Method for removing photoresist

1. A method for removing a photoresist, comprising:

providing a substrate having a photoresist and polymer thereon, wherein the polymer is an etch by-product;

performing an ashing process that uses a plasma containing charged species to remove most of the photoresist;

irradiating the substrate with UV light after the ashing process; and

stripping remaining photoresist and the polymer with a solvent.

2. The method of claim 1 , wherein the photoresist defines a conductive layer on the substrate.

3. The method of claim 2 , wherein the conductive layer includes a titanium layer.

4. The method of claim 2 , wherein the conductive layer includes a diffusion barrier layer and a metal layer on the diffusion barrier layer.

5. The method of claim 4 , wherein the diffusion barrier layer includes a titanium layer.

6. The method of claim 2 , wherein the conductive layer includes a metal layer and an anti-reflection coating on the metal layer.

7. The method of claim 6 , wherein the anti-reflection coating includes a titanium layer.

8. The method of claim 1 , wherein the photoresist defines an opening in the substrate that exposes a conductive layer.

9. The method of claim 8 , wherein the conductive layer includes a metal layer and an anti-reflection coating on the metal layer.

10. The method of claim 9 , wherein the anti-reflection coating includes a titanium layer.

11. The method of claim 1 , wherein a wavelength of the UV light ranges from 280-330 nm.

12. The method of claim 1 , wherein the solvent comprises hydroxyl amine (HA), catechol and monoethanolamine.

13. A method for forming a patterned conductive layer, comprising:

providing a substrate having a conductive layer and a patterned photoresist layer thereon, wherein the patterned photoresist layer is on the conductive layer;

patterning the conductive layer with the patterned photoresist layer as a mask, wherein polymer is formed as an etch by-product;

performing an ashing process that uses a plasma containing charged species to remove most of the photoresist layer;

irradiating the substrate with UV light after the ashing process; and

stripping remaining photoresist layer and the polymer with a solvent.

14. The method of claim 13 , wherein the conductive layer includes a diffusion barrier layer and a metal layer on the diffusion barrier layer.

15. The method of claim 14 , wherein the diffusion barrier layer includes a titanium layer.

16. The method of claim 13 , wherein the conductive layer includes a metal layer and an anti-reflection coating on the metal layer.

17. The method of claim 16 , wherein the anti-reflection coating includes a titanium layer.

18. A method for forming a via hole, comprising:

providing a substrate having a conductive layer, a dielectric layer and a patterned photoresist layer thereon, wherein the patterned photoresist layer is on the dielectric layer;

patterning the dielectric layer using the patterned photoresist layer as a mask to form a via hole that exposes the conductive layer, wherein polymer is formed in the via hole as an etch by-product;

performing an ashing process that uses a plasma containing charged species to remove most of the photoresist layer;

irradiating the substrate with UV light after the ashing process; and

stripping remaining photoresist layer and the polymer with a solvent.

19. The method of claim 18 , wherein the conductive layer includes a metal layer and an anti-reflection coating on the metal layer.

20. The method of claim 19 , wherein the anti-reflection coating comprises a titanium layer.