Surface processing apparatus

Abstract

This surface processing apparatus has a reactor in which plasma is generated and a substrate whose surface is to be processed by the plasma is arranged, and a magnet plate for creating a point-cusp magnetic field distributed in an inner space of the reactor, in which the plasma is generated. The magnet plate has a plurality of magnets. These magnets are arranged by a honeycomb lattice structure in a circular plane facing in parallel a surface of the substrate. One magnetic pole end face of each of magnets is arranged at a position of each of the lattice points forming hexagonal shapes on the circular plane. The polarities of the magnetic pole end faces of two adjoining magnets are arranged to become opposite alternately. The magnet plate may be provided with a plurality of magnets arranged by a lattice structure forming a square and the magnetic force (coercive force) of some of the magnets arranged at the outermost region is reduced. Thereby, the periodicity of the point-cusp magnetic field in the inside space is maintained as much as possible even at the peripheral edge and the asymmetry of the distribution of the magnetic field at the region where the periodicity is disturbed at the peripheral edge is reduced.

1 . A magnetic plate used in a plasma processing apparatus for processing a surface of a substrate using plasma, disposed in parallel to the surface of substrate, and provided with a plurality of magnets, 
 wherein,    said plurality of magnets is disposed so that one magnetic pole end of each of said magnets is arranged at a position of each of a plurality of lattice points on said magnetic plate, polarities of said magnetic pole ends of two adjoining magnets are arranged to become opposite, and a length of magnets disposed in an outermost region of said magnetic plate, in a direction perpendicular to said magnetic plate, is shorter than a length of magnets disposed in the center region of said magnetic plate in said direction.    
   
   
       2 . A magnetic plate as set forth in  claim 1 , wherein said lattice points are those forming a square shape.  
   
   
       3 . A magnetic plate as set forth in  claim 1 , wherein said lattice points are those forming a regular hexagonal shape.  
   
   
       4 . A magnetic plate as set forth in  claim 2 , wherein short length magnets are attached so that their magnetic pole end are positioned at the same heights as the magnetic pole of other said magnets.  
   
   
       5 . A magnetic plate as set forth in  claim 1 , wherein at least two magnets are arranged at positions of each of said lattice points.