Semiconductor integrated circuit device
The invention provides a semiconductor integrated circuit device provided with an SRAM that satisfies the requirements for both the SNM and the write margin with a low supply voltage. The semiconductor integrated circuit device include: multiple static memory cells provided in correspondence with multiple word lines and multiple complimentary bit lines; multiple memory cell power supply lines that each supply an operational voltage to each of the multiple memory cells connected to the multiple complimentary bit lines each; multiple power supply circuits comprised of resistive units that each supply a power supply voltage to the memory cell power supply lines each; and a pre-charge circuit that supplies a pre-charge voltage corresponding to the power supply voltage to the complimentary bit lines, wherein the memory cell power supply lines are made to have coupling capacitances to thereby transmit a write signal on corresponding complimentary bit lines.
1. A semiconductor integrated circuit device comprising:
a plurality of memory cells arranged in a plurality of rows and a plurality of columns, each of the plurality of memory cells including first and second storage nodes,
a first inverter, an input of which is connected to the first storage node and an output of which is connected to the second storage node, including a first p-channel transistor and a first n channel transistor,
a second inverter, an input of which is connected to the second storage node and an output of which is connected to the first storage node, including a second p-channel transistor and a second n-channel transistor,
a third n-channel transistor connected to the first storage node, and
a fourth n-channel transistor connected to the second storage node;
a plurality of word lines provided correspondingly to the plurality of rows, respectively, each word line being connected to gate electrodes of the third and fourth n-channel transistors of the memory cells arranged along a first direction in the corresponding row;
a plurality of bit line pairs provided correspondingly to the plurality of columns, respectively, each bit line pair having a first bit line connected to the third n-channel transistors of the memory cells arranged along a second direction in the corresponding column and a second bit line connected to the second n-channel transistors of the memory cells arranged along the second direction in the corresponding column;
a plurality of memory cell power supply lines provided correspondingly to the plurality of columns, respectively, each memory cell power supply line being connected to source electrodes of the first and second p-channel transistors in the memory cells arranged in the corresponding column,
a power supply line that supplies a power voltage; and
a plurality of power transistors connected to the plurality of memory cell power supply lines, respectively, each power transistor making an electrical pass between the power supply line and the memory cell power supply line connected thereto,
wherein, in each of the plurality of memory cells,
the first n-channel transistor, the first p-channel transistor and the third n-channel transistor are arranged along the first direction with the first p-channel transistor located between the first and third n-channel transistors,
the second n-channel transistor, the second p-channel transistor and the fourth re-channel transistor are arranged along the first direction with the second p-channel transistor located between the second and fourth n-channel transistors,
the second and third n-channel transistors are arranged along the second direction, and
the first and fourth n-channel transistors are arranged along the second direction.
2. The semiconductor device according to claim 1 ,
wherein the plurality of power transistors have respective gate electrodes receiving control signals for tuning on and off the respective power transistors.
3. The semiconductor device according to claim 2 , further comprising:
a control circuit generating the controls signals so that each of the plurality of power transistors is in an off-state when the corresponding column is selected for a write operation.
4. The semiconductor device according to claim 3 , wherein each of the plurality of power transistors is in an on-state in a read operation and when the corresponding column is not selected for a write operation.
5. The semiconductor device according to claim 1 , further comprising:
a column decoder decoding an address to output selection signals for designating a selected column by the address,
wherein the plurality of power transistors have respective gate electrodes receiving control signals based on the selection signals.
6. The semiconductor device according to claim 1 , further comprising:
a plurality of gate circuits generating control signals, respectively,
wherein the plurality of power transistors have respective gate electrodes receiving the control signals, respectively.
7. The semiconductor device according to claim 1 , further comprising:
a column decoder decoding an address to output selection signals for designating a selected column by the address; and
a plurality of gate circuits have respective first inputs receiving the selection signals, respectively, and respective second inputs receiving a common signal having a first logical value in a read operation and a second logical value in a write operation,
wherein the plurality of power transistors have respective gate electrodes receiving control signals based on outputs of the plurality of gate circuits, respectively.
8. The semiconductor device according to claim 1 , wherein each of the plurality of power transistors is a p-channel transistor having a source electrode connected to the power supply line and a drain electrode connected to the memory cell power supply line provided for the corresponding column.
