Planar motor device, stage unit, exposure apparatus and its making method, and device and its manufacturing method

Claims

What is claimed is:

1. A planar motor device comprising:

an armature unit including a plurality of armature coils arranged in a matrix shape along a guide surface, which have a rectangular current path; and

a magnetic pole unit arranged opposing said armature unit with respect to said guide surface, which has a plurality of thrust generating magnets having a rectangular magnetic pole surface with a side length longer than an arrangement period of said armature coil and is not equal to an integral multiple of said arrangement period, said plurality of thrust generating magnets arranged in a matrix shape in an arrangement period of an integral multiple of said arrangement period of said armature coils and having a different adjacent polarity of said magnetic pole surface in a row direction and a column direction, and

said armature unit and said magnetic pole unit relatively move in a direction along the guide surface.

2. A planar motor device according to claim 1, said magnetic pole unit further comprising an interpolating magnet arranged on a magnetic flux path formed on a magnetic pole surface side of said thrust generating magnet opposing said armature unit, said path formed between said thrust generating magnets which are adjacent in said row direction and said column direction, said interpolating magnet being a part of a magnetic circuit, and reinforcing a magnetomotive force.

3. A planar motor device according to claim 1, wherein said thrust generating magnets are arranged in a shape of a two-by-two matrix.

4. A planar motor device according to claim 1, wherein an external shape of a surface of said armature coil which opposes said magnetic pole unit is a square, and said magnetic pole surface of said thrust generating magnets is of a square shape.

5. A planar motor device according to claim 4, wherein

a current path length on an outer side of said armature coil is respectively around 3 times longer than a current path on an inner side,

a magnetic pole surface length of one side of said thrust generating magnets is respectively 4 to 5 times longer than said current path on the inner side, and

said arrangement period of said thrust generating magnets is around 6 times longer than said current path on the inner side.

6. A planar motor device according to claim 1, further comprising a first magnetic member to support said armature coils at a side opposite to said magnetic pole unit.

7. A planar motor device according to claim 1, further comprising a second magnetic member to support said thrust generating magnets at a side opposite to said armature unit.

8. A planar motor device according to claim 1, further comprising at least one guide member arranged between said armature unit and said magnetic pole unit which is made of a material non-magnetic and non-conductive and forms the guide surface.

9. A planar motor device according to claim 8, further comprising a supporting member attached to said magnetic pole unit and has a first vent portion to exhaust a pressurized gas to said guide surface, said supporting member being adapted to support said magnetic pole unit by air levitation via a predetermined air gap.

10. A planar motor device according to claim 9, further comprising a base which includes said guide member and forms a closed space in its interior where said plurality of armature coils are arranged.

11. A planar motor device according to claim 10, further comprising a cooling device which supplies a coolant to said closed space and cools said armature coils.

12. A planar motor device according to claim 9, further comprising a plurality of cases which respectively house said plurality of armature coils.

13. A planar motor device according to claim 12, further comprising a cooling device to respectively cool an interior of said plurality of cases.

14. A planar motor device according to claim 12, wherein an upper surface of said cases respectively structure said guide surface.

15. A planar motor device according to claim 8, further comprising a base which includes said guide member and forms a closed space in its interior where said plurality of armature coils are arranged.

16. A planar motor device according to claim 15, further comprising a cooling device which supplies a coolant to said closed space and cools said armature coils.

17. A planar motor device according to claim 8, further comprising a plurality of cases which respectively house said plurality of armature coils.

18. A planar motor device according to claim 17, further comprising a cooling device to respectively cool an interior of said plurality of cases.

19. A planar motor device according to claim 17, wherein an upper surface of said cases respectively structure said guide surface.

20. A planar motor device comprising:

an armature unit including a plurality of armature coils arranged in a matrix shape along a guide surface, which have a rectangular current path; and

a magnetic pole unit arranged opposing said armature unit with respect to said guide surface including

a plurality of thrust generating magnets which have a rectangular magnetic pole surface and are arranged so as to have a different polarity of an adjacent magnet pole surfaces alternately, and

an interpolating magnet to reinforce a magnetomotive force, which is arranged on a magnetic flux path formed on a magnetic pole surface side of said thrust generating magnet opposing said armature unit, said path formed between said thrust generating magnets which are adjacent, and

said armature unit and said magnetic pole unit relatively move in a direction along the guide surface.

