Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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, accurately detecting Cu that can contaminate Si wafers during a Si wafer reclamation process and of specifying a Cu-contamination-causative process.

Abstract: 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.

Abstract: 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.

Abstract: A method of evaluating the quality of a silicon wafer is characterized by analyzing a silicon wafer by an infrared absorption spectrum, and then evaluating the quality of the silicon crystal based on an absorbance ratio represented by the following formula (1): {(Absorbance &agr;1 at an arbitrary wavenumber between 1055 and 1080 cm−1)−(Absorbance &agr;BL of base line)}/{(Absorbance &agr;2 at an arbitrary wavenumber between 1100 and 1120 cm−1)−(Absorbance &agr;BL of base line)}  (1) wherein absorbances &agr;1 and &agr;2 represent absorbances of the measured silicon wafer, and base line absorbance &agr;BL represents the absorbance of a base line of the measured silicon wafer, which is drawn from 1030 to 1170 cm−1. By using the quality evaluating method of the present invention, internal crystal defects of silicon can be precisely detected in a non-destructive manner.