Patent ID: 7858985

Claim:
A semiconductor device comprising: a DRAM over a substrate, the DRAM comprising: a first gate electrode over the substrate; a first island-shaped semiconductor film over the first gate electrode wherein the first gate electrode and the first island-shaped semiconductor film overlap each other with a first insulating layer interposed therebetween; a second gate electrode over the first island-shaped semiconductor film wherein the first island-shaped semiconductor film and the second gate electrode overlap each other with a second insulating layer interposed therebetween; a bit line electrically connected to the first island-shaped semiconductor film; and a source line electrically connected to the first island-shaped semiconductor film; and a pixel portion over the substrate, the pixel portion comprising: a second island-shaped semiconductor film over the substrate; a third gate electrode over the second island-shaped semiconductor film wherein the second island-shaped semiconductor film and the third gate electrode overlap each other with the second insulating layer; a wiring electrically connected to the second island-shaped semiconductor film; and a pixel electrode electrically connected to the wiring.