21. A planar motor device according to claim 20, wherein an external shape of a surface of said armature coil which opposes said magnetic pole unit is a square, and said magnetic pole surface of said thrust generating magnets is of a square shape.

22. A planar motor device according to claim 21, wherein

a current path length on an outer side of said armature coil is respectively around 3 times longer than

a current path on an inner side, a magnetic pole surface length of one side of said thrust generating magnets is respectively 4 to 5 times longer than said current path on the inner side, and

said arrangement period of said thrust generating magnets is around 6 times longer than said current path on the inner side.

23. A planar motor device according to claim 20, further comprising a first magnetic member to support said armature coils at a side opposite to said magnetic pole unit.

24. A planar motor device according to claim 20, further comprising a second magnetic member to support said thrust generating magnets at a side opposite to said armature unit.

25. A planar motor device according to claim 20, further comprising at least one guide member arranged between said armature unit and said magnetic pole unit which is made of a material non-magnetic and non-conductive and forms the guide surface.

26. A planar motor device according to claim 25, further comprising a supporting member attached to said magnetic pole unit and has a first vent portion for exhausting a pressurized gas to said guide surface, said supporting member being adapted to support said magnetic pole unit by air levitation via a predetermined air gap.

27. A planar motor device according to claim 25, further comprising a base which includes said guide member and forms a closed space in its interior where said plurality of armature coils are arranged.

28. A planar motor device according to claim 27, further comprising a cooling device which supplies a coolant to said closed space and cools said armature coils.

29. A planar motor device according to claim 25, further comprising a plurality of cases which respectively house said plurality of armature coils.

30. A planar motor device according to claim 29, further comprising a cooling device to respectively cool an interior of said plurality of cases.

31. A planar motor device according to claim 29, wherein an upper surface of said cases respectively structure said guide surface.

32. A planar motor device comprising:

a magnetic pole unit which has at least one magnet and moves along a predetermined guide surface in two-dimensional directions;

a supporting member attached to said magnetic pole unit and has a first vent portion to exhaust a pressurized gas to said guide surface, said supporting member being adapted to support said magnetic pole unit by air levitation via a predetermined gap;

a stator including a plurality of armature coils arranged at a side opposite to said magnetic pole unit in respect to a guide surface in two-dimensional directions along said guide surface;

an interferometer system configured to detect a position of said magnetic pole unit; and

a controller connected to said plurality of armature coils and said interferometer system to move said magnetic pole unit in a first linear direction and a second linear direction, said controller controlling said plurality of armature coils in accordance with the detected position of said magnetic pole unit so as to prevent a movement of said magnetic pole unit in a rotative direction on its axis of said magnetic pole unit.

33. A planar motor device according to claim 32, wherein said magnetic pole unit is freely attachable to and detachable from and said supporting member.

34. A planar motor device according to claim 33, wherein said supporting member has an attachment/detachment mechanism to have said magnetic pole unit attached and detached.

35. A planar motor device according to claim 34, wherein said supporting member comprises a second vent portion which exhausts a pressurized gas to said magnetic pole unit so as to support said magnetic pole unit by air levitation against a downward force when said magnetic pole unit is attached to said supporting member, said downward force acting in a direction of gravity and is a sum of a magnetic attraction force of said magnetic pole unit, said armature coil, and said stator and a weight of said magnetic pole unit itself.

36. A planar motor device according to claim 35, wherein said supporting member further comprises a switching mechanism which switches an exhaustion of a gas between an exhaustion of a pressurized gas from said first vent portion and an exhaustion of a pressurized gas from said second vent portion.

