Method of and apparatus for eluting impurities

An apparatus for eluting impurities, comprising:

• a supporting unit including a substrate support configured to support a substrate in the apparatus with a surface of the substrate exposed;
• a sample plate having a plurality of holes therethrough, said sample plate and said substrate support being movable relative to each other in the apparatus such that said sample plate can be positioned on the surface of a substrate supported by said substrate support, whereby said holes are disposed over local areas of the surface of the substrate, respectively;
• and
• a cleaning unit that cleans the sample plate, said cleaning unit disposed adjacent said supporting unit;
• a first transfer robot having a working envelope that encompasses said cleaning unit and said supporting unit, said first transfer robot being operable to move said sample plate between the cleaning unit and the supporting unit;
• an eluant supply system that supplies eluant into the holes in said plate, wherein impurities at the local areas of the surface of the substrate are dissolved by the eluant to produce a sample by which the impurities can be identified, said eluant supply system including at least one nozzle, and a source of eluant connected to said at least one nozzle;
• a sample cup tray, and a plurality of sample cups supported by said tray;
• a second transfer robot to which said at least one nozzle is connected, said transfer robot having a working envelope encompassing said substrate support so as to be operable to move the nozzle between the supporting unit and the sample cup tray;
• and
• an air pressure control unit that can selectively produce a vacuum and air pressure, said air pressure control unit being connected to said at least one nozzle so that said at least one nozzle can collect solution from the local areas of the surface of the substrate through the plurality of the holes of the sample plate and transfer the solution to the sample cups.

A method of identifying impurities in a substrate, said method comprising:

• supporting the substrate such that an upper surface of the substrate is exposed;
• placing a sample plate having a plurality of holes on the substrate such that the holes expose local areas of the upper surface of the substrate, respectively;
• subsequently dispensing eluant into the holes of the sample plate and thereby onto the local areas of the upper surface of the substrate to thereby elute impurities present at the surface of the substrate and produce a sample containing the impurities;
• extracting the sample from the holes of the sample plate;
• and
• subsequently analyzing the sample.