This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2011-128280, filed on Jun. 8, 2011; the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a template, a template manufacturing method, and a template manufacturing apparatus.
As a technique for achieving compatibility between fine pattern formation and volume productivity, the so-called nanoimprint method has been drawing attention. The nanoimprint method is a pattern transfer method for transferring the concave-convex pattern of a template to a resin film on a substrate.
In this pattern transfer method, a resin such as a photocurable resin is dropped on the substrate to form a resin film. A template is brought into contact with this resin film. Then, with the resin filled in the concave-convex pattern of the template, the resin is irradiated with e.g. ultraviolet light through the template. Thus, the resin is cured. Subsequently, the template is released. Thus, a pattern having an inverted shape of the concave-convex pattern is formed on the substrate.
In such a pattern transfer method, further improvement in transfer accuracy is required.
In general, according to one embodiment, a template includes: a base substrate; and a pattern portion provided on the base substrate and including a concave-convex pattern formed from a master pattern. The concave-convex pattern is provided in a distorted state with respect to the master pattern in accordance with a distortion of an underlying pattern formed on a substrate to which a shape of the concave-convex pattern is to be transferred.
In general, according to another embodiment, a template manufacturing method includes: acquiring a surface state of a transfer target to which a shape of a concave-convex pattern included in a pattern portion is to be transferred; determining a correction amount for the concave-convex pattern from the surface state; and forming the pattern portion on a base substrate with the concave-convex pattern formed with correction by the correction amount.
In general, according to another embodiment, a template manufacturing apparatus includes: an acquisition section configured to acquire a surface state of a substrate to which a shape of a concave-convex pattern in a pattern portion of a template is to be transferred; a calculation section configured to calculate a correction amount for the concave-convex pattern from the surface state acquired by the acquisition section; and a formation section configured to form the pattern portion on a base substrate with the concave-convex pattern formed with correction by the correction amount calculated by the calculation section.
Embodiments of the invention will now be described with reference to the drawings.
The drawings are schematic or conceptual. The relationship between the thickness and the width of each portion, and the size ratio between the portions, for instance, are not necessarily identical to those in reality. Furthermore, the same portion may be shown with different dimensions or ratios depending on the figures.
In the present specification and the drawings, components similar to those described previously with reference to earlier figures are labeled with like reference numerals, and the detailed description thereof is omitted appropriately.
As shown in
The template 110 includes a base substrate 10 and a pattern portion 20.
The base substrate 10 is a base for supporting the pattern portion 20. In the embodiment, a base substrate 10 having a uniform thickness and a rectangular outline in plan view is used. As the base substrate 10, for instance, a quartz substrate is used.
The pattern portion 20 includes a concave-convex pattern 21 formed from a master pattern 31. The pattern portion 20 includes an intermediate portion 22 provided between the major surface 10a and the concave-convex pattern 21. The intermediate portion 22 only needs to be provided as necessary. In the case of not providing the intermediate portion 22, the concave-convex pattern 21 is directly provided on the major surface 10a. The concave-convex pattern 21 is provided in a distorted state with respect to the master pattern 31 in accordance with the distortion of the underlying pattern formed on the substrate to which the shape of this concave-convex pattern 21 is to be transferred.
Here, the “distortion” referred to in the embodiments includes at least one of the state inclined, the state expanded in at least one direction, and the state contracted in at least one direction, with respect to the reference pattern.
The double dot-dashed line shown in
In the example shown in
Thus, the concave-convex pattern 21 is formed in accordance with the distortion of the underlying pattern. Accordingly, a new pattern can be accurately transferred onto the underlying pattern formed with distortion. That is, even if the underlying pattern is formed with distortion, a new pattern is accurately transferred onto the underlying pattern in accordance with this distortion.
The pattern portion 20 may be either provided directly on the major surface 10a of the base substrate 10 or provided on the major surface 10a of the base substrate 10 separately from the base substrate 10.
Here, an example method for directly providing a pattern portion 20 on the major surface 10a of the base substrate 10 is described.
First, a hard mask layer (e.g., SiO2) and a resist layer are formed on the major surface 10a of the base substrate 10.
