Selective carbon deposition on top and bottom surfaces of semiconductor substrates

Patent metadata

Field	Value
Publication number	US-12125699-B2
Application number	US-202117359947-A
Country	US
Kind code	B2
Filing date	Jun 28, 2021
Priority date	Jun 28, 2021
Publication date	Oct 22, 2024
Grant date	Oct 22, 2024

Abstract

Semiconductor processing methods are described that include providing a substrate to a reaction chamber, where the substrate includes substrate trenches that have a top surface and a bottom surface. A deposition gas that includes a carbon-containing gas and a nitrogen-containing gas flows into a plasma excitation region of the reaction chamber. A deposition plasma having an electron temperature less than or about 4 eV is generated from the deposition gas. The methods further include depositing a carbon-containing layer on the top surface and the bottom surface of the substrate trenches, where the as-deposited carbon-containing layer has a top surface-to-bottom surface thickness ratio of greater than or about 3:1. Also described are semiconductor structures that include an as-deposited carbon-containing layer on the top and bottom surface of at least a first and second trench, where the carbon-containing layer has a top surface-to-bottom surface thickness ratio of greater than or about 3:1.

First claim

The invention claimed is:

1. A semiconductor processing method comprising:
providing a substrate to a reaction chamber, wherein the substrate comprises substrate trenches having a top surface and a bottom surface;
flowing a deposition gas into a plasma excitation region of the reaction chamber, wherein the deposition gas comprises a carbon-containing gas and a nitrogen-containing gas;
generating a deposition plasma from the deposition gas, wherein the deposition plasma is characterized by an electron temperature less than 4 eV; and
depositing a carbon-containing layer on the top surface and the bottom surface of the substrate trenches, wherein the as-deposited carbon-containing layer has a top surface-to-bottom surface thickness ratio of greater than 3:1.

2. The semiconductor processing method of claim 1 , wherein the deposition gas is argon free and helium free.

3. The semiconductor processing method of claim 1 , wherein the method further comprises heating the substrate to a temperature greater than 100° C. before the deposition of the carbon-containing layer.

4. The semiconductor processing method of claim 1 , wherein the method further comprises etching through at least a portion of the carbon-containing layer in the bottom surface of the substrate trenches, wherein the carbon-containing layer still covers the top surface of the substrate trenches.

5. The semiconductor processing method of claim 4 , wherein the method further comprises removing the carbon-containing layer from the substrate after the etching of the at least a portion of the carbon-containing layer in the bottom surface of the substrate trenches.

6. The semiconductor processing method of claim 1 , wherein the carbon-containing gas comprises methane and the nitrogen-containing gas comprises molecular nitrogen.

7. The semiconductor processing method of claim 1 , wherein the deposition plasma is generated by delivering RF power to the deposition gas, and wherein the RF power is characterized by a power of less than 300 Watts.

8. The semiconductor processing method of claim 1 , wherein the deposition plasma is characterized by a pressure of less than 10 mTorr.

9. The semiconductor processing method of claim 1 , wherein a temperature at the top surface of the trench is greater than 1° C. below the temperature at the bottom surface of the trench during deposition.

10. A semiconductor processing method comprising:
providing a substrate to a reaction chamber, wherein the substrate comprises a first trench with a first aspect ratio greater than 2:1, and a second trench with a second aspect ratio less than 1:2, wherein each of the first trench and the second trench has a top surface and a bottom surface;
heating the substrate to a temperature greater than 100° C.;
flowing a deposition gas into a plasma excitation region of the reaction chamber, wherein the deposition gas comprises a carbon-containing gas and a nitrogen-containing gas;
generating a deposition plasma from the deposition gas, wherein the deposition plasma is characterized by an electron temperature less than 4 eV; and
depositing a carbon-containing layer on the heated substrate, wherein the as-deposited carbon-containing layer has a top surface-to-bottom surface thickness ratio of greater than 3:1 in both the first trench and the second trench.

11. The semiconductor processing method of claim 10 , wherein the method further comprises:
etching through at least a portion of the carbon-containing layer in the bottom surface of the first trench and the second trench, wherein the carbon-containing layer still covers the top surface of the first trench and the second trench; and
removing the carbon-containing layer from the substrate after the etching of the at least a portion of the carbon-containing layer in the bottom surface of the first trench and the second trench.

12. The semiconductor processing method of claim 10 , wherein the deposition plasma is characterized by an electron temperature less than 4 eV.

13. The semiconductor processing method of claim 10 , wherein the first trench is characterized by a first bottom width of less than 50 nm and the second trench is characterized by a second bottom width of greater than 100 nm.

14. The semiconductor processing method of claim 10 , wherein the carbon-containing layer is characterized by a top-surface thickness of greater than 5 nm, and a bottom-surface thickness of less than 1.6 nm.

15. The semiconductor processing method of claim 10 , wherein the carbon-containing layer comprises solid carbon.

Assignees

• Applied Materials Inc

Inventors

• Bagal Abhijeet S
• Fu Qian
• Liu Kuan-Ting
• Liu Chung

Classifications

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P14/6336

  in the presence of a plasma [PECVD] · CPC title

• H10W20/076

  in via holes or trenches · CPC title

• H10P14/6902 Primary

  composed of carbon, e.g. alpha-C, diamond or hydrogen doped carbon · CPC title

• H10P50/73

  using masks for insulating materials · CPC title