设计了一种与CMOS工艺兼容的MEMS片上螺旋电感。电感为矩形平面螺旋线圈结构,并采用电导率较高的铜代替铝制作线圈。利用MEMS技术设计了厚金属线圈,同时在CMOS级低阻硅衬底中刻蚀空腔,减小了线圈的串联电阻和衬底损耗,提高了电感的Q值。设计了与CMOS工艺相兼容的低温MEMS工艺和基于该工艺的1nH电感模型。使用HFSS软件对该电感模型进行仿真,结果表明,该电感在仿真频率为6.6GHz和10GHz时Q值分别达到了22.37和20.74,且自谐振频率大于20GHz,较传统的CMOS片上集成电感有明显改善；同时随着电感线圈厚度的增加,电感的Q值增加,而电感值(L值)则减小,且在仿真频段内电感值的变化小于5.5%。

A CMOS-compatible MEMS integrated on-chip inductor is designed. The square planar spiral coil program is utilized. The coils are made of copper with a higher conductivity than aluminum. In order to improve the quality factor (Q) of the inductor, thick metal coils and cavities etched in the CMOS-grade silicon substrate are designed by the MEMS technology, which can reduce the serial resistance of metal square planar spiral coils and the losses in the low resistance silicon substrate, respectively. A fully CMOS-compatible low temperature MEMS process is presented and a 1nH inductor model with thick metal coils and low-loss MEMS substrate is simulated by using HFSS software. Simulation results show that the inductor obtained by this CMOS-compatible low temperature MEMS process enjoys a high peak quality factor of 22.37 and 20.74 at 6.6GHz and 10GHz with a self-resonant frequency over 20GHz, respectively. The influences of metal coils' thickness on the quality factor and the inductance are also analyzed. When the thickness of the inductor is increased, the quality factor is increased while the inductance is decreased. The fluctuation of the inductance is less than 5.5% in the simulation frequency range.