Next, using the information of the master pattern 31, the resist layer is subjected to e.g. electron beam exposure and development to form a prescribed resist pattern.
Then, the resist pattern is used as a mask to etch the hard mask layer and the base substrate 10.
Accordingly, the portion covered with the resist pattern constitutes a convex pattern 211, and the portion not covered with the resist pattern constitutes a concave pattern 212. Thus, a concave-convex pattern 21 is completed.
In the case of directly providing a concave-convex pattern 21 on the major surface 10a of the base substrate 10, when the resist pattern is formed, the exposure region is corrected in accordance with the distortion of the underlying pattern. For instance, electron beam exposure on the resist layer can be performed with correction to the electron beam irradiation region based on the distortion of the underlying pattern. Thus, the concave-convex pattern 21 is directly formed on the major surface 10a in accordance with the distortion of the underlying pattern.
Next, an example method for separately providing a pattern portion 20 on the major surface 10a of the base substrate 10 is described.
First, a resin layer is formed on the major surface 10a of the base substrate 10.
Next, an original plate 30 with the master pattern 31 formed thereon is prepared. The master pattern 31 of this original plate 30 is brought into contact with the resin layer. The resin of the resin layer is e.g. a photocurable resin or thermosetting resin.
Then, the resin layer in contact with the master pattern 31 is cured by light irradiation or heating. After the resin layer is cured, the original plate 30 is separated.
Accordingly, a concave-convex pattern 21 with the shape of the master pattern 31 transferred to the resin layer is formed.
In the case of separately providing a concave-convex pattern 21 on the major surface 10a of the base substrate 10, when the resin layer in contact with the original plate 30 is cured, for instance, the distortion of a second distortion amount is applied to the base substrate 10. The second distortion amount is the reverse of the distortion amount of the underlying pattern (first distortion amount). In this state, the resin layer is cured. After the resin layer is cured, the original plate 30 is separated. Then, the distortion applied to the base substrate 10 is relieved.
Thus, the concave-convex pattern 21 is formed while the base substrate 10 is distorted. Hence, when the base substrate 10 is relieved from the distortion and returns to the original shape, the concave-convex pattern 21 on the base substrate 10 is distorted oppositely. The concave-convex pattern 21 is distorted by the return of the second distortion amount, i.e., by the first distortion amount.
The method for separately forming a concave-convex pattern 21 on the major surface 10a of the base substrate 10 can form a concave-convex pattern 21 in a shorter time than the directly forming method. Furthermore, reuse of the base substrate 10 is also easy.
In the following, the embodiment is described with reference to an example in which a concave-convex pattern 21 is separately formed on the major surface 10a of the base substrate 10.
In
On the processing substrate 50, the underlying pattern 51 is previously formed. The underlying pattern 51 is formed in the processing substrate 50 or on the surface of the processing substrate 50 by e.g. photolithography and etching. In forming the underlying pattern 51, the shot alignment may deviate from the ideal condition. This deviation is referred to as “alignment error”. In
The concave-convex pattern 21 of the template 110 is formed in accordance with the distortion (alignment error) of the underlying pattern 51 on the processing substrate 50. That is, the distortion amount of the concave-convex pattern 21 with respect to the master pattern 31 is the amount by which the pattern formed by transferring the shape of the concave-convex pattern 21 onto the underlying pattern 51 is made closer to the underlying pattern 51 relative to the design pattern 61. As an example, the distortion amount of the concave-convex pattern 21 with respect to the master pattern 31 is equal to the distortion amount of the underlying pattern 51 with respect to the design pattern 61.
Such a template 110 is used to transfer the shape of the concave-convex pattern 21 onto the underlying pattern 51. Then, the concave-convex pattern 21 can be formed at an accurate position matched with the distortion of the underlying pattern 51.
In the so-called nanoimprint method using this template 110, the shape of the concave-convex pattern 21 is transferred onto the underlying pattern 51. In the template 110 shown in
If the alignment errors for the respective shots of the underlying pattern 51 are in common, then in the transfer for each shot using the single template 110, the shape of the concave-convex pattern 21 can be transferred at an accurate position.