9. A semiconductor integrated circuit device comprising:
a plurality of memory cells arranged in a plurality of rows and a plurality of columns, each of the plurality of memory cells including
first and second storage nodes,
a first inverter, an input of which is connected to the first storage node and an output of which is connected to the second storage node, including a first p-channel transistor and a first n-channel transistor,
a second inverter, an input of which is connected to the second storage node and an output of which is connected to the first storage node, including a second p-channel transistor and a second n-channel transistor,
a third n-channel transistor connected to the first storage node, and
a fourth n-channel transistor connected to the second storage node;
a plurality of word lines, each word line being connected to gate electrodes of the third and fourth n-channel transistors of the memory cells arranged along a first direction in each of the plurality of rows;
a plurality of first bit lines, each first bit line being provided across the plurality of word lines in plan view and being connected to the third n-channel transistors of the memory cells arranged along a second direction in each of the plurality of columns;
a plurality of second bit lines, each second bit line being provided across the plurality of word lines in plan view and being connected to the fourth n-channel transistors of the memory cells arranged along the second direction in each of the plurality of columns;
a plurality of memory cell power supply lines, each memory cell power supply line being provided across the plurality of word lines in plan view and being connected to source electrodes of the first and second p-channel transistors in the memory cells arranged in each of the plurality of columns;
a power supply line that supplies a power voltage; and
a plurality of power transistors connected to the plurality of memory cell power supply lines, each power transistor making an electrical pass between the power supply line and a corresponding connected memory cell power supply line,
wherein, in each of the plurality of memory cells,
a first gate pattern serving as a gate electrode of the first n-channel transistor and a gate electrode of the first p-channel transistor extends along the first direction,
a second gate pattern serving as a gate electrode of the second n-channel transistor and a gate electrode of the second p-channel transistor extends along the first direction,
a third gate pattern serving as a gate electrode of the third n-channel transistor extends along the first direction,
a fourth gate pattern serving as a gate electrode of the fourth n-channel transistor extends along the first direction,
the first and third gate patterns are arranged along the first direction while the second and fourth gate patterns are arranged along the first direction,
the first and fourth gate patterns have respective portions opposite to each other in the second direction,
the second and third gate patterns have respective portions opposite to each other in the second direction, and
the first and second gate patterns have respective another portions opposite to each other in the second direction.
10. The semiconductor device according to claim 9 , wherein each of the plurality of power transistors has a gate electrode to which a variable voltage is applied.
11. The semiconductor device according to claim 9 , further comprising:
a column decoder decoding an address to output selection signals for designating a selected column by the address,
wherein the plurality of power transistor have respective gate electrodes receiving control signals based on the selection signals, respectively.
12. The semiconductor device according to claim 9 , further comprising:
a plurality of gate circuits generating control signals, respectively, wherein the plurality of power transistors have respective gate electrodes receiving the control signals, respectively.
13. The semiconductor device according to claim 9 , further comprising:
a column decoder decoding an address to output selection signals for designating a selected column by the address; and
a plurality of gate circuits have respective first inputs receiving the selection signals, respectively, and respective second inputs receiving a common signal having a first logical value in a read operation and a second logical value in a write operation,
wherein the plurality of power transistor have respective gate electrodes receiving control signals based on corresponding outputs of the plurality of gate circuits, respectively.
14. The semiconductor device according to claim 9 , wherein each of the plurality of power transistors is a p-channel transistor having a source electrode connected to the power supply line and a drain electrode connected to the memory cell power supply line provided for the corresponding column.
15. The semiconductor device according to claim 9 , wherein a plurality of wiring layers are provided over a main surface of a semiconductor substrate so as to be different in height with respect to the main surface,
the plurality of first bit lines, the plurality of second bit lines and the plurality of memory cell power supply lines are constructed by one wiring layer of the plurality of wiring layers, and
the plurality of word lines are constructed by another wiring layer of the plurality of wiring layers, which is different from the one wiring layer used for the plurality of first bit lines, the plurality of second bit lines and the plurality of memory cell power supply lines.
