| 摘要 |
PURPOSE:To correct a sample in a desired flatness by equalizing the potential of a part of a sample holding face composed of a conductive substance to a potential of high or low voltage side to increase an attraction force without necessity of altering an electrode area, a permittivity and an applying voltage. CONSTITUTION:An electrode 3 of high (or low) voltage side and an electrode 4 of low (or high) voltage side are disposed on the same flat face of the top of an electrostatic chuck body 6. An insulatively dielectric layer 2 covering the electrode 3, a conductive material 5 covering the electrode 4, a DC power supply 7 connected between the electrodes 3 and 4, and an insulator 8 having sufficiently low permittivity than an insulator for forming the dielectric layer are provided. With this construction, when a voltage V is applied between the electrodes 3 and 4, the potential of a semiconductor wafer 1 becomes 0V, an attraction force F becomes a function of the voltage V, the thickness (d) and the permittivity epsilon1 of the dielectric layer to generate an attraction force as large as twice. That is, it does not receive a force from a sample holding face equi-potential thereto, but the potential difference which contributes to an electrostatic attraction force by square becomes double as large as a conventional one. Thus, a sample having a large warpage can be held in a preferable flatness state by the large attraction force. |
