Phase change memory cell spacer

Patent metadata

Field	Value
Publication number	US-11930724-B2
Application number	US-202117407519-A
Country	US
Kind code	B2
Filing date	Aug 20, 2021
Priority date	Aug 20, 2021
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

A phase change memory (PCM) cell includes an electrode, a heater electrically connected to the electrode, a PCM material electrically connected to the heater, a second electrode electrically connected to the PCM material, an electrical insulator surrounding the PCM material, and a shield positioned between the PCM material and the electrical insulator, the shield comprising a reactive-ion-etching-resistant material.

First claim

What is claimed is:

1. A method of manufacturing a phase change memory (PCM) cell, the method comprising:
forming a first electrode;
forming a heater on the first electrode;
forming a PCM material on the heater;
forming a second electrode on the PCM material;
forming a first shield around the PCM material, the first shield comprising a first reactive-ion-etching-resistant material; and
forming an electrical insulator surrounding the first shield.

2. The method of claim 1 , wherein the first shield is positioned between the second electrode and the electrical insulator.

3. The method of claim 1 , wherein forming the first shield comprises:
encapsulating the PCM material and the top electrode with a layer of the first reactive-ion-etching-resistant material; and
etching the layer of the first reactive-ion-etching-resistant material so that the layer of the first reactive-ion-etching-resistant material extends between a first side of the second electrode and a second side of the second electrode opposite of the first side.

4. The method of claim 1 , further comprising:
forming a guard positioned between the first shield and the electrical insulator, the guard comprising a reactive-ion-etching-susceptible material.

5. The method of claim 4 , wherein the reactive-ion-etching-susceptible material comprises silicon nitride.

6. The method of claim 4 , further comprising:
forming a second shield positioned between the first shield and the PCM material, the second shield comprising a second reactive-ion-etching-resistant material that is different from the first reactive-ion-etching-resistant material.

7. The method of claim 4 , wherein forming the guard comprises:
encapsulating the PCM material, the top electrode, and a layer of the first reactive-ion-etching-resistant material with a layer of the reactive-ion-etching-susceptible material; and
etching the layer of the reactive-ion-etching-susceptible material so that the layer of the reactive-ion-etching-susceptible material extends between a first side of the second electrode and a second side of the second electrode opposite of the first side.

8. A method of manufacturing a phase change memory (PCM) cell, the method comprising:
forming a first electrode;
forming a heater on the first electrode;
forming a PCM material on the heater;
forming a second electrode on the PCM material;
forming a first layer encapsulating the PCM material and the second electrode, the first layer comprising a first reactive-ion-etching-resistant material; and
forming a second layer on the first layer also encapsulating the PCM material and the second electrode, the second layer comprising a reactive-ion-etching-susceptible material.

9. The method of claim 8 , further comprising:
forming a third layer encapsulating the first layer, the PCM material, and the second electrode, the third layer comprising a second reactive-ion-etching-resistant material that is different from the first reactive-ion-etching-resistant material.

10. The method of claim 9 , wherein the third layer is positioned between the first layer and the second layer.

11. The method of claim 8 , further comprising forming a first electrical insulator surrounding the heater, wherein the first layer extends along a portion of the first electrical insulator.

12. The method of claim 11 , further comprising forming a second electrical insulator surrounding the PCM material.

13. The method of claim 8 , further comprising etching the first layer so that the first layer extends between a first side of the second electrode and a second side of the second electrode opposite of the first side.

Assignees

• IBM

Inventors

• Ok Injo
• Saulnier Nicole
• Sankarapandian Muthumanickam
• Simon Andrew Herbert
• Mcdermott Steven Michael
• Saraf Iqbal Rashid

Classifications

• H10N70/801 Primary

  Constructional details of multistable switching devices · CPC title

• H10N70/063

  by etching of pre-deposited switching material layers, e.g. lithography · CPC title

• H10N70/231

  based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect · CPC title

• H10N70/826

  adapted for essentially vertical current flow, e.g. sandwich or pillar type devices · CPC title

• H10N70/8413

  adapted for resistive heating · CPC title