Simple and Robust Air Gap-Based MEMS Technology for RF-Applications

Phillip EKKELS^1,2, Xavier ROTTENBERG^1,2, Robert PUERS^1,2, Harrie A.C. TILMANS<sup>1

1</sup>IMEC, Kapeldreef 75, 3001 Heverlee, Belgium
²K.U.Leuven, Kasteelpark Arenberg 10, 3001 Heverlee, Belgium

Abstract. The reliability of RF-MEMS switching devices becomes more and
more important. The lifetime of capacitive switches is mainly limited by dielectric
charging. By realizing a capacitive switch without dielectric its lifetime can be
significantly improved. This paper presents a technology to fabricate capacitive RF-
MEMS switching devices without dielectric. It consists of a thick membrane that
defines an airgap capacitor with 2 different states. It is shown how these switched
capacitors, even though having a low capacitance ratio, can still form adequate
switching devices and RF-circuits by proper design and combining these devices with
high-Q inductors and transmission lines. Lifetimes of more than 1×108 cycles with
unipolar actuation are observed.