System and method for shifting critical dimensions of patterned films

Patent metadata

Field	Value
Publication number	US-9977339-B2
Application number	US-201514603595-A
Country	US
Kind code	B2
Filing date	Jan 23, 2015
Priority date	Jan 27, 2014
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

Techniques herein include systems and methods that provide a spatially-controlled projection of electromagnetic radiation, such as light, onto a substrate as a mechanism of controlling or modulating critical dimensions of various features and structures being micro-fabricated on a substrate. Combining such spatial light projection with photolithographic exposure can achieve significant improvements in critical dimension uniformity across a surface of a substrate. In general, methods herein include patterning processes that identify or receive a critical dimension signature that spatially characterizes critical dimension values that correspond to the substrate. A pattern of electromagnetic radiation is projected onto a patterning film coated on substrate using a digital pixel-based projection system. A conventional photolithographic exposure process is executed subsequent to, or prior to, the pixel-based projection. The patterning film can then be developed to yield a relief pattern having critical dimensions shaped by both exposure processes.

First claim

The invention claimed is:

1. A method for patterning a substrate, the method comprising:
identifying a critical dimension signature that spatially characterizes observed critical dimension values of structures on substrates corresponding to a substrate to be processed as compared to predetermined feature dimensions;
coating the substrate with a patterning film, the patterning film being at least initially radiation-sensitive in that a solubility of the patterning film is changeable by exposure to actinic radiation;
projecting a pattern of electromagnetic radiation onto the patterning film coated on the substrate, the pattern of electromagnetic radiation being projected using a digital pixel-based projection system having an array of independently addressable projection points that are selectively addressed to form the projected pattern, the projected pattern being based on the critical dimension signature to compensate for at least one critical dimension value for at least one structure deviating from a predetermined feature dimension value for the at least one structure;
subsequent to the projecting and the substrate being processed via a photolithographic exposure process separate from the projecting, developing the patterning film such that soluble portions of the patterning film are removed resulting in remaining portions of the patterning film forming a relief pattern on the substrate.

2. The method of claim 1 , wherein projecting the pattern of electromagnetic radiation includes projecting electromagnetic radiation having a wavelength less than about 1000 nanometers.

3. The method of claim 2 , wherein the projected electromagnetic radiation has a wavelength less than about 200 nanometers.

4. The method of claim 1 , wherein the critical dimension signature identifies variations in critical dimensions corresponding to physical locations on a representative substrate that has been processed by a specific photolithography exposure system.

5. The method of claim 1 , wherein the digital pixel-based projection system is configured to vary an amount of electromagnetic radiation projected by point location on the projected pattern.

6. The method of claim 1 , wherein using a digital pixel-based projection system includes using a micro-mirror projection device that reflects electromagnetic radiation onto the substrate from a light source.

7. The method of claim 1 , wherein the patterning film includes a photo acid generator; and
wherein projecting the pattern of electromagnetic radiation onto the patterning film causes photo acid to form in the patterning film according to the pattern of electromagnetic radiation.

8. The method of claim 1 , wherein projecting the pattern of electromagnetic radiation onto the patterning film provides a pre-dose of electromagnetic radiation prior to a receiving a mask-based lithographic exposure.

9. The method of claim 1 , wherein projecting the pattern of electromagnetic radiation onto the patterning film provides a dose of electromagnetic radiation that is executed subsequent to a receiving a mask-based lithographic exposure.

10. The method of claim 1 , wherein projecting the pattern of electromagnetic radiation includes projecting light onto the surface of the substrate via a digital light processing (DLP) device.

11. The method of claim 10 , wherein the digital light processing device is configured to vary a light intensity of each independently addressable pixel.

12. A method for patterning a substrate, the method comprising:
identifying a critical dimension signature that spatially characterizes critical dimension values of structures on substrates corresponding to a substrate to be processed according to a predetermined pattern;
calculating an image based on the critical dimension signature to compensate for at least one critical dimension value for at least one structure deviating from a predetermined critical dimension value for the at least one structure and thereby form the predetermined pattern;
projecting the image onto a patterning film deposited on the substrate, the image being projected as a pattern of electromagnetic radiation and projected using a digital pixel-based projection system having an array of independently addressable projection points that are selectively addressed to form the projected pattern; and
subsequent to the projecting and the substrate being processed via a photolithographic exposure process separate from the projecting, developing the patterning film such that soluble portions of the patterning film are removed resulting in remaining portions of the patterning film forming a relief pattern on the substrate.

13. The method of claim 12 , wherein the critical dimension signature identifies variations in critical dimensions corresponding to physical locations on a representative substrate that has been processed by a specific photolithography exposure system.

14. The method of claim 12 , wherein the digital pixel-based projection system is configured to vary an amount of electromagnetic radiation projected by point location on the projected pattern; and
wherein using a digital pixel-based projection system includes using a micro-mirror projection device that reflects electromagnetic radiation onto the substrate from a light source.

15. The method of claim 12 , wherein the patterning film includes a photo acid generator; and
wherein projecting the pattern of electromagnetic radiation onto the patterning film causes photo acid to form in the patterning film according to the pattern of electromagnetic radiation.

16. The method of claim 12 , wherein projecting the pattern of electromagnetic radiation onto the patterning film is selectively executed either prior to a mask-based lithographic exposure or subsequent to mask-based lithographic exposure.

17. The method of claim 12 , wherein projecting the pattern of electromagnetic radiation includes projecting light onto the surface of the substrate via a digital light processing (DLP) device; and
wherein the digital light processing device is configured to vary a light intensity of each independently addressable pixel.

18. A method for patterning a substrate, the method comprising:
identifying a critical dimension signature that spatially characterizes critical dimension values of structures on substrates corresponding to a substrate to be processed according to a predetermined pattern;
calculating an image based on the critical dimension signature to compensate for at least one critical dimension value for at least one structure deviating from a predetermined critical dimension value for the at least one structure and thereby form the predetermined pattern;
projecting the image onto a patterning film deposited on the substrate, the image being projected as a pattern of electromagnetic radiation and generated using a digital pixel-based projection system having an array of independently addressable projection points that are selectively addressed to form the projected pattern, the pattern of electromagnetic radiation causing a first solubility shift in the patterning film; and
executing a reticle-based photolithographic exposure process, the reticle-based photolithographic exposure process causing a second solubility shift in the patterning film, the first solubility shift and the second solubility shift combined defining a latent pattern in the patterning film in that the latent pattern comprises portions of the patterning film that are soluble to a given developer.

19. The method of claim 18 , wherein executing the reti

Assignees

• Tokyo Electron Ltd

Inventors

• Devilliers Anton J
• Fulford Daniel

Classifications

• G03F7/70616 Primary

  Monitoring the printed patterns · CPC title

• G03F7/70425

  Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating lithography- or non-lithography errors, e.g. proximity correction, mix-and-match, stitching or double patterning · CPC title

• G03F7/70558

  Dose control, i.e. achievement of a desired dose · CPC title

• G03F7/70116

  Off-axis setting using a programmable means, e.g. liquid crystal display [LCD], digital micromirror device [DMD] or pupil facets · CPC title

• G03F7/203

  comprising an imagewise exposure to electromagnetic radiation or corpuscular radiation · CPC title