Abstract:
PROBLEM TO BE SOLVED: To provide a doped silica-titania glass that has the required improvements for certain parameters such as a tolerance value for Tzc, CTE vs. temperature slope and Tzc spatial homogeneity and is suitable for use in below 25 nm node lithography as an element of a system.SOLUTION: Selected weight of silica-titania powders and selected weight of dopant powders are weighed out and the silica-titania powders and the selected dopant powders are mixed for forming slurry of the mixed powders using a selected fluid. The slurry is sprayed and dried to form a powder containing free-flowing fine particles having a size of approximately 200 μm diameter or less. The powder is shaped into a shaped article by uniaxial pressing and then further by cold isostatic pressing. The shaped article is consolidated by hot pressing to shape into a doped silica-titania glass blank and further the glass blank is annealed.
Abstract:
PROBLEM TO BE SOLVED: To provide a release sheet which can keep product quality high in the manufacture of silicon carbide or aluminum nitride by press-compacting and improving operation efficiency and the yield and comprises exfoliated graphite as a base mateiral. SOLUTION: The sheet is formed from the exfoliated graphite and has -4 cm 2 /s gas permeability. Because the gas permeability is higher than that of a sheet of graphite felt or the like conventionally used, the deterioration of a mold due to a gas produced by the reaction of a gasified raw material or sheet with the raw material is suppressed by arranging the sheet between the raw material and the mold or the like in the manufacture of metals of silicon carbide, aluminum nitride or the like. Further, the product quality is improved by preventing a problem that bubbles are generated in the product. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To improve machinability and mechanical strength of a free-cutting glass ceramic, in which fluorine mica crystals are dispersed in borosilicate glass, by controlling the growth of the fluorine mica crystals. SOLUTION: A glass body obtained from a raw material blend having a composition comprising, by mass based on the terms of oxide except fluorine, 35-60% SiO 2 , 5-20% Al 2 O 3 , 10-35% MgO, 5-20% K 2 O, 2-10% B 2 O 3 , 0-10% ZrO 2 , and 1-15% F is subjected to a crystallization heat-treatment by a hot isostatic pressing (HIP) method using an inert gas or a mixed gas of the inert gas and oxygen as a pressure medium. It is preferable that the HIP treatment is performed by a first step (crystal nucleus formation) wherein the pressure is ≥50 MPa and the temperature is 650-850°C and a second step (crystal growth) wherein the pressure is ≥80 MPa and the temperature is 900-1,100°C. COPYRIGHT: (C)2007,JPO&INPIT