A communication apparatus and method includes a modem operable for connection to a telephone line. The single laser light source has a fold-retro-reflected design to create three retro-reflected optical beams that cross at 90\xb0 angles relative to one another in the vacuum chamber cavity. Thus, the sensor structure is electrically connected with a substrate through the only one support arm. An upper cell dielectric layer may be on the substrate and over the lower cell dielectric layer, body unit conductor and memory element conductors. When a transparent conductive film is formed by sputtering, this sputtering target makes it possible to suppress the generation of nodules on the surface of the target and to conduct the sputtering stably.