A low-loss RF MEMS silicon switch using reflowed glass structure

This paper reports a low-loss RF MEMS silicon switch that employs reflowed glass as a structural material beneath a contact metal. The glass structure is inserted into a silicon substrate through the glass reflow process to reduce the insertion loss of the RF MEMS switch. To verify this enhancement in the loss characteristic, two types of RF MEMS switches were fabricated with two different structural materials underneath the contact metal: silicon or reflowed glass. The reference RF MEMS switch is totally made of silicon. In the frequency range of 5 to 30 GHz, S-parameter measurements of the fabricated switches were carried out and the insertion losses were measured as 0.12 ~ 0.33 dB and 0.38 ~ 0.53 dB for the proposed and the reference RF MEMS switch, respectively. The insertion loss was reduced as much as 0.26 dB for the proposed RF MEMS switch in the measured frequency range and it was shown that the insertion loss of the RF MEMS switch is effectively reduced by changing the structural material under the contact metal.