Performance improvement of EUV photoresist by ion implantation
A method of patterning a substrate may include providing a blanket photoresist layer on the substrate; performing an ion implantation procedure of an implant species into the blanket photoresist layer, the implant species comprising an enhanced absorption efficiency at a wavelength in the extreme ultraviolet (EUV) range; and subsequent to the performing the ion implantation procedure, performing a patterned exposure to expose the blanket photoresist layer to EUV radiation.
1. A method of patterning a substrate, comprising:
providing a blanket photoresist layer on the substrate;
performing an ion implantation procedure of an implant species into the blanket photoresist layer, the implant species comprising an enhanced absorption efficiency at a wavelength in an extreme ultraviolet (EUV) range; and
subsequent to the performing the ion implantation procedure, performing a patterned exposure to expose the blanket photoresist layer to EUV radiation.
2. The method of claim 1 , wherein the implant species is Xe.
3. The method of claim 1 , wherein the implant species is Sn.
4. The method of claim 1 , wherein the performing the ion implantation procedure comprises generating a peak in a concentration of the implant species as a function of depth below an outer surface of the blanket photoresist layer.
5. The method of claim 1 , wherein the implant species comprises a gaseous species at room temperature.
6. The method of claim 1 , wherein a concentration of the implant species as a function of depth below an outer surface of the blanket photoresist layer increases to a depth of at least 5 nm.
7. The method of claim 1 , wherein the ion implantation procedure comprises performing multiple ion implants into the blanket photoresist layer to produce a non-uniform depth profile.
8. The method of claim 1 wherein the patterned exposure is performed less than 5 hours subsequent to the ion implantation.
9. The method of claim 1 , wherein the wavelength in the EUV range is 13.5 nm.
10. A method of enhancing a photoresist layer, comprising:
applying the photoresist layer as a blanket photoresist layer on a substrate; and
prior to patterning the blanket photoresist layer, performing an ion implantation procedure of an implant species into the blanket photoresist layer, the implant species comprising an enhanced absorption efficiency at a wavelength in an extreme ultraviolet (EUV) range, the enhanced absorption efficiency being greater than 2×10 6 cm 2 /mol.
11. The method of claim 10 , wherein the ion implantation procedure comprises a plurality of ion implantation procedures, wherein an implant depth varies between the plurality of implant procedures.
12. The method of claim 11 , wherein the plurality of implantation procedures generates a non-uniform depth profile of the implant species as a function of depth in the blanket photoresist layer, wherein a concentration of the implant species increases as a function of depth within the blanket photoresist layer.
13. The method of claim 10 , wherein a thickness of the blanket photoresist layer is between 15 nm and 100 nm.
14. The method of claim 10 , wherein an implant energy of the implant species is less than 1000 eV, and wherein an incidence angle of the implant species is greater than 30 degrees with respect to a normal to a plane of the substrate.
15. The method of claim 10 , wherein the blanket photoresist layer comprises a metal oxide photoresist, containing metal oxide particles.
16. The method of claim 10 , wherein the implant species comprises Xe or Sn.