Abstract: A wafer-level package comprises: a first substrate; an electric element provided on the first substrate; a second substrate; an internal electrode pad; a well; and an external electrode pad. The second substrate is opposed to the first substrate with a predetermined gap therebetween. The electric element is provided between the first and second substrates. The internal electrode pad extends onto a first surface of one of the first and the second substrates. The inner electrode pad is connected to the electric element. The well penetrates the one of the first and the second substrates to the internal electrode. The external electrode pad is provided on a second surface of the one of the first and the second substrates and extends onto an inner wall of the well and being connected with the internal electrode pad.

Abstract: The present invention provides a voltage controlled oscillator comprising an thin film BAW resonator and a variable capacitor element. The thin film BAW resonator includes an anchor section formed on a Si substrate, a lower electrode supported on the anchor section and positioned to face the Si substrate, a first piezoelectric film formed on the lower electrode, and an upper electrode formed on the first piezoelectric film. On the other hand, the variable capacitor element includes a stationary electrode formed on a Si substrate, an anchor section formed on the Si substrate, a first electrode supported on the anchor section and positioned to face the Si substrate, a second piezoelectric film formed on the first electrode, and a second electrode formed on the second piezoelectric film.

Abstract: The present invention is intended to provide a thin film bulk acoustic wave resonator, which has a resonant excitation portion free from damage caused by etching, a high electromechanical coupling coefficient kt2 and a high quality coefficient Q value, and to provide a thin film bulk acoustic wave resonator having a plurality of different resonant frequencies, which can be formed on the same substrate without increasing number of lithography process. An internal cavity is provided in a semiconductor or insulative substrate such as crystal silicon. The thin film bulk acoustic wave resonator has a layered member comprising a first electrode film, a piezoelectric film and a second electrode film on a thin wall of e.g. single crystal over the internal cavity.

Abstract: A high frequency filter comprises thin film piezoelectric resonators connected in series between the input/output nodes, thin film piezoelectric resonators connected in parallel between the input/output nodes and a variable voltage circuit adapted to change the voltage applied to at least either the thin film piezoelectric resonators connected in series or the thin film piezoelectric resonators connected in parallel. The resonance characteristic of at least either the thin film piezoelectric resonators connected in series or the thin film piezoelectric resonator connected in parallel is shifted by changing the voltage applied by the variable voltage circuit to change the pass characteristic of the filter.

Abstract: A voltage controlled oscillator includes a resonator configured to resonate with an initial oscillation frequency during starting period of oscillation and a steady oscillation frequency during a steady state oscillation. The resonator includes a film bulk acoustic resonator having a series resonance frequency higher than the steady oscillation frequency. A negative resistance circuit configured to drive the resonator, has a positive increment for reactance in the steady state oscillation compared with reactance in the starting period.

Abstract: The present invention provides an infrared detection element having a single-crystalline base layer 3 with a thickness of 50 nm to 10 ?m having a principal surface, a first electrode layer 4 formed on the principal surface of the single-crystalline base layer 3, a ferroelectric layer 5 which is formed on the first electrode layer 4 and is composed of a single-crystalline layer or a unidirectioally oriented layer. Distortion of the single-crystalline layer or a unidirectioally oriented layer in a surface parallel to the principal surface of the single-crystalline base layer 3 is elastically constrained by the single-crystalline base layer 3. The infrared detection element further has a second electrode layer 6 formed on the ferroelectric layer 5. An amount of charge is changed by changes in temperature caused by irradiation of infrared light to the ferroelectric layer 5. The amount of the charge is detected from the first and the second electrode layer4, 6.

Abstract: To provide a miniaturized voltage controlled oscillator which can oscillate simultaneously a plurality of frequencies and has high stability of frequency, an excellent low phase noise, small variation per hour, and a wide frequency variable range. A thin film bulk acoustic wave resonator using single crystal ferroelectric material equal to or smaller than 10 &mgr;m in thickness whose direction of polarization is aligned to the direction of thickness is utilized as the piezoelectric member. The voltage controlled oscillator having large changing rate of the oscillation frequency of 0.01%/V or more and an extremely small phase noise is provided by changing the voltage applied to the electrodes.

Abstract: An infrared detection element having a single-crystalline base layer 3 with a thickness of 50 nm to 10 &mgr;m having a principal surface, a first electrode layer 4 formed on the principal surface of the single-crystalline base layer 3, a ferroelectric layer 5 which is formed on the first electrode layer 4 and is composed of a single-crystalline layer or a unidirectionally oriented layer. Distortion of the single-crystalline layer or a unidirectionally oriented layer in a surface parallel to the principal surface of the single-crystalline base layer 3 is elastically constrained by the single-crystalline base layer 3. The infrared detection element further has a second electrode layer 6 formed on the ferroelectric layer 5. An amount of charge varies with changes in temperature caused by irradiation of infrared light to the ferroelectric layer 5.

Abstract: A bulk acoustic wave device includes: a bulk acoustic wave element including a piezoelectric layer formed on a substrate, a lower electrode contacting a lower surface of the piezoelectric layer, and an upper electrode contacting an upper surface of the piezoelectric layer and partially overlapping the lower electrode, a lower hollow section being formed between the substrate and the lower surface of the piezoelectric layer, a first through-hole reaching the lower hollow section being formed through the bulk acoustic wave element in a direction perpendicular to a surface of the piezoelectric layer; an upper hollow section forming layer forming an upper hollow section with the upper surface of the piezoelectric layer, a second through-hole reaching the upper hollow section being formed therethrough in a direction perpendicular to a surface thereof; and a sealing layer covering the upper hollow section forming layer and filling up the second through-hole.

