JP3604985B2 - Pattern transfer device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
In the present invention, a resist film which is softened by heat is formed on the surface in the fine processing of circuits and micro parts in the manufacture of semiconductor devices such as liquid crystal displays, field emission displays, plasma display panels, solar cells, and semiconductors. The present invention relates to an apparatus for transferring a pattern to a brittle material substrate such as a glass substrate or a Si substrate by an imprint method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, as a pattern transfer method of a circuit in the manufacture of various semiconductor devices, a photoresist made of a photosensitive agent, a resin, and a chemical solvent is applied to a glass substrate, a Si substrate surface or a glass substrate, a Si substrate Is coated on the surface of a substrate on which a SiO ₂ film, an a-Si film (non-quality silicon film), a p-Si film (polycrystalline silicon film), etc. are laminated, and the pattern shape is transferred by exposure through a photomask and developed. Thereafter, dry etching or wet etching is performed, and thereafter, the resist film is ashed (ashed) or the resist film is peeled off, so that a pattern transfer by a photolithography method of forming an uneven pattern on the substrate or the laminated film is performed. The law is the most common.
As described above, many devices such as a spin coating device, a heating device, a cooling device, an exposure device, a developing solution coating device, an etching device, and an ashing device are required as a pattern transfer device by the photolithography method.
Above all, the exposure apparatus is very expensive, and the stepper generally used in the exposure step has low productivity because the exposure is performed while sequentially moving the photomask, and the throughput is limited by the exposure step. .
In the manufacture of semiconductor devices, wiring patterns are often stacked in layers for high integration, and such pattern transfer is repeated many times in the manufacture of one product. Therefore, the expensive apparatus and the low productivity described above are amplified and affect the price of the product.
[0003]
Also, recently, a pattern member having an uneven pattern is pressed against a resist film formed on a substrate surface by a spin coating method, whereby the resist film is made uneven, and the resist film is etched to form a pattern on the substrate. A pattern transfer method by an imprint method for transferring a shape is being studied (see US005772905A).
In this case, PMMA is used as the material of the resist film, and when pressing the mold member against the resist film, the substrate is heated to 200 ° C. or higher, which is higher than the glass transition temperature of PMMA, and the pressing force of the mold member against the resist film is reduced. It is characterized in that it is performed at about 100 kgf / cm ² .
Further, the pattern transfer method by the imprint method does not require a photosensitive agent unlike the pattern transfer method by the photolithography method, so that it is not necessary to work under a yellow light in a clean room, which is advantageous in workability. It is.
Although the pattern transfer method by the imprint method has not yet been put to practical use, a test is performed by a pattern transfer apparatus such as pressing a mold member having an uneven pattern on one side of a flat plate against a resist film formed on a substrate. .
However, as described above, since the pressing force of the mold member against the resist film is as large as 100 kgf / cm ² , the test piece used for the test can be performed only with a very small size. Has become.
[0004]
[Problems to be solved by the invention]
By the way, in this imprint method, in order to obtain a sufficient pressing depth on the concave / convex pattern of the resist film, an extremely large pressing force as described above is required at the time of imprinting. A commonly used substrate is often a brittle material such as a glass substrate or a Si substrate, and the substrate may be damaged when a large pressing force is applied.
Further, even if the substrate is not damaged, in order to apply a large pressure, the pattern transfer apparatus itself becomes strong, large, and expensive.
Further, when pressing the large plate-shaped mold member against the substrate, it is extremely difficult to make the pressing force of the entire mold uniform, and the uneven pressing force causes an uneven load, and the pressing depth becomes nonuniform. The substrate may be damaged.
Furthermore, when transferring a pattern to a large substrate as in the case of manufacturing a liquid crystal display or a solar cell, imprinting with a flat-shaped mold member requires extremely high flatness and surface accuracy in the mold member. It is expected to be very difficult.
As described above, the need for a very large pressing force is one of the problems that makes it difficult to realize a pattern transfer device by the imprint method.
