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Novel Technique for Reducing Debris Deposition or Adhesion in Laser Ablation

IP.com Disclosure Number: IPCOM000107986D
Original Publication Date: 1992-Apr-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 77K

Publishing Venue

IBM

Related People

Leung, W: AUTHOR [+4]

Abstract

Disclosed is a liquid film moderated laser ablation technique which reduces the amount of debris as well as the adhesion of residual debris.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Novel Technique for Reducing Debris Deposition or Adhesion in Laser Ablation

       Disclosed is a liquid film moderated laser ablation
technique which reduces the amount of debris as well as the adhesion
of residual debris.

      Debris formation and redeposition are a major concern in state-
of-the-art laser ablation, since they require additional cleaning
steps which increase the process complexity and cost or even prevent
certain applications of laser ablation.

      The present manufacturing practice is based on laser ablation
of polymer material, using a high-power excimer laser to irradiate
the surface with a laser fluence exceeding the threshold fluence for
ablating a specific material.  Hot material is ejected from the
irradiated area producing observable plumes of plasma luminescence
at, above and near that area.  The ejected material consists of hot
gases as well as debris of hot condensed particles, mostly carbon
soot.  Part of this solid debris is redeposited mainly in a circular
ring around the irradiated area.  Upon redeposition on the polymer
surface, the carbon soot is still very hot, which accounts for the
strong adhesion of the debris to the surface because of transient
local melting, softening or fusing of the contacted material.

      The proposed technique uses a thin liquid film which may be
deposited on the entire sample area or at least an area considerably
larger than the irradiated one.  The material and thickness of the
liquid film should be chosen to be transparent to laser radiation.
The thickness of the liquid film is selected such that at the desired
laser fluence, the entire liquid film is removed from the irradiated
surfac...