Ushio Denki Kabushiki Kaisha

Tatsumi Hiramoto

Tatsushi Igarashi

Yukio Yasuda

Makoto Kimura

Hiromitsu Matsuno

Akiyasu Yamaguchi

Yasuo Oonishi

Nobuyuki Hishinuma

Takeo Matsushima

Fumitoshi Takemoto

Mitsuo Narita

Motohiro Sakai

Takashi Asahina

Yoshinori Aiura

Masachika Ohyama

Kunio Kasagi

Tsuneo Okanuma

Ikuo Iwai

Yasuhiko Wakahata

Shinichi Iso

Takashi Saga

A mercury lamp of the short arc type which can stably emit an intense spectrum at a wavelength of 365 nm with an extremely narrowed band region over a long time, and which has an anode and a cathode disposed opposite one another in a silica glass arc tube which is filled with mercury and a rare gas, is achieved by the amount of mercury being less than or equal to 1.0 mg/cc of the inside volume of the arc tube and at least one of the gases argon (Ar) and krypton (Kr) are used as the rare gas at room temperature with 1.0 to 8.0 atm.

Mercury lamp of the short arc type and UV emission device

An emission device which operates a cadmium lamp with a light intensity sufficient for used in industrial applications is achieved by an emission device having a cadmium lamp with a fluorescent tube within which a cathode and an anode are space a small distance apart and a buffer gas for easier initiation of luminous operation and metallic cadmium in an amount per unit volume of the fluorescent tube of 1.times.10.sup.-4 g/cm.sup.3 to 3.times.10.sup.-3 g/cm.sup.3 are encapsulated, and a power source device for supplying an electrical input between the cathode and the anode in an electrical input range from 0.5 kW to 5.0 kW with the condition:

Emission device with a cadmium lamp

In a dielectric barrier discharge lamp, in which a discharge vessel, in which a discharge gas forming 'excimer' molecules is encapsulated, is provided with a dielectric provided with a netlike electrode and a window, through which the light goes, the first object of the invention is achieved by an arrangement in which a thickness of ends of the above-described netlike electrodes is greater than the average thickness of the entire electrode. Another object of the invention is achieved by an arrangement in which a holder incorporated in the discharge vessel has an outer dimension that is less than/equal to an outer dimension of the netlike electrodes. A further object of the invention is achieved by an arrangement by which the discharge vessel has a hollow cylindrical shape formed from an external tube and an internal tube and a means for hermetic sealing is arranged inside the internal tube.

Dielectric barrier discharge lamp

An oxidation process for an article to be treated in which, by generating ozone with a high concentration, a high treatment rate is achieved. In particular, an oxygen-containing fluid is irradiated with a vacuum ultraviolet rays emitted from a dielectric barrier discharge lamp in which xenon gas is encapsulated, producing a photochemical reaction from which ozone and an activated oxygen result. By causing this ozone and activated oxygen to contact the surface of the article to be treated, the surface of the article is oxidized. An even higher treatment rate can be achieved by generating the activated oxygen with the simultaneous use of a far ultraviolet ray source, thereby increasing the activity of the activated oxygen. Advantageously, the oxidation of the article to be treated with the vacuum ultraviolet rays and far ultraviolet rays is performed in accordance with the relationship:

Process for oxidation of an article

A discharge lamp uses resonance lines which are emitted by ions in an excitation state and has a high short wave ultraviolet ray output. The lamp is provided with a pair of electrodes, having a reciprocal spacing of equal to or smaller than 12 mm, and is of the electrode-stable type. As the major emission material, cadmium is encapsulated in a quantity permitting a partial pressure P in operation of 3.times.10.sup.3 Pa to 1.3.times.10.sup.5 Pa. The lighting operation is performed in a state in which a lamp current J.sub.L fulfills the following condition (a):

Metal vapor discharge lamp

A dielectric barrier discharge lamp has a discharge vessel having a discharge chamber filled with a discharge gas. Excimer molecules are developed due to a dielectric barrier discharge. The discharge vessel is equipped with a window for the output of the light radiated from the excimer molecules. A getter space, equipped with a getter, communicates with the discharge chamber. A common wall separates the discharge chamber from the getter space, or a separately arranged getter space is connected to the discharge chamber via a tube. In one form, the discharge vessel and window is made of quartz glass containing less than 10 ppm of OH radicals by weight.

