| 摘要 |
PURPOSE:To improve mutual conductance, by making up a high concentration region and a low concentration region constituting the source and the drain of a MOSFET, with a double-layer structure in the depth direction of a semiconductor substrate. CONSTITUTION:In a MOS field effect transistor having an LDD(Lightly Doped Drain) structure, a high concentration region and a low concentration region constituting the source and the drain of the MOS field effect transistor are mode up with a double-layer structure in the depth direction of a semiconductor substrate. The low concentration (N<->) region 5 and the high concentration (N<+>) region 7 are stacked in the depth direction of the semiconductor substrate 1 to form the double-layer structure, so that the N<+> region 7 directly comes into contact with the channel region of the MOSFET. Thereby, mutual conductance can be improve without deteriorating the electric field relaxation effect of the N<-> region 5 in the vicinity of the drain or the source. |
