| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zener diode which has small dispersion within a wafer surface and a high yield, is capable of suppressing the rise of a surge clamp voltage, and is excellent in a surge absorbing performance. Ž<P>SOLUTION: An epitaxially-grown layer 1e having a first conductivity impurity concentration lower than that of the semiconductor wafer of a desired thickness is formed by an epitaxial growth method on the surface of the semiconductor wafer 1 of the first conductivity, first impurities are diffused from the surface of the epitaxially-grown layer and are diffused to reach a depth at which second impurities having the first conductivity in the semiconductor wafer are diffused from the semiconductor wafer and exist, the first and second impurities are diffused over the entire thickness of the epitaxially-grown layer, and thus the wafer excellent in the in-plane uniformity of specific resistance is obtained. Third impurities having a second conductivity are introduced to the wafer and the zener diode is formed of the impurity region of the second conductivity and the semiconductor of the first conductivity. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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