37. A planar motor device according to claim 32, wherein said supporting member further comprises a suction portion to vacuum chuck said supporting member to said guide surface, said supporting member being able to control a dimension of said predetermined air gap by adjusting an exhaustion pressure of said pressurized gas released from said first vent portion and a vacuum suction force of said suction portion.

38. A planar motor device according to claim 32, further comprising a base which forms said guide surface as well as form a closed space in its interior where said plurality of armature coils are arranged.

39. A planar motor device according to claim 38, further comprising a cooling device which supplies a coolant to said closed space and cools said armature coils.

40. A planar motor device according to claim 32, further comprising a plurality of cases which respectively house said plurality of armature coils.

41. A planar motor device according to claim 40, further comprising a cooling device to respectively cool an interior of said plurality of cases.

42. A planar motor device according to claim 40, wherein an upper surface of said cases respectively structure said guide surface.

43. A planar motor device comprising:

a magnetic pole unit which has at least one magnet and moves along a predetermined guide surface in two-dimensional directions;

a base which forms said guide surface and has a closed space formed in its interior;

an armature unit including a plurality of armature coils housed in said closed space of said base which are arranged in two-dimensional directions along said guide surface at predetermined intervals; and

a cooling device which supplies a coolant into said closed space to respectively cool said armature coils, wherein

said closed space formed within said base is divided into a plurality of small chambers which respectively house said armature coils,

said plurality of small chambers respectively have an inlet opening and an outlet opening to supply said coolant from said cooling device,

said small chambers were respectively structured of a plate-shaped member arranged at a side opposite to said guide surface of said plurality of armature coils, and a plurality of box-shaped cases which respectively have an opening on a surface opposing said plate-shaped member and have an opposite side of said surface formed as the guide surface, and

an inlet opening and an outlet opening to respectively supply a coolant to said small chambers are formed in said plate-like member in respect to said plurality of cases.

44. A planar motor device according to claim 43, wherein

said closed space is divided by a dividing member arranged on an opposite side to said guide surface of said plurality of armature coils into a first chamber where said plurality of armature coils are housed, and a second chamber formed by a remaining space, and

an inlet opening and an outlet opening are respectively formed in said dividing member, and

a coolant path is formed in said base in which a coolant supplied from said cooling device flows into said first chamber via said inlet opening and then flows out to said second chamber via said outlet opening.

45. A planar motor device according to claim 44, further comprising secondary cooling fins respectively made of a high thermal conductive material and arranged on said path of said coolant which flows out through said outlet opening.

46. A planar motor device according to claim 43, further comprising a plate-shaped non-magnetic member which serves as said guide surface and is arranged so as to cover said plurality of small chambers.

47. A planar motor device according to claim 43, wherein terminals of said armature coils are exposed from an open end of said case, and a socket portion where said terminal is fitted is provided in a corresponding part of said plate-shaped member.

48. A planar motor device according to claim 43, wherein an additional chamber is arranged in an opposite side to said guide surface of said small chambers within said base, and

a coolant path is formed in said base in which a coolant supplied from said cooling device flows into said case respectively via said inlet opening and then flows out to said additional chamber via said outlet opening.

49. A planar motor device according to claim 43, further comprising secondary cooling fins respectively made of a high thermal conductive material and arranged on said path of said coolant which flows out through said outlet opening.

50. A planar motor device according to claim 43, wherein

said armature coils are respectively a ring-shaped coil with a space formed in its central portion, and

said cooling device supplies said coolant to each of said armature coils via said space formed in its central portion from an opposite side of said guide surface of said armature coils.

51. A planar motor device according to claim 50, further comprising straightening fins to regulate a path of said coolant which flows from said space formed in its central portion to its surroundings.

52. A planar motor device according to claim 43, wherein

said base has a plurality of coolant injecting joints and at least one coolant discharging joint attached, and

said cooling device has an end respectively connected said coolant injecting joint via a coolant supplying pipe, and also has another end connected to said coolant discharging joint via a coolant discharging pipe.

