摘要:
A process capable of reclaiming used semiconductor wafers with a reduced metallic contamination level on wafer surfaces. The process comprises the steps of removing one or more surface layers of the substrate by chemical etching; scraping off one surface of the substrate in small amount by mechanical machining; removing a damage layer, which has occurred due to the mechanical machining, by chemical etching; and polishing the other surface of the substrate into a mirror finish.
摘要:
A method for reclaiming a wafer substrate material having a metallic film and a dielectric film includes a step for removing the entire metallic film and a part of the dielectric film with a chemical etching agent so as not to substantially dissolve the wafer substrate material itself, a step for removing the residual dielectric layer and the degenerated zone beneath the surface of the substrate by chemical-mechanical polishing, and a step for polishing at least one surface of the substrate.
摘要:
A process comprising removing surface layer materials from the wafer by inducing micro-fractures in the surface using a rotating pad and an abrasive slurry until all of the surface layer materials are removed; and chemically etching the surfaces of the wafer until all micro-fractures are removed therefrom. Edge materials are removed by abrasive tape. Wafer thickness reduction during recycling is less than 30 microns per cycle. One of the front and back surfaces of the wafer substrate is polished, any dots or grooves being on the non-polished side. The abrasive slurry contains more than 6 volume percent abrasive particles, and the abrasive slurry has a viscosity greater than about 2 cP at ambient temperature. The preferred pad comprises an organic polymer having a hardness greater than about 40 on the Shore D scale, optimally a polyurethane. The pressure of the pad against the wafer surface preferably does not exceed about 3 psi. Preferably, the chemical etching solution contains potassium hydroxide. An acidic solution can then be applied to the wafer surface. The reclaimed semiconductor wafer can be a silicon wafer having a matted side having etch pits which does not exceed 20 microns in width, an average roughness not exceeding 0.5 microns and a peak-to-valley roughness not exceeding 5 microns. Any laser markings from the original wafer are present on the matted side of the wafer.
摘要:
A carbon substrate manufacturing method includes a hot molding step, a burn-carbonizing step, a hot isostatical pressure treatment step, and a mirror polishing step. In the hot molding step, molding is performed while heating thermosetting resin powders to be a hard carbon substrate after burn-carbonizing, where the thermosetting resin powders are of a particle size 150 .mu.m or more, HPF 80-150 mm, a moisture content 1.0-3.0 weight %, Fe, Ni, Si and Ca respectively 5 ppm or less. In the burn-carbonizing process, a disk shaped resin molded body is filled into a graphite cylinder and burn-carbonized by heating from the external while the condition therefor is maintained in that the disk shaped resin molded body is stacked holding therein a graphite spacer at every one sheet basis or at every plurality of sheet basis and is loaded on its top with a tungsten carbide weight, where the graphite spacer has a heat conductivity 100 kcal/m.hr..degree. C. or less, a bulk density 1.70-1.85, and a flatness degree 10 .mu.m or less.
摘要:
The polishing slurry contains monoclinic zirconium oxide particles having a crystallite size of 10 to 1,000 nm and an average particle diameter of 30 to 2,000 nm in an amount of 1 to 20 weight %, a carboxylic acid having three or more carboxyl groups in the molecule, and a quaternary alkylammonium hydroxide, and has a pH of 9 to 12. The method of reclaiming wafers comprises a step of polishing used test wafers by using the polishing slurry above and removing the films formed on the wafers and the degenerated layers formed on the wafer surfaces, a step of mirror-polishing at least one side of the wafers, and a step of cleaning the wafers.
摘要:
A method of specifying a Cu-contamination-causative step or steps in a Si wafer reclamation process including plural steps in combination, comprising: using p-type Si wafers, or p-type Si wafers and n-type Si wafers as monitor wafers, and performing a measuring operation for measuring the electrical resistance of the monitor wafers at least once before and after a single step or a series of successive steps during the Si wafer reclamation process. The present invention is capable of nondestructively, simply, and accurately detecting Cu that can contaminate Si wafers during a Si wafer reclamation process and is capable of specifying a Cu-contamination-causative process.
摘要:
A method of reclaiming silicon wafers including a film removal process, a polishing process, and a cleaning process, wherein a heating/removal process for removing a silicon wafer surface part by heating at 150-300° C. for 20 minutes to 5 hours is further included between the film removal process and the polishing process is provided. The present invention provides a useful method of reclaiming silicon wafers that removes Cu not only deposited on a surface but also penetrated inside of a silicon wafer, and does not give Cu contamination inside of the silicon wafer.
摘要:
A method of reclaiming silicon wafers including a film removal process, a polishing process, and a cleaning process, wherein a heating/removal process for removing a silicon wafer surface part by heating at 150-300° C. for 20 minutes to 5 hours is further included between the film removal process and the polishing process is provided. The present invention provides a useful method of reclaiming silicon wafers that removes Cu not only deposited on a surface but also penetrated inside of a silicon wafer, and does not give Cu contamination inside of the silicon wafer.
摘要:
A cosmetic liquid applicator having a tubular shaft, a rotary knob at a rear end of the shaft and a piston axially slidable in the shaft upon rotation of the rotary knob. A nib, mounting to a forward end of the tubular shaft, has a passage communicating with a liquid chamber. A plurality of radially extending pojections are provided so that they are gradually reduced in diameter in the forward direction. A discharge hole is communicated with the passage, and a slot extends forwardly and rearwardly from the discharge hole in opposite directions of and transverse to the projections.
摘要:
Provided is an electrode material with excellent tab weldability and realizing decreased contact resistance with an active material layer. A collector (electrode material) (1) is provided with a metal foil substrate (1a) and a carbon-containing conductive substance (1b), and is configured such that, when observed from a square viewfield with a surface area of 0.1 mm2, the conductive substance (1b) is arranged in islands on the surface of the substrate (1a) with a 1-80% coverage ratio of the conductive substance (1b) on the surface of the substrate (1a).