JP3588633B2 - Moving stage for imprint lithography - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a moving stage of an imprint lithography apparatus that moves a stage supporting a sample in order to press a mold having a predetermined pattern against a resist on a sample surface at a plurality of positions. The present invention relates to a moving stage of an imprint lithography apparatus that can uniformly press the entire surface even when inclined.
[0002]
[Prior art]
In recent years, downsizing of ultra LSI devices represented by high density memories and system LSIs has been progressing, and a technology capable of further miniaturization has been required. Therefore, lithography (transfer) technology has been used in a semiconductor manufacturing process. Its importance is increasing. Among them, imprint lithography is a technique of pressing a mold having a predetermined circuit pattern formed thereon against a sample substrate having a surface coated with a resist and transferring the pattern, and various methods have been proposed. This is performed as shown in FIG.
[0003]
In FIG. 3, a reverse pattern corresponding to a mirror image of a pattern to be transferred is first formed on the surface of a mold material 30 by electron beam lithography or the like as shown in FIG. Is created. On the other hand, as shown in FIG. 3B, a resist material such as PMMA is applied and cured on a silicon substrate 33 on which a pattern is to be formed to form a resist layer.
[0004]
Next, the entire silicon substrate 33 provided with the resist layer 34 is heated to about 200 ° C. to slightly soften the resist layer 34. In this state, as shown in FIG. 6C, the uneven shape 31 of the mold 32 is arranged at a predetermined position on the resist layer 34, and the uneven shape 31 is pressed against the resist layer 34. At this time, since the resist layer 34 is softened, the resist layer 34 enters the concave portion of the uneven shape 31, and the resist layer 34 has substantially the same shape as the uneven shape 31. In this state, the entire temperature is lowered to about 105 ° C. to cure the resist layer 34, and then the mold 32 is removed. Thus, a concavo-convex pattern having a predetermined shape is formed on the resist layer 34.
[0005]
In addition, in the imprint lithography method, in addition to the above, for example, a mold is made of a transparent material such as a quartz substrate, and a liquid photo-curable resin is applied on the substrate to be transferred, and the By pressing the mold unevenness, the liquid photocurable resin flows into the unevenness, and in this state, the resin is cured by irradiating ultraviolet light etc. from the back side of the transparent mold, and then the mold is removed to obtain the predetermined shape unevenness. A method of forming a pattern has also been proposed.
[0006]
In the imprint lithography method as described above, it is necessary to make the pressure distribution in the pressing surface when pressing the mold against the sample substrate uniform. In order to make the pressure distribution in the plane uniform, it is necessary to increase the parallelism between the mold and the sample substrate. If both are not parallel, the mutual inclination must be adjusted on the mold side or the sample side.
[0007]
In order to make the in-plane pressure distribution uniform when the mold is pressed against the sample substrate as described above, conventionally, an inclination adjusting mechanism that has an elastic body or a fulcrum and changes the inclination around the fulcrum is used. That is being done. FIGS. 4 and 5 are schematic diagrams showing a case where a tilt adjusting mechanism is used on the mold side. In FIG. 4, a silicon substrate 37 on which a resist 36 is applied is placed on a sample table 35, and a mold 38 is pressed against the resist 36 on the silicon substrate 37 by a pressing mechanism 40. FIG. 4 shows a case where a pivot structure 41 is used as a tilt adjusting mechanism. For example, when the sample table 35 is tilted relatively to the pressing mechanism 40, the mold 38 is moved by the pressing mechanism 40 to the resist 36. , The pivot structure 41 absorbs this inclination, and the mold 38 is pressed against the resist 36 with a uniform force. FIG. 5 shows an example in which the elastic body 42 is used as the inclination adjusting mechanism shown in FIG. 4, and the elastic body 42 can absorb the inclination. As shown in FIG. Pressed with equal force.
