Neuromorphic device including a synapse having carbon nano-tubes

• US 10,559,626 B2
• Filed: 07/12/2017
• Issued: 02/11/2020
• Est. Priority Date: 02/20/2017
• Status: Active Grant

• Current Assignee: SK Hynix Inc.
• Original Assignee: SK Hynix Inc.
• Inventors: Choi, Yong-Soo, Heo, Keun, Lee, Hyung-Dong
• Primary Examiner(s): Muse, Ismail A
• Assistant Examiner(s): Ausar-El, Charles N
• Application Number:
  US15/648,342
• Publication Number:
  US 20180240846A1
• Time in Patent Office: 944 Days
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G06N 3/049 Temporal neural networks, e.g. delay elements, oscillating neurons or pulsed inputs
• CPC Class Codes: G06N 3/065 Analogue means
• CPC Class Codes: H10K 10/26 Diodes comprising organic-organic junctions
• CPC Class Codes: H10K 19/202 Integrated devices comprising a common active layer
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs

Abstract

A neuromorphic device is provided. The neuromorphic device may include a pre-synaptic neuron; a row line extending in a row direction from the pre-synaptic neuron; a post-synaptic neuron; a column line extending in a column direction from the post-synaptic neuron; and a synapse disposed at an intersection between the row line and the column line. The synapse may include a first synapse layer including a plurality of first carbon nano-tubes; a second synapse layer including a plurality of second carbon nano-tubes having different structures from the plurality of first carbon nano-tubes; and a third synapse layer including a plurality of third carbon nano-tubes having different structures from the plurality of first carbon nano-tubes and the plurality of second carbon nano-tubes.

Claims

1. A neuromorphic device comprising:

a pre-synaptic neuron;

a row line extending in a row direction from the pre-synaptic neuron;

a post-synaptic neuron;

a column line extending in a column direction from the post-synaptic neuron; and

a synapse disposed at an intersection between the row line and the column line,

wherein the synapse comprises;

a first synapse layer including a plurality of first carbon nano-tubes;

a second synapse layer including a plurality of second carbon nano-tubes having different structures from the plurality of first carbon nano-tubes; and

a third synapse layer including a plurality of third carbon nano-tubes having different structures from the plurality of first carbon nano-tubes and the plurality of second carbon nano-tubes,

wherein the synapse further comprises a capping layer disposed on the first to third synapse layers,

wherein the capping layer comprises a plurality of horizontal carbon nano-tubes that are densely and horizontally arranged in the capping layer, the plurality of horizontal carbon nano-tubes being arranged denser than the pluralities of the first to third carbon nano-tubes, and

wherein the first synapse layer, the second synapse layer, the third synapse layer, and the capping layer are vertically stacked and horizontally disposed in parallel with each other.

2. The neuromorphic device of claim 1, wherein the plurality of first carbon nano-tubes have first lengths, the plurality of second carbon nano-tubes have second lengths, and the plurality of third carbon nano-tubes have third lengths, the first lengths, the second lengths, and the third lengths being different from each other.

3. The neuromorphic device of claim 1, wherein the plurality of first carbon nano-tubes have first diameters, the plurality of second carbon nano-tubes have second diameters, and the plurality of third carbon nano-tubes have third diameters, the first diameters, the second diameters, and the third diameters being different from each other.

4. The neuromorphic device of claim 1, wherein the plurality of first carbon nano-tubes includes single-wall nano-tubes, the plurality of second carbon nano-tubes includes double-wall nano-tubes, and the plurality of third carbon nano-tubes includes multi-wall nano-tubes.

5. The neuromorphic device of claim 1, wherein lengths of the horizontal carbon nano-tubes are longer than lengths of the first to third carbon nano-tubes.

6. The neuromorphic device of claim 1, wherein the synapse further comprises:

a fourth synapse layer including a plurality of fourth carbon nano-tubes having different structures from the first to third carbon nano-tubes; and

a fifth synapse layer including a plurality of fifth carbon nano-tubes having different structures from the pluralities of first to fourth carbon nano-tubes.