A semiconductor wafer can be exposed by arranging a combination of electrodes in an opposed relation with an interelectrode distance of not more than 15 mm in a closed discharge cavity, enclosing, within the cavity, mercury as a light-emitting discharge component in an amount such that the vapor pressure of mercury reaches 0.4-5 atms during discharge lighting, forming a discharge between the combination of electrodes while controlling the discharge current at not less than 10 A, and irradiating light, which has been radiated as a result of the discharge and contains at least one of light components having wave-lengths of 405 nm and 436 nm respectively, onto the surface of a photoresist applied on the semiconductor wafer through a photomask or reticle and a lens which permits transmission of the light having wavelength of 405 nm or 436 nm therethrough.

Process for the exposure of semiconductor wafer

Disclosed herein is a process for forming a singlecrystalline silicon layer by heating a wafer having a starting silicon layer of amorphous or polycrystalline silicon on the singlecrystalline silicon substrate, in accordance with the epitaxial growth technique. The process comprises providing a heat source comprising a plurality of tubular lamps provided in a parallel second plane above a first plane in which the wafer is placed; lighting the tubular lamps to radiate their light to the wafer so as to hold the starting silicon layer at 1100.degree.-1400.degree. C. for 4 seconds or longer; and then, radiating light from a specific lamp to a portion of the starting silicon layer of the wafer where the temperature of the portion of the starting silicon layer is raised to 1410.degree.-1480.degree. C. and to form a narrow molten region and forming the same narrow molten regions successively one after another in the wafer. The above process can convert the starting silicon layer to a singlecrystalline silicon layer in a relatively short period of time and without danger of damaging the wafer.

Method for forming a single crystal silicon layer

Disclosed herein is a deposition process which comprises, in an air-tight reaction vessel, generating a plasma through a discharge gas by means of a discharge system, disposing a substrate at a position apart from the plasma by a distance greater than the mean free path of species produced by the plasma in such a state that the substrate can be exposed directly to light radiated from the plasma, feeding a carrier gas and photoreactive gas in such a manner that they flow along the substrate, and causing the photoreactive gas to undergo a reaction by the light from the plasma to deposit the reaction product on the substrate. In the deposition process the substrate and a film deposited thereon are prevented from contamination or damage by charged particles. Electrodes are kept free from deposition of the reaction product, thereby allowing to conduct the deposition operation for a long period of time without need for cleaning them frequently.

Deposition process

An annealing method wherein an elongated irradiation area is formed by a light source whose emitted light is controlled so that a peak curve of the illuminance distribution in the area may be substantially linear and that equiluminous curves near the peak curve may be substantially parallel therewith. A semiconductor wafer and the irradiation area are moved relative to each other in such a manner that the entire area of the semiconductor wafer to be annealed may cross all the equiluminous curves, thereby to achieving the annealing of the semiconductor wafer. With this annealing method, semiconductor crystals are satisfactorily recovered from damages incidental to ion implantation into the semiconductor wafer and polycrystalline or amorphous semiconductors are converted into single crystal semiconductors of good quality.

Semiconductor annealing device

Dopant atoms are diffused into a silicon wafer by heating the entirety of the silicon wafer with the dopant atoms to a predetermined diffusing temperature in a short period of time, and more specifically, by applying light onto the silicon wafer under such conditions that the temperature difference between a central part of the silicon wafer and its peripheral part is maintained within 65.degree. C. The above diffusion method permits to carry out diffusion of the dopant atoms into silicon wafers with high productivity but without inducing physical defects such as warping or slip lines. It requires a very short time period for effecting diffusion to a desired extent and it enables to make the depth of diffusion greater.

Method for diffusing dopant atoms

A method of sterilization effected by using a flash discharge ultraviolet lamp which provides a very large instantaneous luminescence output, destroying at an increased sterilization rate and in a reduced irradiation time microorganisms, particularly Aspergillus nigger and those organisms in the lower layers which have been difficult to destroy by the lamp method of the prior art.

Method of sterilization

A semiconductor is annealed by an equipment which comprises a short-arc type rare gas discharge lamp as a heat source possessing the condition, 140.gtoreq.P.times.l.gtoreq.16, where l (mm) is the distance between an anode and a cathode and P is the sealed gas pressure (atmospheric pressure) at room temperature (25.degree. C.), an optical system for converging emitted light from the gas discharge lamp in the required manner, a power source unit capable of controlling the emitted light of the gas discharge lamp, and a stage for mounting the semiconductor. With this equipment, the semiconductor crystal is satisfactorily restored from damages incidental to ion implantation and a polycrystalline or amorphous semiconductor is converted into a good single crystal semiconductor.

Growing community of inventors

Tokyo, Japan

Tatsumi Hiramoto