| 摘要 |
PROBLEM TO BE SOLVED: To stabilize electrical characteristics of a semiconductor integrated circuit device in which lateral MOS transistors of a low breakdown voltage element and a high breakdown voltage element, which have homopolar gates, and a vertical trench MOSFET are merged.SOLUTION: The semiconductor integrated circuit device manufacturing method comprises: forming a photoresist in a region other than the region on a trench gate electrode by using a photolithography method; etching and removing a third gate insulation film on the trench gate electrode by using the photoresist as a mask; subsequently, depositing a non-dope polysilicon layer not only on a second insulation film and the third insulation film but on the trench gate electrode; introducing N-type and P-type high-concentration impurities to the polycrystalline silicon layers of an NMOS transistor and a PMOS transistor of the low breakdown voltage element and the high breakdown voltage element by using masks, respectively, by an ion implantation method; and subsequently, forming a second gate electrode by performing anisotropic etching. By performing the above-described processes, a first gate electrode in the trench and the second electrode used in the lateral MOS transistor are laminated thereby to inhibit variations caused by etching. |
