摘要:
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 μm 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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. Thereby there is obtained a compound semiconductor epitaxial wafer which can effectively eliminate stresses caused by lattice mismatching, can be made thinner with an excellent productivity, and can have a high luminance due to employment of a reflective layer.