Semiconductor memory device and method for writing to semiconductor memory device
View Patent ↗The semiconductor memory device comprising: an n-channel memory cell transistor including: a first diffused region and a second diffused region formed in a semiconductor substrate; a charge storage layer formed over the semiconductor substrate between the first diffused region and the second diffused region; and a gate electrode formed over the charge storage layer; a power supply circuit formed on the semiconductor substrate, the power supply circuit being connectable to the first diffused region, pumping a voltage supplied from an outside power supply and outputting the pumped voltage; and writing means which, upon writing to the n-channel memory cell transistor, applies a reference voltage to the second diffused region, and applies a negative voltage with respective to the reference voltage supplied from the power supply circuit to the first diffused region to thereby flow current between the first diffused region and the second diffused region and to store charges in the charge storage layer.
1. A semiconductor memory device comprising:
an n-channel memory cell transistor including: a first diffused region and a second diffused region formed in a semiconductor substrate; a charge storage layer formed over the semiconductor substrate between the first diffused region and the second diffused region; and a gate electrode formed over the charge storage layer;
a power supply circuit formed on the semiconductor substrate and connected to the first diffused region, the power supply circuit, pumping a voltage supplied from an outside power supply and outputting the pumped voltage; and
writing means which, upon writing to the n-channel memory cell transistor, applies a ground voltage to the second diffused region, and applies a negative voltage supplied from the power supply circuit to the first diffused region to thereby flow current between the first diffused region and the second diffused region and to store charges in the charge storage layer.
2. The semiconductor memory device according to claim 1 , wherein
the power supply circuit is connected to the gate electrode.
3. The semiconductor memory device according to claim 1 , wherein
the first diffused region is connected to the power supply circuit via a bit line, and
the second diffused region is connected to the ground voltage via a source line.
4. The semiconductor memory device according to claim 1 , wherein,
the first diffused region is connected to the power supply circuit via a source line, and
the second diffused region is connected to the ground voltage via a bit line.
5. A method for writing to a semiconductor memory device comprising an n-channel memory cell transistor including a first diffused region and a second diffused region formed in a semiconductor substrate, a charge storage layer formed over the semiconductor substrate between the first diffused region and the second diffused region, and a gate electrode formed over the charge storage layer; and a power supply circuit formed on the semiconductor substrate, the power supply circuit being connected to the first diffused region, pumping a voltage supplied from an outside power supply and outputting the pumped voltage, comprising:
applying a ground voltage to the second diffused region, supplying a negative voltage from the power supply circuit, and applying the negative voltage to the first diffused region, whereby current is flowed between the first diffused region and the second diffused region, and charges are stored in the charge storage layer.
6. The method for writing to a semiconductor memory device according to claim 5 , wherein
a negative voltage is applied to the gate electrode to thereby execute a write-back programming in the n-channel memory cell transistor.
7. The method for writing to a semiconductor memory device according to claim 6 , wherein
the negative voltage supplied from the power supply circuit is applied to the gate electrode.
8. The method for writing to a semiconductor memory device according to claim 5 , wherein
a positive voltage is applied to the gate electrode to thereby write a memory information in the n-channel memory cell transistor.
9. The method for writing to a semiconductor memory device according to claim 5 , wherein
the negative voltage is applied to the first diffused region via a bit line, and
the ground voltage is applied to the second diffused region via a source line.
10. The method for writing to the semiconductor memory device according to claim 5 , wherein
the negative voltage is applied to the first diffused region via a source line, and
the ground voltage is applied to the second diffused region via a bit line.
11. The method for writing to a semiconductor memory device according to claim 5 , wherein
the n-channel memory cell transistor is formed in a p-well formed in an n-well formed in the semiconductor substrate, and
a negative voltage supplied from another power supply circuit which is different from said the power supply circuit is applied to the p-well.
12. A semiconductor memory device comprising:
a p-channel memory cell transistor including: a first diffused region and a second diffused region formed in a semiconductor substrate; a charge storage layer formed over the semiconductor substrate between the first diffused region and the second diffused region; and a gate electrode formed over the charge storage layer;
a power supply circuit formed on the semiconductor substrate and connected to the first diffused region, the power supply circuit pumping a voltage supplied from an outside power supply and outputting the pumped voltage; and
writing means which, upon writing to the p-channel memory cell transistor, applies a ground voltage to the second diffused region, and applies a positive voltage supplied from the power supply circuit to the first diffused region to thereby flow current between the first diffused region and the second diffused region and to store charges in the charge storage layer.
13. The semiconductor memory device according to claim 12 , wherein the power supply circuit is connected to the gate electrode.
14. The semiconductor memory device according to claim 12 , wherein the first diffused region is connected to the power supply circuit via a bit line, and the second diffused region is connected to the ground voltage via a source line.
15. The semiconductor memory device according to claim 12 , wherein,
the first diffused region is connected to the power supply circuit via a source line, and
the second diffused region is connected to the ground voltage via a bit line.
16. A method for writing to a semiconductor memory device comprising a p-channel memory cell transistor including a first diffused region and a second diffused region formed in a semiconductor substrate, a charge storage layer formed over the semiconductor substrate between the first diffused region and the second diffused region, and a gate electrode formed over the charge storage layer; and a power supply circuit formed on the semiconductor substrate, the power supply circuit being connected to the first diffused region, pumping a voltage supplied from an outside power supply and outputting the pumped voltage, comprising:
applying a ground voltage to the second diffused region, supplying a positive voltage from the power supply circuit, and applying the positive voltage to the first diffused region, whereby current is flowed between the first diffused region and the second diffused region, and charges are stored in the charge storage layer.
17. The method for writing to a semiconductor memory device according to claim 16 , wherein
a positive voltage is applied to the gate electrode to thereby execute a write-back programming in the p-channel memory cell transistor.
18. The method for writing to a semiconductor memory device according to claim 17 , wherein
the positive voltage supplied from the power supply circuit is applied to the gate electrode.
19. The method for writing to a semiconductor memory device according to claim 16 , wherein
the positive voltage is applied to the first diffused region via a bit line, and the ground voltage is applied to the second diffused region via a source line.
20. The method for writing to the semiconductor memory device according to claim 16 , wherein
the positive voltage is applied to the first diffused region via a source line, and
the ground voltage is applied to the second diffused region via a bit line.
21. The method for writing to a semiconductor memory device according to claim 16 , wherein
the p-channel memory cell transistor is formed in a n-well formed in an p-well formed in the semiconductor substrate, and
a positive voltage supplied from another power supply circuit which is different from said the power supply circuit is applied to the n-well.
22. The method for writing to a semiconductor memory device according to claim 16 , wherein
a negative voltage is applied to the gate electrode to thereby write a memory information in the p-channel memory cell transistor.