SIBN FILM FOR CONFORMAL HERMETIC DIELECTRIC ENCAPSULATION WITHOUT DIRECT RF EXPOSURE TO UNDERLYING STRUCTURE MATERIAL

• US 20190326110A1
• Filed: 11/16/2017
• Published: 10/24/2019
• Est. Priority Date: 12/22/2016
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: GADRE, Milind, MUKHERJEE, Shaunak, JHA, Praket P., PADHI, Deenesh, DUAN, Ziqing, MALLICK, Abhijit B.
• Granted Patent: US 11,011,371 B2
• Time in Patent Office: Days
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/38 Borides
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02252 formation by plasma treatment, e.g. plasma oxidation of the substrate after treatment of an insulating film by plasma H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence

Abstract

Embodiments disclosed herein relate to methods for forming memory devices, and more specifically to improved methods for forming a dielectric encapsulation layer over a memory material in a memory device. In one embodiment, the method includes thermally depositing a first material over a memory material at a temperature less than the temperature of the thermal budget of the memory material, exposing the first material to nitrogen plasma to incorporate nitrogen in the first material, and repeating the thermal deposition and nitrogen plasma operations to form a hermetic, conformal dielectric encapsulation layer over the memory material. Thus, a memory device having a hermetic, conformal dielectric encapsulation layer over the memory material is formed.

Claims

1. A method, comprising:

thermally depositing a first material over a memory material by flowing one or more first precursors over the memory material at a temperature less than a thermal budget of the memory material;

exposing the first material to a nitrogen plasma to incorporate nitrogen in the first material; and

repeating the thermally depositing the first material and the exposing the first material to the nitrogen plasma to form a dielectric encapsulation layer having a predetermined thickness over the memory material.

2. The method of claim 1, wherein the temperature is less than about 300 degrees Celsius.

3. The method of claim 1, wherein the one or more first precursors include one or more of a silicon-containing precursor and a boron-containing precursor.

4. The method of claim 3, wherein the silicon-containing precursor comprises one or more of silane (SiH₄) and disilane (Si₂H₆.

5. The method of claim 1, wherein the nitrogen plasma comprises one or more of nitrogen gas (N₂) and ammonia (NH₃).

6. The method of claim 5, wherein a flow rate of N₂ is between about 5 liters per minute and about 8 liters per minute.

7. The method of claim 1, wherein the dielectric encapsulation layer comprises nitrogen-doped silicon boride (SiBN).

8. The method of claim 1, wherein the predetermined thickness of the dielectric encapsulation layer is between about 200 angstroms and about 300 angstroms.

16. The method of claim 3, wherein the first material comprises one or more of a silicon boride (SiB_n) material or a boron doped amorphous silicon (aSi) material.

17. The method of claim 3, wherein a thickness of the first material is between about 5 angstroms and about 50 angstroms.

18. The method of claim 4, wherein the boron-containing precursor is diborane (B₂H₆).

19. The method of claim 5, wherein a flow rate of NH₃ is between about 500 standard cubic centimeters per minute and about 2 liters per minute.

9. A method, comprising:

depositing a first material over a memory material by a thermal chemical vapor deposition process comprising;

flowing a silicon-containing first precursor comprising one or more of silane and disilane;

flowing a boron-containing first precursor comprising diborane over the memory material at a temperature less than about 300 degrees Celsius; and

reacting the silicon-containing first precursor and the boron-containing first precursor to deposit the first material;

exposing the first material to a nitrogen plasma comprising one or more nitrogen-containing gases selected from the group consisting of nitrogen gas and ammonia; and

repeating the depositing the first material and the exposing the first material to the nitrogen plasma to form a conformal nitrogen-doped silicon boride dielectric encapsulation layer over the memory material.

10. The method of claim 9, wherein the temperature is between about 200 degrees Celsius and about 250 degrees Celsius.

11. The method of claim 9, wherein the depositing the first material and the exposing the first material to the nitrogen plasma are repeated between about 10 times and about 15 times.

12. The method of claim 9, wherein a flow rate of the silicon-containing first precursor is between about 100 standard cubic centimeters per minute and about 700 sccm standard cubic centimeters per minute.

13. The method of claim 9, wherein a plasma power for the exposing the first material to a nitrogen plasma is between about 100 Watts and about 500 Watts.

20. The method of claim 9, wherein a flow rate of the boron-containing first precursor is generally between about 20 standard cubic centimeters per minute and about 400 standard cubic centimeters per minute.

14. A memory device, comprising:

a substrate;

one or more high aspect ratio features of memory material disposed over portions of the substrate; and

a dielectric encapsulation layer comprising nitrogen-doped silicon boride (SiBN) disposed over the one or more high aspect ratio features of memory material and exposed portions of the substrate.

15. The memory device of claim 14, wherein a thickness of the dielectric encapsulation layer is between about 200 angstroms and about 300 angstroms.