If the alignment errors for the respective shots of the underlying pattern 51 are different, then before transferring the shape of the concave-convex pattern 21 onto each underlying pattern 51, the concave-convex pattern 21 of the template 110 can be formed in accordance with the alignment error of the corresponding shot of the underlying pattern 51.
As shown in
In such a template 120, by a single transfer process, the shapes of the concave-convex patterns 21a-21d are transferred onto the underlying patterns 51a-51d of four shots on the processing substrate 50, respectively. The transfer using the template 120 is sequentially repeated in units of four underlying patterns 51a-51d.
In this template 120, a plurality of concave-convex patterns 21a-21d formed on one base substrate 10 are formed in accordance with the alignment error of the underlying patterns 51a-51d for each shot. Thus, on the underlying pattern 51a-51d for each shot, the shape of the corresponding concave-convex pattern 21a-21d can be transferred at an accurate position. This can improve the manufacturing yield of the device.
In the above example, concave-convex patterns 21a-21d corresponding to four shots are provided on one base substrate 10. However, the embodiment is also applicable to the case of providing concave-convex patterns corresponding to the number of shots other than four.
Next, a template manufacturing method according to a second embodiment is described.
Here, the processing of steps S101-S103 shown in
The template manufacturing method according to the embodiment includes acquiring a surface state (step S101), calculating a correction amount (step S102), and creating a template (step S103). In the following, an example of each step is described. Here, as an example, a method for manufacturing the template 110 shown in
First, the step of acquiring a surface state (step S101) acquires a surface state of the processing substrate (transfer target) 50 to which the concave-convex pattern 21 of the template 110 is to be transferred. Specifically, the alignment error in the shot of the underlying pattern 51 is acquired. The step of acquiring a surface state (step S101) may include the step of measuring the surface state. Furthermore, the step of acquiring a surface state (step S101) may include the step of acquiring a measurement result of the surface state from an instrument for measuring the surface state.
For instance, the instrument for measuring the surface state can be an alignment measuring device. The alignment measuring device measures a plurality of alignment marks present on the underlying pattern 51 formed by a shot. Then, the alignment measuring device calculates an alignment error for the entire shot from the measurement values (coordinate values) of the alignment marks.
Next, based on the information of the alignment error of the underlying pattern 51 acquired in the previous step S101, the step of calculating a correction amount (step S102) calculates a correction amount for the concave-convex pattern 21 matched with the alignment of the shot.
For instance, from the measurement value of the alignment mark, the distortion amount of the underlying pattern 51 is calculated. A correction amount for this distortion amount is determined by calculation.
Next, the step of creating a template (step S103) creates a concave-convex pattern 21 of the template 110 based on the correction amount calculated in the previous step S102. Specifically, a lateral stress is applied to the base substrate 10, which is e.g. a quartz substrate, to distort the base substrate 10. In this state, a concave-convex pattern 21 is created on the major surface 10a. Then, after creating the concave-convex pattern 21, the stress applied to the base substrate 10 is relieved. Thus, a template 110 having a concave-convex pattern 21 matched with the alignment of the underlying pattern 51 is created.
The step of imprinting (step S104) uses the template 110 created in steps S101-S103 to transfer the shape of the concave-convex pattern 21 of the template 110 onto the underlying pattern 51 of the processing substrate 50.
Even if the shot of the underlying pattern 51 has deviated from the ideal condition, by using the template 110 manufactured in the embodiment, the concave-convex pattern 21 can be accurately formed at a position matched with the alignment error of the underlying pattern 51.
First, as shown in
Then, on this original plate 30, a resin 2 is applied. Alternatively, the resin 2 may be applied to the major surface 10a of the base substrate 10. The material of the resin 2 is e.g. a photocurable resin or thermosetting resin.
Next, as shown in
Next, as shown in
The process shown in
Here, from one original plate 30, a plurality of templates 110 can be created. Furthermore, from one template 110, the shape of the master pattern 31 can be transferred to a plurality of processing substrates 50.
For the used template 110, the pattern portion 20 is stripped from the base substrate 10 by e.g. ashing or washing treatment. After the pattern portion 20 is stripped, the base substrate 10 is reused.