[0005]
Further, as described above, when the mold member is pressed against the substrate, it is necessary to heat the resist member to a temperature higher than the glass transition temperature of the resist film. This is because the resist film is softened by heating so that a pattern can be easily formed when the mold member is pushed.
Further, after pressing the mold member, it is necessary to cool the substrate in order to carry it to the next etching step.
Due to such temperature changes such as heating and cooling of the substrate, high productivity cannot be expected, which is another problem in pattern transfer by the imprint method.
[0006]
The present invention solves these problems, provides an apparatus capable of realizing pattern transfer by the imprint method at a low cost, and further overcomes a production defect that involves a temperature change, and provides a highly productive pattern transfer apparatus. It will not be provided.
[0007]
[Means for Solving the Problems]
The present invention is an apparatus for performing pattern transfer by an imprint method on a brittle material substrate such as a glass substrate or a Si substrate on which a resist film softened by heat is formed on a surface, and on a plate for mounting and fixing the substrate, It has a pattern-shaped concavo-convex pattern on its circumferential surface, and a positively rotating cylindrical mold member is installed so as to be able to move up and down.A control mechanism is also provided for controlling the load applied to the resist film on the substrate. Means for transferring a pattern by rotating and pressing the mold member against the resist film of the substrate on the plate, and providing a mold for transferring the pattern onto the resist film of the substrate. A pattern transfer apparatus is provided by providing a substrate pre-heating unit in a process preceding the member pressing process and a substrate cooling unit in a process subsequent to the member pressing process.
By using a plate for mounting and fixing the substrate and a cylindrical mold member, the contact area between the mold member and the substrate at the time of pressing can be made very small, so that the total pressing load can be made very small. It becomes.
As described above, since the total pressing load can be reduced, damage to the substrate due to the uneven load of the pressing load can be reduced, and the pattern transfer device can be manufactured smaller and less expensively than the pattern transfer device using a flat mold member. It becomes possible.
Furthermore, when transferring a pattern to a large substrate as in the case of manufacturing a liquid crystal display or a solar cell, high flatness and surface accuracy are required, but in general, a cylindrical shape provides a higher processing accuracy than a flat plate shape. Since the mold member has a cylindrical shape, processing accuracy can be more easily obtained than a mold member having a flat plate shape.
[0008]
Further, the present invention provides heating means for both the plate and the mold member, and further has a temperature control mechanism.In pattern transfer by the imprint method, the resist film is softened by heating the substrate and the resist film, The pattern formation when the mold member is pushed in becomes easy.
The entire substrate and the resist film on the plate are preliminarily heated, and the transferred portion is further heated by the mold member at the time of pattern formation, and the resist film softening temperature, so that efficient heating is achieved.
Then, the pattern can be easily formed by the temperature control mechanism of the plate or the mold member.
[0009]
Further, in the present invention, a substrate pre-heating unit is installed in a step before the step of pressing the mold member against the substrate, and a substrate cooling unit is installed in a post-step.
In the step of pressing the mold member, it is necessary to heat the substrate or the mold member in order to soften the resist film and facilitate pattern formation as described above.
By heating the substrate in advance in the substrate preheating section, the heating time in the mold member pressing step can be shortened.
After the pressing of the mold member, the resist film is etched. However, it is necessary to cool the substrate in order to transfer the resist film to the etching apparatus. As described above, the substrate can be cooled quickly by installing the substrate cooling unit, and the substrate can be transferred to the next step.
As described above, the time required for temperature changes such as heating and cooling of the substrate is reduced by installing the substrate pre-heating unit in the process before the process of pressing the mold member against the substrate and installing the substrate cooling unit in the process after the process. And increase productivity.
[0010]
Further, the present invention is a pattern transfer device comprising a sensor for detecting the height of both sides of a mold member from a substrate, and a control mechanism for controlling the height of the mold member from the substrate.
