PHASE CHANGE MEMORY AND FABRICATION METHOD THEREOF

• US 20180269393A1
• Filed: 03/13/2018
• Published: 09/20/2018
• Est. Priority Date: 03/17/2017
• Status: Active Grant

• Current Assignee: Semiconductor Manufacturing International Corporation
• Original Assignee: Semiconductor Manufacturing International Corporation
• Inventors: ZHANG, Chao, ZHOU, Ru Ling, ZHANG, Qing Yong
• Granted Patent: US 10,497,869 B2
• Time in Patent Office: Days
• CPC Class Codes: H10N 70/021 Formation of the switching material, e.g. layer deposition
• CPC Class Codes: H10N 70/026 by physical vapor deposition, e.g. sputtering
• CPC Class Codes: H10N 70/063 by etching of pre-deposited switching material layers, e.g. lithography
• CPC Class Codes: H10N 70/231 based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
• CPC Class Codes: H10N 70/826 adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
• CPC Class Codes: H10N 70/8413 adapted for resistive heating
• CPC Class Codes: H10N 70/8613 Heating or cooling means other than resistive heating electrodes, e.g. heater in parallel
• CPC Class Codes: H10N 70/8616 Thermal insulation means
• CPC Class Codes: H10N 70/8828 Tellurides, e.g. GeSbTe

Abstract

A phase change memory and a fabrication method are provided. The fabrication method includes: providing a substrate; forming a heating layer on the substrate; forming a phase change layer on and in contact with one sidewall surface of the heating layer. The phase change memory includes: a substrate; a heating layer on the substrate; and a phase change layer on and in contact with one sidewall surface of the heating layer.

Claims

1. A method of forming a phase change memory, comprising:

providing a substrate;

forming a heating layer on the substrate; and

forming a phase change layer on and in contact with one sidewall surface of the heating layer.

2. The method according to claim 1, further comprising:

forming a thermal insulation layer on the heating layer, before forming the phase change layer on the heating layer, wherein;

the thermal insulation layer exposes another sidewall surface of the heating layer, and

the phase change layer is formed on the thermal insulation layer.

3. The method according to claim 2, wherein forming the phase change layer comprises:

forming an initial phase change layer on the thermal insulation layer and on sidewall surfaces of the heating layer; and

removing a portion of the initial phase change layer from the other sidewall surface of the heating layer.

4. The method according to claim 3, wherein removing the portion of the initial phase change layer from the other sidewall surface of the heating layer comprises:

forming a patterned layer on the initial phase change layer, wherein;

the pattern layer exposes the portion of the initial phase change layer on the other sidewall surface of the heating layer, and the pattern layer and the heating layer are partially overlapped when being projected on the substrate; and

using the patterned layer as a mask to etch the initial phase change layer to form the phase change layer.

5. The method according to claim 4, wherein:

using the patterned layer as the mask to etch the initial phase change layer includes one of a dry etching process and a wet etching process.

6. The method according to claim 2, wherein:

the thermal insulation layer is made of a material including silicon nitride.

7. The method according to claim 6, wherein:

forming the thermal insulation layer includes a chemical vapor deposition process.

8. The method according to claim 2, wherein:

the thermal insulation layer has a thickness in a range of about 600 angstroms to about 800 angstroms.

9. The method according to claim 1, wherein:

the heating layer is made of a material including titanium nitride, tantalum nitride, titanium, and tungsten; and

forming the heating layer includes a physical vapor deposition process.

10. The method according to claim 1, wherein:

the phase change layer is made of a material including GeSbTe; and

forming the phase change layer includes a physical vapor deposition process.

11. The method according to claim 1, wherein:

the heating layer has a thickness in a range of about 60 nm to about 80 nm.

12. The method according to claim 1, wherein:

a projected pattern of the heating layer on the substrate is rectangular or circular.

13. The method according to claim 12, wherein:

the projected pattern of the heating layer on the substrate is a square, and a side length of the projected pattern of the heating layer on the substrate is in a range of about 270 nm to about 330 nm.

14. The method according to claim 1, further including:

forming a first plug in the substrate, wherein the first plug is connected to the heating layer; and

forming a second plug on the phase change layer.

15. A phase change memory, comprising:

a substrate;

a heating layer on the substrate; and

a phase change layer on and in contact with one sidewall surface of the heating layer.

16. The phase change memory according to claim 15, further comprising:

a thermal insulation layer on the heating layer, wherein;

the thermal insulation layer exposes another sidewall surface of the heating layer, and

the phase change layer is formed on the thermal insulation layer.

17. The phase change memory according to claim 16, wherein:

the thermal insulation layer is made of a material including silicon nitride.

18. The phase change memory according to claim 16, wherein:

the thermal insulation layer has a thickness in a range of about 600 angstroms to about 800 angstroms.

19. The phase change memory according to claim 15, wherein:

the heating layer has a thickness in a range of about 60 nm to about 80 nm.

20. The phase change memory of claim 15, wherein:

a projected pattern of the heating layer on the substrate is rectangular or circular.