Memory device and semiconductor device
First Claim
1. A semiconductor device comprising:
- a first line;
a second line;
a third line;
a fourth line; and
a memory cell comprising a first transistor and a second transistor,wherein the first transistor comprises;
a first gate electrode;
a first insulating film over the first gate electrode;
a first semiconductor film over the first insulating film;
a first source electrode over in electrical contact with the first semiconductor film;
a first drain electrode over in electrical contact with the first semiconductor film;
a second insulating film over the first semiconductor film, the first source electrode, and the first drain electrode; and
a second gate electrode over the second insulating film, wherein the second transistor comprises;
a third gate electrode;
the first insulating film over the third gate electrode;
a second semiconductor film over the first insulating film;
a second source electrode over in electrical contact with the second semiconductor film;
a second drain electrode over in electrical contact with the second semiconductor film; and
the second insulating film over the second semiconductor film, the second source electrode, and the second drain electrode;
wherein the first gate electrode of the first transistor is electrically connected to the first line,wherein the third gate electrode of the second transistor is electrically connected to the second line,wherein one of the first source electrode and the first drain electrode of the first transistor is electrically connected to the third line,wherein one of the second source electrode and the second drain electrode of the second transistor is electrically connected to the fourth line,wherein the other one of the second source electrode and the second drain electrode of the second transistor is directly connected to the second gate electrode of the first transistor, andwherein the second semiconductor film includes an oxide semiconductor.
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Accused Products
Abstract
It is an object to provide a memory device whose power consumption can be suppressed and a semiconductor device including the memory device. As a switching element for holding electric charge accumulated in a transistor which functions as a memory element, a transistor including an oxide semiconductor film as an active layer is provided for each memory cell in the memory device. The transistor which is used as a memory element has a first gate electrode, a second gate electrode, a semiconductor film located between the first gate electrode and the second gate electrode, a first insulating film located between the first gate electrode and the semiconductor film, a second insulating film located between the second gate electrode and the semiconductor film, and a source electrode and a drain electrode in contact with the semiconductor film.
173 Citations
30 Claims
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1. A semiconductor device comprising:
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a first line; a second line; a third line; a fourth line; and a memory cell comprising a first transistor and a second transistor, wherein the first transistor comprises; a first gate electrode; a first insulating film over the first gate electrode; a first semiconductor film over the first insulating film; a first source electrode over in electrical contact with the first semiconductor film; a first drain electrode over in electrical contact with the first semiconductor film; a second insulating film over the first semiconductor film, the first source electrode, and the first drain electrode; and a second gate electrode over the second insulating film, wherein the second transistor comprises; a third gate electrode; the first insulating film over the third gate electrode; a second semiconductor film over the first insulating film; a second source electrode over in electrical contact with the second semiconductor film; a second drain electrode over in electrical contact with the second semiconductor film; and the second insulating film over the second semiconductor film, the second source electrode, and the second drain electrode; wherein the first gate electrode of the first transistor is electrically connected to the first line, wherein the third gate electrode of the second transistor is electrically connected to the second line, wherein one of the first source electrode and the first drain electrode of the first transistor is electrically connected to the third line, wherein one of the second source electrode and the second drain electrode of the second transistor is electrically connected to the fourth line, wherein the other one of the second source electrode and the second drain electrode of the second transistor is directly connected to the second gate electrode of the first transistor, and wherein the second semiconductor film includes an oxide semiconductor. - View Dependent Claims (2, 3, 4, 5)
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6. A semiconductor device comprising:
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a first line; a second line; a third line; a fourth line; and a memory cell comprising a first transistor and a second transistor, wherein the first transistor comprises; a first gate electrode; a first insulating film over the first gate electrode; a first semiconductor film over the first insulating film; a first source electrode over in electrical contact with the first semiconductor film; a first drain electrode over in electrical contact with the first semiconductor film; a second insulating film over the first semiconductor film, the first source electrode, and the first drain electrode; and a second gate electrode over the second insulating film, wherein the second transistor comprises; a third gate electrode; the first insulating film over the third gate electrode; a second semiconductor film over the first insulating film; a second source electrode over in electrical contact with the second semiconductor film; a second drain electrode over in electrical contact with the second semiconductor film; and the second insulating film over the second semiconductor film, the second source electrode, and the second drain electrode; wherein the first gate electrode of the first transistor is electrically connected to the first line, wherein the third gate electrode of the second transistor is electrically connected to the second line, wherein one of the first source electrode and the first drain electrode of the first transistor is electrically connected to the third line, wherein one of the second source electrode and the second drain electrode of the second transistor is electrically connected to the fourth line, wherein the other one of the second source electrode and the second drain electrode of the second transistor is directly connected to the second gate electrode of the first transistor, and wherein the first semiconductor film and the second semiconductor film include an oxide semiconductor. - View Dependent Claims (7, 8, 9, 10)
