X-ray transfer device

Abstract

Abstract PURPOSE:To prevent the occurrence of camber of the wafer, by providing a vacuum adsorption hole to fix the wafer on the material stand and by exhausting air of the adsorption hole with two or more different pressures when the wafer is fixed. CONSTITUTION:For suction of wafer 5 to materials stand 7, when the same suction force is given to adsorption holes A, B and C, wafer 5 is not sucked in respective positions by the same force because one adsorption hole exists in the center and plural ring-form adsorption holes exist around the center. Therefore, wafer 5 is concaved partially to have a complicated pressure distribution. A pressure regulator is provided and pressure of adsorption holes A, B and C is controlled to C<B<A to adsorb wafer 5 for the purpose of preventing this complicated pressure distribution, and therefore, the occurrence of camber and sag of wafer 5 is reduced. In the actual measurement, the camber quantity is reduced to the 1/5 of the conventional quantity approximately.

Inventors

• 👤 Masahiro Okabe
• 👤 Yoshitaka Kitamura

Bibliographic Details