53. A planar motor device comprising:

a magnetic pole unit which has at least one magnet and moves along a predetermined guide surface in two-dimensional directions;

a plurality of armature coils arranged with respect to said guide surface at predetermined intervals in two-dimensional directions along the guide surface at a side opposing said magnetic pole unit;

a plurality of cases which individually house said plurality of armature coils;

an interferometer system configured to detect a position of said magnetic pole unit; and

a controller connected to said plurality of armature coils and said interferometer system to move said magnetic pole unit in a first linear direction and a second linear direction, said controller controlling said plurality of armature coils in accordance with the position of said magnetic pole unit so as to prevent a movement of said magnetic pole unit in a rotative direction on its axis of said magnetic pole unit.

54. A planar motor device according to claim 53, further comprising a cooling device to respectively cool an interior of said plurality of cases.

55. A planar motor device according to claim 53, wherein an upper surface of said cases respectively structure said guide surface.

56. A stage device comprising:

a planar motor device, including,

an armature unit including a plurality of armature coils arranged in a matrix shape along a guide surface which have a rectangular current path, and

a magnetic pole unit arranged opposing said armature unit with respect to said guide surface, which has a plurality of thrust generating magnets having a rectangular magnetic pole surface with a side length longer than an arrangement period of said armature coil and is not equal to an integral multiple of said arrangement period, said plurality of thrust generating magnets arranged in a matrix shape in an arrangement period of an integral multiple of said arrangement period of said armature coils and having a different adjacent polarity of said magnetic pole surface in a row direction and a column direction,

wherein said armature unit and said magnetic pole unit relatively move in a direction along the guide surface;

a movable body which moves integrally with one of said magnetic pole unit and said armature unit; and

a controller which controls at least one of an amount and direction of electric current supplied respectively to said armature coils of said armature unit.

57. A stage device according to claim 56, further comprising:

a position detecting system which detects a positional relationship between said magnetic pole unit and said armature unit; and

said controller controls at least one of said amount and direction of electric current supplied respectively to said armature coils of said armature unit according to a detecting result of said position detecting system.

58. A stage device according to claim 57, wherein said controller

specifies respectively an intersection area between a magnetic flux path due to said magnetic unit and said armature coils based on said detection result of said position detecting system, and

controls at least one of said amount and direction of electric current supplied respectively to said armature coils according said specified intersection area.

59. An exposure apparatus comprising:

an illumination system which emits an energy beam for exposure; and

a stage device which mounts an object to be arranged on a path of the energy beams,

wherein said stage device comprises:

a planar motor device, including,

an armature unit including a plurality of armature coils arranged in a matrix shape along a guide surface, which have a rectangular current path, and

a magnetic pole unit arranged opposing said armature unit with respect to said guide surface, which has a plurality of thrust generating magnets having a rectangular magnetic pole surface with a side length longer than an arrangement period of said armature coil and is not equal to an integral multiple of said arrangement period, said plurality of thrust generating magnets arranged in a matrix shape in an arrangement period of an integral multiple of said arrangement period of said armature coils and having a different adjacent polarity of said magnetic pole surface in a row direction and a column direction,

wherein said armature unit and said magnetic pole unit relatively move in a direction, along the guide surface;

a movable body which moves integrally with one of said magnetic pole unit and said armature unit; and

a controller which controls at least one of an amount and direction of electric current supplied respectively to said armature coils of said armature unit.

60. An exposure apparatus according to claim 59, wherein said object is a substrate onto which a predetermined pattern is transferred by exposing said energy beams.

61. A method of making an exposure apparatus, the method comprising:

providing a planar motor device, including,

an armature unit including a plurality of armature coils arranged in a matrix shape along a guide surface which have a rectangular current path, and

a magnetic pole unit arranged opposing said armature unit with respect to said guide surface, which has a plurality of thrust generating magnets having a rectangular magnetic pole surface with a side length longer than an arrangement period of said armature coil and is not equal to an integral multiple of said arrangement period, said plurality of thrust generating magnets arranged in a matrix shape in an arrangement period of an integral multiple of said arrangement period of said armature coils and having a different adjacent polarity of said magnetic pole surface in a row direction and a column direction,

wherein said armature unit and said magnetic pole unit relatively move in a direction along the guide surface;

providing a movable body which moves integrally with one of a magnetic pole unit and an armature unit; and

providing a controller which controls at least one of said amount and direction of electric current supplied respectively to said armature coils of said armature unit.

