Patent ID: 11923230
Assignee: MONOLITHIC 3D INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC H  G  B | IPC G  H

Claim 7:
8. A 3D semiconductor device, the device comprising:
a first level comprising a first single crystal layer, said first level comprising first transistors,
wherein each of said first transistors comprises a single crystal channel;

first metal layers interconnecting at least said first transistors;
a second metal layer overlaying said first metal layers;
a second level comprising second transistors,
wherein said second level overlays said first level,
wherein said second level comprises a plurality of first DRAM memory cells, and
wherein each of said plurality of first DRAM memory cells comprises at least one of said second transistors;

a third level comprising third transistors,
wherein said third level overlays said second level,
wherein said third level comprises a plurality of second DRAM memory cells, and
wherein each of said plurality of second DRAM memory cells comprises at least one of said third transistors; and

a fourth level comprising fourth transistors,
wherein said fourth level overlays said third level,
wherein said fourth level comprises a plurality of third DRAM memory cells, and
wherein each of said plurality of third DRAM memory cells comprises at least one of said fourth transistors, and

wherein said third level is directly bonded to said second level.