| 摘要 |
PROBLEM TO BE SOLVED: To provide a transistor with a high threshold voltage or a MOS transistor with low current capability easily without increasing the area and the number of masks and processes. SOLUTION: The MOS transistor 1 of a multi-gate structure has first source and drain regions 21a and 21b formed in a semiconductor substrate 13 on one and the other end sides of a group of gate electrodes comprising a plurality of gate electrodes 20a to 20c which are formed adjacent to each other on the semiconductor substrate 13 via a gate insulation film 14, and second source and drain regions 22a and 22b formed in the semiconductor substrate 13 between the gate electrodes 20a to 20c. By forming the first source and drain regions 21a and 21b and the second source and drain regions 22a and 22b simultaneously by tilted ion implantation, the impurity concentration of the second source and drain regions 22a and 22b can be made lower than that of the first source and drain regions 21a and 21b by a shadow effect, resulting in increasing the threshold voltage while reducing the current capability. COPYRIGHT: (C)2009,JPO&INPIT
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