Electrical generator or motor structure – Dynamoelectric – Linear
Reexamination Certificate
2001-12-03
2004-12-28
Le, Dang (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Linear
C310S013000, C310S014000
Reexamination Certificate
active
06836031
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an exposure apparatus used in a semiconductor manufacturing process and, more particularly, to a linear motor which is suitable for a projection exposure apparatus for projecting and transferring a reticle pattern onto a silicon wafer, and is suitable for moving a reticle and wafer on reticle and wafer stages for sequentially moving the reticle and silicon wafer with respect to a projection exposure system when projecting a reticle pattern onto the wafer.
The present invention relates to a linear motor suitable for transmitting the reaction forces of the reticle and wafer stages of an exposure apparatus, or a linear motor suitable for damping that is set on the mount of a main body structure which supports each stage and a projection optical system.
BACKGROUND OF THE INVENTION
FIGS. 17A and 17B
schematically show the coil of a linear motor and a coil fixing method in a conventional exposure apparatus.
FIG. 17A
is a plan view, and
FIG. 17B
is a cross-sectional view. As shown in
FIG. 16
, a coil
116
uses a round wire coil
116
a
, and is constituted such that a round wire obtained by covering an insulating a copper wire
116
b
with an insulating layer
116
c
of polyimide or the like is wound into a corner-rounded rectangular shape. The coil
116
has a hollow structure. In other words, the inside of the conductor-wounded coil
116
is hollow like a so-called doughnut shape.
The coil
116
is fixed to a linear motor main body by fitting positioning portions
154
in the hollow coil portion. In general, the coil positioning precision greatly influences the thrust performance of a linear motor, so the positioning precision required to fix a coil is very strict. Particularly, a linear motor used for nm-order positioning in an exposure apparatus or the like often requires a coil fixing precision of 100 &mgr;m or less. Along with recent increases in the output and efficiency of linear motors, the linear motors are using a foil coil wounded with a copper foil-like film with which the coil wire moment can be designed higher than with a round wire.
A linear motor used in an exposure apparatus together with a hollow coil has a structure as shown in
FIGS. 15A and 15B
. In
FIGS. 15A and 15B
, a plurality of coils
116
are aligned within an effective stroke in the driving direction of a linear motor
109
, and the lead line of each coil
116
is connected to a connector
118
. A member movable with respect to the linear motor stationary member incorporates movable magnets
119
. By flowing a driving current through the coils
116
, the movable magnets
119
magnetized by a Lorentz force as shown in
FIG. 15B
are moved in a moving direction indicated by the arrow. This linear motor is used for a wafer stage or the like in an exposure apparatus.
The structure using the hollow portion of a hollow coil for coil positioning, like the above prior art, suffers the following problems.
1. In order to precisely fix the coil to the linear motor main body, the dimensional precision of an inner coil surface must be increased. The inner coil surface is made of a wire, so the dimensional precision must be increased by grinding the inner coil surface. If the dimensional precision does not increase, it adversely affects the positioning precision of a positioning device and the exposure precision of an exposure apparatus. To prevent this, the winding precision must be very strict even in winding a wire, which poses technical and cost problems.
2. In forming a coil, a wire is wound around a winding jig (to be referred to as a core member hereinafter) having a shape corresponding to an inner coil shape. Then, the core member is removed. However, it is technically difficult and costly to remove the core member while keeping high dimensional precision of the inner coil surface.
3. Even if problems 1 and 2 are solved and a high-precision coil can be formed, the wire may be damaged in assembling the coil into a linear motor housing. Although the positioning precision for fixing the coil must be high, the coil must be loosely fitted on the linear motor housing. Thus, the coil and exposure apparatus cannot ensure high reliability.
When a round wire is wounded as a coil wire, like the prior art, the strength and rigidity of the wire are relatively high, and the above problems hardly occur. As for a coil wounded with a foil-like conductor, the wire itself readily deforms and is damaged. The above problems cause an insulation failure. From this, demands have strongly arisen for a foil coil structure which can be securely assembled into a linear motor housing with high yield.
SUMMARY OF THE INVENTION
The present invention has been proposed to solve the conventional problems, and has as its object to provide an exposure apparatus and a linear motor suitable for the same that can increase coil fixing/positioning precision, workability in assembling a coil into a linear motor housing, exposure speed, and reliability.
To achieve the above object, a linear motor according to the present invention provides a core member; a coil obtained by winding a foil-like conductor having an insulating layer around the core member in a multilayered structure; and a coil fixing portion fixing the coil, wherein the coil is fixed to the coil fixing portion by using the core member.
In the linear motor according to the present invention, the core member is preferably formed from an insulating material.
In the linear motor according to the present invention, the core member is preferably formed from a material having a low thermal conductivity.
In the linear motor according to the present invention, the core member is preferably formed from the same material as a material of the coil fixing portion or a material having substantially the same linear expansion coefficient.
In the linear motor according to the present invention, the core member is preferably formed from a ceramic.
In the linear motor according to the present invention, the core member is preferably formed from a resin material.
In the linear motor according to the present invention, the core member is preferably annular and is fixed by being fitted on the coil fixing portion.
In the linear motor according to the present invention, preferably an outer circumferential surface of the coil wounded with the foil-like conductor in the multilayered structure is covered with an electrically insulating material.
In the linear motor according to the present invention, the coil fixing portion is preferably shaped such that an area in a direction in which a large force is received under influence of a magnetic field is larger than an area in a direction in which a small force is received.
In the linear motor according to the present invention, preferably, the core member also serves as a winding jig used to form a coil.
To achieve the above object, a method of manufacturing a linear motor according to the present invention comprises a step of causing a core member of the linear motor to serve as a winding jig and winding a foil-like conductor around the core member; and a step of manufacturing the linear motor by using the core member as part of a coil after the winding step, wherein the linear motor includes a core member, a coil obtained by winding the foil-like conductor having an insulating layer around the core member in a multilayered structure, and a coil fixing portion fixing the coil, and the coil is fixed to the coil fixing portion by using the core member.
An exposure apparatus according to the present invention comprises a reticle stage scanning a reticle; a wafer stage scanning a wafer; a projection optical system arranged so that the reticle scanned is projected on the wafer scanned via the optical unit; and a linear motor being used in the apparatus having, (i) a core member, (ii) a coil obtained by winding a foil-like conductor having an insulating layer around the core member in a multilayered structure; and (iii) a coil fixing portion fixing the coil, wherein the coil is fixed to the coil fixing portion b
Emoto Keiji
Miyajima Yoshikazu
Outuka Kazuhito
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