For instance, a plurality of processing substrates 50 are managed in units of lots. The lot is associated with one base substrate 10. Before imprinting, the base substrate 10 is used to manufacture a template 110. Here, in manufacturing the template 110, the distortion matched with the alignment error of the underlying pattern 51 described above is provided in the concave-convex pattern 21.
The template 110 made of the resin 2 can be manufactured in a short time. Hence, even if a template 110 including a concave-convex pattern 21 matched with each shot of the processing substrate 50 is manufactured for each shot, the manufacturing time is not significantly delayed. On the other hand, the shape of the concave-convex pattern 21 can be accurately transferred in accordance with the alignment error of each shot. Hence, products with high yield can be provided.
As an example of matching the distortion of the concave-convex pattern 21 with the shot alignment error, in the embodiment, the step shown in
As shown in
In forming the concave-convex pattern 21 of the template 110, a distortion is applied to the base substrate 10 so that the formed concave-convex pattern 21 is matched with the first distortion amount DS1 of the underlying pattern 51. Specifically, as shown in
The second distortion amount DS2 is the reverse of the first distortion amount DS1. The base substrate 10 is a rectangular substrate having first to fourth sides 11a-11d. In the rectangular base substrate 10, the first side 11a and the second side 11b are opposed to each other, and the third side 11c and the fourth side 11d are opposed to each other.
The second distortion amount DS2 is the reverse of the distortion amount of the underlying pattern 51 distorted like a parallelogram with respect to the rectangular design pattern 61. To the region of the base substrate 10 where the concave-convex pattern 21 is to be formed, a distortion of the second distortion amount DS2 can be applied as follows, for instance. A stress P1 is applied to the end portion of the third side 11c close to the first side 11a. A stress P2 is applied to the end portion of the fourth side 11d close to the second side 11b. The stresses P1 and P2 are produced by forces in the elastic deformation region of the base substrate 10. Thus, the entirety of the base substrate 10 is elastically deformed like a parallelogram. With this deformation, the region for forming a concave-convex pattern 21 is also deformed like a parallelogram. That is, the region for forming a concave-convex pattern 21 is distorted by the second distortion amount DS2.
Then, in this state, as shown in
As shown in
The base substrate 10 having been elastically deformed returns to the original rectangular shape. Then, the concave-convex pattern 21 formed on this base substrate 10 is distorted oppositely. That is, a first distortion amount DS1 is applied to the concave-convex pattern 21. The first distortion amount DS1 is the reverse distortion amount of the second distortion amount DS2.
Here, the underlying pattern 51 shown in
Next, an example of the pattern formation method based on the imprint method is described.
First, as shown in
Next, as shown in
Next, as shown in
As described above, the concave-convex pattern 21 of the template 110 is formed in a distorted state in accordance with the distortion of the underlying pattern to which the shape of this concave-convex pattern 21 is to be transferred. Although not shown in
Next, as shown in
The wavelength of the ultraviolet radiation UV1 is e.g. approximately 300-400 nm. Here, the base substrate 10 and the pattern portion 20 are made of materials sufficiently translucent to the ultraviolet radiation UV1. The transfer target 70 is cured into a transfer pattern 70a having an inverted concave-convex shape of the concave-convex pattern 21. By using the template 110, the transfer pattern 70a is formed in accordance with the distortion of the underlying pattern (not shown) provided on the processing substrate 50.
Next, as shown in
Next, as shown in
Next, a template manufacturing method according to a third embodiment is described.
The flow of the template manufacturing method according to the embodiment is similar to the flow chart shown in
Next, an example of the embodiment is described with reference to
First, as shown in
Next, shown in
Next, imprinting using this template 130 is described.
As shown in
Next, as shown in
If a missing portion 25 occurs in the pattern portion 20, the pattern portion 20 can be stripped from the base substrate 10. After the pattern portion 20 is stripped, the base substrate 10 is reused. Thus, using the same base substrate 10, a pattern portion 20 can be formed again, and a new template 130 can be formed.
