Apparatus for contamination removal using magnetic particles

Abstract

Methods and apparatus are provided for cleaning a substrate (e.g., wafer) in the fabrication of semiconductor devices utilizing a composition of magnetic particles dispersed within a base fluid to remove contaminants from a surface of the substrate.

1 . An apparatus for cleaning a substrate, the apparatus comprising:
 a containment vessel for receiving and containing a fluid composition therein;   a substrate support configured to hold a substrate, the substrate comprising a semiconductor device structure;   a source of the fluid composition, the fluid composition comprising magnetic particles having functional reactive groups formulated to conjugate with contaminants on the substrate; and   at least one magnetic field generator configured to generate a sufficient magnetic field to draw contaminant-conjugated magnetic particles from the substrate without causing damage to the semiconductor device structure.   
     
     
         2 . The apparatus of  claim 1 , wherein the at least one magnetic field generator comprises a plurality of magnetic field generators. 
     
     
         3 . The apparatus of  claim 1 , wherein the at least one magnetic field generator comprises a plurality of magnetic field generators situated on opposing sides of the containment vessel. 
     
     
         4 . The apparatus of  claim 2 , wherein the plurality of magnetic field generators at least partially surround the containment vessel. 
     
     
         5 . The apparatus of  claim 2 , wherein the plurality of magnetic field generators are situated at a plurality of positions surrounding the containment vessel. 
     
     
         6 . The apparatus of  claim 1 , wherein the at least one magnetic field generator is situated beneath a base of the containment vessel. 
     
     
         7 . The apparatus of  claim 2 , wherein the at least one magnetic field generator is positioned above the containment vessel. 
     
     
         8 . The apparatus of  claim 2 , wherein the at least one magnetic field generator is movable about the containment vessel. 
     
     
         9 . The apparatus of  claim 1 , wherein the containment vessel comprises an outlet for discharging a fluid composition therefrom. 
     
     
         10 . The apparatus of  claim 9 , further comprising a magnetic field generator situated proximal to the outlet of the containment vessel. 
     
     
         11 . The apparatus of  claim 1 , wherein the at least one magnetic field generator is in communication with a controller comprising a computer device configured under control of a program to control the magnetic field. 
     
     
         12 . An apparatus for cleaning a substrate, the apparatus comprising:
 a substrate support configured to hold a substrate comprising protruding structures with a recess therebetween;   a containment vessel for receiving and containing a fluid composition therein;   a source of the fluid composition, the fluid composition comprising magnetic particles having functional reactive groups formulated to conjugate with contaminants on the substrate; and   a magnetic field generator configured to laterally move contaminant-conjugated magnetic particles in a single direction across the substrate and substantially parallel to the protruding structures.   
     
     
         13 . The apparatus of  claim 12 , further comprising a dispensing device for applying the fluid composition to the substrate. 
     
     
         14 . The apparatus of  claim 12 , wherein the containment vessel comprises an inlet and an outlet for passage of the fluid composition into and out of the containment vessel. 
     
     
         15 . The apparatus of  claim 12 , further comprising an insulator between the magnetic field generator and the containment vessel or the substrate to shield the substrate from a magnetic field generated by the magnetic field generator. 
     
     
         16 . The apparatus of  claim 12 , wherein the magnetic field generator is incorporated into the containment vessel. 
     
     
         17 . An apparatus for cleaning a substrate, the apparatus comprising:
 a substrate support configured to hold a substrate comprising semiconductor structures in linear arrays;   a containment vessel for receiving and containing a fluid composition therein;   a source of the fluid composition, the fluid composition comprising magnetic particles having functional reactive groups configured to conjugate with contaminants on the substrate; and   a magnetic field generator perpendicular to the linear arrays of semiconductor structures, the magnetic field generator configured to move contaminant-conjugated magnetic particles in a lateral direction parallel to the linear arrays of semiconductor structures.   
     
     
         18 . The apparatus of  claim 17 , wherein the magnetic field generator is configured to laterally move contaminant-conjugated magnetic particles without damaging the semiconductor structures. 
     
     
         19 . The apparatus of  claim 17 , further comprising:
 an outlet for discharging the fluid composition; and   a collection device within or proximal to the outlet to isolate and collect the magnetic particles and the contaminant-conjugated magnetic particles.   
     
     
         20 . The apparatus of  claim 17 , further comprising a device for applying a dilute ammonium hydroxide/hydrogen peroxide (SC1) solution or a dilute hydrofluoride solution to the substrate.