A glass-based MEMS switch approach for harsh environments and high-performance RF applications

Inhalt:
In this paper we present the development and manufacturing of a glass-based MEMS switch for DC and RF applications. The MEMS switch was monolithic fabricated by LIDE(c) – a laser inducesd etching process – using 200 µm thick borosilicate glass including micro-spring structures, electrostatic and thermo-electric actuators, and sidewall switch contacts. Additional fabrication processes are Cr, Cu, Ti and Al sputtering as well as electroless plating of Cu, Ag and Au. The base material has a high specific AC (50 Hz) resistance at high temperatures of 1.18 × 10⁸ Ω cm and 4.24 × 10⁸ Ω cm at 520 K and 620 K, respectively, and shows a low dielectric dissipation factor (tan δ) of 73 × 10^-4 @ 5 GHz and 140 × 10^-4 @ 77 GHz. Therefore, it is suitable for harsh environments and RF application, in particular. We show the functionality of the 2.5 × 4 mm² all-in-glass MEMS switch with a switching voltage of 3.3 V and minimum holding voltage of ~6.8 V.