A height detection sensor for controlling the height of the mold member is installed, and the height of the mold member is controlled by making the height from the substrate equal on both sides of the mold member. It is possible to prevent the unbalanced load caused by the backlash. Further, it is possible to control the depth of pushing of the mold member.
[0011]
In addition, the present invention has a position correcting mechanism of the concave and convex pattern of the mold member and the concave and convex pattern formed on the substrate at the time of pattern superposition, and performs the pattern superposition by correcting the position of the mold member or the substrate. This is a pattern transfer device characterized by the following.
As described above, since these pattern transfer operations are repeated several times for one product, the patterns can be superimposed by the pattern position correcting mechanism as described above.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 3 show an embodiment of the present invention.
FIG. 1 shows the configuration of the pattern transfer device of the present invention, and the pattern transfer process in the pattern transfer device of the present invention will be described with reference to FIG.
First, the substrate 2 on which the resist film 1 is formed is placed on the plate 3 of the substrate preheating unit. Assuming a pattern transfer by an imprint method in the manufacture of a liquid crystal display, a description will be given on the assumption that the material of the resist film is PMMA, the substrate is a glass substrate, and the substrate size is 650 × 850 mm.
A heat source 22 such as a heating wire is provided in the plate 3 of the substrate preheating unit, and is heated to a softening temperature of the resist film, for example, 200 ° C., and the resist film is softened by heating. Thereafter, the substrate is transported to the mold member pressing section.
[0013]
The plate 5 of the mold member pushing part B has a heat source 22 inside like the substrate preheating part and is heated to the softening temperature of the resist film 1, and the substrate 2 is placed and fixed on the plate 5.
Since the resist film 1 is already heated in the substrate preheating section A, the temperature at the time when the mold member is pushed is reached in the mold member pushing section B in a short heating time.
Next, the cylindrical mold member 6 is pressed against the resist film 1. The circumferential length of the cylindrical mold member 6 may be the same as the length of the substrate 2, or a shorter circumferential mold member may be used if the same pattern is required repeatedly.
By rotating the cylindrical mold member 6 while pressing it against the resist film 1, an uneven shape is formed on the resist film 1.
In this case, the substrate 2 may be fixed on the plate 5 and the mold member 6 may be rotated while moving in parallel. Alternatively, the plate 5 on which the substrate 2 is fixed may be moved in parallel and the mold member 6 is rotated in place. Is also good.
[0014]
A heating means may be provided on the mold member 6 instead of the plate 5, and the resist film 1 of the substrate 2 on the plate 5 may be heated to the softening temperature when the mold member 6 is pushed.
FIG. 4 shows another configuration example in which the heating means 22 is provided on the mold member 6, in which the resist film 1 of the substrate 2 on the plate 5 is heated to the softening temperature when the mold member is pushed.
Further, as shown in FIG. 4, if the heating means 22 is provided on both the plate 5 and the mold member 6, the heating efficiency is further improved.
[0015]
When the mold member 6 is pressed against the substrate 2, the height of the mold member 6 from the substrate 2 is determined by a height detection sensor 7 installed on both side ends of the mold member 6 or a height detection sensor installed on the substrate side. It measures and adjusts so that the height of the mold member 6 from the board | substrate 2 may become equal on both side ends. Thereby, the pressing of the mold member 6 can be made equal at both side ends of the mold member 6, and the uneven load on the substrate 2 can be prevented.
Further, the height of the mold member 6 from the substrate 2 is set by the height detection sensor 7 so that the depth of the press of the mold member 6 into the resist film 1 is obtained, and the mold member 6 is rotated as described above. By pressing the substrate against the substrate 2, pattern transfer can be performed.
The height detection sensor 7 for measuring the height needs to use a measuring device having a resolution of the order of μm or less, such as a laser displacement meter, because the unevenness of the pattern in the manufacture of the semiconductor device is on the order of μm. is there.
