Abstract: A double-gate field-effect transistor includes a substrate, an insulation film formed on the substrate, source, drain and channel regions formed on the insulation film from a semiconductor crystal layer, and two insulated gate electrodes electrically insulated from each other. The gate electrodes are formed opposite each other on the same principal surface as the channel region, with the channel region between the electrodes. The source, drain and channel regions are isolated from the surrounding part by a trench, forming an island. Gate insulation films are formed on the opposing side faces of the channel region exposed in the trench. The island region between the gate electrodes is given a width that is less than the length of the channel region to enhance the short channel effect suppressive property of structure.

Abstract: The present invention provides a novel electrostrictive material which has a large strain relative to an input electric field, is a non-lead material, and is low in temperature dependency and hysteresis, and a manufacturing method thereof. The electrostrictive material of the invention comprises a compound composed of two or more elements obtained by selecting one or more elements from the group consisting of Sr, Ba, Mg, Ca, Zn and Cd, and the group consisting of Al, Ga and Si, respectively, and oxygen; or a compound represented by MxAlyO(2x+3y)/2 (where, M represents one or more elements selected from the group consisting of Sr, Mg, Ca, Ba, Zn and Cd; and x and y take values each within a range from 1 to 20); or a compound achieved by adding one or more rare-earth or transition metal elements in an amount within a range from 0.001 to 20 mol. %.