Fluid bearing vacuum seal assembly

An ion implanter comprising:

• an ion beam generator to generate a beam of ions to be implanted;
• a process chamber into which the ion beam is directed;
• an annular stator mounted upon the process chamber, said stator having first and second opposed surfaces, at least part of said first surface defining a first bearing surface and said stator also defining an aperture having a wall extending between said first and second surfaces;
• a rotor having first and second opposed surfaces, the second surface defining in part a second bearing surface supported relative to said first bearing surface so that the rotor is rotatable relative to said stator;
• a cylindrical wall projecting axially from said second surface of said rotor through said aperture defined by said stator;
• an annular flange projecting radially outwardly from said cylindrical wall adjacent said second surface of said stator;
• and
• at least one annular channel defined in each of said first and second surfaces of said stator and said wall of said stator.

A fluid bearing vacuum seal assembly comprising:

• an annular stator having first and second opposed surfaces, at least part of said first surface defining a first bearing surface, said stator also defining an aperture having a wall extending between the first and second opposed surfaces;
• a rotor having first and second opposed surfaces, said second surface defining in part a second bearing surface supported relative to said first bearing surface in use so that the rotor is rotatable relative to said stator;
• means projecting axially from said second surface of said rotor through said aperture adjacent said wall stator and projecting radially outwardly adjacent said second surface of said stator, said means defining an extension of said second surface of said rotor;
• and
• at least one annular differential pumping channel defined in each of said first and second surfaces of said stator and said wall of said stator.