Flash memory array system including a top gate memory cell
View Patent ↗A memory system includes memory cells arranged in sectors. A decoder corresponding to a sector disables memory cells having a defective top gate. The decoder may include a low voltage or high voltage latch for the disabling. A top gate handling algorithm is included. The memory system may include dynamic top gate coupling. A programming algorithm and waveforms with top gate handling is included.
1. A memory system comprising:
a plurality of memory cells arranged in sectors,
wherein top gates of memory cells in a sector are configured to program the memory cells and are coupled to a first line,
wherein source lines of memory cells in the sector are coupled to a second line, and
wherein each memory cell includes:
a floating gate positioned for electrical coupling with a top gate of the top gates configured to program the memory cells,
wherein each floating gate has a tip adjacent to the top gate for erasing the floating gate through the tip to the top gate.
2. The memory system of claim 1 wherein the memory cells are multilevel memory cells.
3. The memory system of claim 2 wherein the memory cells are tip erased memory cells.
4. The memory system of claim 2 wherein the memory cells are source side injection memory cells.
5. The memory system of claim 1 wherein the memory cells are tip erased memory cells.
6. The memory system of claim 1 wherein the memory cells are source side injection memory cells.
7. The memory system of claim 6 , wherein each memory cell further comprising:
a select gate,
wherein said floating gate having the tip adjacent to said select gate for erasing said floating gate through said tip to said select gate.
8. The memory system of claim 1 , wherein each memory cell further comprising:
a select gate,
wherein said floating gate having the tip adjacent to said select gate for erasing said floating gate through said tip to said select gate.
9. The memory system of claim 1 further comprising a logic circuit configured to disable a memory cell in response to a defective top gate.
10. The memory system of claim 1 further comprising a transistor coupled to a top gate line and configured to be set in a state wherein the top gate line floats such that the top gate line voltage follows a word line voltage.
11. The memory system of claim 10 , further comprising a logic circuit configured to disable a memory cell in response to a defective top gate.
12. A memory system comprising:
a plurality of memory cells arranged in sectors,
wherein source lines of memory cells in a sector being coupled to a first line, and
top gate lines of memory cells in said sector are configured to program the memory cells and are coupled to individual lines,
wherein each memory cell includes:
a floating gate positioned for electrical coupling with a top gate of the top gates lines configured to program the memory cells,
wherein each floating gate has a tip adjacent to the top gate for erasing the floating gate through the tip to the top gate.
13. The memory system of claim 12 wherein the memory cells are multilevel memory cells.
14. The memory system of claim 12 further comprising:
a plurality of word lines coupled to at least one other individual line.
15. The memory system of claim 12 wherein the memory cells are tip erased memory cells.
16. The memory system of claim 12 wherein the memory cells are source side injection memory cells.
17. The memory system of claim 12 , wherein each memory cell further comprising:
a select gate,
wherein said floating gate having the tip adjacent to said select gate for erasing said floating gate through said tip to said select gate.
18. The memory system of claim 12 further comprising a—logic circuit that disables a memory cell in response to a defective top gate.
19. The memory system of claim 12 wherein a top gate line is floating.
20. The memory system of claim 12 further comprising a transistor coupled to a top gate line and configured to be set in a state wherein the top gate line floats such that the top gate line voltage follows a word line voltage.