METHOD OF EVALUATING METAL CONTAMINATION IN BORON-DOPED P-TYPE SILICON WAFER, DEVICE OF EVALUATING METAL CONTAMINATION IN BORON-DOPED P-TYPE SILICON WAFER, AND METHOD OF MANUFACTURING BORON-DOPED P-TYPE SILICON WAFER
First Claim
1. A method of evaluating metal contamination in a boron-doped p-type silicon wafer, which comprises:
- measuring over time by a microwave photoconductive decay method a recombination lifetime following irradiation with light of a silicon wafer being evaluated and obtaining information on change over time of the recombination lifetime; and
comparing the information on change over time of the recombination lifetime that has been obtained with reference information on change over time that has been obtained by calculation or actual measurement of a recombination lifetime of an Fe-contaminated boron-doped p-type silicon wafer to determine whether or not metal contamination other than Fe is present in the silicon wafer being evaluated.
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Abstract
An aspect of the present invention relates to a method of evaluating metal contamination in a boron-doped p-type silicon wafer, which comprises measuring over time by a microwave photoconductive decay method a recombination lifetime following irradiation with light of a silicon wafer being evaluated and obtaining information on change over time of the recombination lifetime, and comparing the information on change over time of the recombination lifetime that has been obtained with reference information on change over time that has been obtained by calculation or actual measurement of a recombination lifetime of an Fe-contaminated boron-doped p-type silicon wafer to determine whether or not metal contamination other than Fe is present in the silicon wafer being evaluated.
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Citations
19 Claims
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1. A method of evaluating metal contamination in a boron-doped p-type silicon wafer, which comprises:
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measuring over time by a microwave photoconductive decay method a recombination lifetime following irradiation with light of a silicon wafer being evaluated and obtaining information on change over time of the recombination lifetime; and comparing the information on change over time of the recombination lifetime that has been obtained with reference information on change over time that has been obtained by calculation or actual measurement of a recombination lifetime of an Fe-contaminated boron-doped p-type silicon wafer to determine whether or not metal contamination other than Fe is present in the silicon wafer being evaluated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of manufacturing one or more boron-doped p-type silicon wafers, which comprises:
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preparing a lot of silicon wafers comprised of multiple boron-doped p-type silicon wafers; extracting at least one silicon wafer from the lot; evaluating metal contamination in the silicon wafer that has been extracted; and shipping, as a product, one or more other silicon wafers within the same lot as a silicon wafer for which metal contamination other than Fe has been determined by the evaluating to be equal to or less than a permitted level; and
whereinthe metal contamination of the silicon wafer that has been extracted is evaluated by a method of evaluating metal contamination in a boron-doped p-type silicon wafer, which comprises; measuring over time by a microwave photoconductive decay method a recombination lifetime following irradiation with light of a silicon wafer being evaluated and obtaining information on change over time of the recombination lifetime; and comparing the information on change over time of the recombination lifetime that has been obtained with reference information on change over time that has been obtained by calculation or actual measurement of a recombination lifetime of an Fe-contaminated boron-doped p-type silicon wafer to determine whether or not metal contamination other than Fe is present in the silicon wafer being evaluated. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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Specification