Abstract: A PWM (Pulse Width Modulation) circuit of the present invention includes a reference pulse sequence generating section for outputting a reference pulse sequence, an up-down counter, a trigger signal generating section for generating from an input signal a trigger signal for the up-down counter having a period which is a natural number multiple of one cycle the period of PWM, and a comparator for comparing the output of the up-down counter and the reference pulse sequence.

Abstract: An angular substrate polishing method includes the steps of holding an angular substrate having a surface to be polished within a guide ring of a substrate holding head; pressing the substrate surface to be polished, and also one surface of the guide ring, against a polishing pad; and independently rotating the polishing pad and the substrate-holding head together with the substrate it holds while pressing the polishing pad-contacting surface of the guide ring against the polishing pad, to thereby polish the substrate surface. During the polishing step, a pressing force is applied to the guide ring which is separate from the pressing force applied to the substrate, enhancing the flatness of the polished substrate.

Abstract: A square substrate has a pair of opposed major surfaces and peripheral end faces therebetween, wherein a tapered edge portion is disposed between the peripheral end face and each major surface to define an inner boundary with the major surface, and has a width of 0.2-1 mm from the peripheral end face. Both or either one of the major surfaces of the substrate has a flatness of up to 0.5 &mgr;m in an outside region of the substrate that extends between a position spaced 3 mm inward from the peripheral end face and the inner boundary of the tapered edge portion.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: In a current shared memory cycle, the memory access band value of each bus master is calculated at any time and discriminated to determine the next memory cycle control before completion of the current shared memory cycle, so that the minimum memory access band value required by each bus master is maintained with the result that the shared memory can be efficiently utilized. Thus, there is provided a shared memory control apparatus and a shared memory control method, capable of realizing a memory control of an excellent efficiency by maintaining the memory access band width per unit time, required by the master.

Abstract: The present invention provides a magnetron sputtering system, which ensures a formation of a desired thin film, using a thick target. In the sputtering process, a portion of the target does not have erosion free portions. The present invention provides a magnetron sputtering system comprising a chamber for sputtering, a target electrode 5 installed inside said chamber, a substrate electrode 6 installed in the chamber opposite to the target electrode, a ring-shaped magnet 2 installed so as to enclose the side surface of the target electrode, and a semi-circular disk shaped magnet installed opposite to the target-mounted surface of the target electrode, wherein the semi-circular disk shaped magnet is rotated in the circumferential direction of the target electrode and is magnetized in the direction perpendicular to the target electrode. This ensures a specific magnetic field component to be generated over the thick planar target surface 3.

Abstract: A semiconductor integrated circuit 10 comprises an internal logic circuit 16, a delay detecting circuit 11 which monitors changes in delay length within the semiconductor integrated circuit 10, and a central control circuit 14 which controls the quantity of processing per unit time length by the internal logic circuit 16 on the basis of changes in delay length monitored by the delay detecting circuit 11.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A phase shift mask blank includes a transparent substrate and a phase shift film composed primarily of a metal and silicon. The substrate has an etch rate A and the phase shift film has an etch rate B when the blank is patterned by reactive ion etching, such that the etch selectivity B/A is at least 5.0. When a phase shift mask is manufactured from the blank, the substrate is less prone to overetching, providing good controllability and in-plane uniformity of the phase shift in patterned areas. The phase shift mask can be used to fabricate semiconductor integrated circuits to a smaller minimum feature size and a higher level of integration.

Abstract: The invention provides a second level cache memory system of the direct map type which moderates possible drawbacks arising from a limitation to such second level cache memory system to realize high speed processing while suppressing the cost as far as possible. The second level cache memory system includes a first level cache memory built in a CPU, and a second level cache memory of the direct map write back type for storing part of addresses and data of a main memory. The second level cache memory allows read/write operations at a higher speed than that for the main memory.

Abstract: The present invention relates to an active oxygen scavenging agent and a cancer chemopreventing agent both comprising a dried Grifola, a dry Grifola powder and/or a Grifola extract, and to a food or animal feed comprising the active oxygen scavenging agent or the cancer chemopreventing agent.

Abstract: A method for fabricating a compound semiconductor epitaxial wafer having a uniform epitaxial layer-thickness distribution independently of positions of compound semiconductor wafers placed within a reaction furnace (19), and a vapor phase growth apparatus for implementing the method. A group III source gas (13) is flowed from a gas inlet (14) of the reaction furnace (19) to a gas outlet (16) thereof, whereas a group V source gas (15) is supplied as dispersedly from a plurality of groups of gas discharge ports (18a, 18b, 18c) provided in a flow direction of the group III source gas (13).

Abstract: A method for manufacturing compound semiconductor epitaxial wafer allowing sharp changes in alloy composition and growth of high-quality epitaxial layers.

Abstract: At the time of forming an alloy composition gradient layer 4 of gallium arsenide phosphide GaAs.sub.x P.sub.1-x having an arsenic alloy composition x changed in such a range as not to exceed a predetermined alloy composition a with an increase of a layer thickness d between a GaP layer 3 and a composition constant layer 5 of gallium arsenide phosphide GaAs.sub.a P.sub.1-a having the predetermined alloy composition a to be grown above the GaP layer; the alloy composition x is abruptly ascended as in composition ascending zones C11 to C13 with the ascended thickness d of an epitaxial layer and then descended as in crystal stabilizing zones S11 to S13 in such a range as not to cancel the previous ascent amount. One or more combinations of such ascent and descent in the alloy composition are repeated to form as distributed in the alloy composition gradient layer 4, and then the alloy composition x is ascended to the predetermined alloy composition a.

Abstract: A GaAsP epitaxial wafer 10 which has a GaAs.sub.1-x P.sub.x (0.45<x<1) constant nitrogen concentration layer 6 formed by doping a constant composition layer with nitrogen wherein the constant nitrogen concentration layer 6 has the following upper and lower limits of nitrogen concentration:Upper limit: N=(6.25x-1.125).times.10.sup.18 cm.sup.-3Lower limit: N=(5x-1.5).times.10.sup.18 cm.sup.

Abstract: A compound semiconductor epitaxial wafer added with nitrogen to provide a high luminous efficiency. Epitaxial layers are grown on a single crystalline substrate 4 made of gallium phosphide or gallium arsenide to form a compound semiconductor epitaxial wafer EW. The epitaxial layers include at least an nitrogen-added gallium phosphide arsenide mixed crystalline epitaxial layer having an n-type carrier concentration descending gradually toward the uppermost surface of the grown layer in a continuous or stepwise manner before p-type impurity is diffused, and contain an intermediate layer 83 with an n-type carrier concentration of 4.times.10.sup.14 /cm.sup.3 or more and less than 3.5.times.10.sup.15 /cm.sup.3, and a surface layer 84 having an n-type carrier concentration equals to or lower than that for the intermediate layer 83.