An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

In a keyboard electronic musical instrument having tone generators of frequency divider systems, every key is associated with and controls a plurality of tone keyers which respectively gate tone signals having frequencies being harmonically related with each other. The tone signal gated by one of the keyers is passed through a frequency shifter, while the tone signal gated by the rest of the keyers is not. Among the tone keyers, the above-mentioned one is a keyer for producing an attack signal, while the remainder are keyers for producing a normal lasting signal. Both signals, now being slightly out of harmonic relation, are mixed together and finally transduced into sound by a loudspeaker. The produced sound has subtly fine musical results with a sense of many different tone sources as in an individual--oscillator system instrument.

Electronic musical instrument

A power conversion device includes a power switching circuit that supplies AC voltages generated between switching elements operating as upper arms and switching elements operating as lower arms, and a control circuit that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements by a PWM method in a first operational region in which frequency of an AC power to be outputted is low, and that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements at timings based upon the phase of the AC power to be outputted in an operational region in which the frequency of the AC power to be outputted is higher than in the first operational region.

Power Conversion Device

A semiconductor memory device comprises memory cells, a bitline connected to the memory cells, a read circuit including a precharge circuit, and a first transistor connected between the bitline and the read circuit, wherein a first voltage is applied to a gate of the first transistor when the precharge circuit precharges the bitline, and a second voltage which is different from the first voltage is applied to the gate of the first transistor when the read circuit senses a change in a voltage of the bitline.

Semiconductor memory device.

The invention is directed to a semi-conductor wafer processing machine including an arm having a wafer carrier disposed at one end. The wafer carrier is rotatable with the rotating motion imparted to a semi-conductor wafer held thereon. In first embodiment, the machine further includes a rotatable polishing pad having an upper surface divided into a plurality of wedge-shaped sections, including an abrasion section and a polishing section. The abrasion section has a relatively rough texture and the polishing section has a relatively fine texture as compared to each other. In an alternative embodiment, the pad includes an underlayer and surface layer. The surface layer includes two sections of differing hardness, both of which are harder than the underlayer. Alternatively, the surface layer may include one relatively hard section, and the underlayer may include two sections, one of which has the same hardness as the surface layer and the other of which is softer than the surface layer. In a further embodiment, the polishing pad has an annular shape, and a chemical processing table is disposed within the open central region of the pad.

Apparatus for processing semiconductor wafers

A switched capacitor filter having at its input, a signal converter for creating so-called 100% sample and hold signals. The signal converter comprises a plurality of switched capacitors. The switched capacitors, connected in parallel with each other, receive the same successive input signals and supply the so-called 100% sample and hold input signals to the switched-capacitor filter. The switched capacitors, on one hand, charge each of said input signals sequentially and, on the other hand, alternately discharge the respective stored input signals one by one.

Switched-capacitor filter

A programmable integrated circuit has multi-layer wiring with openings over fuses, and a fabrication method forms the openings for each fuse, to avoid damage due to the blowing off of the fuses. The forming of the openings is performed by etching each insulating layer on the fuses after it is formed over the pre-formed wiring-layers. This results in shorter etching time as compared to the prior art etching method where the openings are etched in all the layers for the whole depth in one process step. Because of the shorter time necessary for each etching, overetching and side-etching are reduced, thus providing the openings with more accurately determined dimensions, which provides higher yield for manufacturing the device. The contact holes and the windows for the bonding pads in each insulating layer are etched in the same fabrication step for forming the openings for the fuses in the same insulating layer. This requires no additional fabrication processes for the IC and results in no increase of the fabrication time and cost.

Method for fabricating an integrated circuit with multi-layer wiring having opening for fuse

A clock generator circuit for generating two pairs of clock signals (φ2, φ 2 - φ1, φ 1) comprises a NAND circuit (51) and a NOR circuit (52) cross-coupled to each other and each having an input for receiving a reference clock signal (φ0). A first inverter (53) is provided between the output of the NAND cicuit (51) and the other input of the NOR circuit (52), and a second inverter (54) is provided between the output of the NOR circuit (52) and the other input of the NAND circuit (51). A pair of clock signals (φ 2, φ2) are generated from the NAND circuit (51) and the first inverter (53), while the other pair of clock signals (φ1, φ 1) are generated from the NOR circuit (52) and the second inverter (54). Unwanted overlap of such clock signals can thereby be avoided.

Clock generator circuit

An integrator for use in a switched capacitor-filter, in which switching elements are connected to an input and to an output of an operational amplifier included in the integrator for clamping the input and output to a ground potential during suspension of the integral operation, in order to prevent potentials at the input and output of the operational amplifier from varying and hence ensure rapid stabilization of the integral operation of the integrator.

Integrator for a switched capacitor-filter

A switching power supply apparatus rectifies an AC power input in a rectifier circuit, switches a rectified output and rectifies and smoothes the same in a switching circuit, and a desired DC voltage is derived A current limiting circuit limits a current supplied to a smoothing capacitor of the rectifier circuit A voltage detecting circuit detects a rectified output of the rectifier circuit A current limiting control circuit controls the current limiting circuit in response to a detected voltage The current limiting control circuit activates the current limiting circuit in a first preset period in which the detected voltage is equal to or lower than a preset level Further, the current limiting control circuit activates the current limiting circuit for a second preset period after the detected voltage is first changed from a level equal to or higher than the preset level to a level lower than the preset level and then returned to the level equal to or higher than the preset level

Akihiko Ito

Papers

Switched-capacitor filter

Method for fabricating an integrated circuit with multi-layer wiring having opening for fuse

Clock generator circuit

Integrator for a switched capacitor-filter

Switching power supply apparatus