresist, has been developed to satisfy high planar surface requirements for metal sub-THz waveguides. It will be demonstrated that, for a given thickness, it is more effective to stack a number of layers of SU-8 with lower thickness rather than using a single thick layer obtained at lower spin rate. The multiple layer approach provides the planarity and the surface quality required for electroforming of ground planes or assembly surfaces and for assuring low ohmic losses of waveguides. A systematic procedure is provided to calculate soft and post-bake times to produce high homogeneity SU-8 multiple layer coating as a mold for very high quality metal waveguides. A double corrugated waveguide designed for 0.3 THz operating frequency, to be used in vacuum electronic devices, was fabricated as test structure.The proposed process based on UV LIGA will enable low cost production of high accuracy sub-THz 3D waveguides. This is fundamental for producing a new generation of affordable sub-THz vacuum electron devices, to fill the technological gap that still prevents a wide diffusion of numerous applications based on THz radiation.