A semiconductor package including a plurality of stacked semiconductor die, and methods of forming the semiconductor package, are disclosed. A first resistor is connected between a control electrode and any one of the pair of the main electrodes of the first field effect transistor, and a second resistor is connected between a control electrode and any one of the pair of the main electrodes of the second field effect transistor. The mask blank is deformed against the portion of the user’s face to cause the mask blank to conform substantially optimally to the user’s unique bone structure and facial features, the mask blank once conformed substantially optimally to the user’s unique bone structure and facial features becoming the custom fitted mask. The invention solves the problem of difficulty in locating wrong corrections of optic fiber cables. The methods for production of copper oxide which comprises contacting copper chloride particles with superheated steam and production of oxygen comprises reaction of copper oxide with dry chlorine as a part of hydrogen production by thermochemical Copper-Chlorine cycle. Each end portion of the feed screw is provided with a cylindrical portion having an outer diameter smaller than an inner diameter of the feed screw, and a resetting elastic portion supported by the fixing portion or the movable portion is provided for pressing the movable portion in the direction opposite to the pressing direction of the coil spring.