摘要:
Material and impurity gases are introduced into a crystal growth chamber (32) to grow a crystal film on a GaAs substrate (10). A light beam emitted from a variable-wavelength light source (35) is applied to the crystal film being grown on the substrate (10) while varying the wavelength of the light beam. The dependency, on the wavelength of the light beam, of the intensity of light reflected by the crystal film is measured, and an optimum wavelength is selected for measurement depending on the type of molecules adsorbed while the crystal film is being grown. Light is then applied at the optimum wavelength to the crystal film being grown, and a time-dependent change in the intensity of light reflected by the crystal film is measured. The rate at which the material gases are introduced into the crystal growth chamber (32) is adjusted to control the growth rate of the crystal film, the composition ratio of a mixed crystal thereof, and the density of the impurity therein.
摘要:
A semiconductor material to be etched is held in a reaction chamber at a predetermined temperature. A reactive etching gas such as a chlorine gas is introduced into the reaction chamber for a first period of time. Thereafter, the reaction chamber is evacuated for a second period of time, and ultraviolet radiation is applied to the semiconductor material for a third period of time within the second period of time for thereby etching the semiconductor material to a depth on the order of a molecular or atomic layer.
摘要:
Improvements on a field effect or static induction transistor type photoelectric converter having a plurality of gate regions for controlling a main current at both sides of a source region. The distance between the gate regions at each side of the source region and the source region are different, thereby isolating the functions of the gates in high performance.
摘要:
A pressurized contact type double gate static induction thyristor comprising a semiconductor body located in a casing and having cathode electrodes and a first gate electrode at one principal surface side thereof and anode electrodes and a second gate electrode at the other principal surface side thereof. A first thermal expansion stress buffer plate is located in the casing to be in contact with the cathode electrode, and a second thermal expansion stress buffer plate is located at the other principal surface side of the semiconductor body. This second plate is composed of at least two metal members electrically insulated from each other and integrally bonded by an insulating material, one of the two metal members being in contact with the anode electrode and the other metal member being in contact with the second gate electrode.
摘要:
In a phototransistor having an emitter, a collector and a base, the impurity density of the base regions (20, 21) is irregular, a minority of carriers produced by a light are stored in the base region (20) having a large impurity density, and the majority of carriers are stored in the base region (21), with a low impurity density, in such a way that they are easily removed. The two base regions are placed in such a manner that the voltages of the base regions of large and small impurity densities are coupled to each other. This phototransistor can operate at extremely high sensitivity and high speed.
摘要:
In a method of and an apparatus for epitaxially growing a chemical-compound crystal, a plurality of raw-material gasses are alternately introduced into a closed chamber of a crystal growing device to grow the crystal placed within the closed chamber. At growing of the crystal, a light from a light source is emitted to a crystal growing film of the crystal. Intensity of a light reflected from the crystal growing film and received by a photo detector is measured. Charge amounts of the respective raw-material gasses are controlled by a control system on the basis of a change in the reflected-light intensity, thereby controlling a growing rate of the growing film.
摘要:
Material and impurity gases are introduced into a crystal growth chamber (32) to grow a crystal film on a GaAs substrate (10). A light beam emitted from a variable-wavelength light source (35) is applied to the crystal film being grown on the substrate (10) while varying the wavelength of the light beam. The dependency, on the wavelength of the light beam, of the intensity of light reflected by the crystal film is measured, and an optimum wavelength is selected for measurement depending on the type of molecules adsorbed while the crystal film is being grown. Light is then applied at the optimum wavelength to the crystal film being grown, and a time-dependent change in the intensity of light reflected by the crystal film is measured. The rate at which the material gases are introduced into the crystal growth chamber (32) is adjusted to control the growth rate of the crystal film, the composition ratio of a mixed crystal thereof, and the density of the impurity therein.