Dual resistance heater for phase change devices and manufacturing method thereof

• US 20060246712A1
• Filed: 12/19/2005
• Published: 11/02/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Kim, Yudong, Karpov, Ilya V., Kuo, Charles C., Atwood, Greg, Marangon, Maria Santina, Lowrey, Tyler
• Granted Patent: US 7,880,123 B2
• Time in Patent Office: Days
• US Class Current: 438/622
• CPC Class Codes: H10B 63/24 of the Ovonic threshold switching type
• CPC Class Codes: H10N 70/011 Manufacture or treatment of multistable switching devices
• CPC Class Codes: H10N 70/066 by filling of openings, e.g. damascene method
• 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 70/882 Compounds of sulfur, selenium or tellurium, e.g. chalcogenides

Abstract

A dual resistance heater for a phase change material region is formed by depositing a resistive material. The heater material is then exposed to an implantation or plasma which increases the resistance of the surface of the heater material relative to the remainder of the heater material. As a result, the portion of the heater material approximate to the phase change material region is a highly effective heater because of its high resistance, but the bulk of the heater material is not as resistive and, thus, does not increase the voltage drop and the current usage of the device.

Claims

1. A method for manufacturing a phase change device having a heater and a phase change material layer in contact therewith, the method comprising:

forming the heater; and

increasing the resistance of a surface of the heater by implanting said surface with ions selected from the group consisting of silicon ions and oxygen ions.

2. The method of claim 1, wherein said heater is of titanium nitride and the step of increasing the resistance comprises implanting said surface with silicon to form titanium silicon nitride.

3. The method of claim 1, wherein increasing the resistance of a surface of a heater includes exposing said surface to a plasma.

4. The method of claim 3, wherein the plasma is oxygen plasma.

5. The method of claim 1, further including forming said heater in a pore in a dielectric layer and increasing the resistance of the surface of said heater in said pore in said dielectric layer.

6. The method of claim 5, wherein, before forming said heater, a spacer is formed within said pore.

7. The method of claim 5, wherein forming a heater comprises depositing said heater in said pore.

8. The method of claim 7, further including filling said pore with said heater.

9. A phase change device comprising:

a phase change material region; and

a heater, said heater having a surface in contact with said phase change material region, said surface having a higher resistance than another portion of said heater.

10. The device of claim 9, wherein said surface of said heater has implanted silicon atoms.

11. The device of claim 10, wherein said surface of said heater has a higher concentration of oxygen atoms than the remainder of said heater.

12. The device of claim 9, further including a dielectric layer having a pore therein, said heater being formed in said pore.

13. The device of claim 12, further including a spacer in said pore, said heater being formed within said spacer.

14. The device of claim 12, wherein said heater completely fills said pore.

15. The device of claim 9, wherein said phase change material region is of a chalcogenide material.

16. The device of claim 12, wherein said phase change material region is of a chalcogenide material and extends in said pore in contact with said heater.

17. The device of claim 9, wherein said heater includes titanium silicon nitride in the surface.

18. A system comprising:

a controller;

a battery coupled to said controller; and

a phase change device coupled to said controller, said phase change device including a phase change material region and a heater, said heater having a surface in contact with said phase change material region, said surface having a higher resistance than another portion of said heater.

19. The system of claim 18 wherein the surface of the heater includes titanium silicon nitride and the other portion of the heater includes titanium nitride.

20. A method of manufacturing a phase change device comprising:

providing a dielectric layer;

forming a resistive material layer in the dielectric layer;

said resistive material layer having a top surface region and a bulk region, and the top surface region being substantially coplanar with a surface of the dielectric layer;

implanting ions into the surface of the dielectric layer and the top surface region of the resistive layer to form an adhesion layer in the dielectric layer while simultaneously increase the resistance of the top surface region of the resistive layer;

forming a phase change material layer overlying the resistive material layer and the dielectric layer, said phase change material layer being in contact with the top surface region of the resistive material layer.

21. The method of claim 20 wherein the top surface region is implanted with silicon.

22. The method of claim 21 wherein the bulk region of the resistive material is titanium nitride and the top surface region is titanium silicon nitride.

23. The method of claim 20 wherein the top surface region is treated with oxygen plasma.