[0016]
The pressing load of the mold member 6 is detected by a load cell 8 installed on the mold member 6. The pressing load is greatly affected by the pattern shape of the mold member 6.
For example, in the case of the mold member 6 having a relatively large convex area or a dense pattern, there is little escape of the resist film 1 when pressed, so that a sufficient pressing depth is not applied unless a large pressing load is applied. Cannot be obtained.
In pattern transfer by the imprint method, since the concave portion is etched after the formation of the concave / convex pattern, it is desirable that the indentation depth is uniform.
Therefore, as described above, by setting the height of the mold member 6 from the substrate 2 so as to be equal to the depth of pushing the mold member 6 into the resist film 1, the pushing depths of the pushed concave portions are all equal. To do.
However, since there is no relief place of the resist film 1 when the resist film 1 is pushed in as in the case of the uneven load or the above-mentioned example, when a large concentrated load is applied, the load is detected by the load cell 8 to prevent the substrate 2 from being damaged. However, it is necessary to interlock at a certain load.
When there is a possibility that a large concentrated load as described above may occur, it can be improved by setting the conditions such as lowering the rotation speed of the mold member 6 or increasing the substrate heating temperature in the condition setting stage.
[0017]
The pressing load is compared between the case where the shape of the mold member 6 is a flat plate and the case where the shape is a cylinder. As described above, if the size of the glass substrate is 650 × 850 mm, and the entire substrate is pressed with the above-described pressing load of 100 kgf / cm ² by a flat plate-shaped mold member, a pressing load of 552.5 t is required.
However, in the case of a cylindrical mold member, only circular contacts are in line contact with the substrate, but if the contact area with the substrate is 650 × 10 mm, the pressing load is 6.5t, which is 1/85 of the flat plate. .
As described above, since the pressing force can be made extremely small by making the mold member a cylindrical shape, it is possible to manufacture a pattern transfer device more compactly and inexpensively than in the case of a flat mold member. Become.
In addition, the flatness of the flat mold member must be uniformly pressed on the entire substrate, so that the flatness of the entire mold is extremely severe. However, the cylindrical mold member has a small shape contact tolerance due to a small contact area with the substrate. There is an advantage that the shape is easy to produce and that the shape is easier than the flat shape because of the cylindrical shape.
[0018]
As described above, the concavo-convex pattern is formed on the resist film 1. Thereafter, the substrate 2 is transferred to the substrate cooling section C, cooled to a temperature suitable for the transfer, and transferred to the next step of etching the resist film 1. Incidentally, a cooling device for circulating water may be used as the cooling source 23 of the cool plate 9 of the substrate cooling unit C, and the cooling temperature may be set to about room temperature or a temperature close to the etching process.
Depending on the process, cooling may be performed rapidly by using a cooling device having a built-in Peltier element to improve productivity.
[0019]
In the transfer of the substrate between the steps in the pattern transfer apparatus of the present invention, it is desirable that the substrate be made of a material having heat resistance, such as a ceramic hand that holds the suction end or a side end surface.
Further, the substrate preheating unit A, the mold member pressing unit B, and the substrate cooling unit C each have a substrate elevating mechanism such as a lift pin 4 so that the substrate can be easily transported.
[0020]
Further, as in the present invention, by installing the substrate pre-heating unit A in the process preceding the mold member pushing unit B and the substrate cooling unit C in the subsequent process, it becomes possible to flow the glass substrate sequentially, thereby improving productivity. It can be greatly improved.
[0021]
Next, FIG. 2 and FIG. 3 show an example of the configuration of the pressing portion of the mold member, and the process of the die member pressing portion B and the overlapping of the patterns will be described.
In FIG. 2, the substrate 2 transported from the substrate preheating unit A is placed on a plate 5 set at the softening temperature of the resist film 1. At that time, the mold member stands by at a place where it does not hinder the transfer of the substrate.
