KR20050037773A - Stamper-manufacturing method for imprint lithography - Google Patents

Abstract

Disclosed is a method for manufacturing a stamper for imprint lithography that can minimize process time and cost.

In the method of manufacturing a stamper for imprint lithography of the present invention, after forming a thin film and a polymer on a large area stamper substrate, the polymer is patterned using a thermosetting method or an ultraviolet curing method based on a plurality of small area stampers provided in advance. do. Subsequently, the thin film is patterned using the patterned polymer as an etch mask, and then the patterned polymer is removed to prepare a large area stamper.

By using the large area stamper manufactured as described above to form a large area nanodevice pattern at a time, the process time and cost can be significantly shortened.

Description

Stamper-manufacturing method for imprint lithography

FIELD OF THE INVENTION The present invention relates to imprint lithography, and more particularly to a method for producing a stamper having a large area.

Nano Technology (NT) is attracting attention as a new paradigm that will lead industrial development in the 21st century along with Information Technology (IT) and Bio Technology (BT).

The nanotechnology is a fusion of several scientific and technological fields, such as physics, chemistry, biology, electronics and materials engineering, overcoming the limitations of existing technologies and innovating technology in various industries to dramatically improve the quality of human life. It is expected to be.

Nanotechnology can be divided into top-down and bottom-up approaches, depending on the approach. The approach from top to bottom, as evidenced by the history of semiconductor direct devices that have evolved over the last few decades, seeks to further advance existing microstructure fabrication techniques down to the nanometer scale to continue increasing information storage capacity and information processing speed. It is a technique to do. In contrast, the approach from bottom to top controls materials at the atomic or molecular level, or uses spontaneous nanostructure formation to induce new physical and chemical properties that would not be possible with existing technologies, and use them to create new materials and devices. It is a technique to make.

Representative examples of the approach from top to bottom include optical lithography techniques used in existing semiconductor device manufacturing processes. The technological developments of the 20th century, called the information technology revolution, have relied heavily on the miniaturization and directization of semiconductor devices, and the optical lithography technology is the core technology of the semiconductor device manufacturing process. Currently, light source of optical lithography is moving from krypton fluoride (KrF) laser with minimum line width to argon fluoride (ArF) laser of high resolution. However, the minimum line width of a semiconductor device manufactured by argon fluoride laser is 100 nm, but it is expected that a minimum line width of 90 nm in 2003, 65 nm in 2005, and 45 nm in 2007 will be required.

In such a situation, it is expected that ultrafine technologies are F2 laser lithography, extreme ultraviolet lithography, electron beam projection lithography, and X-ray lithography. These lithography techniques can be applied to pattern fabrication from 40nm to 70nm, but as micronization progresses, the mask has the same resolution as the wavelength of light used, with an exponential increase in the initial investment of the exposure equipment itself. There are a number of problems, including the surge in prices. In other words, the existing lithography technologies raise the question of whether the technology has economic utility along with the difficulty of developing technology that extends to the nanometer range.

What emerges in this situation is nano imprint technology. Nanoimprint technology is a nanodevice fabrication method introduced by Professor Stephen Y. Chou of the United States in the mid-1990s, attracting attention as an alternative to low-productivity electron beam lithography or expensive optical lithography.

Nanoimprint technology is an embossing technique for lithography that is used for mass production of polymer material products with microscale patterns such as compact discs (CD). The core of nanoimprint is to produce a stamper (or mold) having a nanoscale structure by using electron beam lithography or other methods, and to imprint the structure of the nanoscale by imprinting the fabricated stamper on a polymer thin film and repeating the same. By overcoming the problem of productivity of electron beam lithography.

1 (a) to 1 (d) and 2 (a) to 2 (d) briefly illustrate two types of nano imprint processes. That is, FIGS. 1 (a) to 1 (d) show a nano imprint process using a thermosetting method, and FIGS. 2 (a) to 2 (d) show a nano imprint process using a UV curing method. to be.

As shown in FIG. 1A, in the thermosetting method, a polymer thin film 113 is formed on a substrate 111 such as silicon by spin coating. At this time, the stamper 115 (or mold) prepared in advance is positioned in parallel to the substrate 111 and heated to the glass transition temperature of the polymer thin film 113.

Subsequently, the stamper 115 is brought into physical contact with the polymer thin film 113, and then the pressure is lowered (FIG. 1B).

As shown in Fig. 1 (c), when the temperature is below the glass transition temperature, the stamper 115 is separated from the polymer thin film 113 (c).

When the residual polymer is removed, a predetermined pattern is formed on the polymer thin film 113 on the substrate 111 (FIG. 1 (d)).

On the other hand, as shown in Figure 2 (a), in the ultraviolet curing method, the polymer thin film 123 is formed on the substrate 121, such as silicon by spin coating, the photocurable liquid material on the polymer thin film 123 125 is raised.

At this time, ultraviolet rays (UV) are irradiated while bringing the pre-made stamper 127 into contact with the photocurable liquid material 125, and as a result, the liquid material is cured, and the pattern of the stamper 127 is cured. Is imprinted (FIG. 2 (b)). Here, the stamper 127 may be coated with a material to facilitate separation from the cured liquid 125.

