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US 6,349,054 B1Granted
Thin film magnetic memory device including memory cells having a magnetic tunnel junction
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorHideto Hidaka
Life of this patent
Estimating the term…
Abstract
In the data read operation, a memory cell and a dummy memory cell are respectively coupled to two bit lines of a selected bit line pair, and a data read current is supplied thereto. In the selected memory cell column, a read gate drives the respective voltages on a read data bus pair, according to the respective voltages on the bit lines. A data read circuit amplifies the voltage difference between the read data buses so as to output read data. The use of the read gate enables the read data buses to be disconnected from a data read current path. As a result, respective voltage changes on the bit lines are rapidly produced, whereby the data read speed can be increased.
Claims15
A thin film magnetic memory device, comprising:
- a memory array including a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells having either a first or second resistance value according a storage data level thereof;
- a plurality of first bit lines provided corresponding to the respective columns of the magnetic memory cells;
- a plurality of read word lines provided corresponding to the respective rows of the magnetic memory cells, for electrically coupling the magnetic memory cells corresponding to an addressed row between said plurality of first bit lines each being set to a first voltage and a second voltage so as to pass a data read current through the magnetic memory cells;
- a first read data line for transmitting read data;
- a read gate circuit for setting a voltage of said first read data line according to a voltage on one of said plurality of first bit lines that corresponds to an addressed column;
- and
- a data read circuit for setting a level of the read data according to the voltage on the first read data line.
4 more elements
A thin film magnetic memory device, comprising:
- a memory array including a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including a magnetic storage portion having either a first or second resistance value according to a level of storage data written when a data write magnetic field applied by first and second data write currents is larger than a predetermined magnetic field;
- a plurality of write word lines provided corresponding to the respective rows of the magnetic memory cells, and each selectively activated according an address selection result so as to pass said first data write current therethrough in a data write operation;
- and
- a plurality of bit line pairs provided corresponding to the respective columns of the magnetic memory cells, for passing said second data write current therethrough, each of said plurality of bit line pairs including first and second bit lines,
- said first and second bit lines are respectively formed by using wirings respectively formed in first and second metal wiring layers with the magnetic storage portions interposed therebetween on a semiconductor substrate;
- a plurality of coupling circuits provided respectively corresponding to said plurality of bit line pairs, each for electrically coupling the corresponding first and second bit lines to each other, wherein
- said second data write current flows as a reciprocating current through the first and second bit lines electrically coupled to each other by the corresponding coupling circuit.
4 more elements
A thin film magnetic memory device, comprising:
- a memory array including a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including a magnetic storage portion having a different resistance value according to a level of storage data written when a data write magnetic field applied by first and second data write currents is larger than a predetermined magnetic field;
- a plurality of bit lines provided corresponding to the respective columns of the magnetic memory cells, each for passing said first data write current therethrough in a data write operation;
- and
- a plurality of write word lines provided corresponding to the respective rows of the magnetic memory cells, and selectively activated according an address selection result so as to pass said second data write current therethrough in the data write operation, wherein
- each of said write word lines includes first and second sub write word lines respectively formed in first and second metal wiring layers with the magnetic storage portions interposed therebetween in a vertical direction on a semiconductor substrate, the thin film magnetic memory device further comprising:
- a plurality of coupling circuit provided respectively corresponding to said plurality of write word lines, each for electrically coupling the corresponding first and second sub write word lines to each other, wherein
- the second data write current flows as a reciprocating current through the first and second sub write word lines electrically coupled to each other by a corresponding one of said plurality coupling circuit.
4 more elements
Dependencies are inferred from the claim text.