Then, the substrate 2 is fixed by the chuck 10 installed on the plate 5. The chuck 10 may be driven by using an air cylinder, a motor, or the like, or may be chucked by mounting an air (vacuum) chuck or an electrostatic chuck on the plate 5.
Further, a shock absorber may be used to prevent the substrate from being damaged during chucking. The presence or absence of the substrate is confirmed by installing the sensor 11 on the fixing chuck or the plate 5, and the heating temperature of the plate 5 is controlled by the temperature controller 20.
[0022]
When the heating means 22 is provided on the mold member 6, the temperature controller 20 is similarly provided to adjust the temperature. FIG. 5 shows an example of a configuration in which the heating means is provided on both the plate 5 and the mold member 6. It is shown.
[0023]
Next, as shown in FIG. 3, markings 12 for pattern positioning are formed on both front ends of the substrate 2 in advance.
Further, a bracket 14 is installed from the bearing portion 13 of the mold member 6, and an image processing camera 15 is installed on the bracket 14. The image processing camera 15 is installed in advance in parallel with the axis of the mold member 6.
Then, the mold member 6 is moved by the X and Y axis position control mechanism 16 to a position where the image processing camera 15 matches the alignment mark 12 on the substrate 2. Incidentally, the X, Y axis position control mechanism 16 can be implemented by a configuration such as a servomotor, a ball screw, and a linear motion guide, or a linear motor may be used when performing high-precision positioning.
Then, the substrate 2 and the plate 5 are rotated by the θ correction mechanism 17 and the X and Y axis position control mechanisms 16 so that the center of the image processing camera 15 and the center of the alignment marking 12 of the substrate 2 are matched. In the figure, reference numeral 21 denotes an image processing device.
As described above, the straight line connecting the axis of the mold member 6 and the two points of the alignment marking 12 is set in parallel.
[0024]
Next, the X / Y-axis position control mechanism 16 moves the axial center position of the mold member 6 to the position of the end of the substrate 2. Further, the mold member 6 is rotated by the mold member rotating motor 18 so that the position of the initial pattern is located at the bottom of the mold member 6.
In this case, the origin position in the rotation direction of the mold member 6 is set in advance, and the pattern position can be controlled by the mold member rotation motor 18.
Thereafter, the lowermost convex portion of the mold member 6 is pushed down by the Z-axis position control mechanism 19 to the same position as the indentation depth of the resist film 1.
The Z-axis position control mechanism 19 can be implemented by a configuration such as a servomotor, a ball screw, and a linear motion guide, like the X- and Y-axis control mechanisms 16. In the case of the Z-axis position control, an accurate position from the substrate 2 is controlled by detecting the height of the mold member 6 from the substrate 2 by the height detection sensor 7 described above.
[0025]
Next, the X-axis position control mechanism 16 synchronizes the movement of the mold member 6 in the X direction with the rotation of the mold member rotating motor 18 to press the mold member 6 against the substrate 2 to transfer a pattern. At this time, the detection is performed while detecting whether an abnormal load is applied by the load cell 8 as described above.
When the mold member 6 reaches the end of the substrate 2, the pressing load on the load cell 8 decreases. Upon detecting this, the Z-axis position control mechanism 19 raises the mold member 6 to a position where it does not hinder the substrate conveyance.
Thereafter, as shown in FIG. 1 described above, the substrate 2 is transferred to the substrate heating section, cooled, and then transported to the next step.
[0026]
【The invention's effect】
As described above, according to the pattern transfer apparatus of the present invention, the use of a flat plate and a cylindrical mold member allows the pressing load to be extremely reduced, so that a brittle material substrate such as a glass substrate or a Si substrate is used. When performing pattern transfer by the imprint method, it is possible to reduce the damage to the substrate due to the uneven load of the pressing load, and it is possible to manufacture the transfer device compactly and inexpensively.
Furthermore, pattern transfer on a large-area substrate requires high flatness and surface accuracy, but in general, a cylindrical shape is easier to achieve processing accuracy than a flat plate shape. By doing so, it is possible to more easily achieve processing accuracy than a plate-shaped mold member.