Abstract: A piezoelectric thin film resonator which comprises a first electrode, a second electrode, and a piezoelectric film which is interposed between the first electrode and the second electrode, and formed of an epitaxial ferroelectric thin film containing barium titanate, a spontaneous polarization of the epitaxial ferroelectric thin film being uniaxially orientated in a direction normal to a film surface.

Abstract: An integrated circuit device comprises an insulation layer formed on a substrate, a plurality of lattice relaxed SiGe layers each formed in an island form on the insulation layer, wherein a maximum size of the island form thereof is 10 &mgr;m or less, one of a strained Si layer, a strained SiGe layer and a strained Ge layer formed on at least one of the plurality of lattice relaxed SiGe layers, and a field effect transistor having a gate electrode and source and drain regions, wherein the gate electrode is formed on one of the strained Si layer, the strained SiGe layer and the strained Ge layer with a gate insulation film is disposed therebetween, and the source and drain regions is formed to sandwich a channel region formed below the gate electrode with the gate insulation film disposed therebetween.

Abstract: The present invention is intended to provide a thin film bulk acoustic wave resonator, which has a resonant excitation portion free from damage caused by etching, a high electromechanical coupling coefficient kt2 and a high quality coefficient Q value, and to provide a thin film bulk acoustic wave resonator having a plurality of different resonant frequencies, which can be formed on the same substrate without increasing number of lithography process.

Abstract: To provide a miniaturized voltage controlled oscillator which can oscillate simultaneously a plurality of frequencies and has high stability of frequency, an excellent low phase noise, small variation per hour, and a wide frequency variable range. A thin film bulk acoustic wave resonator using single crystal ferroelectric material equal to or smaller than 10 &mgr;m in thickness whose direction of polarization is aligned to the direction of thickness is utilized as the piezoelectric member. The voltage controlled oscillator having large changing rate of the oscillation frequency of 0.01%/V or more and an extremely small phase noise is provided by changing the voltage applied to the electrodes.

Abstract: A high frequency filter comprises thin film piezoelectric resonators connected in series between the input/output nodes, thin film piezoelectric resonators connected in parallel between the input/output nodes and a variable voltage circuit adapted to change the voltage applied to at least either the thin film piezoelectric resonators connected in series or the thin film piezoelectric resonators connected in parallel. The resonance characteristic of at least either the thin film piezoelectric resonators connected in series or the thin film piezoelectric resonator connected in parallel is shifted by changing the voltage applied by the variable voltage circuit to change the pass characteristic of the filter.

Abstract: A semiconductor memory device is manufactured by uniformly forming an epitaxial capacitor layer on the whole surface of a single-crystal semiconductor layer, finely dividing the capacitor layer into individual capacitors by etching, using the individual capacitors as a mask to etch the single-crystal semiconductor layer and forming semiconductor columnar portions, and preparing vertical field effect transistors each having a channel portion in the semiconductor columnar portion. Thereby, the vertical field effect transistor can be formed under the epitaxial capacitor in a self aligning manner.

Abstract: A piezoelectric thin film resonator which comprises a first electrode, a second electrode, and a piezoelectric film which is interposed between the first electrode and the second electrode, and formed of an epitaxial ferroelectric thin film containing barium titanate, a spontaneous polarization of the epitaxial ferroelectric thin film being uniaxially orientated in a direction normal to a film surface.

Abstract: A method of manufacturing an epitaxially-strained lattice film of an oxide, in which epitaxially-strained lattices having a good crystalline property are formed by applying RF power to a substrate holder and irradiating positive ions having a moderate energy while preventing damage to the strained lattice film to be stacked by oxygen negative ions. This method simultaneously overcomes both the problem of damage to the film by irradiation of oxygen negative ions, which is peculiar to sputtering of oxides, and the problem of failure to strain due to relaxation of the strain during deposition.

Abstract: An integrated circuit device comprises an insulation layer formed on a substrate, a plurality of lattice relaxed SiGe layers each formed in an island form on the insulation layer, wherein a maximum size of the island form thereof is 10 &mgr;m or less, one of a strained Si layer, a strained SiGe layer and a strained Ge layer formed on at least one of the plurality of lattice relaxed SiGe layers, and a field effect transistor having a gate electrode and source and drain regions, wherein the gate electrode is formed on one of the strained Si layer, the strained SiGe layer and the strained Ge layer with a gate insulation film is disposed therebetween, and the source and drain regions is formed to sandwich a channel region formed below the gate electrode with the gate insulation film disposed therebetween.

Abstract: The present invention provides an infrared detection element having a single-crystalline base layer 3 with a thickness of 50 nm to 10 &mgr;m having a principal surface, a first electrode layer 4 formed on the principal surface of the single-crystalline base layer 3, a ferroelectric layer 5 which is formed on the first electrode layer 4 and is composed of a single-crystalline layer or a unidirectioally oriented layer. Distortion of the single-crystalline layer or a unidirectioally oriented layer in a surface parallel to the principal surface of the single-crystalline base layer 3 is elastically constrained by the single-crystalline base layer 3. The infrared detection element further has a second electrode layer 6 formed on the ferroelectric layer 5. An amount of charge is changed by changes in temperature caused by irradiation of infrared light to the ferroelectric layer 5. The amount of the charge is detected from the first and the second electrode layer 4, 6.

Abstract: A semiconductor memory device is manufactured by uniformly forming an epitaxial capacitor layer on the whole surface of a single-crystal semiconductor layer, finely dividing the capacitor layer into individual capacitors by etching, using the individual capacitors as a mask to etch the single-crystal semiconductor layer and forming semiconductor columnar portions, and preparing vertical field effect transistors each having a channel portion in the semiconductor columnar portion. Thereby, the vertical field effect transistor can be formed under the epitaxial capacitor in a self aligning manner.