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11. A semiconductor device comprising:
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a first line; a second line; a third line; a fourth line; and a memory cell comprising a first transistor and a second transistor, wherein the first transistor comprises; a first gate electrode; a first insulating film over the first gate electrode; a first semiconductor film over the first insulating film; a first source electrode over in electrical contact with the first semiconductor film; a first drain electrode over in electrical contact with the first semiconductor film; a second insulating film over the first semiconductor film, the first source electrode, and the first drain electrode; and a second gate electrode over the second insulating film, wherein the second transistor comprises; a third gate electrode; the first insulating film over the third gate electrode; a second semiconductor film over the first insulating film; a second source electrode over in electrical contact with the second semiconductor film; a second drain electrode over in electrical contact with the second semiconductor film; and the second insulating film over the second semiconductor film, the second source electrode, and the second drain electrode; wherein the first gate electrode of the first transistor is electrically connected to the first line, wherein the third gate electrode of the second transistor is electrically connected to the second line, wherein one of the first source electrode and the first drain electrode of the first transistor is electrically connected to the third line, wherein one of the second source electrode and the second drain electrode of the second transistor is electrically connected to the fourth line, wherein the other one of the second source electrode and the second drain electrode of the second transistor is directly connected to the second gate electrode of the first transistor, wherein the second semiconductor film includes an oxide semiconductor, and wherein at least one of the first source electrode and the first drain electrode overlaps with the second gate electrode, the second insulating film being interposed between the second gate electrode and the at least one of the first source electrode and the first drain electrode. - View Dependent Claims (12, 13, 14, 15)
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16. A semiconductor device comprising:
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a first line; a second line; a third line; a fourth line; and a memory cell comprising a first transistor and a second transistor, wherein the first transistor comprises; a first gate electrode; a first insulating film over the first gate electrode; a first semiconductor film over the first insulating film; a first source electrode over in electrical contact with the first semiconductor film; a first drain electrode over in electrical contact with the first semiconductor film; a second insulating film over the first semiconductor film, the first source electrode, and the first drain electrode; and a second gate electrode over the second insulating film, wherein the second transistor comprises; a third gate electrode; the first insulating film over the third gate electrode; a second semiconductor film over the first insulating film; a second source electrode over in electrical contact with the second semiconductor film; a second drain electrode over in electrical contact with the second semiconductor film; and the second insulating film over the second semiconductor film, the second source electrode, and the second drain electrode; wherein the first gate electrode of the first transistor is electrically connected to the first line, wherein the third gate electrode of the second transistor is electrically connected to the second line, wherein one of the first source electrode and the first drain electrode of the first transistor is electrically connected to the third line, wherein one of the second source electrode and the second drain electrode of the second transistor is electrically connected to the fourth line, wherein the other one of the second source electrode and the second drain electrode of the second transistor is directly connected to the second gate electrode of the first transistor, wherein the first semiconductor film and the second semiconductor film include an oxide semiconductor, and wherein at least one of the first source electrode and the first drain electrode overlaps with the second gate electrode, the second insulating film being interposed between the second gate electrode and the at least one of the first source electrode and the first drain electrode. - View Dependent Claims (17, 18, 19, 20)
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21. A semiconductor device comprising:
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a memory cell comprising; a first transistor; and a second transistor, wherein the first transistor comprises; a first gate electrode; a second gate electrode over the first gate electrode; and a first channel formation region between the first gate electrode and the second gate electrode, wherein the second transistor comprises a second channel formation region, the second channel formation region including an oxide semiconductor, and wherein one of a source electrode and a drain electrode of the second transistor over the second channel formation region is directly connected to the second gate electrode of the first transistor. - View Dependent Claims (22, 23, 24)
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25. A semiconductor device comprising:
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a first transistor comprising; a first gate electrode; a first insulating film over the first gate electrode; a first semiconductor film over the first insulating film; a first source electrode over and a first drain electrode each in electrical contact with the first semiconductor film; a second insulating film over the first semiconductor film, the first source electrode, and the first drain electrode; and a second gate electrode over the second insulating film, a second transistor comprising; a third gate electrode; a third insulating film over the third gate electrode; a second semiconductor film over the third insulating film; a fourth insulating film over the second semiconductor film; and a second source electrode over and a second drain electrode each in electrical contact with the second semiconductor film, wherein one of the second source electrode and the second drain electrode of the second transistor is directly connected to the second gate electrode of the first transistor, and wherein the first semiconductor film and the second semiconductor film each includes an oxide semiconductor. - View Dependent Claims (26, 27, 28, 29, 30)
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Specification