7. A neuromorphic device comprising:

a lower electrode;

an upper electrode;

a synapse disposed between the lower electrode and the upper electrode;

a first sidewall spacer; and

a second sidewall spacer,

wherein the synapse includes;

a lower synapse layer having a plurality of first carbon nano-tubes;

a middle synapse layer having a plurality of second carbon nano-tubes; and

an upper synapse layer having a plurality of third carbon nano-tubes,

wherein the lower synapse layer, the middle synapse layer, and the upper synapse layer are in parallel with each other, and

wherein the lower synapse layer, the middle synapse layer, and the upper synapse layer each contact the lower electrode and the upper electrode,

wherein the first sidewall spacer is disposed on an outer side surface of the lower electrode, and the second sidewall spacer is disposed on an outer side surface of the upper electrode,

wherein the outer side surface of the lower electrode is opposite to the outer side surface of the upper electrode,

wherein the synapse further comprises a capping layer disposed on the upper synapse layer, and

wherein the capping layer comprises a plurality of horizontal carbon nano-tubes that are densely and horizontally arranged in the capping layer, the plurality of horizontal carbon nano-tubes being arranged denser than the pluralities of the first to third carbon nano-tubes.

8. The neuromorphic device of claim 7,

wherein second lengths of the plurality of second carbon nano-tubes are longer than first lengths of the plurality of first carbon nano-tubes, and

wherein third lengths of the plurality of third carbon nano-tubes are longer than the second lengths of the plurality of second carbon nano-tubes.

9. The neuromorphic device of claim 7,

wherein second diameters of the plurality of second carbon nano-tubes are greater than first diameters of the plurality of first carbon nano-tubes, and

wherein third diameters of the plurality of third carbon nano-tubes are greater than the second diameters of the plurality of second carbon nano-tubes.

10. The neuromorphic device of claim 7, wherein:

the plurality of first carbon nano-tubes includes single-wall nano-tubes,

the plurality of second carbon nano-tubes includes double-wall nano-tubes, and

the plurality of third carbon nano-tubes includes multi-wall nano-tubes.

11. The neuromorphic device of claim 7,

wherein lengths of the horizontal carbon nano-tubes are longer than lengths of the plurality of third carbon nano-tubes.

12. The neuromorphic device of claim 7, further comprising:

a lower interconnection layer;

a lower via plug connecting the lower interconnection layer to the lower electrode;

an upper interconnection layer; and

an upper via plug connecting the upper interconnection layer to the upper electrode.

13. The neuromorphic device of claim 12,

wherein the lower interconnection layer and the upper interconnection layer extend in different directions, the different directions being perpendicular with each other.

15. The neuromorphic device of claim 7,

wherein the lower electrode is in direct contact with a first side surface of the lower synapse layer, a first side surface of the middle synapse layer, and a first side surface of the upper synapse layer,

wherein the upper electrode is in contact with a second side surface of the lower synapse layer, a second side surface of the middle synapse layer, and a second side surface of the upper synapse layer, and

wherein the first side surfaces are opposite to the second side surfaces.

14. A neuromorphic device comprising:

a lower electrode;

an upper electrode;

a synapse disposed between the lower electrode and the upper electrode;

a first sidewall spacer; and

a second sidewall spacer,

wherein the synapse includes;

a lower synapse layer having a plurality of first carbon nano-tubes;

a middle synapse layer having a plurality of second carbon nano-tubes; and

an upper synapse layer having a plurality of third carbon nano-tubes,

wherein the lower synapse layer, the middle synapse layer, and the upper synapse layer are in parallel with each other,

wherein the first sidewall spacer is disposed on first side surfaces of the lower synapse layer, the middle synapse layer, and the upper synapse layer,

wherein the second sidewall spacer is disposed on second side surfaces of the lower synapse layer, the middle synapse layer, and the upper synapse layer, the first sidewall surfaces being opposite to the second sidewall surfaces,

wherein the first and second sidewall spacers include an insulating material,

wherein the synapse further comprises a capping layer disposed on the upper synapse layer, and

wherein the capping layer comprises a plurality of horizontal carbon nano-tubes that are densely and horizontally arranged in the capping layer, the plurality of horizontal carbon nano-tubes being arranged denser than the pluralities of the first to third carbon nano-tubes.