Charged particle beam masking for laser ablation micromachining
AssigneeFEI Company
InventorsMarcus Straw, Milos Toth, Steven Randolph, Michael Lysaght, Mark Utlaut
Life of this patent
Estimating the term…
Abstract
An improved method for substrate micromachining. Preferred embodiments of the present invention provide improved methods for the utilization of charged particle beam masking and laser ablation. A combination of the advantages of charged particle beam mask fabrication and ultra short pulse laser ablation are used to significantly reduce substrate processing time and improve lateral resolution and aspect ratio of features machined by laser ablation to preferably smaller than the diffraction limit of the machining laser.
Claims24
A method of forming a microscopic structure on a substrate of a material having a first ablation threshold using a laser beam, the laser beam having a spot size, the method comprising:
- forming a mask of a material having a second ablation threshold on the substrate surface using a fabrication process capable of producing mask features smaller than the laser beam spot size, the second ablation threshold being higher than the first ablation threshold;
- and
- directing the laser beam toward the substrate surface, the laser beam having a fluence above the first ablation threshold and having a spot size that is larger than the smallest design features of the mask, the mask protecting portions of the substrate that are covered by the mask to produce features in the substrate by laser processing, the features in the processed substrate being smaller than the laser beam spot size.
A system for modifying a work piece, comprising:
- a charged particle beam focusing column;
- a vacuum chamber for containing the work piece to be modified;
- an ultra-fast pulsed laser system having a maximum fluence;
- a work piece to be modified positioned in the vacuum chamber, the work piece including a substrate composed of a substrate material and a mask composed of a mask material, the ablation threshold of the substrate material being lower than the ablation threshold of the mask material, the maximum fluence of the laser system being greater than the ablation threshold of the substrate material.
Dependencies are inferred from the claim text.