Method and apparatus for cleaning surfaces

Abstract

This invention relates to a method and apparatus for cleaning solid surfaces like Si substrate, disk or magnetic head slider where contaminants, including organic contaminants, especially particles in the micron or sub-micron scale are effectively remove from the solid surfaces. The invention achieves this by generating a strong laser-induced liquid jet and shock wave near the solid surfaces immersed in liquid. The liquid is a solution of water and other solvents to help reduce adhesion force and enhance cleaning efficiency.

1 . An apparatus, for cleaning a surface, comprising: 
 a laser beam source;    an optical system for focusing a laser beam generated by the laser beam source, wherein the laser beam is focused at a point in a liquid to create jet and shock wave in the liquid to clean the surface.    
     
     
         2 . The apparatus of  claim 1 , wherein the laser beam is focused proximate to the surface to be cleaned.  
     
     
         3 . The apparatus of  claim 2 , wherein the laser beam is focused in a range from 0.1 mm to 10 cm close to the surface.  
     
     
         4 . The apparatus of  claim 1 , further comprises a stage for holding the surface in position for cleaning.  
     
     
         5 . The apparatus of  claim 4 , wherein the stage is to move the surface into and out of the liquid.  
     
     
         6 . The apparatus of  claim 4 , wherein the surface can be immersed fully or partially in the liquid by the stage.  
     
     
         7 . The apparatus of  claim 6 , wherein the stage can move the surface in a horizontal direction in the liquid.  
     
     
         8 . The apparatus of  claim 6 , wherein the stage can move the surface in a vertical direction in the liquid.  
     
     
         9 . The apparatus of  claim 7 , wherein the stage can move the surface in a vertical direction.  
     
     
         10 . The apparatus of  claim 1 , wherein the surface is formed of one of a group consisting a Si substrate, a disk, and a magnetic head slider.  
     
     
         11 . The apparatus of  claim 1 , further comprising a filter system for filtering particles from the liquid.  
     
     
         12 . The apparatus of  claim 1 , wherein the laser beam source has a pulse duration in the range from 1 nanosecond to 100 microseconds.  
     
     
         13 . The apparatus of  claim 1 , wherein the laser beam source is one of a group consisting of YAG laser, an excimer laser and CO 2  laser.  
     
     
         14 . The apparatus of  claim 12 , wherein the laser beam from the laser beam source has a laser fluence in the range of 0.5 J/cm 2  to 100J/cm 2 .  
     
     
         15 . The apparatus of  claim 12 , wherein the laser beam has a wavelength in the range from 157 nm to 10.6 μm.  
     
     
         16 . The apparatus of  claim 13 , wherein the laser beam has a frequency range from 1 Hz to 10 kHz.  
     
     
         17 . The apparatus of  claim 13 , wherein the laser beam has a pulse number from 1 to 10000 for cleaning a position.  
     
     
         18 . The apparatus of  claim 1 , further comprising a gas blower to dry the cleaned surface.  
     
     
         19 . The apparatus of  claim 1 , further comprises a container to hold the liquid.  
     
     
         20 . The apparatus of  claim 1 , wherein the liquid is to reduce adhesion forces of particles on the surface to be cleaned and enhance cleaning efficiency.  
     
     
         21 . The apparatus of  claim 20 , wherein the liquid is pure water.  
     
     
         22 . The apparatus of  claim 20 , wherein the liquid is a mixture of water and a solvent.  
     
     
         23 . The apparatus of  claim 22 , wherein the solvent is one of a group consisting alcohols, aromatics, ethers, ketones, alkanes, halogenated hydrocarbons and commercial washing solution.  
     
     
         24 - 47 . (Cancelled)