The switch contacts of a MEMS relay for a circuit interrupter are coated with a thin layer of liquid metal, and the MEMS relay is disposed in a sealed enclosure containing a gas medium. The gas medium provides an environmentally desirable alternative to sulfur hexafluoride (SF.sub.6), prevents oxidation of the liquid metal coating the relay switch contacts, and has sufficient dielectric strength in order to prevent current flow after separation of the switch contacts.

Described herein is a technique capable of forming a sacrificial film with a high wet etching rate so as to obtain a wet etching selectivity with respect to a movable electrode when manufacturing a cantilever structure sensor. According to one aspect of the technique of the present disclosure, there is provided a method of manufacturing a semiconductor device including: (a) placing a substrate with a sacrificial film containing impurities on a substrate support in a process chamber, wherein the sacrificial film is formed so as to cover a control electrode, a pedestal and a counter electrode formed on the substrate; (b) heating the substrate; and (c) modifying the sacrificial film into a modified sacrificial film by supplying an oxygen-containing gas in a plasma state to the substrate to desorb the impurities from the sacrificial film after (b).

Described herein is a technique capable of forming a sacrificial film with a high wet etching rate so as to obtain a wet etching selectivity with respect to a movable electrode when manufacturing a cantilever structure sensor. According to one aspect of the technique of the present disclosure, there is provided a method of manufacturing a semiconductor device including: (a) placing a substrate with a sacrificial film containing impurities on a substrate support in a process chamber, wherein the sacrificial film is formed so as to cover a control electrode, a pedestal and a counter electrode formed on the substrate; (b) heating the substrate; and (c) modifying the sacrificial film into a modified sacrificial film by supplying an oxygen-containing gas in a plasma state to the substrate to desorb the impurities from the sacrificial film after (b).

A microelectromechanical systems (MEMS) switch device including current sensing and overcurrent protection can include a movable plate movable between an open position and a closed position, wherein the moveable plate is moved by applying at least one or more of an electrostatic force and a magnetic force to move the movable plate. The movable plate can include a shunt operable to conduct current when the movable plate is the closed position. An inductive coil electronically coupled to the shunt can detect current conducted through the shunt.