Then, the entire substrate and resist film are preliminarily heated by the plate, and further, the transferred portion is further heated by the mold member at the time of pattern formation.
In addition, by heating the substrate pre-heating unit in the process preceding the mold member pushing unit and the substrate in advance in the substrate pre-heating unit, the heating time in the mold member pushing process can be further shortened and efficiency can be improved. it can.
In addition, by installing a substrate cooling unit in a post-process, it becomes possible to flow glass substrates sequentially, and a time loss caused by a change in heat of the substrate can be reduced, so that productivity can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing one configuration example of a pattern transfer device of the present invention.
FIG. 2 is a diagram showing an example of a configuration of a mold member pushing section of the pattern transfer apparatus of the present invention.
FIG. 3 is a plan view of a mold member pushing portion of the pattern transfer device of the present invention.
FIG. 4 is a diagram illustrating another configuration example of the partial mold member pushing portion of the pattern transfer device of the present invention.
FIG. 5 is a view showing another configuration example of the mold member pushing section of the pattern transfer apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Resist film 2 Substrate 3 Plate 4 Lift pin 5 Plate 6 Mold member 7 Height detection sensor 8 Load cell 9 Cool plate 10 Chuck 11 Substrate presence / absence confirmation sensor 12 Alignment marking 13 Bearing unit 14 Bracket 15 Image processing camera 16 X, Y position Control mechanism 17 θ correction mechanism 18 Mold member rotation motor 19 Z-axis position control mechanism 20 Temperature controller 21 Image processing device 22 Heat source 23 Cooling source A Substrate preheating section B Mold member pushing section C Substrate cooling

Claims (5)

An apparatus for transferring a pattern by an imprint method to a brittle material substrate such as a glass substrate or a Si substrate on which a resist film softened by heat is formed on the surface, and has a pattern shape on a plate on which the substrate is mounted and fixed. Having concavities and convexities on the circumferential surface, a positively rotating cylindrical mold member is installed so as to be able to move up and down, a control mechanism for pressing load on the resist film of the substrate is provided, and a heating means is provided on the plate and the mold member, Further, a parallel moving means is provided on either the mold member or the plate, and the pattern is transferred by rotating and pressing the mold member on the resist film of the substrate on the plate, and the process of pressing the mold member on the resist film of the substrate is performed. A pattern transfer apparatus comprising: a substrate preheating unit provided in a preceding step; and a substrate cooling unit provided in a subsequent step. An apparatus for transferring a pattern by a imprint method to a brittle material substrate such as a glass substrate or a Si substrate on which a resist film softened by heat is formed on a surface, and on a plate on which the substrate is mounted and fixed in the manufacture of a semiconductor device. In addition to the above, a cylindrical mold member which has a pattern of concavities and convexities on its circumferential surface, a positively rotating cylindrical mold member is installed so as to be able to move up and down, and a control mechanism of a load for pressing a substrate against a resist film is provided. Provide a heating means, further provide a parallel moving means to either the mold member or the plate, perform pattern transfer by rotating and pressing the mold member against the resist film of the substrate on the plate, and to the resist film of the substrate A pattern pre-heating unit is provided in a step preceding the mold member pressing step and a substrate cooling unit is provided in a step subsequent thereto. 3. The pattern transfer device according to claim 1, wherein the heating means has a temperature control mechanism. 4. The pattern transfer apparatus according to claim 1, further comprising a sensor for detecting the height of both side ends of the mold member from the substrate, and a control mechanism for controlling the height of the mold member from the substrate. 2. The method according to claim 1, further comprising a position correcting mechanism for correcting the position of the concave / convex pattern of the mold member and the concave / convex pattern formed on the resist film of the substrate, and performing pattern superposition by correcting the position of the mold member or the substrate. 5. The pattern transfer device according to 2, 3, or 4.

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