| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve performance of a semiconductor device. <P>SOLUTION: Channel doping ion implantation is done by converging an ion beam 22 passed through a filter FL with multiple fine openings OP regularly arranged by a lens 26 and by irradiating a semiconductor wafer 1W with the ion beam. In this step, a voltage of the same polarity as the ion beam 22 is applied to the filter FL. Impurity ions incident toward the center of the openings OP of the filter FL can keep going straight and pass through the openings OP, while impurity ions incident toward the regions other than the center of the openings OP of the filter FL cannot pass through the openings OP because the travelling direction is changed by an electric field of the filter FL. Thus the impurity ions implanted in the semiconductor wafer 1W are regularly arranged and the variation in the threshold voltage of a MISFET can be suppressed. <P>COPYRIGHT: (C)2012,JPO&INPIT |
