电容式RF MEMS开关介质层电荷积累消除方法

Dielectric Charging-Eliminating Technology for Capacitive RF MEMS Switches

电容式RF MEMS开关是下一代高频通信领域中的关键部件。首先,介绍了电容式RF MEMS开关的结构、工作原理以及失效机理。介质充电是制约电容式RF MEMS开关长期可靠性的主要原因,介质膜中的陷阱以及施加在介质膜中高电场是引起介质层中电荷积累的根源。在此基础上,归纳总结了前期减少电荷积累所采用的不同途径,如改善介质层、降低驱动电压、优化驱动波形、优化结构设计和采用非静电的驱动方式等,并举例说明了这些途径的优缺点,最后讨论并指出了未来消除电荷积累的可行性研究方向。

Capacitive RF MEMS switches are the key parts for the next generation of the high fre- quency communication. Firstly, the typical structure, working principle and failure mechanism of capacitive RF MEMS switches are discussed. It is concluded that the dielectric charging is the major failure mechanism which hinders the long term application of capacitive RF MEMS swit- ches, and the charge accumulation in the dielectric is mainly caused by the traps in the dielectric film and the high electric field applied to the dielectric film. On this basis, the previous approa- ches of reducing the charge accumulation are summarized, such as improving the dielectric layer, reducing the actuation voltage, optimizing the design of the switch structure, applying the actua- tion waveform and non-electrostatic actuation mode, besides that the advantages and disadvanta- ges of which are illustrated with examples. Finally, the feasible directions in the future research to eliminate the charge accumulation in the dielectric of capacitive RF MEMS switches are discussed and proposed.