SEMICONDUCTOR DEVICE INCLUDING AN EMBEDDED CONTACT PLUG

A semiconductor device includes an active area isolated by an isolation area on a semiconductor substrate. A transistor includes a gate electrode extending across the active area, source/drain regions formed in the active area on both sides of the gate electrode, and impurity-containing contact plugs connected to the source/drain regions. The source/drain regions are formed by thermal diffusion of impurities from the impurity-containing contact plugs toward the active area,