DRAM memory device with oxide semiconductor access transistor and method of controlling plate line potential
AssigneeKioxia Corporation
InventorMasaharu Wada
Life of this patent
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Abstract
A semiconductor memory device includes a memory cell that includes a capacitor including a first and second end and a first transistor. The first transistor includes a third and fourth end, is coupled to the first end at the fourth end, and contains an oxide semiconductor. A bit line is coupled to the third end. A sense amplifier is coupled to the bit line and coupled between a first node of a first potential and a second node of a second potential lower than the first potential. A potential generator is configured to supply the second end with a fourth potential that is different from a third potential intermediate between the first potential and the second potential.
Claims13
A semiconductor memory device comprising:
- a memory cell including:
- a capacitor including a first end and a second end;
- and
- a first transistor including a third end and a fourth end, being coupled to the first end at the fourth end, and containing an oxide semiconductor;
- a bit line coupled to the third end;
- a sense amplifier coupled to the bit line and coupled between a first node of a first potential and a second node of a second potential lower than the first potential;
- and
- a potential generator configured to supply the second end with a fourth potential that is different from a third potential intermediate between the first potential and the second potential, wherein
- the fourth potential is lower than the third potential,
- the sense amplifier is further configured to set the bit line to the third potential during data read to the memory cell,
- a potential of the bit line falls from the third potential while the first transistor is off during the data read, and
- the fourth potential is based on an amount by which the potential of the bit line falls from the third potential.
A semiconductor memory device comprising:
- a memory cell including:
- a capacitor including a first end and a second end;
- and
- a first transistor including a third end and a fourth end, being coupled to the first end at the fourth end, and containing an oxide semiconductor;
- a bit line coupled to the third end;
- a sense amplifier coupled to the bit line and coupled between a first node of a first potential and a second node of a second potential lower than the first potential;
- and
- a potential generator configured to supply the second end with a fourth potential that is different from a third potential intermediate between the first potential and the second potential, wherein
- the fourth potential is lower than the third potential,
- the sense amplifier is further configured to set the bit line to the third potential during data read to the memory cell, and
- a potential of the bit line falls from the third potential to the fourth potential while the first transistor is off during the data read.
A semiconductor memory device comprising:
- a memory cell including:
- a capacitor including a first end and a second end;
- and
- a first transistor including a third end and a fourth end, being coupled to the first end at the fourth end, and containing an oxide semiconductor;
- a bit line coupled to the third end;
- a sense amplifier coupled to the bit line and coupled between a first node of a first potential and a second node of a second potential lower than the first potential;
- and
- a potential generator configured to supply the second end with a fourth potential that is different from a third potential intermediate between the first potential and the second potential, wherein
- the sense amplifier includes:
- a second transistor of a first conductivity type including a fifth end and a sixth end, the fifth end being coupled to the first node, and the sixth end being coupled to a third node;
- a third transistor of a second conductivity type including a seventh end and an eighth end, the seventh end being coupled to the third node, and the eighth end being coupled to the second node;
- a fourth transistor including a ninth end and a tenth end, the ninth end being coupled to the third node, and the tenth end being coupled to a gate of the third transistor;
- a fifth transistor of the first conductivity type including an eleventh end and a twelfth end, the eleventh end being coupled to the first node, the twelfth end being coupled to a fourth node, the fourth node being coupled to a gate of the second transistor, and a gate of the fifth transistor being coupled to the third node;
- a sixth transistor of the second conductivity type including a thirteenth end and a fourteenth end, the thirteenth end being coupled to the fourth node, and the fourteenth end being coupled to the second node;
- and
- a seventh transistor including a fifteenth end and a sixteenth end, the fifteenth end being coupled to the fourth node, and the sixteenth end being coupled to a gate of the sixth transistor.
A semiconductor memory device comprising:
- a memory cell including:
- a capacitor including a first end and a second end;
- and
- a first transistor including a third end and a fourth end, being coupled to the first end at the fourth end, and containing an oxide semiconductor;
- a bit line coupled to the third end;
- a sense amplifier coupled to the bit line and coupled between a first node of a first potential and a second node of a second potential lower than the first potential;
- and
- a potential generator configured to supply the second end with a fourth potential that is different from a third potential intermediate between the first potential and the second potential, wherein
- the sense amplifier includes:
- a second transistor of a first conductivity type between the first node and a third node;
- a third transistor of a second conductivity type between the third node and the second node;
- a fourth transistor between the third node and a gate of the third transistor;
- a fifth transistor of the first conductivity type between the first node and a fourth node;
- a sixth transistor of the second conductivity type between the fourth node and the second node;
- a seventh transistor between the fourth node and a gate of the sixth transistor,
- the second transistor has a first on-resistance,
- the third transistor has a second on-resistance,
- the first potential and the second potential have a first potential difference, and
- the fourth potential is based on a product of the first potential difference and a ratio of the second on-resistance to a sum of the first on-resistance and the second on-resistance.
A semiconductor memory device comprising:
- a memory cell including:
- a capacitor including a first end and a second end;
- and
- a first transistor including a third end and a fourth end, being coupled to the first end at the fourth end, and containing an oxide semiconductor;
- a bit line coupled to the third end;
- a sense amplifier coupled to the bit line and coupled between a first node of a first potential and a second node of a second potential lower than the first potential;
- and
- a potential generator configured to supply the second end with a fourth potential that is different from a third potential intermediate between the first potential and the second potential, wherein
- the sense amplifier includes:
- a second transistor of a first conductivity type between the first node and a third node;
- a third transistor of a second conductivity type between the third node and the second node;
- a fourth transistor between the third node and a gate of the third transistor;
- a fifth transistor of the first conductivity type between the first node and a fourth node;
- a sixth transistor of the second conductivity type between the fourth node and the second node;
- a seventh transistor between the fourth node and a gate of the sixth transistor,
- the second transistor has a first on-resistance,
- the third transistor has a second on-resistance, and
- the potential generator includes:
- a first resistor whose resistance is substantially equal to the first on-resistance;
- a second resistor including a fifth end coupled to the first resistor and having resistance substantially equal to the second on-resistance;
- and
- an operational amplifier circuit including a non-inverting input terminal coupled to the fifth end, an inverting input terminal coupled to the second end, and an output terminal.
Dependencies are inferred from the claim text.