A helical antenna includes a ground plate, a first helical portion spirally wound perpendicular to the plate, a second helical portion spirally wound perpendicular to the plate and surrounding the first helical portion radially outward of the first helical portion, and a feeder circuit. The heliostat includes a target sensor for controlling reflected light from a mirror component to direct it to the target sensor 19, and a search sensor for catching sunlight to guide reflected light from the mirror component to the target sensor, thereby to autonomously start control by the target sensor. An etching stopper 50 is formed on at least either of the gate-insulating film 32 exposed from the edge 48 of the interlayer insulating film 42 or the passivation film 38. The contact pad is available during a probe stage of the in-process memory device, but once the device is packaged, access to that contact pad is prevented.