Debris removal in high aspect structures
View Patent ↗A system for removing debris from a surface of a photolithographic mask is provided. The system includes an atomic force microscope with a tip supported by a cantilever. The tip includes a surface and a nanometer-scaled coating disposed thereon. The coating has a surface energy lower than the surface energy of the photolithographic mask.
1. A method for removing debris from a trench formed on a photolithographic mask, comprising:
positioning a tip within the trench, the tip including a surface and a nanometer-scaled coating disposed thereon, the nanometer-scaled coating having a surface energy lower than a surface energy of the photolithographic mask;
moving the tip within the trench to physically adhere debris to the tip;
moving the tip with the debris away from the trench; and
removing the debris from the tip.
2. The method of claim 1 , wherein the nanometer-scaled coating is polytetrafluoroethylene.
3. The method of claim 1 , wherein the tip includes a metallic material disposed between the surface and the nanometer-scaled coating.
4. The method of claim 1 , wherein the tip includes an oxide material disposed between the surface and the nanometer-scaled coating.
5. The method of claim 1 , wherein the tip includes a metal oxide material disposed between the surface and the nanometer-scaled coating.
6. The method of claim 1 , further comprising replenishing the nanometer-scaled coating by physically interacting the tip with a material having a surface energy lower than the surface energy of the photolithographic mask.
7. The method of claim 6 , further comprising removing the debris from the tip by imbedding the debris in the material.
8. The method of claim 6 , wherein the material is polytetrafluoroethylene.
9. The method of claim 6 , further comprising replenishing the nanometer-scaled coating by plunging the tip into the material.
10. The method of claim 9 , wherein the replenishing step includes moving the tip laterally along the material.
11. The method of claim 6 , further comprising pushing the debris away from an apex of the tip and toward an atomic force microscope cantilever that supports the tip.
12. The method of claim 1 , wherein the debris from the tip is imbedded in a target by indenting the tip into the target, the target being softer than the tip.