Method for globally adjusting spacer critical dimension using photo-active self-assembled monolayer

Patent metadata

Field	Value
Publication number	US-11567407-B2
Application number	US-201916586011-A
Country	US
Kind code	B2
Filing date	Sep 27, 2019
Priority date	Sep 28, 2018
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A method of processing a substrate includes: providing structures on a surface of a substrate; depositing a self-assembled monolayer (SAM) over the structures and the substrate, the SAM being reactive to a predetermined wavelength of radiation; determining a first pattern of radiation exposure, the first pattern of radiation exposure having a spatially variable radiation intensity across the surface of the substrate and the structures; exposing the SAM to radiation according to the first pattern of radiation exposure, the SAM being configured to react with the radiation; developing the SAM with a predetermined removal fluid to remove portions of the SAM that are not protected from the predetermined fluid; and depositing a spacer material on the substrate and the structures, the spacer material being deposited at varying thicknesses based on an amount of the SAM remaining on the surface of the substrate and the structures.

First claim

What is claimed is:

1. A method of processing a substrate, the method comprising:
providing structures on a surface of a substrate;
depositing a self-assembled monolayer (SAM) over the structures and the substrate, the SAM being reactive to a predetermined wavelength of radiation;
determining a first pattern of radiation exposure, the first pattern of radiation exposure having a spatially variable radiation intensity across the surface of the substrate and the structures to provide a spatially non-uniform activation level of the SAM;
exposing the SAM to radiation according to the first pattern of radiation exposure having the spatially variable radiation intensity across the surface of the substrate and the structures, the SAM being configured to react with the radiation;
developing the SAM with a predetermined removal fluid to remove portions of the SAM that are not protected from the predetermined removal fluid; and
depositing a spacer material on the substrate and the structures, the spacer material being deposited at a greater thickness in areas with more of the SAM remaining on the surface of the substrate and the structures as compared to areas with less of the SAM remaining.

2. The method of claim 1 , wherein the SAM reacts to the radiation by de-protecting the SAM from the predetermined removal fluid.

3. The method of claim 2 , wherein the predetermined removal fluid for developing the SAM includes at least one of a solvent, a base, or any combination thereof.

4. The method of claim 1 , wherein the SAM reacts to the radiation by protecting the SAM from the predetermined removal fluid.

5. The method of claim 4 , wherein the radiation increases cross-linking at an exposed portion of the SAM.

6. The method of claim 4 , wherein
the portions of the SAM that are not protected from the predetermined removal fluid are portions having not been exposed to the radiation; and
developing the SAM includes removing the unexposed portions.

7. The method of claim 4 , wherein the predetermined removal fluid for developing the SAM includes at least one of a solvent, a base, or any combination thereof.

8. The method of claim 1 , wherein
the first pattern of radiation exposure is based on a critical dimension (CD) signature; and
the CD signature characterizes CD values of the structures across the substrate at coordinate locations.

9. The method of claim 8 , wherein the CD signature is determined from simulation results, the simulation results determining the CD values of resulting structures from the deposition of the spacer material without the SAM deposition and developing.

10. The method of claim 8 , wherein the CD signature is determined from metrology of the structures prior to deposition of the SAM.

11. The method of claim 8 , wherein the CD signature is determined from metrology of resulting structures from another substrate having had the spacer material deposited without the SAM deposition and developing.

12. The method of claim 1 , wherein depositing the spacer material is performed using plasma enhanced deposition.

13. The method of claim 1 , wherein depositing the spacer material is performed using an ozone process.

14. The method of claim 1 , wherein
the structures include a first structure and a second structure,
the first pattern of radiation exposure exposes the SAM deposited over the first structure more than the second structure and more of the SAM deposited over the first structure is removed than the SAM deposited over the second structure, and
the method further comprises
recessing the spacer material below a top of the first structure and the second structure to form a first spacer and a second spacer adjacent to the first structure and a third spacer and a fourth spacer adjacent to the second structure, the first spacer and the second spacer having a width greater than a width of the third spacer and the fourth spacer based on the spatially variable radiation intensity according to the first pattern of radiation exposure; and
removing the first structure and the second structure.

15. A method of multi patterning a semiconductor substrate, comprising:
providing a substrate having microstructure mandrels formed across a surface of the substrate;
depositing a self-assembled monolayer (SAM) material on the surface of the substrate to cover the mandrels, said SAM material being reactive to light radiation;
exposing the SAM to light having a spatially variable activating intensity that is a gradient across the surface of the substrate to provide a spatially non-uniform activation level of the SAM;
developing the SAM with a removal fluid that removes an amount of the SAM material based on the activation level provided by the exposing; and
depositing a spacer material on the substrate and the microstructures, the spacer material being deposited at a greater thickness in areas with more of the SAM remaining on the surface of the substrate and the microstructures as compared to areas with less of the SAM remaining.

16. The method of claim 15 , wherein said exposing comprises exposing the SAM to light while changing at least one of an intensity and a wavelength of the light across the surface of the substrate to provide the spatially non-uniform activation level of the SAM.

17. The method of claim 15 , wherein said exposing comprises causing the SAM to have hydrophilic or hydrophobic characteristics across the surface of the substrate.

18. A method of processing a substrate, the method comprising:
providing structures on a surface of a substrate;
depositing a self-assembled monolayer (SAM) over the structures and the substrate, the SAM being reactive to a predetermined wavelength of radiation;
determining a first pattern of radiation exposure, the first pattern of radiation exposure having a spatially variable radiation intensity across the surface of the substrate and the structures;
exposing the SAM to radiation according to the first pattern of radiation exposure, the SAM being configured to react with the radiation by protecting the SAM from the predetermined removal fluid;
developing the SAM with a predetermined removal fluid to remove portions of the SAM that are not protected from the predetermined removal fluid; and
depositing a spacer material on the substrate and the structures, the spacer material being deposited at varying thicknesses based on an amount of the SAM remaining on the surface of the substrate and the structures.

Assignees

• Tokyo Electron Ltd

Inventors

• Farrell Richard
• Kang Hoyoung
• O'Meara David L

Classifications

• G03F7/11 Primary

  having cover layers or intermediate layers, e.g. subbing layers {(G03F7/091 - G03F7/093, B41N3/03 take precedence)} · CPC title

• G03F7/038

  Macromolecular compounds which are rendered insoluble or differentially wettable (G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021) · CPC title

• G03F7/16

  Coating processes; Apparatus therefor (applying coatings to base materials in general B05; applying photosensitive compositions to base for photographic purposes G03C1/74) · CPC title

• H01L21/0274

  Electricity · mapped topic

• G03F7/2002

  with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image · CPC title