Patents Assigned to Handotai Kenkyu Shinkokai
  • Patent number: 4811064
    Abstract: A static induction transistor (SIT) which is made to operate with a forward gate bias by maintaining the width of the channel region at an appropriate value. Such an improved SIT is used as the inverter transistor in a merged transistor logic (MTL) semiconductor IC (integrated circuit) to reduce the time delay-power product by an order or more. The collector region of a bipolar load transistor is continuous to or also serves as the gate region of the inverter SIT. A plurality of channel regions are formed penetrating through this collection/gate region. This SIT is simple in structure, which enables a marked increase in the integration density.
    Type: Grant
    Filed: January 28, 1987
    Date of Patent: March 7, 1989
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventors: Jun-Ichi Nishizawa, Bogdan M. Wilamowski
  • Patent number: 4799090
    Abstract: A tunnel injection controlling type semiconductor device comprising a source semiconductor region having a certain conductivity type for supplying carriers, a drain semiconductor region for receiving the carriers, and a gate electrode for controlling the flow of these carriers. A highly-doped semiconductor region having a conductivity type opposite to that of the source semiconductor region is provided in contact with the source region or contained locally in the source region to cause tunnel injection of carriers. The potential level of this highly-doped region is varied by virtue of the static induction effect exerted by the voltage applied to the gate electrode which is provided at a site close to but separate from the highly-doped region, and to the drain semiconductor region.
    Type: Grant
    Filed: October 23, 1981
    Date of Patent: January 17, 1989
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventor: Jun-ichi Nishizawa
  • Patent number: 4783426
    Abstract: A semiconductor device made of a II-VI compound semiconductor and having a p type semiconductor crystal. The p type semiconductor crystal is one obtained by growing the II-VI compound semiconductor crystal by relying on a liquid phase crystal growth process using a solvent comprised of one of Group II and Group VI elements constituting the Group II-VI compound semiconductor and having a higher vapor pressure over the other of these elements in an atmosphere comprised of the other of the elements having a lower vapor pressure under controlled vapor pressure of the atmosphere, and by doping into the solvent a p type impurity element selected from Group Ia and Ib elements in an amount of a range from 1.times.10.sup.-3 to 5.times.10.sup.-1 mol %. Thus, p type semiconductor crystals for use in semiconductor devices can be obtained easily from II-VI compound semiconductors. The present invention is especially effective in ZnSe crystals.
    Type: Grant
    Filed: November 19, 1987
    Date of Patent: November 8, 1988
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventor: Jun-ichi Nishizawa
  • Patent number: 4772926
    Abstract: In a static induction type thyristor comprising a low impurity concentration channel region having opposed first and second major surfaces, a first main electrode region having one conductivity type and a second main electrode region having another conductivity type opposite to the one conductivity type and provided on the first and second major surfaces, respectively, and a gate region provided in the vicinity of the first main electrode region, there intervenes, between the channel region and the second main electrode region, a thin layer region having the same conductivity type as that of first main electrode region. The provision of this thin layer region contributes to allowing a markedly low impurity concentration as well as a decreased thickness of the channel region for a given maximum forward blocking voltage, making it feasible to obtain a high maximum forward blocking voltage and a high switching speed.
    Type: Grant
    Filed: April 4, 1986
    Date of Patent: September 20, 1988
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventors: Jun-ichi Nishizawa, Tadahiro Ohmi
  • Patent number: 4745374
    Abstract: An extremely-high frequency semiconductor oscillator which produces a large but substantially noise-free output power with minimized fluctuation of output power for changes in device temperature is realized by using, as its power producing component, a semiconductor transit time diode having a frequency-dependent negative resistance mounted in a cavity resonator of a wave guide means provided with a tuning short at one side of the waveguide means and being designed to perform carrier injection by a combination of tunnel and avalanche phenomena.
    Type: Grant
    Filed: June 17, 1986
    Date of Patent: May 17, 1988
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventors: Jun-ichi Nishizawa, Kaoru Motoya
  • Patent number: 4725563
    Abstract: A green color light emitting ZnSe diode having a pn junction is fabricated by the use of a ZnSe crystal having a good crystal perfection and being obtained by a solution growth method relying on the temperature difference technique using a solvent containing at least Te and Se and using atoms of at least one kind of impurity selected from Group Ib elements of the Periodic Table as a principal impurity for producing a p type region in the crystal.
    Type: Grant
    Filed: March 26, 1987
    Date of Patent: February 16, 1988
    Assignee: Zaidan Hojim Handotai Kenkyu Shinkokai
    Inventor: Jun-ichi Nishizawa
  • Patent number: 4692194
    Abstract: In a solution growth method to perform an epitaxial growth by doping an amphoteric impurity into a Group III-V compound semiconductor crystal, vapor of a crystal-constituting Group V element is supplied to the solution, during the growth process, from above this solution under a controlled vapor pressure, while maintaining the growth temperature at a constant value by relying on, for example, a temperature difference technique, whereby the conductivity type in the grown crystal layer can be controlled easily as desired, and also a pn junction can be conveniently formed in the grown crystal.