According to the embodiment, even if there is foreign matter 55 on the surface of the processing substrate 50, the base substrate 10 can be used for the next transfer processing without influence such as flaws on the base substrate 10 of the template 130. This can contribute to reducing the manufacturing cost of the template 130.
Next, a template manufacturing method according to a fourth embodiment is described.
The flow of the template manufacturing method according to the embodiment is similar to the flow chart shown in
Next, an example of the embodiment is described with reference to
First, as shown in
Next, as shown in
The height h5 of the convex-shaped pattern 37 (the height with reference to the bottom surface of the concave portion of the concave-convex pattern 31b) is matched with the height h4 of the convex portion 57a of the processing substrate 50. In the embodiment, an original plate 30 is prepared in which the height h5 of the convex-shaped pattern 37 is matched with the height h4 of the convex portion 57a measured previously. Such an original plate 30 is formed after measuring the height h4 of the convex portion 57a. Alternatively, after measuring the height h4 of the convex portion 57a, the original plate 30 may be appropriately selected from among a plurality of original plates 30 including convex-shaped patterns 37 with different heights h5.
Then, as shown in
Next, imprinting using this template 140 is described.
First, as shown in
Next, as shown in
Then, in this state, the transfer target 70 is cured by light irradiation or heating. After curing the transfer target 70, the template 140 is released. Thus, as shown in
More specifically,
First, as shown in
By using this first original plate 301, a first pattern portion 201 including a concave-convex pattern 21b is formed on the major surface 10a of the base substrate 10. The first pattern portion 201 is provided with a concave flat portion 21c having an inverted shape of the convex flat portion 31c of the first original plate 301.
Next, as shown in
By using this second original plate 302, a second pattern portion 202 is formed in the first pattern portion 201. More specifically, the second pattern portion 202 includes a concave-convex pattern 21a formed in the concave flat portion 21c of the first pattern portion 201. The concave-convex pattern 21a is constituted by a resin filled between the concave flat portion 21c and the concave-convex pattern 31e. No resin is interposed between the concave-convex pattern 21b and the flat portion 31d. Hence, no pattern is formed therein.
When the concave-convex pattern 21a is formed in this concave flat portion 21c, the spacing between the concave-convex pattern 31e of the second original plate 302 and the concave flat portion 21c is adjusted in accordance with the height h4 of the convex portion 57a measured previously. Thus, the template 104 is completed. This manufacturing method can also manufacture the template 104 matched with the height h4 of the convex portion 57a of the processing substrate 50.
The template 104 described above is an example including a concave-convex pattern 21a in which the transfer pattern 70a is formed on both the convex portion 57a and the concave portion 57b of the processing substrate 50. However, the embodiment is also applicable to an example in which the concave-convex pattern 21 is formed on one of the convex portion 57a and the concave portion 57b of the processing substrate 50.
According to the embodiment, even if a step difference is provided on the processing substrate 50, the transfer pattern 70a can be accurately formed on the processing substrate 50 by the template 140 matched with the step difference. This can contribute to improving the manufacturing yield of the device.
As shown in
The acquisition section 501 performs processing for acquiring a surface state of the substrate to which the shape of the concave-convex pattern in the pattern portion of the template is to be transferred. In the first configuration example, the acquisition section 501 includes an input section 501a. The input section 501a performs processing for inputting the surface state of the substrate from outside. More specifically, the input section 501a performs processing for inputting the information DT1 of the surface state from an external measurement device.
The external measurement device can be e.g. an alignment measurement device, surface inspection device, or foreign matter inspection device. In the case of the alignment measurement device, the information DT1 represents measurement values (coordinate values) of alignment marks M of the underlying pattern 51 shown in
The calculation section 502 performs processing for calculating a correction amount for the concave-convex pattern from the information DT1 of the surface state acquired by the acquisition section 501. For instance, in the case where the information DT1 represents measurement values of alignment marks M, the calculation section 502 calculates the distortion amount of the underlying pattern 51 from the measurement values of alignment marks M, and calculates a correction amount corresponding to this distortion amount. In the case where the information DT1 represents the height h1 of foreign matter 55 and the height h4 of the convex portion 57a, the calculation section 502 calculates a correction amount for the pattern portion 20 corresponding to these heights h1 and h4.
