Positioning device, lithographic apparatus and device manufacturing method

A positioning device configured to position an object, the positioning device comprising:

• an object table configured to hold the object;
• a positioning module configured to position the object table, the positioning module comprising a top module and a bottom module;
• the top module comprising:
• a first top module member configured to hold the object table;
• a second top module member configured to co-operate with the first op module member to generate a first force on the object table;
• the bottom module comprising:
• at least one actuator;
• a first bottom module member onto which the second top module member is displaceably mounted by means of the at least one actuator;
• at least one actuator being configured to displace move the second top module member in a vertical direction relative to the first bottom module member;
• a second bottom module member configured to support the first bottom module member and to co-operate with the first bottom module member to generate a second force on the first top module member;
• a support frame configured to support the second bottom module member;
• a position measurement system configured to measure a position of the object table with respect to a reference frame;
• a control unit configured to control a position of the object table by providing an object table control signal to the positioning module to generate the first force and the second force, based on the measured position of the object table and a set point for the object table;
• wherein the control unit is further configured to control a vertical position of the second top module member by providing an actuator control signal to the at least one actuator, in order to maintain the second top module member within the operating range of the first top module member in the vertical direction.

A lithographic apparatus comprising:

• an illumination system configured to condition a radiation beam;
• a support constructed to support a patterning device, the patterning device being capable of imparting a pattern to a cross-section of the radiation beam to form a patterned radiation beam;
• a substrate table constructed to hold a substrate;
• and
• a projection system configured to project the patterned radiation beam onto a target portion of the substrate, wherein the lithographic apparatus further comprises a positioning device, the positioning device comprising a positioning module configured to position the object table, the positioning module comprising
• a first positioning module member configured to hold the object table,
• a second positioning module member configured to support the first positioning module member and to co-operate with the first positioning module member to generate a first force,
• a support frame configured to support the second positioning module member,
• at least one actuator configured to displace the second positioning module member in a vertical direction relative to the support frame,
• a position measurement system configured to measure a position of the object table with respect to a reference frame, and
• a control unit configured to control a position of the object table by providing an object table control signal to the positioning module to generate the first force, based on the measured position of the object table and a set point for the object table;
• wherein the control unit is further configured to control a vertical position of the second position module member by providing an actuator control signal to the at least one actuator, so as to maintain a top surface of the second positioning module member substantially parallel to a bottom surface of the first positioning module member.

A method of manufacturing a device, the method comprising the steps of:

• providing a positioning device comprising a positioning module configured to position the object table, the positioning module comprising a first positioning module member configured to hold the object table, a second positioning module member configured to support the first positioning module member and to co-operate with the first positioning module member to generate a first force, a support frame configured to support the second positioning module member, at least one actuator configured to displace the second positioning module member in a vertical direction relative to the support frame, a position measurement system configured to measure a position of the object table with respect to a reference frame, and a control unit configured to control a position of the object table by providing an object table control signal to the positioning module to generate the first force, based on the measured position of the object table and a set point for the object table, wherein the control unit is further configured to control a vertical position of the second position module member by providing an actuator control signal to the at least one actuator, so as to maintain a top surface of the second positioning module member substantially parallel to a bottom surface of the first positioning module member;
• using the positioning device to position a substrate to a position at which a patterned beam of radiation may be projected;
• projecting the patterned beam of radiation onto the substrate.