Granted Patent B2

US 8,623,697 · App. 13/132,311 · Granted Jan 7, 2014

Abstract

Claims (68)

1. A method comprising:

forming a stack comprising

forming a metal heater layer,

forming a chalcogenide over the metal heater layer such that a lowermost portion of the chalcogenide is only partially in contact with the metal heater, and

forming a first dielectric on top of the chalcogenide;

defining the first dielectric using a photo resist as a mask, defining the first dielectric being followed by removing the photo resist prior to defining the chalcogenide;

defining the chalcogenide using the defined first dielectric as a mask; and

sealing sidewalls of the chalcogenide with a second dielectric.

2. The method of claim 1 , wherein the stack further comprises forming a metal cap over the chalcogenide, wherein defining the first dielectric further comprises defining the metal cap.

3. The method of claim 2 , wherein defining the metal cap uses Cl/Ar dry etch chemistry.

4. The method of claim 2 , wherein defining the metal cap partially removes the metal cap.

5. The method of claim 1 , wherein the photo resist is removed by O 2 /N 2 /H 2 based plasma dry removal process.

6. The method of claim 1 , wherein the chalcogenide is defined by CF 4 based dry etch chemistry.

7. The method of claim 1 , wherein sealing sidewalls of the chalcogenide with a second dielectric further comprises forming the second dielectric over the stack and anisotropically etching the second dielectric to form sidewall spacers for the chalcogenide.

8. The method of claim 7 , wherein etching the second dielectric further comprises:

forming a surrounding dielectric material on the sides of the metal heater layer;

etching the metal heater layer beneath the chalcogenide; and

etching the surrounding dielectric material formed on the sides of the metal heater layer.

9. The method of claim 8 , wherein etching the second dielectric uses SF 6 based dry etch chemistry.

10. The method of claim 1 , further comprises forming an enclosure dielectric over the stack after sealing the sidewalls of the chalcogenide.

11. A method of forming a storage element structure, the method comprising:

forming a portion of a multilayer stack comprising a metal heater and a dielectric hard mask layer with a chalcogenide layer disposed therebetween, the metal heater being coupled to a portion of a lowermost section of the chalcogenide layer;

depositing and patterning a photo resist layer on top of the portion of the multilayer stack;

etching the dielectric hard mask layer with CF 4 based dry etch chemistry using the photo resist layer as an etch mask;

after the dielectric hard mask layer is etched, removing the photo resist layer before etching the chalcogenide layer;

etching the chalcogenide layer using the dielectric hard mask layer as an etch mask;

forming a spacer dielectric over at least a portion of the multilayer stack; and

anisotropically etching the spacer dielectric to form sidewall spacers for the at least the portion of the multilayer stack.

12. A method of forming a storage element structure, the method comprising:

forming a portion of a multilayer stack comprising a metal heater and a dielectric hard mask layer with a chalcogenide layer disposed therebetween, the metal heater being coupled to a portion of a lowermost section of the chalcogenide layer;

depositing and patterning a photo resist layer on top of the portion of the multilayer stack;

etching the dielectric hard mask layer using the photo resist layer as an etch mask;

after the dielectric hard mask layer is etched, removing the photo resist layer before etching the chalcogenide layer, the photo resist layer being removed by O 2 /N 2 /H 2 based plasma dry removal process;

etching the chalcogenide layer using the dielectric hard mask layer as an etch mask;

forming a spacer dielectric over at least a portion of the multilayer stack; and

anisotropically etching the spacer dielectric to form sidewall spacers for the at least the portion of the multilayer stack.

13. A method of forming a storage element structure, the method comprising:

forming a portion of a multilayer stack comprising a metal heater and a dielectric hard mask layer with a chalcogenide layer disposed therebetween, the metal heater being coupled to a portion of a lowermost section of the chalcogenide layer;

depositing and patterning a photo resist layer on top of the portion of the multilayer stack;

etching the dielectric hard mask layer using the photo resist layer as an etch mask;

after the dielectric hard mask layer is etched, removing the photo resist layer before etching the chalcogenide layer;

etching the chalcogenide layer using the dielectric hard mask layer as an etch mask, the chalcogenide layer being etched by CF 4 based dry etch chemistry;

forming a spacer dielectric over at least a portion of the multilayer stack; and

anisotropically etching the spacer dielectric to form sidewall spacers for the at least the portion of the multilayer stack.

14. A method of forming a storage element structure, the method comprising:

forming a portion of a multilayer stack comprising a metal heater and a dielectric hard mask layer with a chalcogenide layer disposed therebetween, the metal heater being coupled to a portion of a lowermost section of the chalcogenide layer;

depositing and patterning a photo resist layer on top of the portion of the multilayer stack;

etching the dielectric hard mask layer using the photo resist layer as an etch mask;

after the dielectric hard mask layer is etched, removing the photo resist layer before etching the chalcogenide layer;

etching the chalcogenide layer using the dielectric hard mask layer as an etch mask;

forming a spacer dielectric over at least a portion of the multilayer stack; and

anisotropically etching the spacer dielectric to form sidewall spacers for the at least the portion of the multilayer stack, the spacer dielectric being anisotropically etched by SF 6 based dry etch chemistry.

15. A method of forming a storage element structure, the method comprising:

forming a portion of a multilayer stack comprising a metal heater and a dielectric hard mask layer with a chalcogenide layer disposed therebetween, forming the multilayer stack further comprising forming a surrounding first dielectric material on the sides of the metal heater and forming a second dielectric beneath the metal heater, the metal heater being coupled to a portion of a lowermost section of the chalcogenide layer;

depositing and patterning a photo resist layer on top of the portion of the multilayer stack;

etching the dielectric hard mask layer using the photo resist layer as an etch mask;

after the dielectric hard mask layer is etched, removing the photo resist layer before etching the chalcogenide layer;

etching the chalcogenide layer using the dielectric hard mask layer as an etch mask;

forming a spacer dielectric over at least a portion of the multilayer stack; and

anisotropically etching the spacer dielectric to form sidewall spacers for the at least the portion of the multilayer stack.

16. A method of forming a storage element structure, the method comprising:

forming a portion of a multilayer stack comprising a refractory ternary metal nitride heater and a dielectric hard mask layer with a chalcogenide layer disposed therebetween, the refractory ternary metal nitride heater comprising TiSiN, about 80 nm thick, coupled to a portion of a lowermost section of the chalcogenide layer;

depositing and patterning a photo resist layer on top of the portion of the multilayer stack;

etching the dielectric hard mask layer using the photo resist layer as an etch mask;

after the dielectric hard mask layer is etched, removing the photo resist layer before etching the chalcogenide layer;

etching the chalcogenide layer using the dielectric hard mask layer as an etch mask;

forming a spacer dielectric over at least a portion of the multilayer stack; and

anisotropically etching the spacer dielectric to form sidewall spacers for the at least the portion of the multilayer stack.

Assignments (10)