EEPROM array with well contacts
A semiconductor integrated circuit device includes a cell well, a memory cell array formed on the cell well and having a memory cell area and cell well contact area, first wiring bodies arranged in the memory cell area, and second wiring bodies arranged in the cell well contact area. The layout pattern of the second wiring bodies is the same as the layout pattern of the first wiring bodies. The cell well contact area comprises cell well contacts that have the same dopant type as the cell well and that function as source/drain regions of dummy transistors formed in the cell well contact area.
1. A semiconductor integrated circuit device comprising:
a cell well,
first wirings,
second wirings which intersect with the first wirings,
third wirings arranged parallel to the second wirings,
transistors arranged at intersections between the first wirings and the second wirings and having the cell well as backgates thereof,
dummy transistors arranged at intersections between the first wirings and the third wirings and having the cell well as backgates thereof, one of source and drain portions thereof being set to have the same conductivity type as that of the cell well,
first contacts respectively connected to the second wiring and to corresponding ones of the source and drain portions of the transistors, and
second contacts respectively connected to the third wiring and to corresponding ones of the source and drain portions of the dummy transistors.
2. The device according to claim 1 , wherein the first and second contacts are formed of metal.
3. The device according to claim 1 , wherein the first and second contacts are aligned in the row direction.
4. The device according to claim 1 , wherein the first wirings are word lines, the second wirings are bit lines and the third wirings are cell well bias lines.
5. The device according to claim 4 , wherein the transistor which is arranged adjacent to the bit line and cell well bias line, connected to the bit line and having the word line as a gate thereof is a memory cell transistor.
6. The device according to claim 1 , wherein the first wirings are block selection lines, the second wirings are bit lines and the third wirings are cell well bias lines.
7. The device according to claim 6 , wherein the transistor which is arranged adjacent to the bit line and cell well bias line, connected to the bit line and having the block selection line as a gate thereof is a block selection transistor.
8. A semiconductor integrated circuit device comprising:
a cell well,
a first wiring,
a plurality of second wirings which intersect with the first wiring,
a plurality of third wirings arranged parallel to the second wirings,
a plurality of first transistors arranged at intersections between the first wiring and the plurality of second wirings and having the cell well as backgates thereof,
a plurality of dummy transistors arranged at intersections between the first wiring and the plurality of third wirings and having the cell well as backgates thereof, one of source and drain portions thereof being set to have the same conductivity type as that of the cell well,
a plurality of first contacts respectively connected to the plurality of second wirings and to corresponding ones of the source and drain portions of the plurality of transistors, and
a plurality of second contacts respectively connected to the plurality of third wirings and to corresponding ones of the source and drain portions of the plurality of dummy transistors.
9. The device according to claim 8 , wherein the first and second contacts are formed of metal.
10. The device according to claim 8 , wherein the first wiring is a word line, the plurality of second wirings are bit lines and the plurality of third wirings are cell well bias lines.
11. The device according to claim 10 , wherein the plurality of transistors which are arranged adjacent to one of the plurality of bit lines and one of the plurality of cell well bias lines, connected to the plurality of bit lines and each having the word line as a gate thereof are memory cell transistors.
12. The device according to claim 8 , wherein the first wiring is a block selection line, the plurality of second wirings are bit lines and the plurality of third wirings are cell well bias lines.
13. The device according to claim 12 , wherein the plurality of transistors which are arranged adjacent to one of the plurality of bit lines and one of the plurality of cell well bias lines, connected to the above bit line and having the block selection line as a gate thereof are block selection transistors.