An electrostatic adsorption member includes a dielectric member having a first surface and a second surface opposite to the first surface and formed with a through-hole penetrating from the first surface to the second surface, and a porous body provided in the through-hole and having a third surface flush with the first surface. The through-hole has a first opening apart from the first surface by a first distance in a first direction perpendicular to the first surface, and a second opening apart from the first surface by a second distance larger than the first distance in the first direction. In a plan view from the first direction, at least a portion of the first opening is inside the second opening, and the porous body has a first portion located inside the first opening, and a second portion connected to the first portion and located outside the first opening.

An electrostatic adsorption member includes a dielectric member having a first surface and a second surface opposite to the first surface and formed with a through-hole penetrating from the first surface to the second surface, and a porous body provided in the through-hole and having a third surface flush with the first surface. The through-hole has a first opening apart from the first surface by a first distance in a first direction perpendicular to the first surface, and a second opening apart from the first surface by a second distance larger than the first distance in the first direction. In a plan view from the first direction, at least a portion of the first opening is inside the second opening, and the porous body has a first portion located inside the first opening, and a second portion connected to the first portion and located outside the first opening.

This disclosure describes systems, methods, and apparatus for non-invasive wafer chuck monitoring using a low voltage AC signal injected into a high voltage DC chucking voltage provided to a wafer chuck. Monitoring the injected signal can provide insight into the wafer chucking state and remedial actions, such as realignment of the wafer with the wafer chuck, can be carried out. Because of the low voltage nature of the AC signal, wafer chuck monitoring can be performed without influencing chucking performed by the higher voltage DC chucking voltage.

This disclosure describes systems, methods, and apparatus for non-invasive wafer chuck monitoring using a low voltage AC signal injected into a high voltage DC chucking voltage provided to a wafer chuck. Monitoring the injected signal can provide insight into the wafer chucking state and remedial actions, such as realignment of the wafer with the wafer chuck, can be carried out. Because of the low voltage nature of the AC signal, wafer chuck monitoring can be performed without influencing chucking performed by the higher voltage DC chucking voltage.

An electrostatic chuck of an embodiment includes a base, a dielectric layer, and a chuck main body. The dielectric layer is provided on the base, and is fixed to the base. The chuck main body is mounted on the dielectric layer. The chuck main body has a ceramic main body, a first electrode, a second electrode, and a third electrode. The ceramic main body has a substrate mounting region. The first electrode is provided in the substrate mounting region. The second electrode and the third electrode form a bipolar electrode. The second electrode and the third electrode are provided in the ceramic main body, and are provided between the first electrode and the dielectric layer.

An electrostatic chuck of an embodiment includes a base, a dielectric layer, and a chuck main body. The dielectric layer is provided on the base, and is fixed to the base. The chuck main body is mounted on the dielectric layer. The chuck main body has a ceramic main body, a first electrode, a second electrode, and a third electrode. The ceramic main body has a substrate mounting region. The first electrode is provided in the substrate mounting region. The second electrode and the third electrode form a bipolar electrode. The second electrode and the third electrode are provided in the ceramic main body, and are provided between the first electrode and the dielectric layer.

Disclosed is an object table for holding an object, comprising: an electrostatic clamp arranged to clamp the object on the object table; a neutralizer arranged to neutralize a residual charge of the electrostatic clamp; a control unit arranged to control the neutralizer, wherein the residual charge is an electrostatic charge present on the electrostatic clamp when no voltage is applied to the electrostatic clamp.

Disclosed is an object table for holding an object, comprising: an electrostatic clamp arranged to clamp the object on the object table; a neutralizer arranged to neutralize a residual charge of the electrostatic clamp; a control unit arranged to control the neutralizer, wherein the residual charge is an electrostatic charge present on the electrostatic clamp when no voltage is applied to the electrostatic clamp.

An apparatus, methods and controllers for electrostatically chucking varied substrate materials are disclosed. Some embodiments of the disclosure provide electrostatic chucks with variable polarity and/or voltage. Some embodiments of the disclosure provide electrostatic chucks able to operate as monopolar and bipolar electrostatic chucks. Some embodiments of the disclosure provide bipolar electrostatic chucks able to compensate for substrate bias and produce approximately equal chucking force at different electrodes.

An apparatus, methods and controllers for electrostatically chucking varied substrate materials are disclosed. Some embodiments of the disclosure provide electrostatic chucks with variable polarity and/or voltage. Some embodiments of the disclosure provide electrostatic chucks able to operate as monopolar and bipolar electrostatic chucks. Some embodiments of the disclosure provide bipolar electrostatic chucks able to compensate for substrate bias and produce approximately equal chucking force at different electrodes.