| 摘要 |
PROBLEM TO BE SOLVED: To improve characteristics of a semiconductor device having a nonvolatile memory (MONOS).SOLUTION: In a semiconductor device, a MONOS is formed on an SOI substrate 1 having a support substrate S, an insulation layer BOX formed thereon, and a silicon layer SR formed thereon. The MONOS has a control gate electrode CG and a memory gate electrode MG formed so as to be adjacent to the control gate electrode CG, above the silicon layer SR. The MONOS also has an impurity region VTC (CT) formed in the support substrate S under the control gate electrode CG and an impurity region VTC (MT) formed in the support substrate S under the memory gate electrode MG and having a lower effective carrier concentration than that of the impurity region VTC (CT). Thus, the impurity region VTC (CT) for adjusting threshold of a control transistor and the impurity region VTC (MT) for adjusting threshold of a memory transistor are provided, thereby reducing variations in the threshold for each transistor to reduce GiDL. |