62. A making method of an exposure apparatus according to claim 61, further comprising:

providing a position detecting system which detects a positional relationship between said magnetic pole unit and said armature unit.

63. A device manufactured by using an exposure apparatus including:

an illumination system which emits an energy beam for exposure; and

a stage device which mounts an object to be arranged on a path of the energy beams,

wherein said stage device comprises:

a planar motor device, including,

an armature unit including a plurality of armature coils arranged in a matrix shape along a guide surface, which have a rectangular current path, and

a magnetic pole unit arranged opposing said armature unit with respect to said guide surface, which has a plurality of thrust generating magnets having a rectangular magnetic pole surface with a side length longer than an arrangement period of said armature coil and is not equal to an integral multiple of said arrangement period, said plurality of thrust generating magnets arranged in a matrix shape in an arrangement period of an integral multiple of said arrangement period of said armature coils and having a different adjacent polarity of said magnetic pole surface in a row direction and a column direction,

wherein said armature unit and said magnetic pole unit relatively move in a direction along the guide surface;

a movable body which moves integrally with one of said magnetic pole unit and said armature unit; and

a controller which controls at least one of an amount and direction of electric current supplied respectively to said armature coils of said armature unit.

64. A device manufacturing method including a lithographic process,

wherein said lithographic process uses said exposure apparatus made by a method of making an exposure apparatus, the method of making said exposure apparatus comprising:

providing a planar motor device, including,

an armature unit including a plurality of armature coils arranged in a matrix shape along a guide surface, which have a rectangular current path, and

a magnetic pole unit arranged opposing said armature unit with respect to said guide surface, which has a plurality of thrust generating magnets having a rectangular magnetic pole surface with a side length longer than an arrangement period of said armature coil and is not equal to an integral multiple of said arrangement period, said plurality of thrust generating magnets arranged in a matrix shape in an arrangement period of an integral multiple of said arrangement period of said armature coils and having a different adjacent polarity of said magnetic pole surface in a row direction and a column direction,

wherein said armature unit and said magnetic pole unit relatively move in a direction along the guide surface;

providing a movable body which moves integrally with one of a magnetic pole unit and an armature unit; and

providing a controller which controls at least one of said amount and direction of electric current supplied respectively to said armature coils of said armature unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a planar motor device, a stage unit, an exposure apparatus and its making method, and a device and its manufacturing method. More particularly, the present invention relates to a planar motor device that has a mover and a stator and operates to drive the mover in a noncontacting manner in two-dimensional directions by electromagnetic force, a stage unit including a movable body to which the mover of the planar motor device is integrally attached, and an exposure apparatus incorporating the stage unit, and a method of making the exposure apparatus, and a device to be manufactured by using the exposure apparatus, and a device manufacturing method using the exposure apparatus.

2. Description of the Related Art

Conventionally, in a lithographic process for manufacturing semiconductor devices and liquid crystal display devices, an exposure apparatus that transfers a pattern formed on a mask or a reticle (hereunder generically referred to as a "reticle") through a projection optical system onto a substrate such as a wafer or a glass plate (hereunder generically referred to as a "substrate or wafer"), on which a resist is coated, has been used. This exposure apparatus is required to position the wafer at an exposure position with high precision. Thus, the wafer is held on a wafer holder by vacuum chucking, and the wafer holder is fixed onto a wafer table (that is, movable body) which structures a stage unit.

Recently, to position the wafer more quickly and with high precision without being affected by the mechanical accuracy of a guide surface, as well as to avoid mechanical friction and to prolong the life of the stage unit, a stage unit is being developed. This stage unit performs positional control of the wafer by supporting the movable body on which the wafer is placed above a supporting member by levitation and drives the movable body in a non-contacting manner. To accomplish such a stage unit, the key technology is the technique of levitating a mover above a stator of a planar motor device, and driving the mover in a predetermined direction (including a rotational direction) in an XY plane in order to move the mover. On driving such a planar motor device, a variable reluctance driving method and a Lorentz (electromagnetic) force method can be employed.

