Abstract: For disposing projections of insulating film protruding into a hollow part in CMUT in order to suppress injection of electrical charge into the insulating film due to contact of a lower surface of a membrane with a lower surface of the hollow part, there are provided a structure of disposed projections preferred for suppressing increase in driving voltage for CMUT and decrease in receiving sensitivity, and an ultrasonic diagnostic apparatus using the same.

Abstract: An ultrasonic transducer includes a first electrode, a first insulation film covering the first electrode, a hollow part overlapping the first electrode on the first insulation film, a second insulation film covering the hollow part, a second electrode overlapping the hollow part on the second insulation film, and an interconnection joined to the second electrode. An edge of the first electrode is formed so as to moderate a step of the first electrode.

Abstract: Spurious response resulting from a high-order vibration mode that occurs when the cell shape of a capacitive micro-machined ultrasonic transducer is anisotropic is reduced. Assuming that a ratio between a long direction (l) and a short direction (w) of a diaphragm forming a capacitive micro-machined ultrasonic transducer is a representative aspect ratio (l/w), the representative aspect ratio is set to a value at which a dip of 6 dB or greater would not be formed within a transmit and receive bandwidth of a probe. Alternatively, the representative aspect ratio is so set that there would be six or more vibration modes for which the value obtained by dividing the frequency of a vibration mode having an odd number of anti-nodes by a fundamental mode frequency would be 2 or less.

Abstract: In an ultrasonic transducer comprising a first electrode, a first insulating film disposed on the first electrode, a hollow part provided above the first insulating film and disposed between surfaces above and below the hollow part, a second insulating film disposed above the hollow part, and a second electrode disposed on the second insulating film, a first conductive film disposed on a side of the surface below the hollow part and a second conductive film disposed on a side of the surface above the hollow part are provided, the first conductive film and the second conductive film are disposed so that they overlap with a region in which the surfaces above and below the hollow part contact with each other as seen from above when the transducer is driven, and they do not overlap with each other in the region as seen from above.

Abstract: A technology capable of preventing the degradation of operation reliability of CMUT when a lower electrode for CMUTs arranged in an array is divided in order to control the CMUTs independently is provided. Also, a technology capable of preventing the formation of a convex or concave distortion in an insulating film (membrane) of the cavity is provided. For its achievement, a size of a lower electrode divided for independently controlling each CMUT is set to be larger than that of a cavity. Also, a size of an upper electrode of the CMUT is set to be larger than that of the cavity.

Abstract: High transfer sound pressure and high reception sensitivity are realized, and reliability is improved in terms of long term operation, in a capacitive detector-type ultrasonic transducer (CMUT).

Abstract: The manufacturing yield of semiconductor devices (CMUTs) is improved. Before a polyimide film serving as a protective film is formed, a membrane is repeatedly vibrated to evaluate the breakdown voltage between an upper electrode and a lower electrode, and the upper electrode of a defective CMUT cell whose breakdown voltage between the upper electrode and the lower electrode is reduced due to the repeated vibrations of the membrane is removed in advance to cut off the electrical connection with other normal CMUT cells. By this means, in a block RB or a channel RCH including the recovered CMUT cell RC, reduction in the breakdown voltage between the upper electrode and the lower electrode after the repeated vibrations of the membrane is prevented.

Abstract: An ultrasonic transducer includes a first electrode, a first insulation film covering the first electrode, a hollow part overlapping the first electrode on the first insulation film, a second insulation film covering the hollow part, a second electrode overlapping the hollow part on the second insulation film, and an interconnection joined to the second electrode. An edge of the first electrode is formed so as to moderate a step of the first electrode.

Abstract: In an ultrasonic transducer comprising a first electrode, a first insulating film disposed on the first electrode, a hollow part provided above the first insulating film and disposed between surfaces above and below the hollow part, a second insulating film disposed above the hollow part, and a second electrode disposed on the second insulating film, a first conductive film disposed on the side of the surface below the hollow part and a second conductive film disposed on the side of the surface above the hollow part are provided, the first conductive film and the second conductive film are disposed so that they overlap with a region in which the surfaces above and below the hollow part contact with each other as seen from above when the transducer is driven, and they do not overlap with each other in the region as seen from above.

Abstract: This invention provides a technique whereby, even if a step is produced by splitting a lower electrode into component elements, resistance increase of an upper electrode, damage to a membrane and decrease of dielectric strength between an upper electrode and the lower electrode, are reduced. In an ultrasonic transducer comprising plural lower electrodes, an insulation film covering the lower electrodes, plural hollow parts formed to overlap the lower electrodes on the insulation film, an insulation film filling the gaps among the hollow parts, an insulation film covering the hollow parts and insulation film, plural upper electrodes formed to overlap the hollow parts on the insulation film and plural interconnections joining them, the surfaces of the hollow parts and insulation film are flattened to the same height.

Abstract: An ultrasonic transducer includes a first electrode, a second electrode, an insulating film disposed between the first and second electrodes, and a cavity disposed between the first and second electrodes. The insulating film includes a projection extending in the cavity, and a portion of the cavity is disposed between the projection and the first electrode. A portion of one of the first electrode and the second electrode has an opening corresponding to a position of the projection of the insulating film when viewed in plan view.