    Type: Grant
    Filed: September 25, 1986
    Date of Patent: September 8, 1987
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventor: Jun-ichi Nishizawa
  • Patent number: 4668306
    Abstract: A semiconductor device having an uneven distribution of impurity concentration is manufactured easily and with good reproducibility from a wafer of a Group III-V or Group II-VI compound semiconductor by first forming a thin layer of impurity in a desired region of a principal surface of the wafer by, for example, an ion-implantation technique, and then subjecting the wafer to heat treatment under a controlled vapor pressure of at least one of the component elements of the compound semiconductor in order to maintain the stoichiometric composition of the impurity layer.
    Type: Grant
    Filed: May 23, 1985
    Date of Patent: May 26, 1987
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventor: Jun-ichi Nishizawa
  • Patent number: 4660062
    Abstract: An insulated gate transistor including a semiconductor substrate, high impurity source and drain regions formed above a channel region of low conductivity, a high impurity concentration region having a conductivity type opposite to that of the source region, a gate insulating layer extending into the channel region farther inwardly of the substrate than the source region, and a gate electrode positioned on the gate insulating layer. The gate electrode is made of a material having a high potential barrier with respect to the source region. The insulated gate transistor may be used as a driver transistor in an integrated circuit, as a switching transistor in a dynamic RAM memory cell, static RAM memory cell and in a complementary configuration.
    Type: Grant
    Filed: September 16, 1983
    Date of Patent: April 21, 1987
    Assignee: Handotai Kenkyu Shinkokai
    Inventors: Junichi Nishizawa, Tadahiro Ohmi
  • Patent number: 4644386
    Abstract: An insulated gate electrostatic induction transistor and an integrated circuit employing such an insulating gate electrostatic induction transistor as a drive transistor. A highly resistive channel region is provided on a semiconductor substrate of higher conductivity. A highly doped source region is formed adjacent the channel region, and a gate electrode, separated from the channel region by a thin insulating layer, is formed above the channel region. The gate electrode has a high diffusion potential with respect to the source region. The depth of the highly doped source region is less than that of a distribution of carriers in an inversion layer formed under the gate electrode.
    Type: Grant
    Filed: June 29, 1983
    Date of Patent: February 17, 1987
    Assignee: Handotai Kenkyu Shinkokai
    Inventors: Junichi Nishizawa, Tadahiro Ohmi
  • Patent number: 4619811
    Abstract: An apparatus for growing a GaAs single crystal by relying on the floating zone technique in a cylinder charged with a GaAs polycrystal and a GaAs single seed crystal, comprising an As container communicating with the interior of the cylinder to supply an optimum vapor pressure of As into the cylinder under the condition that a continuous temperature variation is established between this As container and the GaAs crystals charged in the cylinder, whereby a GaAs single crystal having little deviation from stoichiometry and having a good crystal perfection is obtained.
    Type: Grant
    Filed: September 17, 1985
    Date of Patent: October 28, 1986
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventor: Jun-ichi Nishizawa
  • Patent number: 4608582
    Abstract: The new kind of field effect transistor having a non-saturating characteristic, i.e. static induction transistor (SIT), proposed by the present inventor is modified to serve as a substitute of any conventional bipolar transistor in a given circuitry. That is, the gate-to-gate distance and the impurity concentration of the channel region of an SIT are so selected that the channel is pinched off by the depletion layer at a predetermined forward gate bias. When the forward gate bias applied is below a certain level, the drain current will increase fundamentally exponentially with an increase of the drain voltage above some threshold voltage, whereas when the gate bias applied is above the certain value, the drain current will increase rapidly with a small increase in the drain voltage.
    Type: Grant
    Filed: July 20, 1983
    Date of Patent: August 26, 1986
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventor: Jun-ichi Nishizawa
  • Patent number: 4572763
    Abstract: In conducting a liquid phase epitaxial growth of a Zn crystal on a substrate wherein a batch of Se melt serving as a solvent is used and relying on a vapor pressure controlling technique and a temperature difference method, a Zn vapor pressure controlling region is disposed, via the Se melt, in a direction vertical to the surface of the substrate which is contained in the growth region, and a ZnSe source crystal is disposed in such a way that it is supplied into the Se melt in a lateral direction of this melt. Whereby, a ZnSe single crystal having a good crystal perfection, and a good linearity of the thickness of the grown crystal relative to time can be obtained.
    Type: Grant
    Filed: July 13, 1983
    Date of Patent: February 25, 1986
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventor: Jun-ichi Nishizawa
  • Patent number: 4571727
    Abstract: A far-infrared electromagnetic wave generator comprises a semiconductor containing at least one impurity which has an energy difference, close to a quantum energy of optical phonon, between its transition levels; a resonator having two reflectors for effecting positive feedback of an electromagnetic wave corresponding to the quantum energy; and means for applying an electric current across the semiconductor. The semiconductor may have p-i, n-i, p-i-n, p-n, or n-p.sup.- junction. One of the reflectors of the resonator may have a diffraction grating so that the wavelength of the electromagnetic wave to be generated can be varied by adjusting an angle of the diffraction grating.