16. The semiconductor device according to claim 15 , wherein, in each of the plurality of memory cells,
respective drain electrodes of the first p-channel transistor and the first n-channel transistor are coupled to each other via a first wiring,
respective drain electrodes of the second p-channel transistor and the second n-channel transistor are coupled to each other via a second wiring, and
the first and second wirings are constructed by a further wiring layer of the plurality of wiring layers, which is lower than the wiring layers used for the plurality of word lines, the plurality of first bit lines, the plurality of second bit lines and the plurality of memory cell power supply lines.
17. A semiconductor integrated circuit device comprising:
a plurality of memory cells arranged in a plurality of rows and a plurality of columns, each of the plurality of memory cells including
first and second storage nodes,
a first inverter, an input of which is connected to the first storage node and an output of which is connected to the second storage node, including a first p-channel transistor and a first n-channel transistor,
a second inverter, an input of which is connected to the second storage node and an output of which is connected to the first storage node, including a second p-channel transistor and a second n-channel transistor,
a third n-channel transistor connected to the first storage node, and
a fourth n-channel transistor connected to the second storage node, the first and fourth n-channel transistors being provided over a first P-well region, the second and third n-channel transistors being provided over a second P-well region, the first and second p-channel transistors being provided over an N-well region located between the first and second P-well regions with the first P-well region, the N-well region and the second P-well region arranged along a first direction;
a plurality of word lines, each word line being connected to gate electrodes of the third and fourth n-channel transistors of the memory cells arranged along the first direction in each of the plurality of rows;
a plurality of first bit lines, each first bit line being provided across the plurality of word lines in plan view and being connected to the third n-channel transistors of the memory cells arranged along a second direction in each of the plurality of columns;
a plurality of second bit lines, each second bit line being provided across the plurality of word lines in plan view and being connected to the fourth n-channel transistors of the memory cells arranged along the second direction in each of the plurality of columns;
a plurality of memory cell power supply lines, respectively, each memory cell power supply line being provided across the plurality of word lines in plan view and being connected to source electrodes of the first and second p-channel transistors in the memory cells arranged in each of the plurality of columns;
a power supply line that supplies a power voltage; and
a plurality of power transistors connected to the plurality of memory cell power supply lines, respectively, each power transistor making an electrical pass between the power supply line and the corresponding memory cell power supply line connected thereto.
18. The semiconductor device according to claim 17 , wherein each of the plurality of power transistors has a gate electrode to which a variable voltage is applied.
19. The semiconductor device according to claim 17 , further comprising:
a column decoder decoding an address to output selection signals for designating a selected column by the address,
wherein the plurality of power transistors have respective gate electrodes receiving control signals based on the selection signals, respectively.
20. The semiconductor device according to claim 17 , further comprising:
a plurality of gate circuits generating control signals, respectively,
wherein the plurality of power transistors have respective gate electrodes receiving the control signals, respectively.
21. The semiconductor device according to claim 17 , further comprising:
a column decoder decoding an address to output selection signals for designating a selected column by the address; and
a plurality of gate circuits have respective first inputs receiving the selection signals, respectively, and respective second inputs receiving a common signal having a first logical value in a read operation and a second logical value in a write operation,
wherein the plurality of power transistor have respective gate electrodes receiving control signals based on outputs of the plurality of gate circuits, respectively.
22. The semiconductor device according to claim 17 , wherein each of the plurality of power transistors is a p-channel transistor having a source electrode connected to the power supply line and a drain electrode connected to the memory cell power supply line provided for the corresponding column.
23. The semiconductor device according to claim 17 , wherein a plurality of wiring layers are provided over a main surface of a semiconductor substrate so as to be different in height with respect to the main surface,
the plurality of first bit lines, the plurality of second bit lines and the plurality of memory cell power supply lines are constructed by one wiring layer of the plurality of wiring layers, and
the plurality of word lines are constructed by another wiring layer of the plurality of wiring layers, which is different from the one wiring layer used for the plurality of first bit lines, the plurality of second bit lines and the plurality of memory cell power supply lines.
24. The semiconductor device according to claim 23 , wherein, in each of the plurality of memory cells,
respective drain electrodes of the first p-channel transistor and the first n-channel transistor are coupled to each other via a first wiring,
respective drain electrodes of the second p-channel transistor and the second n-channel transistor are coupled to each other via a second wiring, and
the first and second wirings are constructed by a further wiring layer, which is lower than the wiring layers used for the plurality of word lines, the plurality of first bit lines, the plurality of second bit lines and the plurality of memory cell power supply lines.