Photoresist system and method
In an embodiment a radical inhibitor is included within a photoresist in order to reduce the amount of cross-linking that occurs during subsequent processing, such as an ion implantation process, that would otherwise form a crust within the photoresist. The crust can be removed in a separate process, such as a dry etch with an oxidative or reductive etchant. Alternatively, the crust may be treated to make it more hydrophyilic such that it can be removed simultaneously with the photoresist.
1. A method of manufacturing a semiconductor device, the method comprising:
applying an anti-reflective coating (ARC) layer over at least a portion of a substrate;
applying a photoresist over the ARC layer, the photoresist comprising a solvent, a polymer, a photoactive compound, and a radical inhibitor;
performing an ion implantation while at least a portion of the photoresist is over the substrate; and
the radical inhibitor inhibiting ion-implantation-induced cross-linking of the photoresist during ion implantation.
2. The method of claim 1 , further comprising removing from the photoresist a crust formed by the performing the ion implantation.
3. The method of claim 2 , further comprising removing the photoresist, wherein the removing the photoresist and the removing from the photoresist the crust are performed simultaneously.
4. The method of claim 3 , wherein the removing the photoresist is performed at least in part with a sulfuric peroxide mixture.
5. The method of claim 2 , further comprising removing the photoresist, wherein the removing the photoresist and the removing from the photoresist the crust are performed in separate process steps.
6. The method of claim 1 , wherein the radical inhibitor is a persistent radical.
7. The method of claim 1 , wherein the radical inhibitor is an alkenyl anhydride.
8. A method of manufacturing a semiconductor device, the method comprising:
applying a photoresist over a substrate, the substrate comprising semiconductor fins, the photoresist comprising a polymer and a radical inhibitor;
patterning the photoresist to expose a portion of the substrate;
implanting ions into the semiconductor fins and the photoresist, wherein a photoresist crust is formed within a portion of the photoresist;
the radical inhibitor inhibiting ion-implantation-induced cross-linking of the polymer during ion implantation to the photoresist; and
selectively removing the photoresist crust from the photoresist without removing the photoresist.
9. The method of claim 8 , wherein the removing the photoresist crust from the photoresist is performed at least in part with an oxidative etchant.
10. The method of claim 9 , wherein the oxidative etchant is oxygen (O 2 ).
11. The method of claim 8 , wherein the removing the photoresist crust from the photoresist is performed at least in part with a reductive etchant.
12. The method of claim 11 , wherein the reductive etchant is hydrogen (H 2 ).
13. The method of claim 8 , wherein the radical inhibitor comprises a persistent radical.
14. The method of claim 13 , wherein the radical inhibitor comprises an alkenyl anhydride.
15. The method of claim 14 , wherein the radical inhibitor is maleic anhydride.
16. A method of manufacturing a semiconductor device, the method comprising:
applying a photoresist over a substrate, the photoresist comprising a solvent, a photoactive compound, a polymer resin, and a radical inhibitor;
performing an ion implantation to the substrate; and
the radical inhibitor inhibiting ion-implantation-induced cross-linking of the polymer resin.
17. The method of claim 16 , wherein the radical inhibitor is a persistent radical.
18. The method of claim 17 , wherein the persistent radical comprises one of:
19. The method of claim 16 , wherein the radical inhibitor is an alkenyl anhydride.
20. The method of claim 19 , wherein the radical inhibitor is maleic anhydride.
21. The method of claim 16 , further comprising the ion implantation producing a first photoresist crust layer on the photoresist, the first photoresist crust layer having a first thickness, the first thickness less than a second thickness of a second photoresist crust layer otherwise formed by ion-implantation-induced cross-linking of the photoresist without the radical inhibitor.