MEMS RF switch with controlled contact landing

摘要

The MEMS switch includes an RF electrode 102, a pull-down electrode 104, and an anchor electrode 108 disposed on a substrate 101. A plurality of islands 226 are provided on the pull down electrode and electrically isolated therefrom. Above the RF electrode is an RF contact 206 that forms an ohmic contact in the pull-down state of the MEMS bridge 212, 214. The pull-down electrode 104 is coated with a dielectric layer 202 to avoid a short between the bridge and the pull-down electrode. The contact stopper 224 is disposed on the dielectric layer 202 at a location corresponding to the island 226, and the gap created between the bridge and the dielectric layer in the pull-down state reduces the dielectric charge. In an alternative embodiment, the contact stoppers are provided inside the dielectric layer 202, or are disposed above the island itself and below the dielectric layer. The switch provides good control of the contact resistance of the MEMS switch over a wide voltage operating range.