[0008]
Although the above-described example shows an example in which the tilt adjusting mechanism is used on the pressure side, the same operation can be performed by using the tilt adjusting mechanism on the sample side, and examples thereof are shown in FIGS. ) And (c). 11A shows an example in which the sample table 35 is supported by a pivot structure 43, FIG. 12B shows an elastic body 44 on the bottom surface of the sample table 35, and FIG. An example in which an elastic body 44 is provided is shown. In any of these methods, when the sample is not moved, the tilt adjustment mechanism functions as expected.
[0009]
[Problems to be solved by the invention]
As described above, in order to press the mold with a uniform force against the resist, a tilt adjustment mechanism made of a pivot or an elastic body is provided on the pressure side or the side to be pressurized. When the mold is pressed against a plurality of locations, when the tilt adjustment mechanism is provided on the pressing side as shown in FIGS. 4 and 5, the tilt adjustment mechanism acts on the entire surface. As shown in (1), if it is provided on the side to be pressurized, it cannot function over the entire surface.
[0010]
FIGS. 7A, 7B, and 7C schematically show the problem when the tilt adjusting mechanism is added to the side to be pressed as described above. The figure shows an example in which a sample moving stage 45 is added to those shown in FIGS. 6 (a), (b) and (c). In the figure, the mold is shown tilted for easy understanding of the problem, but the same is true even if the moving stage side is tilted. In the example shown in FIG. 7A, when the mold 38 is pressed against the resist 36, only the A side of the mold 38 is pressed, and the B side cannot be pressed, and the tilt adjustment does not function at all. The same applies to the example shown in FIG. Further, in the example shown in FIG. 3C, if the substrate 37 is deformed, it is considered that the inclination adjustment functions slightly, but the stress in the portion A may damage the substrate 37. As described above, in imprint lithography involving movement of a sample, it is a problem to realize a tilt adjustment mechanism on the side of the sample to be pressurized when the tilt adjustment mechanism cannot be added to the mold side.
[0011]
Therefore, the present invention provides a method for pressing a mold having a predetermined pattern against a resist on a sample surface at a plurality of positions. It is an object of the present invention to provide a transfer stage for imprint lithography that can apply a uniform pressure to a resist at all positions even when a mechanism is provided.
[0012]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 includes an inclination adjustment mechanism fixed to a support on a surface plate, a movement stage movably provided on the surface plate, and an elastic member on the movement stage. A stage for imprint lithography, comprising: a sample supported and supported; and a mold arranged to be movable up and down in opposition to the upper part of the tilt adjustment mechanism, and to press a resist on the sample surface. It is.
[0013]
The invention according to claim 2 is the moving stage for imprint lithography according to claim 1, wherein the tilt adjustment mechanism is a pivot mechanism.
[0014]
The invention according to claim 3 is the moving stage for imprint lithography according to claim 1, wherein the tilt adjustment mechanism is an elastic member.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1A and 1B are schematic views showing a basic configuration of a moving stage for imprint lithography of the present invention. FIG. 1A shows a state in which a sample is moved, and FIG. The case where the mold 2 on the mold holding unit 1 is pressed against the resist 4 on the silicon substrate 3 is shown. The sample holding member 5 holding the peripheral portion on the silicon substrate 3 is supported between the lower surface thereof and the upper surface of the moving stage 6 via an elastic member 7 having a very small spring constant. The moving stage 6 is fixed on a moving mechanism 10 that can freely move on the surface plate 8, so that when the moving stage 6 moves in a plane on the surface plate 8, the silicon substrate 3 supported by the moving stage 6 is moved. Also move together.
[0016]
A column 11 extending from the back surface of the silicon substrate 3 is fixed substantially at the center of the platen 8, and a pivot mechanism 12 as an inclination adjusting mechanism is provided on an upper end surface of the column 11. The pivot mechanism 12 includes a pivot 13 that forms a fulcrum, and a pivot receiver 14 that is swingably supported by the pivot 13 and receives the back surface of the sample substrate 8 at its upper end surface.
[0017]
FIG. 2 is an enlarged view of the pivot mechanism as an example of the tilt adjustment mechanism. In this pivot mechanism, a pivot 13 having a conical projection 15 and constituting the fulcrum, and a pivot receiver 14 having a conical depression 16 are provided, and the center of the conical depression 16 of the pivot receiver 14 is The point of the projection 15 of the cone of the pivot 13 comes into contact, and the two can relatively tilt around this point.