The formation section 503 performs processing for forming a concave-convex pattern with correction by the correction amount calculated by the calculation section 502 in forming a pattern portion on the base substrate. More specifically, the formation section 503 performs processing for forming the template 110, 120, 130, and 140 by steps S101-S103 shown in
This template manufacturing apparatus 510 can manufacture the template 110 and 120 including a concave-convex pattern 21 matched with the distortion of the underlying pattern 51, and the template 130 and 140 including a pattern portion 20 matched with the heights h1 and h4 on the processing substrate 50.
As shown in
The acquisition section 501 performs processing for acquiring a surface state of the substrate to which the shape of the concave-convex pattern in the pattern portion of the template is to be transferred. In the second configuration example, the acquisition section 501 includes a measurement section 501b. The measurement section 501b performs processing for measuring the surface state of the substrate. More specifically, in the manufacturing apparatus 520, the measurement section 501b provided therein measures the surface state of the substrate to which the shape of the concave-convex pattern of the template is to be transferred. The measurement section 501b outputs the information DT1 of the measured surface state to the calculation section 502.
The measurement section 501b can perform processing for measuring e.g. the coordinate values of alignment marks M of the underlying pattern 51 shown in
The processing of the calculation section 502 and the formation section 503 is the same as that of the first configuration example shown in
This template manufacturing apparatus 520 can manufacture the template 110 including a concave-convex pattern 21 matched with the distortion of the underlying pattern 51, and the template 140 including a pattern portion 20 matched with the heights h1 and h4 on the processing substrate 50.
Next, a template manufacturing program according to a sixth embodiment is described.
More specifically,
As shown in
The input section 803 includes a keyboard and a pointing device as well as interfaces for inputting information from external devices through e.g. a network. The output section 804 includes a display as well as interfaces for outputting information to external devices.
As shown in
The acquisition unit 901 performs processing for acquiring a surface state of the substrate to which the concave-convex pattern in the pattern portion of the template is to be transferred (step S201 of
In the case where the external device is an alignment measurement device, the acquisition unit 901 acquires, as the information DT1, measurement values (coordinate values) of alignment marks of the underlying pattern measured by the alignment measurement device. In the case where the external device is a surface inspection device or foreign matter inspection device, the acquisition unit 901 acquires, as the information DT1, the height of the substrate surface inspected by the surface inspection device or foreign matter inspection device.
The calculation unit 902 performs processing for calculating a correction amount for the concave-convex pattern from the information DT1 of the surface state acquired by the acquisition unit 901 (step S202 of
In the case where the information DT1 represents measurement values of alignment marks, the calculation unit 902 calculates the distortion amount of the underlying pattern from the measurement values of alignment marks, and calculates a correction amount corresponding to this distortion amount. In the case where the information DT1 represents the height of the substrate surface, the calculation section 502 calculates a correction amount for the pattern portion corresponding to this height. The calculation result TP1 produced by the calculation unit 902 is outputted in a prescribed data format from the output section 804 of the computer 800. Then, the calculation result TP1 is sent to an external manufacturing device MC.
The manufacturing device MC manufactures a template by applying correction to the pattern portion using the calculation result TP1. Thus, a template including a pattern portion matched with the underlying pattern can be manufactured.
The template manufacturing program according to the embodiment can be practiced as an implementation executed on a computer as described above. Furthermore, the template manufacturing program according to the embodiment can also be practiced as an implementation stored in a prescribed storage medium. Furthermore, the template manufacturing program according to the embodiment can also be practiced as an implementation distributed via a network.
As described above, the embodiments can provide a template, a template manufacturing method, a template manufacturing apparatus, and a template manufacturing program capable of improving the pattern transfer accuracy.
The embodiments and the variations thereof have been described above. However, the invention is not limited to these examples. For instance, those skilled in the art can modify the above embodiments or the variations thereof by suitable addition, deletion, and design change of components, and by suitable combination of the features of the embodiments. Such modifications are also encompassed within the scope of the invention as long as they fall within the spirit of the invention.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
Number | Date | Country | Kind |
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2011-128280 | Jun 2011 | JP | national |