Memory cell, memory cell arrangement, and methods thereof
Various aspects relate to a memory cell including: a field-effect transistor memory structure, wherein a source/drain current through the field-effect transistor memory structure is a function of a gate voltage supplied to a gate of the field-effect transistor memory structure and a memory state in which the field-effect transistor memory structure is residing in; and an access device coupled to the gate of the field-effect transistor memory structure, wherein the access device is configured to control a voltage present at the gate of the field-effect transistor memory structure.
1. A memory cell comprising:
a source-line node, a bit-line node, a word-line node, and an operating-line node;
a field-effect transistor memory structure comprising a field-effect transistor structure and memory element, the memory element comprising a spontaneously polarizable layer, wherein a first source/drain node of the field-effect transistor memory structure is coupled to the source-line node, and wherein a second source/drain node of the field-effect transistor memory structure is coupled to the bit-line node; and
an access device, coupled to a gate of the field-effect transistor memory structure, to the word-line node, and to the operating-line node, wherein the access device is configured to control a voltage at the gate of the field-effect transistor memory structure on both a word-line voltage provided at the word-line node and an operating-line voltage provided at the operating-line node,
wherein a first electrical conductance state associated with the field-effect transistor memory structure corresponds to a polarization state of the spontaneously polarizable layer of the memory element, and
wherein a second electrical conductance state distinct from the first electrical conductance state associated with the field-effect transistor memory structure corresponds to a second polarization state of the spontaneously polarizable layer of the memory element, and
wherein a transition from the first electrical conductance state to the second electrical conductance state is associated with a change in a residual polarization of the spontaneously polarizable layer of the memory element.
2. The memory cell according to claim 1 ,
wherein the field-effect transistor memory structure is configured such that a polarization state of the spontaneously polarizable layer of the memory element defines a memory state of the field-effect transistor memory structure.
3. The memory cell according to claim 1 ,
wherein the spontaneously polarizable layer is remanently polarizable.
4. The memory cell according to claim 1 ,
wherein the spontaneously polarizable layer comprises at least one remanent polarizable material.
5. The memory cell according to claim 1 ,
wherein the field-effect transistor memory structure comprises a capacitive memory structure formed by the memory element and a first electrode layer and a second electrode layer, wherein the memory element is in direct physical contact with both the first electrode and the second electrode.
6. The memory cell according to claim 1 ,
wherein the field-effect transistor memory structure comprises a gate electrode layer, a dielectric layer, and a channel region, and wherein at least one of:
the memory element is disposed between the gate electrode layer and the channel region of the field-effect transistor memory structure, and/or
the memory element is in direct physical contact with both the gate electrode layer and the dielectric layer of the field-effect transistor memory structure, and/or
the memory element is disposed between the gate electrode layer and the dielectric layer of the field-effect transistor memory structure.
7. The memory cell according to according to claim 1 ,
wherein the access device comprises an access field-effect transistor structure, wherein a first source/drain node of the access field-effect transistor structure is coupled to the operating-line node, wherein a second source/drain node of the access field-effect transistor structure is coupled to the gate of the field-effect transistor memory structure, and wherein a gate of the access field-effect transistor structure is coupled to the word-line node.
8. A memory cell arrangement comprising:
a plurality of memory cells, each memory cell of the plurality of memory cells comprising:
a source-line node, a bit-line node, a word-line node, and an operating-line node; a field-effect transistor memory structure comprising a field-effect transistor structure and memory element, the memory element comprising a spontaneously polarizable layer, wherein a first source/drain node of the field-effect transistor memory structure is coupled to the source-line node, and wherein a second source/drain node of the field-effect transistor memory structure is coupled to the bit-line node; and
an access device, coupled to a gate of the field-effect transistor memory structure, to the word-line node, and to the operating-line node, wherein the access device is configured to control a voltage at the gate of the field-effect transistor memory structure on both a word-line voltage provided at the word-line node and an operating-line voltage provided at the operating-line node;
a memory control circuit configured to write a selected memory cell of the plurality of memory cells and to inhibit writing of one or more non-selected memory cells of the plurality of memory cells by a pre-write operation and a write operation subsequent to the pre-write operation.
9. The memory cell arrangement according to claim 8 , wherein the memory control circuit is configured to operate the memory cells of the plurality of memory cells.
10. The memory cell arrangement according to claim 8 ,
wherein memory cells of a first subset of the plurality of memory cells share a first word-line electrically connected to respective word-line nodes of the memory cells of the first subset; and/or
wherein memory cells of a first subset of the plurality of memory cells share a first source-line electrically connected to respective source-line nodes of the memory cells of the first sub set.
11. The memory cell arrangement according to claim 8 ,
wherein memory cells of a second subset of the plurality of memory cells share a second word-line electrically connected to respective word-line nodes of the memory cells of the second subset; and/or
wherein memory cells of a second subset of the plurality of memory cells share a second source-line electrically connected to respective source-line nodes of the memory cells of the second subset.
12. The memory cell arrangement according to claim 8 ,
wherein memory cells of a third subset of the plurality of memory cells share a first bit-line electrically connected to respective bit-line nodes of the memory cells of the third subset; and/or
wherein memory cells of a third subset of the plurality of memory cells share a first operating-line electrically connected to respective operating-line nodes of the memory cells of the third subset.
13. The memory cell arrangement according to claim 8 ,
wherein memory cells of a fourth subset of the plurality of memory cells share a second bit-line electrically connected to respective bit-line nodes of the memory cells of the fourth subset; and/or
wherein memory cells of a fourth subset of the plurality of memory cells share a second operating-line electrically connected to respective operating-line nodes of the memory cells of the fourth subset.