[0018]
1A, the periphery of the silicon substrate 3 is supported by the elastic member 7, and the back surface of the silicon substrate 3 is supported by the swing member 14 of the pivot 12 in a state where the elastic member 7 is compressed. Alternatively, it is supported by the elastic member 7 with a slight gap. As a result, when the moving mechanism 10 moves on the surface plate 8, the singing member 14 of the pivot 12 is lightly in contact with the back surface of the silicon substrate 3, or is kept in a state of no contact.
[0019]
When the mold 2 is pressed against the resist 4 on the silicon substrate 3, for example, if the mold 2 is inclined as shown in the figure, the two are parallel to each other according to the inclination of the mold 2 as shown in FIG. The silicon substrate 3 is inclined by compressing the elastic member 7 so that the silicon substrate 3 is inclined. The above inclination is relative to the mold 2 and the silicon substrate 3. Even if the mold 2 side is horizontal and the silicon substrate 3 side is inclined, the same operation is performed, and both are inclined with respect to the horizontal plane. The same is true for
[0020]
When the mold 2 presses the resist 4, when the center of the pressing force applied to the mold 2 substantially coincides with the tip of the pivot 12, the pressing force is applied to the elastic member 7 supporting the silicon substrate 3. Imprint is performed in a state where the inclination of the mold 2 and that of the silicon substrate 3 coincide with little action.
[0021]
After performing the above-described imprinting at a predetermined position of the resist 4, when performing imprinting at another location on the surface of the resist 4, the position where the next imprinting is performed is moved by the moving mechanism 10 to the mold 2. , And perform the same operation.
[0022]
In the above embodiment, the pivot is used as the tilt adjusting mechanism on the column 11, but the same operation can be performed by using an elastic member as shown in FIG. 5, for example. And the pivot structure can be used in combination.
[0023]
【The invention's effect】
As described above, the moving stage for imprint lithography of the present invention can effectively perform the tilt adjustment function even when moving the sample while incorporating the tilt adjustment mechanism on the sample side. In particular, the present invention is effective when it is difficult to add a tilt adjustment function to the mold side.
[Brief description of the drawings]
1A and 1B are schematic diagrams of the present invention, wherein FIG. 1A shows a state in which a mold is separated from a resist and a sample is moved, and FIG. 1B is a state in which a mold on a mold holding unit is pressed against a resist on a silicon substrate. Is shown.
FIG. 2 is a view showing a pivot mechanism as an inclination adjusting mechanism.
FIG. 3 is a diagram illustrating a pattern transfer method by imprint lithography.
FIG. 4 is a schematic view of an imprint lithography apparatus provided with a tilt adjustment mechanism having a pivot structure on a mold pressing side.
FIG. 5 is a schematic view of an imprint lithography apparatus provided with a tilt adjustment mechanism made of an elastic member on a mold pressing side.
FIG. 6 is a schematic view of an imprint lithography apparatus provided with a tilt adjustment mechanism on a sample side.
FIG. 7 is a schematic diagram of an imprint lithography apparatus provided with a tilt adjustment mechanism and a movement mechanism on the sample side.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mold holding part 2 Mold 3 Silicon substrate 4 Resist 5 Sample holding member 6 Moving stage 7 Elastic member 8 Surface plate 10 Moving mechanism 11 Support 12 Pivot mechanism 13 Pivot 14 Pivot receiver 15 Projection 16 Recess

Claims (3)

An inclination adjustment mechanism fixed to a support on the surface plate,
A moving stage provided movably on the surface plate,
A sample supported on the moving stage via an elastic member,
A moving stage for imprint lithography, comprising: a mold arranged to be movable up and down so as to face the upper part of the tilt adjusting mechanism, and to press a resist on a sample surface. The moving stage for imprint lithography according to claim 1, wherein the tilt adjusting mechanism is a pivot mechanism. The moving stage for imprint lithography according to claim 1, wherein the tilt adjustment mechanism is an elastic member.

Images