Semiconductor integrated circuit
A semiconductor integrated circuit having a substantially rectangular standard cell divided by first borderlines opposed to other standard cells longitudinally adjacent to the standard cell and second borderlines opposed to other standard cells laterally adjacent to the standard cell, the standard cell has: a p-type MOS transistor having first diffused regions and a first gate electrode; an n-type MOS transistor having second diffused regions and a second gate electrode with STI disposed for device isolation between the n-type MOS transistor and the p-type MOS transistor substantially in parallel with the first borderlines; dummy p-type MOS transistors having third gate electrodes disposed on the second borderlines so as to be adjacent to the first diffused regions of the p-type MOS transistor, the third gate electrodes being connected to power supply wiring so as to turn off the dummy p-type MOS transistors; and dummy n-type MOS transistors having fourth gate electrodes disposed on the second borderlines so as to be adjacent to the second diffused regions of the n-type MOS transistor, the fourth gate electrodes being connected to ground wiring so as to turn off the dummy n-type MOS transistors.
1. A semiconductor integrated circuit having a substantially rectangular standard cell divided by first borderlines opposed to other standard cells longitudinally adjacent to the standard cell and second borderlines opposed to other standard cells laterally adjacent to the standard cell,
the standard cell comprising:
a p-type MOS transistor having first diffused regions and a first gate electrode;
an n-type MOS transistor having second diffused regions and a second gate electrode with STI disposed for device isolation between the n-type MOS transistor and the p-type MOS transistor substantially in parallel with the first borderlines;
dummy p-type MOS transistors having third gate electrodes disposed on the second borderlines so as to be adjacent to the first diffused regions of the p-type MOS transistor, the third gate electrodes being connected to power supply wiring so as to turn off the dummy p-type MOS transistors; and
dummy n-type MOS transistors having fourth gate electrodes disposed on the second borderlines so as to be adjacent to the second diffused regions of the n-type MOS transistor, the fourth gate electrodes being connected to ground wiring so as to turn off the dummy n-type MOS transistors,
wherein an absolute value of threshold voltage of the dummy p-type MOS transistor is higher than an absolute value of threshold voltage of the p-type MOS transistor, and
an absolute value of threshold voltage of the dummy n-type MOS transistor is higher than an absolute value of threshold voltage of the n-type MOS transistor.
2. The semiconductor integrated circuit according to claim 1 , wherein the power supply wiring is formed on a layer disposed above a layer in which the third gate electrodes are formed,
the ground wiring is formed on a layer disposed above a layer in which the fourth gate electrodes are formed,
the third gate electrodes of the dummy p-type MOS transistors are connected to the power supply wiring via first contacts, and
the fourth gate electrodes of the dummy n-type MOS transistors are connected to the ground wiring via second contacts.
3. The semiconductor integrated circuit according to claim 2 , wherein the first contacts are formed on intersection points of the second borderlines and the first borderline disposed close to the p-type MOS transistor, and
the second contacts are formed on intersection points of the second borderlines and the first borderline disposed close to the n-type MOS transistor.
4. The semiconductor integrated circuit according to claim 1 , wherein distances between the first gate electrode of the p-type MOS transistor and the third gate electrodes of the dummy p-type MOS transistors are 2 μm or less, and
distances between the second gate electrode of the n-type MOS transistor and the fourth gate electrodes of the dummy n-type MOS transistors are 2 μm or less.
5. The semiconductor integrated circuit according to claim 2 , wherein distances between the first gate electrode of the p-type MOS transistor and the third gate electrodes of the dummy p-type MOS transistors are 2 μm or less, and
distances between the second gate electrode of the n-type MOS transistor and the fourth gate electrodes of the dummy n-type MOS transistors are 2 μm or less.
6. The semiconductor integrated circuit according to claim 3 , wherein distances between the first gate electrode of the p-type MOS transistor and the third gate electrodes of the dummy p-type MOS transistors are 2 μm or less, and
distances between the second gate electrode of the n-type MOS transistor and the fourth gate electrodes of the dummy n-type MOS transistors are 2 μm or less.
