Patent ID: 7592669
Filing Date: 2009-09-22
Classification: H01L

Abstract:
1. A semiconductor device having a first MISFET comprising: a first well of a first conduction type formed in a semiconductor substrate; a gate insulating film of the first MISFET formed over the semiconductor substrate; a gate electrode of the first MISFET formed over the gate insulating film; first semiconductor regions of a second conduction type opposite to the first conduction type formed in the first well and serving as part of source and drain regions of the first MISFET; second semiconductor regions of the second conduction type formed in the first well, having a lower impurity concentration than that of the first semiconductor regions and serving as part of source and drain regions of the first MISFET; and an insulating film formed in the first well and embedded into a trench formed in the semiconductor substrate; wherein the second semiconductor regions surround the first semiconductor regions and the insulating film, wherein, in a gate length direction of the first MISFET, the insulating film is arranged between the first semiconductor regions and a channel region under the gate insulating film, wherein, in the gate length direction, ends of the gate electrode are formed over the insulating film, wherein third semiconductor regions of the first conduction type are formed at ends of the channel region in a gate width direction of said MISFET, and the third semiconductor regions are away from the source and drain regions of the first MISFET, and wherein an impurity concentration of the third semiconductor regions is higher than that of the first well.