As a planar motor device used in the variable reluctance driving method, a motor as in a Sawyer motor, which has a structure of linear pulse motor s using the variable reluctance driving method respective to two axes being combined with each other, is the current mainstream. With the linear pulse motor using the variable reluctance driving method, it has a stator structured of; for instance, a plate-shaped magnetic substance having a gear tooth port ion (with an uneven shape) arranged along the longitudinal direction in equivalent intervals. It also has a mover that has a plurality of armature coils having an uneven portion different in phase with the gear tooth portion of the stator. The plurality of armature coils are arranged opposing the tooth portion of the stator, and are connected via a permanent magnet. And, the mover is driven by utilizing a force generated so as to minimize the magnetic reluctance between the stator and the mover at each point. That is, by adjusting and controlling the value and phase of pulse current supplied to each armature coil, the mover can be driven stepwise in a stepping operation.

Such a Sawyer type motor is configured of combining linear pulse motors that respectively correspond to 2 axes, on a moving plane. The driving portion which drive the mover movable in a plane in each axis direction, however, is separated from each other, thus making the mover heavy. To improve such inconvenience, an improved planar motor that can be moved on a plane by a single driving portion is being developed.

Also, with the planar motor device based on the Lorentz force method, the driving force is obtained by utilizing a Lorentz force F. This force is generated in the direction determined according to Fleming's left hand law in the presence of an electric current I and a magnetic flux density B, which are perpendicular to each other, and expressed by the following equation:

F=I.times.B.times.L (1)

In this equation, F designates a force generated on a current path; and L denotes the length of the current path. A conventionally proposed Lorentz force driving planar motor device is disclosed in, for example, the U.S. Pat. No. 5,196,745. With this planar motor device, magnets are respectively arranged so that the adjacent pairs of magnetic arrays alternately have the opposite polarity in the X-axis direction on a mover (or a stator). The magnets in the Y-axis direction are arranged in the Y-axis direction so that the adjacent pairs of magnetic arrays alternately have the opposite polarity, without the array intersecting that of the X-axis direction. Also, on a stator (or a mover), multi-phase coils for driving operations in the X-axis direction are arranged along the X-axis while multi-phase coils for the Y-axis direction are arranged along the Y-axis direction without the array intersecting with those of the X-axis direction. Thus, the thrust in the X-axis direction is generated by generating a Lorentz force, by sending an electric current to the multi-phase coil oppositely facing the magnets used for driving operations in the X-axis direction. And, the thrust in the Y-axis direction is also generated by generating a Lorentz force, by sending an electric current to the multi-phase coil oppositely facing the magnets used for driving operations in the Y-axis direction.

Among the conventional planar motor devices described above, the planar motor devices employing the variable reluctance method obtained high thrust between magnetic substances or between a magnetic substance and a permanent magnet by magnetic attraction or by repulsive force. It was, however, essentially difficult to reduce thrust variation, that is thrust cogging, when the current was not supplied to create a magnetized state. Furthermore, thrust generated by current excitation varies with the movable position. Therefore, to stabilize the thrust force that varies with the movable position, a higher level of a current pattern was required.

Also, the variable reluctance motor usually is configured of what is called an iron core coil, which is formed of winding an armature coil around a magnetic substance. Since it has a high armature coil inductance, the response time is slow; therefore a high voltage power supply is required to increase the response time, depriving the motor of its efficiency.

Furthermore, with the iron core coil, magnetic saturation of the iron core is caused due to the current flowing through it, so it is difficult to obtain the thrust linearity in a high current region making the design of the control system complex.

Meanwhile, with the conventional Lorentz force driving planar motor device, it excels in controllability, thrust linearity, and positioning ability. However, due to the limitation of the magnetic and coil array, the number of magnets and coils that are used for driving operations cannot be increased, therefore, it is difficult for this planar motor device to increase the thrust to be generated. Accordingly, it is difficult to move the mover, which carries an object of a certain weight such as a wafer holder or a substrate table, at a high speed.

