| 摘要 |
PROBLEM TO BE SOLVED: To provide an electrostatic chuck which attracts an insulating substrate independently of its type. SOLUTION: When a voltage is applied so as to make electrodes 9 and 10 opposite to each other in polarity, an irregular electric field is generated between the electrodes 9 and 10 to generate a gradient force (F) attracting a glass substrate W. At this point, when the width W of the electrodes and a distance g between the electrodes 9 and 10 are set smaller, the irregular electric field can be generated by a small applied voltage but becomes small in area, so that a problem, wherein the glass substrate where a conductive film is formed can be attracted but the glass substrate where no conductive film is formed can not be attracted, is generated. When a dielectric layer 8 is made too thick, a problem, wherein an irregular electric field is not formed on the front surface of the dielectric layer 8, and an attractive power can not be displayed, is generated, and when the dielectric layer 8 is made too thin, a problem wherein the dielectric layer 8 becomes low in durability. Then, the distance g between the electrodes 9 and 10 is set at 0.5 to 2.0 mm, and the width W of the electrodes is set at 1.0 to 4.0 mm. The thickness of the dielectric layer 8 is set at 0.2 to 2.0 mm, and furthermore the volume resistivity of the dielectric layer 8 is set at 10<SP>15</SP>Ω-cm or above so as to prevent an abnormal electric discharge. COPYRIGHT: (C)2006,JPO&NCIPI |
