US Patent 7944677 Electrostatic chuck

An electrostatic chuck includes a dielectric board having an upper surface on which a plurality of projections for supporting a substrate on top surfaces and recesses surrounding the projections are formed, an electrode formed inside the dielectric board, and an external power supply which applies a voltage to the electrode. The dielectric board includes a conductor film formed on at least the top surface of each projection, and has a three-dimensional structure which causes the conductor film to generate a Johnson-Rahbeck force between the substrate and conductor film when a voltage is applied to the electrode.