Method for producing a 3D semiconductor memory device and structure
A method for producing a 3D memory device, the method including: providing a first level including a single crystal layer and first alignment marks; forming memory control circuits including first single crystal transistors, where the first single crystal transistors include portions of the single crystal layer; forming at least one second level above the first level; performing a first etch step including etching lithography windows within the at least one second level; performing a first lithographic step over the at least one second level aligned to the first alignment marks; and performing additional processing steps to form a plurality of first memory cells within the at last one second level, where each of the plurality of first memory cells include one of a plurality of second transistors, and where the plurality of second transistors are aligned to the first alignment marks with a less than 40 nm alignment error.
1. A method for producing a 3D memory device, the method comprising:
providing a first level comprising a single crystal layer and first alignment marks;
forming memory control circuits comprising first single crystal transistors,
wherein said first single crystal transistors comprise portions of said single crystal layer;
forming at least one second level above said first level;
performing a first lithographic step over said at least one second level aligned to said first alignment marks;
forming at least one third level above said at least one second level;
performing a second lithographic step over said third level;
performing a first etch step comprising etching holes within said third level defined by said second lithographic step;
performing a third lithographic step over said at least one third level;
performing a second etch step comprising etching holes within said at least one third level and said at least one second level defined by said third lithographic step; and
performing additional processing steps to form a plurality of first memory cells within said at least one second level and a plurality of second memory cells within said at least one third level,
wherein each of said plurality of first memory cells comprise one second transistor, and
wherein each of said plurality of second memory cells comprise one third transistor.
2. The method according to claim 1 ,
wherein said processing steps to form a plurality of first memory cells comprise a gate replacement process.
3. The method according to claim 1 ,
wherein one of said at least one third level comprises at least two overlying layers comprising different materials.
4. The method according to claim 1 ,
wherein a plurality of said one third transistor are aligned to said first alignment marks with a less than 40 nm alignment error.
5. The method according to claim 1 , further comprising:
forming a fourth level comprising a second single crystal layer, said fourth level disposed above said third level.
6. The method according to claim 1 ,
wherein said memory control circuits comprise a first metal layer overlaid by a second metal layer, and
wherein said first metal layer is substantially thicker than said second metal layer.
7. The method according to claim 1 ,
wherein said plurality of first memory cells and said plurality of second memory cells are a NAND nonvolatile type memory.
8. A method for producing a 3D memory device, the method comprising:
providing a first level comprising a single crystal layer and first alignment marks;
forming memory control circuits comprising first single crystal transistors,
wherein said first single crystal transistors comprise portions of said single crystal layer;
forming at least one second level above said first level;
performing a first etch step comprising etching lithography windows within said at least one second level;
performing a first lithographic step over said at least one second level aligned to said first alignment marks;
forming at least one third level above said at least one second level;
performing a second lithographic step over said at least one third level;
performing a second etch step comprising etching holes within said at least one third level defined by said second lithographic step;
performing a third lithographic step over said at least one third level;
performing a third etch step comprising etching holes within said at least one third level and said at least one second level defined by said third lithographic step; and
performing additional processing steps to form a plurality of first memory cells within said at least one second level and a plurality of second memory cells within said at least one third level,
wherein each of said plurality of first memory cells comprise one second transistor, and
wherein each of said plurality of second memory cells comprise one third transistor.
9. The method according to claim 8 ,
wherein said processing steps to form a plurality of first memory cells comprise a gate replacement process.
10. The method according to claim 8 ,
wherein one of said at least one third level comprises at least two overlying layers comprising different materials.
11. The method according to claim 8 ,
wherein a plurality of said one third transistor are aligned to said first alignment marks with a less than 40 nm alignment error.
12. The method according to claim 8 , further comprising:
forming a fourth level comprising a second single crystal layer, said fourth level is disposed above said at least one third level.
13. The method according to claim 8 ,
wherein said memory control circuits comprise a first metal layer overlaid by a second metal layer, and
wherein said first metal layer is substantially thicker than said second metal layer.
14. The method according to claim 8 ,
wherein said plurality of first memory cells and said plurality of second memory cells are a NAND nonvolatile type memory.
15. A method for producing a 3D memory device, the method comprising:
providing a first level comprising a single crystal layer and first alignment marks;
forming memory control circuits comprising first single crystal transistors,
wherein said first single crystal transistors comprise portions of said single crystal layer;
forming at least one second level above said first level;
performing a first etch step comprising etching lithography windows within said at least one second level;
performing a first lithographic step over said at least one second level aligned to said first alignment marks; and
performing additional processing steps to form a plurality of first memory cells within said at last one second level,
wherein each of said plurality of first memory cells comprise one of a plurality of second transistors, and
wherein said plurality of second transistors are aligned to said first alignment marks with a less than 40 nm alignment error.
16. The method according to claim 15 ,
wherein said processing steps to form a plurality of first memory cells comprise a gate replacement process.
17. The method according to claim 15 ,
wherein each of said at least one second level comprises at least two overlying layers comprising different materials.
18. The method according to claim 15 , further comprising:
forming a third level comprising a second single crystal layer, said third level is disposed above said at least one second level.
19. The method according to claim 15 ,
wherein said memory control circuits comprise a first metal layer overlaid by a second metal layer, and
wherein said first metal layer is substantially thicker than said second metal layer.
20. The method according to claim 15 ,
wherein said first memory cells are a NAND nonvolatile type memory.