| 摘要 |
PURPOSE:To prevent the characteristics from being deteriorated due to a short channel effect by a method wherein an insulator is formed prior to the processing of gate polysilicon and a mask in the form of a resist is placed in such a way that an impurity is not implanted into a P-type MOS region in order to prevent that a distribution of the impurity in a channel region is changed after the impurity has broken through the polysilicon during an ion- implantation process. CONSTITUTION:After a well region 2, a device isolation region 3 and a gate oxide film 4 have been formed on a semiconductor substrate 1, polysilicon 5 is deposited thereon. An insulator 6 is also formed thereon. When a P-type MOS region is covered with a photoresist 7 and a primary N-type impurity, e.g. phosphorus, is implanted into a side part of a gate in a self-aligned manner, the impurity does not break through the polysilicon 5. It is not implanted into a P-type MOS region. After that, the resist 7 is exfoliafed and an insulator 9 is formed on the side part of the gate. After an insulator 12 has been deposited and a contact hole has been opened, a metal wiring part 13 is formed. Because the N-type impurity is not implanted into a P-type channel impurity layer, the parasitic resistance is not increased and a threshold voltage is not changed; it is not required to diffuse the P-type impurity diffusion layer; accordingly, the characteristics of a transistor are not deteriorated due to a short channel effect.
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