| 摘要 |
PROBLEM TO BE SOLVED: To reduce variation in threshold of a RAM region of an embedded memory logic device. SOLUTION: A semiconductor device includes a silicon substrate 1 having a logic region 101 and the RAM region 102, an NMOS transistor 20 formed in the logic region 101, and an NMOS transistor 40 formed in the RAM region 102. Each of the NMOS transistors 20, 40 has a stack structure obtained by sequentially stacking a gate insulating film 5 and a metal gate electrode 6 over the silicon substrate 1. The NMOS transistor 20 has a cap metal 4 containing an element selected from a group consisting of lanthanum, ytterbium, magnesium, strontium, and erbium as a composition element between the silicon substrate 1 and metal gate electrode 6. The cap metal 4 is not formed in the NMOS transistor 40. COPYRIGHT: (C)2011,JPO&INPIT |