Also, in order to use the planar motor device based on the variable reluctance driving method for precise positioning and to achieve high speed positioning, a large driving force is necessary. Naturally, a large current needs to be supplied to the armature coil. This, however, results in increasing the amount of heat generated in the armature coil. Such an increase in the amount of heat generated in the armature coil similarly occurs in the case of the planar motor device employing the Lorentz force method, in which the armature coil has to be supplied with a large current so as to obtain high thrust. Therefore, in consideration of the environment for a precise positioning system, it is essential for the planar motor to have a cooling system designed, and reduce thermal influence caused by the motor.

Furthermore, in the case of structuring a precise positioning stage with a planer motor device using a variable reluctance driving method, bearings, such as air bearings, to levitate the stage are essential. However, the planer motor device employing a variable reluctance driving method has a driving principle utilizing magnetic attraction as a driving force. The distance between the mover and the stator, therefore, is set at a very small value. The magnetic attraction force between the mover and stator serves as a reaction force against the stage levitation force by the air bearings. As a result, the amount of air supplied to levitate the stage and the power consumption of the air pump that supplies the air, are increased. In the case of using a planar motor device employing the Lorentz force driving method, when it is used for the driving source of the stage, it is desirable that the power consumption for levitating the stage is reduced.

SUMMARY OF THE INVENTION

The present invention has been made in view of the conditions above. Accordingly, a first object of the present invention is to provide a planar motor device that excels in controllability, thrust linearity, and positioning ability.

A second object of the present invention is to provide a stage that can perform and control high precision positioning of an object mounted on stage.

Also, a third object of the present invention is to provide an exposure apparatus that can perform high precision exposure by performing high precision positioning of a substrate and.

Finally, a fourth object of the present invention is to provide a device on which a fine pattern is formed with high accuracy.

To achieve the foregoing objects, according to a first aspect of the present invention, there is provided a first planar motor device comprising: an armature unit including a plurality of armature coils arranged in a matrix shape along a guide surface, which have a rectangular current path; and a magnetic pole unit arranged opposing the armature unit with respect to the guide surface, which has a plurality of thrust generating magnets having a rectangular magnetic pole surface with a side length longer than an arrangement period of the armature coil and is not equal to an integral multiple of the arrangement period, the plurality of thrust generating magnets arranged in a matrix shape in an arrangement period of an integral multiple of the arrangement period of the armature coils and having a different adjacent polarity of the magnetic pole surface in a row direction and a column direction, and the armature unit and the magnetic pole unit relatively move in a direction along the guide surface.

In the case of the first planar motor device of the present invention, to generate an efficient magnetic flux, that is to generate a magnetic circuit with a high magnetic density, a magnetic circuit which reluctance is low is structured. This is structured, by arranging the thrust generating magnets in a magnetic pole unit in the shape of a matrix, so that the polarities of adjacent magnet pole surfaces alternately differs from each other. And, in the armature coil unit, the armature coils are arranged in the shape of a matrix, and the amount and direction of the Lorentz force generated in the armature coils are changed by changing the amount and direction of the current being supplied to the armature coils. Accordingly, there are no exclusive driving direction of the respective thrust generating magnets arranged in the magnetic pole unit, and the respective armature coils arranged in the armature unit. Consequently, when the magnetic pole unit an d the armature unit relatively move in a desired direction, every thrust generating magnets and armature coils opposing these magnets can be used for moving them in the desired driving direction. This allows motor driving by a high thrust.

