Methods for producing a 3D semiconductor device and structure with memory cells and multiple metal layers
A method for producing a 3D semiconductor device including: providing a first level including a first single crystal layer; forming a first metal layer on top of the first level; forming a second metal layer on top of the first metal layer; forming at least one second level above the second metal layer; performing a first lithography step on the second level; forming a third level on top of the second level; performing processing steps to form first memory cells within the second level and form second memory cells within the third level, where the first memory cells include at least one second transistor, and the second memory cells include at least one third transistor; and then at performing at least one deposition step which deposits gate electrodes for both the second and the third transistors, and forming at least four independent memory arrays.
1. A method for producing a 3D semiconductor device, the method comprising:
providing a first level, said first level comprising a first single crystal layer;
forming a first metal layer on top of said first level;
forming a second metal layer on top of said first metal layer;
forming at least one second level disposed on top of or above said second metal layer;
performing a first lithography step on said second level;
forming at least one third level disposed on top of or above said at least one second level;
performing additional processing steps to form a plurality of first memory cells within said at least one second level;
performing said additional processing steps to form a plurality of second memory cells within said at least one third level,
wherein said additional processing steps comprise deposition processes and etch processes,
wherein each of said plurality of first memory cells comprises at least one second transistor,
wherein each of said plurality of second memory cells comprises at least one third transistor; and then
performing at least one deposition step which deposits gate electrodes for both said at least one second transistor and said at least one third transistor; and
forming at least four independent memory arrays,
wherein said at least four independent memory arrays comprise portions of said plurality of first memory cells and/or portions of said plurality of second memory cells.
2. The method according to claim 1 , further comprising:
forming a third metal layer disposed on top of or above said at least one third level; and
forming a through layer via (TLV) connecting said third metal layer to said second metal layer,
wherein a typical diameter of said through layer via is less than 400 nm.
3. The method according to claim 1 , further comprising:
performing a second lithography step on said third level after said step of forming at least one third level.
4. The method according to claim 1 , further comprising:
forming peripheral circuitry on top of said third level,
wherein said peripheral circuitry comprises single crystal transistors.
5. The method according to claim 1 ,
wherein said gate electrodes comprise metal.
6. The method according to claim 1 , further comprising:
forming a plurality of single crystal transistors within said first level prior to said step of forming a first metal layer.
7. The method according to claim 1 , further comprising:
performing a bonding step of a support wafer disposed on top of said third level,
wherein said bonding comprise oxide to oxide bonds.
8. A method for producing a 3D semiconductor device, the method comprising:
providing a first level, said first level comprising a first single crystal layer;
forming a first metal layer on top of said first level;
forming a second metal layer on top of said first metal layer;
forming at least one second level disposed on top of or above said second metal layer;
performing a first lithography step on said second level;
forming at least one third level disposed on top of or above said at least one second level;
performing additional processing steps to form a plurality of first memory cells within said at least one second level;
performing said additional processing steps to form a plurality of second memory cells within said at least one third level,
wherein said additional processing steps comprise deposition processes and etch processes,
wherein each of said plurality of first memory cells comprises at least one second transistor,
wherein each of said plurality of second memory cells comprises at least one third transistor; and then
performing at least one deposition step which deposits gate electrodes for both said at least one second transistor and at least one said third transistor,
wherein said first metal layer has a typical thickness which is 50% greater than a typical thickness of said second metal layer.
9. The method according to claim 8 , further comprising:
forming a third metal layer disposed on top of or above said at least one third level; and
forming a through layer via (TLV) connecting said third metal layer to said second metal layer,
wherein a typical diameter of said through layer via is less than 400 nm.
10. The method according to claim 8 , further comprising:
performing a second lithography step on said third level after said step of forming at least one third level.
11. The method according to claim 8 , further comprising:
forming peripheral circuitry on top of said third level,
wherein said peripheral circuitry comprises single crystal transistors.
12. The method according to claim 8 ,
wherein said gate electrodes comprise metal.
13. The method according to claim 8 , further comprising:
forming a plurality of single crystal transistors within said first level prior to said step of forming a first metal layer.
14. The method according to claim 8 , further comprising:
performing a bonding step of a support wafer disposed on top of said third level,
wherein said bonding comprises oxide to oxide bonds.
15. A method for producing a 3D semiconductor device, the method comprising:
providing a first level, said first level comprising a first single crystal layer;
forming a first metal layer on top of said first level;
forming a second metal layer on top of said first metal layer;
forming at least one second level disposed on top of or above said second metal layer;
performing a first lithography step on said second level;
forming at least one third level disposed on top of or above said at least one second level;
performing additional processing steps to form a plurality of first memory cells within said at least one second level;
performing said additional processing steps to form a plurality of second memory cells within said at least one third level,
wherein said additional processing steps comprise deposition processes and etch processes,
wherein each of said plurality of first memory cells comprises at least one second transistor,
wherein each of said plurality of second memory cells comprises at least one third transistor; and then
performing at least one deposition step which deposits gate electrodes for both said at least one second transistor and said at least one third transistor,
wherein said at least one deposition step comprises Atomic Level Deposition (“ALD”).
16. The method according to claim 15 , further comprising:
forming a third metal layer disposed on top of or above said at least one third level; and
forming a through layer via (TLV) connecting said third metal layer to said second metal layer,
wherein a typical diameter of said through layer via is less than 400 nm.
17. The method according to claim 15 , further comprising:
performing a second lithography step on said third level after said step of forming at least one third level.
18. The method according to claim 15 ,
wherein said gate electrodes comprise metal.
19. The method according to claim 15 , further comprising:
forming a plurality of single crystal transistors within said first level prior to said step of forming a first metal layer.
20. The method according to claim 15 , further comprising:
performing a bonding step of a support wafer disposed on top said third level,
wherein said bonding comprises oxide to oxide bonds.