High aspect ratio spiral microcoils fabricated by a silicon lost molding technique
High aspect ratio spiral microcoils fabricated by a silicon lost molding technique
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DOI：
10.1088/0960-1317/16/5/025
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发表时间：
2006-05
影响因子：
2.3
通讯作者：
Y. Jiang;T. Ono;M. Esashi
中科院分区：
文献类型：
--
作者：
Y. Jiang;T. Ono;M. Esashi
本文介绍了一种用于制造高Q值的高深宽比微线圈的硅消失模工艺。该工艺采用了深反应离子刻蚀、电镀和XeF2硅刻蚀。制造纵横比为16且内径为80 µm至200 µm的微弹簧圈。使用网络分析仪和双端射频探头测量电特性。对于内径为130 µm、三个绕组和外径为240 µm的微弹簧圈，在1.6 GHz频率下的品质因数为85。邻近效应和寄生电容被发现是限制微线圈在高频下的最大Q因子的关键问题。微线圈的高Q值使其对于高分辨率微MRI（磁共振成像）应用具有吸引力。
In this paper, a silicon lost molding process is described for fabricating high aspect ratio microcoils with high Q factors. Deep reactive ion etching, electroplating and XeF2 silicon etching are utilized in this process. Microcoils with an aspect ratio of 16 and inner diameters from 80 µm to 200 µm are fabricated. The electrical characteristics are measured using a network analyzer and a two-terminal radio frequency probe. For a microcoil with an inner diameter of 130 µm, three windings and an outer diameter of 240 µm, the quality factor is 85 at a frequency of 1.6 GHz. The proximity effect and parasitic capacitance are found to be the key issues for limiting the maximum Q factor of the microcoil at high frequencies. The high Q values of the microcoils make them attractive for high resolution micro-MRI (magnetic resonance imaging) applications.