Memory cell structure
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorJhon-Jhy Liaw
Life of this patent
Estimating the term…
Abstract
A memory structure that reduces soft-errors for us in CMOS devices is provided. The memory cell layout utilizes transistors oriented such that the source-to-drain axis is parallel a shorted side of the memory cell. The dimensions of the memory cell are such that it has a longer side and a shorter side, wherein the longer side is preferably about twice as long as the shorter side. Such an arrangement uses a shorter well path to reduce the resistance between transistors and the well strap. The shorter well strap reduces the voltage during operation and soft errors.
Claims26
A memory cell comprising:
- a p-well area having at least one NMOS transistor formed therein, the NMOS transistor having an NMOS active area;
- and
- an n-well area having at least one PMOS transistor formed therein;
- and
- wherein the memory cell is a 6T-SRAM memory cell and wherein the memory cell has a long side and a short side, the long side being at least twice as long as the short side, a longitudinal axis of the p-well being parallel to the short side.
A memory cell comprising:
- a p-well area having at least one NMOS transistor formed therein, the NMOS transistor having au NMOS active area;
- and
- an n-well area having at least two PMOS transistors formed therein;
- and
- wherein the memory cell is an 8T-SRAM cell, wherein the memory cell has a long side and a short side, the long side being at least twice as long as the short side a longitudinal axis of the p-well being parallel to the short side, wherein a short side of the p-well is shorter than a long side of the p-well, and wherein the PMOS transistors are oriented such that source-to-drain axes of the PMOS transistors are parallel to a longitudinal axis of the n-well, and wherein source/drain regions of the PMOS transistors do not overlap in a direction perpendicular to the longitudinal axis of the n-well.
Dependencies are inferred from the claim text.