| 摘要 |
PROBLEM TO BE SOLVED: To improve MISFET characteristics by controlling concentration profiles in each of impurity regions in an MISFET. SOLUTION: A gate oxide film 8 is formed by thermal oxidation on a semiconductor substrate 1, and then gate electrodes G are formed by dry-etching a polycrystalline silicon film 9 on the gate oxide film 8. Next, boron (B, p-type impurity) is implanted into p-type wells 3 in the substrate 1 from above the substrate 1 for formations of channel impurity regions CH and pocket regions PK. The channel impurity regions CH and the pocket regions PK are formed immediately under and on both sides of the electrodes G, respectively, by making use of steps formed around the gate electrodes G, and concentration profiles in these regions are appropriately controlled. COPYRIGHT: (C)2004,JPO
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