Abstract: Spurious response resulting from a high-order vibration mode that occurs when the cell shape of a capacitive micro-machined ultrasonic transducer is anisotropic is reduced. Assuming that a ratio between a long direction (l) and a short direction (w) of a diaphragm forming a capacitive micro-machined ultrasonic transducer is a representative aspect ratio (l/w), the representative aspect ratio is set to a value at which a dip of 6 dB or greater would not be formed within a transmit and receive bandwidth of a probe. Alternatively, the representative aspect ratio is so set that there would be six or more vibration modes for which the value obtained by dividing the frequency of a vibration mode having an odd number of anti-nodes by a fundamental mode frequency would be 2 or less.

Abstract: For disposing projections of insulating film protruding into a hollow part in CMUT in order to suppress injection of electrical charge into the insulating film due to contact of a lower surface of a membrane with a lower surface of the hollow part, there are provided a structure of disposed projections preferred for suppressing increase in driving voltage for CMUT and decrease in receiving sensitivity, and an ultrasonic diagnostic apparatus using the same.

Abstract: The receive sensitivity of an ultrasound array transducer structured with a diaphragm electro-acoustic transducer (101) being a basic unit is affected by change in a charge amount with elapsed time due to leakage or the like, which causes drift of the primary beam sensitivity, degradation in the acoustic SN ratio due to a rise in the acoustic noise level, and degradation in the directivity of an ultrasound beam. To addressing this problem, a charge controller (charge monitor 211) is provided to control charge in an electro-acoustic transducer (101). A charge monitoring section (102) monitors the change in the charge amount. When change in the charge amount is small, transmit sensitivity or receive sensitivity is calibrated by a controller (104) by, for example, multiplying a receive signal by a calibration coefficient corresponding to the change amount. Further, when the change in the charge amount is large, for example, charges can be re-emitted from a charge emitter (103).

Abstract: A manufacturing yield of a semiconductor device (capacitive micromachined ultrasonic transducer) is increased. A plurality of first chips 1 in which a plurality of cells each having functions of transmitting and receiving ultrasonic waves are formed on a front surface of a first semiconductor wafer are manufactured, and each of the first chips 1 is judged as a superior/inferior product, and then, the first semiconductor wafer is sigulated into a plurality of first chips 1. Next, a plurality of second chips 2 in which a wiring layer is formed on a front surface of a second semiconductor wafer are manufactured, and each of the second chips 2 is judged as a superior/inferior product, and then, the second semiconductor wafer is sigulated into a plurality of second chips 2.

Abstract: A technique of manufacturing a semiconductor device capable of performing a probe test by a common test apparatus as normal LSI chips even for large-area chips is provided. A chip comprising a device formed on a device area by a semiconductor process and including a plurality of test areas sectioned by chip areas is prepared. Next, pads to be electrically connected to the device are formed at corresponding positions on the respective plurality of test areas. Subsequently, the respective test areas are tested by a same probe card via the plurality of pads.

Abstract: Disclosed is an art for a capacitive micromachined ultrasonic transducer (CMUT), which suppresses deformation in a cavity, non-uniformity in the thickness of an insulating film enclosing the cavity, and deterioration in the flatness of the surface profile of a membrane, even when the bottom electrode of the ultrasonic transducer is electrically connected from the bottom of the bottom electrode. The ultrasonic transducer is provided with: a bottom electrode (306); an electric connection part (304) which is connected to the bottom electrode from the bottom of the bottom electrode; a first insulating film which is formed so as to cover the bottom electrode; a cavity (308) which is formed on the first insulating film so as to overlap the bottom electrode when seen from above; a second insulating film which is formed so as to cover the cavity (308); and a top electrode (310) which is formed on the second insulating film so as to overlap the cavity (308) when seen from above.

Abstract: The manufacturing yield of semiconductor devices (CMUTs) is improved. Before a polyimide film serving as a protective film is formed, a membrane is repeatedly vibrated to evaluate the breakdown voltage between an upper electrode and a lower electrode, and the upper electrode of a defective CMUT cell whose breakdown voltage between the upper electrode and the lower electrode is reduced due to the repeated vibrations of the membrane is removed in advance to cut off the electrical connection with other normal CMUT cells. By this means, in a block RB or a channel RCH including the recovered CMUT cell RC, reduction in the breakdown voltage between the upper electrode and the lower electrode after the repeated vibrations of the membrane is prevented.

Abstract: A manufacturing yield of a semiconductor device (capacitive micromachined ultrasonic transducer) is increased. A plurality of first chips 1 in which a plurality of cells each having functions of transmitting and receiving ultrasonic waves are formed on a front surface of a first semiconductor wafer are manufactured, and each of the first chips 1 is judged as a superior/inferior product, and then, the first semiconductor wafer is sigulated into a plurality of first chips 1. Next, a plurality of second chips 2 in which a wiring layer is formed on a front surface of a second semiconductor wafer are manufactured, and each of the second chips 2 is judged as a superior/inferior product, and then, the second semiconductor wafer is sigulated into a plurality of second chips 2.

Abstract: A lower electrode is formed over a semiconductor substrate via an insulator film, first and second insulator films are formed to cover the lower electrode, an upper electrode is formed over the second insulator film, third to fifth insulator films are formed to cover the upper electrode and a void is formed between the first and second insulator films between the lower and upper electrodes. An ultrasonic transducer comprises the lower electrode, the first insulator film, the void, the second insulator film and the upper electrode. A portion of the first insulator film contacting with the lower electrode is made of silicon oxide, a portion of the second insulator film contacting with the upper electrode is made of silicon oxide and the first or second insulator film includes a silicon nitride film positioned between the upper and lower electrodes and not in contact with the upper and lower electrodes.