    Type: Grant
    Filed: August 9, 1983
    Date of Patent: February 18, 1986
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventors: Jun-ichi Nishizawa, Ken Suto
  • Patent number: 4565156
    Abstract: A solution growth apparatus for conducting an epitaxial growth of a compound semiconductor crystal from solution by relying on the temperature difference technique at a constant growth temperature and on a mass production scale without deranging the control of the growth temperature applied externally of the growth apparatus and with the application of only a small heating power and only a small cooling power, by enhancing the thermal exchange efficiency through the provision of heating means, via an insulator, for the melt-containing reservoir provided on the growth boat housed within a quartz reactor and by the provision of cooling means at the bottom of the boat within the reactor.
    Type: Grant
    Filed: February 28, 1983
    Date of Patent: January 21, 1986
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventors: Jun-ichi Nishizawa, Yasuo Okuno
  • Patent number: 4558660
    Abstract: A semiconductor fabricating apparatus is capable of fabricating a high quality semiconductor with utilization of crystal growth, thermal oxidation of CVD membrane growth at low temperature. The semiconductor fabricating apparatus includes a reaction chamber having a gas inlet and a gas outlet, an insulative support means disposed in the reaction chamber for supporting semiconductor wafers thereon, an infrared lamp means for irradiating exposed surfaces of the semiconductor wafers and an ultra-violet lamp means for irradiating the exposed surfaces of the semiconductor wafers overlappingly with the infrared irradiation.
    Type: Grant
    Filed: March 16, 1983
    Date of Patent: December 17, 1985
    Assignee: Handotai Kenkyu Shinkokai
    Inventors: Jun-ichi Nishizawa, Tadahiro Ohmi
  • Patent number: 4504847
    Abstract: In a static induction type semiconductor device comprising a semiconductor region having one conductivity type and a low impurity concentration and gate regions having an opposite conductivity type and a high impurity concentration formed in the semiconductor region to thereby define a channel region between these gate regions, there is provided a subsidiary semiconductor region having the one conductivity type and a relatively high impurity concentration either around each gate region to leave an effective channel region in the semiconductor region, or adjacent to the effective channel region in the entire channel region on the drain side. By so constructing the device, this effective channel region has a relatively low potential difference even when the channel region is completely depleted, and provides a relatively wide current path.
    Type: Grant
    Filed: June 8, 1982
    Date of Patent: March 12, 1985
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventor: Jun-ichi Nishizawa
  • Patent number: 4484207
    Abstract: A hetero-junction static induction transistor (SIT) of normal or upside-down type to be operated by applying a forward bias across the gate and source regions, in which at least its source region and gate region among the source, drain and gate regions is formed with a material having a band gap broader than that of the channel region. Such a SIT provides a large current amplification factor, improved frequency characteristics and is suitable for high power operation and for use in semiconductor integrated circuits.
    Type: Grant
    Filed: July 26, 1983
    Date of Patent: November 20, 1984
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventors: Jun-ichi Nishizawa, Tadahiro Ohmi, Nobuo Takeda
  • Patent number: 4482910
    Abstract: A thermionic emission transistor comprising: an emitter region formed with a semiconductor material having a first conductivity type and a high impurity concentration; a collector region formed with a semiconductor material having a first conductivity type and a high impurity concentration; a base region made of a semiconductor material having a second conductivity type opposite to said first conductivity type and a high impurity concentration, that portion of said emitter region located adjacent to said base region having an energy band gap broader than that of the base region, that portion of said base region located adjacent to the emitter region having an impurity concentration of about 3.times.10.sup.18 cm.sup.-3 or more. Such new transistor has a large transconductance and can be operated with a very large current gain in spite of a very small size of the whole device, and is very suitable for integrated circuit.
    Type: Grant
    Filed: January 30, 1984
    Date of Patent: November 13, 1984
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventors: Jun-ichi Nishizawa, Tadahiro Ohmi
  • Patent number: 4470059
    Abstract: A gallium arsenide static induction transistor of normally-off type simple in manufacture and exhibiting a superior function and suitable for use in low and medium power operation in integrated circuit is obtained by arranging so that its channel region has a length l (.mu.m), a width (.mu.m) and an impurity concentration N (cm.sup.-3), and that the ratio l/w is 0.5-5.0 and that the product Nw.sup.2 is not larger than 2.5.times.10.sup.15 cm.sup.-3..mu.m.sup.2.
    Type: Grant
    Filed: April 19, 1982
    Date of Patent: September 4, 1984
    Assignee: Zaidan Hojin Handotai Kenkyu Shinkokai
    Inventors: Jun-ichi Nishizawa, Tadahiro Ohmi