Abstract:
A power amplifier includes: a plurality of field effect transistors connected in parallel and each having a first and second ends, the first end being connected to ground; an amplifying unit which includes at least one of an inductor, a capacitor and a band pass filter and has a third and fourth ends, the third end being connected to the second ends of the field effect transistors, and the fourth end outputting an amplified output signal; and an amplitude controller which sends control signals respectively to gates of the field effect transistors to turn on or off the field effect transistors based on an address signal for performing selection on the field effect transistors and a clock signal. Channel widths of the field effect transistors are different from each other.
Abstract:
In a wiring structure of a semiconductor device, dielectric tolerance of the wiring is improved by preventing diffusion of the wiring material. The wiring structure of the semiconductor device includes a first insulating film having plural grooves, plural wiring films formed protrusively above tops of the first insulating film among the grooves, plural barrier films formed on bottoms of the wiring films and up to a position on sides of the wiring films higher than the tops of the first insulating film; first cap films comprising metal films formed on tops of the wiring films, and a second cap film formed on at least respective sides of the first cap films and the barrier films.
Abstract:
A method of producing a semiconductor device includes, in order to electrically connect a lower layer wiring and an upper layer wiring opposite to each other with an interlayer insulation film intervening between them, a step of forming a via-hole, which exposes the lower layer wiring upward from the lower layer wiring through the interlayer insulation film, a step of forming a protective film for preventing erosion, and a step of forming a plug for electrically connecting the lower layer wiring to the upper layer wiring, wherein the protective film is formed by a CVD process in order to cover a residue having stuck to the inner wall of the hole concerned during forming the via-hole.
Abstract:
A digital demodulator includes a resonator having a resonance frequency same as a carrier frequency to store a charge corresponding to a digital signal modulated by phase shift keying, a capacitor to store the charge of the resonator, an amplifier including an input node and an output node between which the capacitor is connected to convert a stored charge of the capacitor into a voltage signal, and a controller configured to accumulate in the resonator the charge induced by the frequency signal modulated by phase shift keying in a first control mode and configured to transfer the charge of the resonator to the capacitor in a second control mode, to output the voltage signal corresponding to the stored charge of the capacitor from the output node of the amplifier.
Abstract:
In a MEMS type variable capacity having a piezoelectric driving mechanism, a movable head having movable electrodes are arranged thereon, stationary electrodes is positioned to face the movable electrodes, and a piezoelectric driving beam structure is joined to the movable head and have one end fixed to the substrate. The movable electrode and the stationary electrode form a variable capacity. In the variable capacity, the distance and capacitance between the movable electrode and the stationary electrode of the variable capacity can be maintained constant so as to realize a reproducibility and a reliable controllability.
Abstract:
A film bulk acoustic-wave resonator encompasses a substrate having a cavity; a bottom electrode partially fixed to the substrate, part of the bottom electrode is mechanically suspended above the cavity; a piezoelectric layer provided on the bottom electrode; and a top electrode provided on the piezoelectric layer having crystal axes oriented along a thickness direction of the piezoelectric layer, a full width at half maximum of the distribution of the orientations of the crystal axes is smaller than or equal to about six degrees.
Abstract:
A filter control apparatus which controls a frequency variable filter capable of changing a transmission band width by controlling a capacitance of at least a portion of a plurality of voltage variable capacitors connected in series and parallel to a resonator has an input unit, and a filter control circuit. The input unit inputs a reference signal with a predetermined reference frequency to the frequency variable filter. The filter control circuit controls a center frequency and the transmission band width of the frequency variable filter by detecting a phase change generated when the reference signal passes through the frequency variable filter and by variably controlling the capacitance of at least a portion of the voltage variable capacitor by using a direct voltage in proportion to the phase change.
Abstract:
A method of forming buried wiring, includes the steps of forming an insulating layer having a trench on a semiconductor substrate; forming a conductive layer mainly composed of copper on the insulating layer in such a manner that the trench is filled with the conductive layer; removing an oxide layer generated in a surface of the conductive layer by oxidation; forming a cap layer made of a material having less mechanical strength than the oxide layer, on the conductive layer; and removing the cap layer and a part of the conductive layer by chemical mechanical polishing in such a manner that the conductive layer is left in the trench.
Abstract:
A piezoelectric thin film device includes an amorphous metal film disposed on a substrate and a piezoelectric film disposed on the amorphous metal. One of crystal axis of the piezoelectric film is aligned in a direction perpendicular to a surface of the amorphous metal.
Abstract:
There is disclosed a method for forming an interconnection in the semiconductor element, including a process for forming a groove 117 on an underlying substrate so as to correspond to the designed pattern, a process for forming an underlayer to improve crystalline of an interconnection which will be formed in the succeeding stage on said underlying substrate with said groove, a process for forming a thin film of the interconnection material, a heat-treatment process to fill the said groove with the thin film of the interconnection material formed on the underlying substrate, and a process for forming the interconnection by polishing the surface of the thin film by predetermined quantity.