Semiconductor device
AssigneeRenesas Electronics Corporation
InventorsTohru KAWAI, Masahiro SHIMIZU
Life of this patent
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Abstract
A semiconductor device aims to prevent a leak current from flowing between a well and a corner of an active region formed on an upper surface of another well in an SRAM. In a memory cell of the SRAM, a load MOSFET is formed. An end of an active region extending in y-direction is arranged to gradually go away from a p-well as it goes from a gate electrode G2 side to a gate electrode G4 side in such a manner that a distance in x-direction between the end of the active region and the p-well is larger than a shortest distance in the x-direction between the p-well and the active region.
Claims15
A semiconductor device comprising a memory cell having an SRAM structure formed on a semiconductor substrate, the memory cell including:
- a first p-type well, an n-type well, and a second p-type well formed in an upper surface of the semiconductor substrate in that order in a first direction along the upper surface of the semiconductor substrate;
- a first n-type field effect transistor and a second n-type field effect transistor formed in a first active region on an upper surface of the first p-type well;
- a first p-type field effect transistor formed in a second active region closest to the first p-type well in the first direction on an upper surface of the n-type well;
- a second p-type field effect transistor formed in a third active region closest to the second p-type well in the first direction on the upper surface of the n-type well;
- and
- a third n-type field effect transistor and a fourth n-type field effect transistor formed in a fourth active region on an upper surface of the second p-type well,
- wherein the second active region includes an extending portion extending in a second direction along a direction perpendicular to the first direction in a plan view and an end in the second direction of the second active region, and
- wherein a distance between a portion of a boundary between the first p-type well and the n-type well and the end portion that are adjacent to each other in the first direction is larger than a distance between a portion of the boundary and the extending portion that are adjacent to each other in the first direction.
Dependencies are inferred from the claim text.