With the first planar motor device of the present invention, the matrix-shaped arrangement period of the thrust generating magnets of the magnetic pole unit is determined at a value that is an integral multiple of the arrangement period of the armature coils of the armature unit. Therefore, when the arrangement direction of the thrust generating magnets is parallel to that of the armature coils, the positional relationship between a thrust generating magnet and an armature coil opposing this magnet is similar to that of another thrust generating magnet and an armature coil opposing this magnet. Accordingly, when the magnetic pole unit and the armature unit are relatively moved to perform a translation in a desired direction, the direction of electric current supplied to the armature coil depends on the polarity of the magnetic pole surface opposing the armature unit. Basically, however, when an electric current is supplied to an armature coil opposing a thrust generating magnet to generate a thrust in the desired driving direction, the driving unit can similarly supply current other armature coils opposing the thrust generating magnets, which simplifies the control of motor driving.

Also, with the first planar motor device of the present invention, the side length of the magnetic pole surface of the thrust generating magnet is determined at a value longer than the arrangement period of the armature coils. It is also a value that is not equal to the integral multiple of the arrangement period of the armature coils. Accordingly, the positional relationship between the thrust generating magnet and the armature coil in which the thrust becomes zero in regardless of the current supplied to the armature coil does not exist. The thrust becomes zero, when the side length of the magnetic pole surface of the thrust generating magnet is an integral multiple of the arrangement period of the armature coils.

Therefore, according to the first planar motor device of the present invention, by utilizing the merits of the Lorentz force driving method that excels in controllability, thrust linearity, and positioning ability, a stable and high powered thrust can be generated by a simple control of the current supplied.

In the first planar motor device of the present invention, the magnetic pole unit can be structured further comprising an interpolating magnet arranged on a magnetic flux path formed on a magnetic pole surface side of the thrust generating magnet opposing the armature unit, the path formed between the thrust generating magnets which are adjacent in the row direction and the column direction, the interpolating magnet being a part of a magnetic circuit, and reinforcing a magnetomotive force. In such a case, on structuring a magnetic circuit, both the thrust generating magnets and the interpolating magnet serve as a magnetomotive source. This result in increasing in the absolute value of the magnetic flux density B of the magnetic flux formed on the current path of the armature coil due to the magnetic pole unit.

In general, in the case of increasing the numbers of the rows and columns of the arrangement of the thrust generating magnets, when the magnetic pole unit and the armature unit relatively moves and the position where the magnetic flux is created on the armature unit side also move, the polarity of the magnetic pole surfaces adjacent in the row direction and column direction alternately differ. This causes the direction of the magnetic flux to be frequently reversed. So, for example, in the case of using magnetic members to reduce the reluctance at the armature unit side, the direction of the magnetic flux is frequently reversed, in turn generating an eddy current in the magnetic member. As a result, the reluctance is increased, which prevents a high-density magnetic flux from being generated, increasing the energy loss.

Thus, according to the first planar motor device of the present invention, with consideration to this view, the thrust generating magnets can be arranged in a shape of a two-by-two matrix. In such a case, the frequency of the direction of the magnetic flux reversing at the armature unit side while the magnetic pole unit and the armature unit are relatively moving is minimized. Therefore, the magnetic circuit can keep a low reluctance, thus, making it possible for a high thrust to be generated and reducing the loss. Also, in such a case, with the magnet pole unit in which the thrust generating magnets are arranged in a square matrix shape so as to symmetrically generate a magnetic flux with a high magnetic flux density, the number of thrust generating magnets is minimized, naturally, simplifying the configuration.

With the first planar motor device of the present invention, the external shape of the magnetic pole surface of the armature unit opposing the magnetic pole unit or the magnetic pole surface of the thrust generating magnet may be of various shapes. However, the external shape of a surface of the armature coil which opposes the magnetic pole unit can be a square, and the magnetic pole surface of the thrust generating magnets can be of a square shape. In such a case, when the magnetic pole unit and the armature unit move relatively in one of two directions being perpendicular, electric current can be supplied to the armature coils arranged along in the moving direction similarly, as when these units move relatively in the other direction. That is, in the two directions perpendicular to each other, electric current can be symmetrically supplied to the armature coils. Accordingly, the magnetic pole unit and the armature unit can be relatively moved in the two-dimensional direction by a simplified control.

In the first planar motor device, various relations can be considered on the shape and arrangement of the armature coils, and the shape and arrangement of the thrust generating magnets. The current path length on an outer