14. The memory cell arrangement according to claim 8 ,
wherein memory cells of a first subset of the plurality of memory cells share a first word-line electrically connected to respective word-line nodes of the memory cells of the first subset, and
wherein memory cells of a second subset of the plurality of memory cells share a second word-line electrically connected to respective word-line nodes of the memory cells of the second subset; and
wherein memory cells of the first subset of the plurality of memory cells and memory cells of the second subset of the plurality of memory cells share a common source-line electrically connected to respective source-line nodes of the memory cells of the first subset and of the second subset.
15. The memory cell arrangement according to claim 8 ,
wherein memory cells of a third subset of the plurality of memory cells share a first operating-line electrically connected to respective operating-line nodes of the memory cells of the third subset, and wherein memory cells of a fourth subset of the plurality of memory cells share a second operating-line electrically connected to respective operating-line nodes of the memory cells of the fourth subset; and
wherein memory cells of the third subset of the plurality of memory cells and memory cells of the fourth subset of the plurality of memory cells share a common bit-line electrically connected to respective bit-line nodes of the memory cells of the third subset and of the fourth sub set.
16. The memory cell arrangement according to claim 8 ,
wherein an active bit-line and an active source-line correspond to the selected memory cell, and wherein one or more passive bit-lines and one or more passive source-lines correspond to memory cells of one or more non-selected memory cells, and
wherein at least one of:
the active source-line and at least one of the one or more passive source-lines are configured as a shared source-line, and/or
the active bit-line and at least one of the one or more passive bit-lines are configured as a shared bit-line.
17. The memory cell arrangement according to claim 8 ,
wherein the pre-write operation comprises a pre-program operation, the pre-program operation comprising:
providing a first supply voltage level at the active word-line and the one or more passive word-lines; and
providing a second supply voltage level at the active operating-line, the one or more passive operating-lines, the active bit-line, the one or more passive bit-lines, the active source-line, and the one or more passive source-lines.
18. The memory cell arrangement according to claim 8 ,
wherein the write operation comprises a program operation, the program operation comprising:
providing a first supply voltage level at the active word-line and the active operating-line; and
providing a second supply voltage level or an inhibit voltage at each of the one or more passive operating-lines, the active source-line, the one or more passive source-lines, the active bit-line, and the one or more passive bit-lines.
19. The memory cell arrangement according to claim 8 ,
wherein the pre-write operation comprises a pre-erase operation, the pre-erase operation comprising:
providing a write voltage at the active word-line, the one or more passive word-lines; the active operating-line, the one or more passive operating-lines, the active bit-line, the one or more passive bit-lines, the active source-line, and the one or more passive source-lines.
20. The memory cell arrangement according to claim 8 ,
wherein the write operation comprises an erase operation, the erase operation comprising:
providing a first supply voltage level at the active word-line, the active bit-line, the one or more passive bit-lines, the active source-line, and the one or more passive source-lines; and
providing a first supply voltage level or an inhibit voltage at the one or more passive operating lines; and
providing a second supply voltage level at the one or more passive word-lines, and the active operating line.
21. A method for writing a selected memory cell of a memory cell arrangement, the memory cell arrangement comprising:
a plurality of memory cells, each memory cell of the plurality of memory cells comprising:
a field-effect transistor memory structure connecting a source-line node and a bit-line node of the memory cell with one another, and
an access field-effect transistor structure coupled to the field-effect transistor memory structure to control a voltage at a gate of the field-effect transistor memory structure as a function of both a word-line voltage provided to the access field-effect transistor structure via a word-line node of the memory cell and an operating-line voltage provided to the access field-effect transistor structure via an operating-line node of the memory cell;
the method comprising:
writing the selected memory cell by pre-charge operation and a subsequent write operation corresponding to the pre-charge operation,
wherein a respective gate of one or more of the field-effect transistor memory structures of the plurality of memory cells is pre-charged to a predefined voltage level by the pre-charge operation, and
wherein the selected memory cell of a memory cell arrangement is written by the subsequent write operation and wherein a writing of one or more non-selected memory cells of the memory cell arrangement is inhibited during the subsequent write operation.
22. The method of claim 21 ;
wherein writing the selected memory cell is based on three or less distinct supply voltage levels.
23. A memory cell arrangement comprising:
a plurality of memory cells, each memory cell of the plurality of memory cells comprising:
a source-line node, a bit-line node, a word-line node, and an operating-line node; a field-effect transistor memory structure comprising a field-effect transistor structure and memory element, the memory element comprising a spontaneously polarizable layer, wherein a first source/drain node of the field-effect transistor memory structure is coupled to the source-line node, and wherein a second source/drain node of the field-effect transistor memory structure is coupled to the bit-line node; and
an access device, coupled to a gate of the field-effect transistor memory structure, to the word-line node, and to the operating-line node, wherein the access device is configured to control a voltage at the gate of the field-effect transistor memory structure on both a word-line voltage provided at the word-line node and an operating-line voltage provided at the operating-line node; and
wherein memory cells of a subset of the plurality of memory cells share at least one of:
a word-line electrically connected to respective word-line nodes of the memory cells of the subset,
a source-line electrically connected to respective source-line nodes of the memory cells of the subset,
a bit-line electrically connected to respective bit-line nodes of the memory cells of the subset, and/or
an operating-line electrically connected to respective operating-line nodes of the memory cells of the subset.
24. The memory cell arrangement according to claim 23 ,
wherein memory cells of a subset of the plurality of memory cells share a word-line electrically connected to respective word-line nodes of the memory cells of the subset and a source-line electrically connected to respective source-line nodes of the memory cells of the sub set.
25. The memory cell arrangement according to claim 24 ,
wherein memory cells of another subset of the plurality of memory cells share a bit-line electrically connected to respective bit-line nodes of the memory cells of the other subset and an operating-line electrically connected to respective operating-line nodes of the memory cells of the other subset.