Scalable split gate memory cell array
View Patent ↗A split gate memory array includes a first row having memory cells; a second row having memory cells, wherein the second row is adjacent to the first row; and a plurality of segments. Each segment includes a first plurality of memory cells of the first row, a second plurality of memory cells of the second row, a first control gate portion which forms a control gate of each memory cell of the first plurality of memory cells, and a second control gate portion which forms a control gate of each memory cell of the second plurality of memory cells. The first control gate portion and the second control gate portion converge to a single control gate portion between neighboring segments of the plurality of segments.
1. A split gate memory array having a plurality of rows, comprising:
a first segment of split gate memory cells, comprising:
a first plurality of split gate memory cells of the first segment along a first row of the first segment;
a second plurality of split gate memory cells of the first segment along a second row of the first segment, wherein the second row is adjacent the first row;
a first control gate conductor of the first segment which forms a control gate of each of the first plurality of split gate memory cells of the first segment;
a second control gate conductor of the first segment which forms a control gate of each of the second plurality of split gate memory cells of the first segment; and
a row strap conductor of the first segment which is physically connected between the first control gate conductor of the first segment and the second control gate conductor of the first segment;
a second segment of split gate memory cells, comprising:
a first plurality of split gate memory cells of the second segment along a first row of the second segment;
a second plurality of split gate memory cells of the second segment along a second row of the second segment, wherein the second row of the second segment is adjacent the first row of the second segment;
a first control gate conductor of the second segment which forms a control gate of each of the first plurality of split gate memory cells of the second segment;
a second control gate conductor of the second segment which forms a control gate of each of the second plurality of split gate memory cells of the second segment; and
a row strap conductor of the second segment which is physically connected between the first control gate conductor of the second segment and the second control gate conductor of the second segment; and
a segment strap conductor physically connected between the row strap conductor of the first segment and the row strap conductor of the second segment.
2. The split gate memory array of claim 1 , further comprising:
a first select gate conductor which forms a select gate of each of the first plurality of split gate memory cells of the first segment and of the second segment; and
a second select gate conductor which forms a select gate of each of the second plurality of split gate memory cells of the first segment and of the second segment;
wherein the segment strap conductor is located between the first select gate conductor and the second select gate conductor.
3. The split gate memory array of claim 1 , wherein the segment strap conductor comprises polysilicon.
4. The split gate memory array of claim 3 , wherein the segment strap conductor is formed in a same polysilicon layer as the first and second control gate conductors of the first and second segments.
5. The split gate memory array of claim 3 , further comprising:
a first contact connected to the first select gate conductor between the first segment and the second segment; and
a second contact connected to the second select gate conductor between the first segment and the second segment, wherein the segment strap conductor is located between the first and second contacts.
6. The split gate memory array of claim 1 , wherein the first segment further comprises:
a plurality of active regions which are intersected by the first control gate conductor of the first segment and the second control gate conductor of the first segment, wherein each intersection corresponds to a split gate memory cell; and
a dummy active region, wherein the row strap conductor is over the dummy active region.
7. The split gate memory array of claim 6 , wherein the first segment further comprises:
a first source/drain contact connected to each of the active regions of the first segment, each of the first source/drain contacts located between the first control gate conductor and the second control gate conductor of the first segment.
8. The split gate memory array of claim 7 , wherein the first segment further comprises:
a second source/drain contact connected to each of the active regions of the first segment, wherein the second control gate conductor of the first segment is located between the second source/drain contacts and the first source/drain contacts.
9. The split gate memory array of claim 1 , wherein the row strap conductor of the first segment is substantially perpendicular to the first and second control gate conductors of first segment and the row strap conductor of the second segment is substantially perpendicular to the first and second control gate conductors of the second segment.
10. A split gate memory array, comprising:
a first row having memory cells;
a second row having memory cells, wherein the second row is adjacent to the first row; and
a plurality of segments, wherein each segment includes:
a first plurality of memory cells of the first row,
a second plurality of memory cells of the second row,
a first control gate portion which forms a control gate of each memory cell of the first plurality of memory cells, and
a second control gate portion which forms a control gate of each memory cell of the second plurality of memory cells,
wherein the first control gate portion and the second control gate portion of one segment of the plurality of segments merge into a single control gate portion between the one of the plurality of segments and a neighboring segment of the plurality of segments.
11. The split gate memory array of claim 10 , further comprising:
a first select gate portion which forms a select gate of each memory cell of the first plurality of memory cells; and
a second select gate portion which forms a select gate of each memory cell of the first plurality of memory cells.
12. The split gate memory array of claim 11 , wherein the first select gate portion forms a select gate of a third plurality of memory cells of the first row of a neighboring segment of the plurality of segments, and the second select gate portion forms a select gate of a fourth plurality of memory cells of the second row of the neighboring segment of the plurality of segments.
13. The split gate memory array of claim 11 , wherein each single control gate portion is located between the first select gate portion and the second select gate portion.
14. The split gate memory array of claim 11 , further comprising:
a first contact connected to the first select gate portion between neighboring segments of the plurality of segments; and
a second contact connected to the second select gate portion between neighboring segments of the plurality of segments.
15. The split gate memory array of claim 14 , wherein each single control gate portion between neighboring segments is located between the first contact and the second contact between the neighboring segments.
16. The split gate memory array of claim 11 , wherein each segment includes:
a plurality of active regions which are intersected by the first control gate portion and the second control gate portion;
a first dummy active region; and
a second dummy active region, wherein the plurality of active regions is located between the first and second dummy active regions.
17. The split gate memory array of claim 16 , wherein the merge between the first and second control gate portions of the one of the plurality of segments is located between the plurality of active regions of the one of the plurality of segments and the plurality of active regions of the neighboring segment.
18. The split gate memory array of claim 16 , wherein each segment includes:
a first plurality of source/drain contacts connected to each of the plurality of active regions between the first control gate portion and the second control gate portion; and
a second plurality of source/drain contacts connected to each of the plurality of active regions, wherein the second control gate portion and the second select gate portion are located between the first plurality of source/drain contacts and the second plurality of source/drain contacts.
19. The split gate memory array of claim 10 , wherein the single control gate portion is formed in a same polysilicon layer as the first and second control gate portions.
20. The split gate memory array of claim 10 , wherein the single control gate portion is substantially parallel to the first and second control gate portions.