| 摘要 |
PURPOSE:To enable to obtain the desired value for substrate specific resistance even when a silicon substrate, which was pulled up by the aid of the CZ method (czochralsky method), is used. CONSTITUTION:Silicon oxide films 12 and 12' are formed on both sides of the silicon substrate 11 which was pulled up by the CZ method of an N type impurity density below 10<16> atom/cm<3> and having the substrate specific resistance somewhat higher than that required in the final stage, an aperture is selectively provided on an oxide film 12, P type and N type impurities are diffused and regions 13 and 14 are obtained. Besides, another oxide film 12' is removed, the specific resistance of the substrate is measured from the reverse side, a heat treatment is performed at the temperature range of 300-550 deg.C in oxidizing, neutral and inert atmospheres for the prescribed period of time when the desired characteristics are not attained, and the desired specific resistance is obtained. This measurement of specific resistance and the heat treatment may be performed before the formation of electrodes 15 and 16, or after the grinding process to be performed on the back side of the substrate is performed. |
