Large bit-per-cell three-dimensional mask-programmable read-only memory

• US 8,884,376 B2
• Filed: 09/16/2013
• Issued: 11/11/2014
• Est. Priority Date: 05/24/2010
• Status: Expired due to Fees

• Current Assignee: ChengDu HaiCun IP Technology LLC, Guobiao Zhang
• Original Assignee: ChengDu HaiCun IP Technology LLC, Guobiao Zhang
• Inventors: Zhang, Guobiao
• Primary Examiner(s): Such, Matthew W
• Assistant Examiner(s): Naraghi, Ali
• Application Number:
  US14/028,504
• Publication Number:
  US 20140015103A1
• Time in Patent Office: 421 Days
• Field of Search: 257/50, 257/209, 257529-530
• US Class Current: 257/390
• CPC Class Codes: G11C 17/10 in which contents are determined during manufacturing by a predetermined arrangement of coupling elements, e.g. mask-programmable ROM
• CPC Class Codes: H01L 28/20 Resistors
• CPC Class Codes: H01L 29/868 PIN diodes
• CPC Class Codes: H10B 20/00 Read-only memory [ROM] devices

Abstract

A large bit-per-cell three-dimensional mask-programmable read-only memory (3D-MPROM_B) is disclosed. It can achieve large bit-per-cell (e.g. 4-bpc or more). 3D-MPROM_B can be realized by adding resistive layer(s) or resistive element(s) to the memory cells.

Claims

1. A three-dimensional mask-programmable read-only memory including a plurality of mask-programmable read-only memory levels stacked above and coupled to a semiconductor substrate, comprising:

a first memory cell comprising a first quasi-conduction layer;

a second memory cell comprising a second quasi-conduction layer and a resistive layer, wherein said resistive layer is not an insulating layer;

a third memory cell comprising a third quasi-conduction layer different from said first quasi-conduction layer;

wherein said first, second and third memory cells have different current-voltage characteristics.

2. The three-dimensional mask-programmable read-only memory according to claim 1, wherein said third quasi-conduction layer comprises more concentration of at least one resistive element than said first quasi-conduction layer.

3. The three-dimensional mask-programmable read-only memory according to claim 2, wherein said resistive element increases the resistance of said third quasi-conduction layer.

4. The three-dimensional mask-programmable read-only memory according to claim 2, wherein said resistive element is selected from a group of elements consisting of oxygen, nitrogen and carbon.

5. The three-dimensional mask-programmable read-only memory according to claim 1, wherein said resistive layer has a resistance comparable to said second quasi-conduction layer.

6. A three-dimensional mask-programmable read-only memory including a plurality of mask-programmable read-only memory levels stacked above and coupled to a semiconductor substrate, comprising:

a first memory cell comprising a first quasi-conduction layer;

a second memory cell comprising a second quasi-conduction layer and a resistive layer, wherein said resistive layer has a resistance comparable to said second quasi-conduction layer;

a third memory cell comprising a third quasi-conduction layer different from said first quasi-conduction layer;

wherein said first, second and third memory cells have different current-voltage characteristics.

7. The three-dimensional mask-programmable read-only memory according to claim 6, wherein said third quasi-conduction layer comprises more concentration of at least one resistive element than said first quasi-conduction layer.

8. The three-dimensional mask-programmable read-only memory according to claim 7, wherein said resistive element increases the resistance of said third quasi-conduction layer.

9. The three-dimensional mask-programmable read-only memory according to claim 7, wherein said resistive element is selected from a group of elements consisting of oxygen, nitrogen and carbon.

10. The three-dimensional mask-programmable read-only memory according to claim 6, wherein said resistive layer is not an insulating layer.