Ngk Insulators, Inc.

Takuya Yanoh

Hideyoshi Tsuruta

Tetsuya Kawajiri

Kengo Torii

Kazuma Ohba

A wafer holding table includes a ceramic electrostatic chuck, a metal cooling plate, a resin layer having predetermined thermal resistance, and a stress relaxation layer having lower Young's modulus than the resin layer. The resin layer and the stress relaxation layer are disposed between the electrostatic chuck and the cooling plate. The resin layer is disposed closer to the electrostatic chuck, and the stress relaxation layer is disposed closer to the cooling plate. The resin layer has a multilayer structure including a plurality of resin sheets laminated one on another. The resin layer is thinner than a comparative sample with a single-layer structure made of a material identical to a material of the resin sheet and having thermal resistance identical to thermal resistance of the resin layer.

Wafer holding table

A wafer holderincludes a resin adhesive layerbetween a ceramic electrostatic chuckand a metal cooling plate. The adhesive layerincludes a first layerin contact with the electrostatic chuck, a second layerin contact with the cooling plate, and an intermediate layerlocated between the first layerand the second layer. Heat resistance of each of the first layerand the intermediate layeris higher than heat resistance of the second layer, flexibility of the second layeris higher than flexibility of each of the first layerand the intermediate layer, and the layers are in hermetic contact with each other.

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Handa, Japan

Takuya Yanoh