Displacement device, lithographic apparatus and positioning method

摘要

A displacement device with a first and second part which are displaceable relative to one another, the first part being provided with a system of magnets, the second part being provided with a set of coil block units including: at least three first coil block units having current conductors oriented parallel to a second direction, at least two second coil block units having current conductors oriented parallel to a first direction, wherein the displacement device includes a controller configured to control the position of the second part relative to the first part, and wherein when the second part mainly moves in the second direction the controller is configured to levitate the second part from the first part in the third direction by using first coil block units only.

主权项

1. A displacement device comprising:
a first part and a second part, wherein the second part is displaceable relative to the first part in a first direction, a second direction substantially perpendicular to the first direction, and a third direction substantially perpendicular to both the first and second direction, the first part comprising a carrier that extends substantially parallel to the first and second direction and on which a system of magnets is arranged in accordance with a pattern, wherein the system of magnets includes first magnets having a magnetization direction substantially perpendicular to the carrier and directed towards the second part and second magnets having a magnetization direction substantially perpendicular to the carrier and directed away from the second part, the first and second magnets being arranged in accordance with a pattern of rows and columns substantially perpendicular thereto and enclosing an angle of approximately 45° with one of the first or second direction, such that the first magnets and the second magnets are arranged in each row and in each column alternately, wherein the second part includes an electric coil system having a set of coil block units, each coil block unit having current conductors that are arranged in a magnetic field of the system of magnets and are, in use, fed by a multi-phase system, wherein the set of coil block units comprises at least three first coil block units having current conductors oriented substantially parallel to the second direction, the at least three first coil block units spaced apart from each other along the first direction or the second direction or both the first and the second direction; at least two second coil block units having current conductors oriented substantially parallel to the first direction, and wherein the displacement device comprises a controller configured to control the position of the second part relative to the first part by driving the coil block units with the multi-phase system, wherein when the second part mainly moves in the second direction the controller is configured to levitate the second part from the first part in the third direction by using first coil block units only.