7. A semiconductor integrated circuit having a substantially rectangular standard cell divided by first borderlines opposed to other standard cells longitudinally adjacent to the standard cell and second borderlines opposed to other standard cells laterally adjacent to the standard cell,
the standard cell comprising:
a p-type MOS transistor having first diffused regions and a first gate electrode;
an n-type MOS transistor having second diffused regions and a second gate electrode with STI disposed for device isolation between the n-type MOS transistor and the p-type MOS transistor substantially in parallel with the first borderlines;
dummy p-type MOS transistors having third gate electrodes disposed on the second borderlines so as to be adjacent to the first diffused regions of the p-type MOS transistor, the third gate electrodes being connected to power supply wiring so as to turn off the dummy p-type MOS transistors; and
dummy n-type MOS transistors having fourth gate electrodes disposed on the second borderlines so as to be adjacent to the second diffused regions of the n-type MOS transistor, the fourth gate electrodes being connected to ground wiring so as to turn off the dummy n-type MOS transistors,
wherein the dummy p-type MOS transistor has a gate length greater than a gate length of the p-type MOS transistor, and
the dummy n-type MOS transistor has a gate length greater than a gate length of the n-type MOS transistor.
8. The semiconductor integrated circuit according to claim 7 , wherein the power supply wiring is formed on a layer disposed above a layer in which the third gate electrodes are formed,
the ground wiring is formed on a layer disposed above a layer in which the fourth gate electrodes are formed,
the third gate electrodes of the dummy p-type MOS transistors are connected to the power supply wiring via first contacts, and
the fourth gate electrodes of the dummy n-type MOS transistors are connected to the ground wiring via second contacts.
9. The semiconductor integrated circuit according to claim 8 , wherein the first contacts are formed on intersection points of the second borderlines and the first borderline disposed close to the p-type MOS transistor, and
the second contacts are formed on intersection points of the second borderlines and the first borderline disposed close to the n-type MOS transistor.
10. The semiconductor integrated circuit according to claim 7 , wherein distances between the first gate electrode of the p-type MOS transistor and the third gate electrodes of the dummy p-type MOS transistors are 2 μm or less, and
distances between the second gate electrode of the n-type MOS transistor and the fourth gate electrodes of the dummy n-type MOS transistors are 2 μm or less.
11. The semiconductor integrated circuit according to claim 8 , wherein distances between the first gate electrode of the p-type MOS transistor and the third gate electrodes of the dummy p-type MOS transistors are 2 μm or less, and
distances between the second gate electrode of the n-type MOS transistor and the fourth gate electrodes of the dummy n-type MOS transistors are 2 μm or less.
12. The semiconductor integrated circuit according to claim 9 , wherein distances between the first gate electrode of the p-type MOS transistor and the third gate electrodes of the dummy p-type MOS transistors are 2 μm or less, and
distances between the second gate electrode of the n-type MOS transistor and the fourth gate electrodes of the dummy n-type MOS transistors are 2 μm or less.
13. A semiconductor integrated circuit having a substantially rectangular standard cell divided by first borderlines opposed to other standard cells longitudinally adjacent to the standard cell and second borderlines opposed to other standard cells laterally adjacent to the standard cell,
the standard cell comprising:
a p-type MOS transistor having first diffused regions and a first gate electrode;
an n-type MOS transistor having second diffused regions and a second gate electrode with STI disposed for device isolation between the n-type MOS transistor and the p-type MOS transistor substantially in parallel with the first borderlines;
dummy p-type MOS transistors having third gate electrodes disposed on the second borderlines so as to be adjacent to the first diffused regions of the p-type MOS transistor, the third gate electrodes being connected to power supply wiring so as to turn off the dummy p-type MOS transistors; and
dummy n-type MOS transistors having fourth gate electrodes disposed on the second borderlines so as to be adjacent to the second diffused regions of the n-type MOS transistor, the fourth gate electrodes being connected to ground wiring so as to turn off the dummy n-type MOS transistors,
wherein the third gate electrodes of the dummy p-type MOS transistors are connected to the power supply wiring formed on a wiring layer disposed above a layer in which the third gate electrodes are formed, and
the fourth gate electrodes of the dummy n-type MOS transistors are connected to the ground wiring formed on a wiring layer disposed above a layer in which the fourth gate electrodes are formed.
14. The semiconductor integrated circuit according to claim 13 , wherein distances between the first gate electrode of the p-type MOS transistor and the third gate electrodes of the dummy p-type MOS transistors are 2 μm or less, and
distances between the second gate electrode of the n-type MOS transistor and the fourth gate electrodes of the dummy n-type MOS transistors are 2 μm or less.