Next, as shown in FIG. 2C, the imprinted stamper 127 is separated from the cured liquid material 125. Thus, a pattern is formed on the cured liquid material 125 on the polymer thin film 123.

In this case, the polymer thin film 123 is etched by using the pattern of the cured liquid material 125 as a mask for exposure, and then the cured material 125 is removed to remove the cured material 125 on the substrate 121. 123) a pattern is formed (FIG. 2 (d)).

Here, since the imprint lithography technique using the ultraviolet curing method does not require high temperature and pressure, a lot of research has recently been conducted.

Recently, thanks to the development of imprint-related device technology, step-and-repeat is performed to produce a small area stamper, perform an imprint process on a portion of the wafer, and perform an iterative imprint process while moving the position of the stamper. There is a lot of research into the method. In particular, the step repetitive imprint technology using the ultraviolet curing method has been evaluated as the best technology to date.

3 (a) to 3 (d) are views for briefly explaining a step repetitive imprint lithography process using a conventional ultraviolet curing method.

A small area stamper 135 prepared in advance is aligned on a portion of the substrate 131 on which the polymer thin film 133 is formed (FIG. 3A).

Next, a small area stamper 135 is imprinted onto the polymer thin film 133 while irradiating ultraviolet (UV) light (FIG. 3B).

Subsequently, the small area stamper 135 is separated from the polymer thin film 133, and then the substrate 131 is moved forward by a predetermined distance (FIG. 3C).

Next, as shown in FIG. 3 (d), the process of aligning and then imprinting the stamper 135 having a small area again is repeated. This process is repeatedly performed over all the regions on the substrate 131.

At this time, the size of the stamper determines the area that can be printed at a time, and has become an important factor in determining the productivity of the nanoimprint.

However, the conventional step repetitive imprint technique repeatedly moves a substrate every time an imprint is performed with a small stamper, so that every time the substrate is moved to form a pattern for one entire substrate, alignment and ultraviolet irradiation and imprint are performed. By repeating the process, there is a problem that a lot of time and costs are generated.

Accordingly, an object of the present invention is to provide a stamper manufacturing method that can reduce the process cost and time in the imprint lithography to solve the above problems.

According to a preferred embodiment of the present invention for achieving the above object, a method for manufacturing a stamper for imprint lithography, comprising the steps of continuously forming a thin film and a polymer on a substrate; Forming a pattern on the polymer using a thermosetting method based on a plurality of small area stampers provided in advance; Etching the thin film using the patterned polymer as an etching mask; And removing the patterned polymer to complete a large area stamper.

According to another preferred embodiment of the present invention, a method for manufacturing a stamper for lithography for imprint comprises the steps of: continuously forming a thin film and a polymer on a substrate; Forming a pattern on the polymer using an ultraviolet curing method based on a plurality of small area stampers provided in advance; Etching the thin film using the patterned polymer as an etching mask; And removing the patterned polymer to complete a large area stamper.

Hereinafter, a method for manufacturing a stamper for imprint lithography according to the present invention will be described in detail with reference to the accompanying drawings.

The present invention relates to a method for manufacturing a stamper for imprint lithography, and more particularly to a method for manufacturing a large area stamper.

Figure 4 is a flow chart briefly showing a method of manufacturing a stamper for imprint lithography according to an embodiment of the present invention.

As shown in FIG. 4, the present invention provides a process of manufacturing a plurality of small area stampers by a large area size (S 10), and a process of manufacturing a large area stamper using the manufactured small area stampers (S 20). Is done.

First, a method of manufacturing a small area stamper will be described with reference to FIG.

5 (a) to 5 (d) is a view schematically showing a process for manufacturing a small area stamper in a method for manufacturing a stamper for lithography according to an embodiment of the present invention.

First, the photosensitive polymer 33 is coated on a small area stamper 31 having a small constant size (Fig. 5 (a)).

At this time, the small area stamper 31 is made of silicon (Si). SiO ₂ , quartz glass, nickel (Ni), platinum (Pt), chromium (Cr), polymer materials, and the like may be used. Here, the materials described above may be used for thermosetting imprint lithography. In addition, quark glass or a transparent polymer material can be used in the ultraviolet curing method.

The photosensitive polymer 33 is patterned on the small area stamper 31 coated with the photosensitive polymer 33 by using electron beam lithography, laser lithography, semiconductor exposure equipment, or the like (FIG. 5B).

Subsequently, the small area stamper 31 is etched through dry or wet etching using the patterned photosensitive polymer 33 as an etching mask (FIG. 5C).

As such, when the small area stamper 31 is etched to a certain depth, the photosensitive polymer 33 is removed (FIG. 5 (d)). Accordingly, a pattern having a predetermined fine line width is formed on the small area stamper 31. In this case, the surface of the small area stamper 31 may be surface treated using a chemical agent containing a silane group to facilitate separation from the polymer during the imprint process.

A plurality of small area stampers 31 patterned in this manner can be manufactured by a desired large area size.

As such, when all of the small area stampers for manufacturing the large area stamper are manufactured, the large area stamper is manufactured using the plurality of small area stampers.

The method for manufacturing such a large area stamper can be largely manufactured using either a thermosetting method or an ultraviolet curing method.

First, a method of manufacturing a large area stamper using a thermosetting method will be described.

6 (a) to 6 (h) is a view showing a method for manufacturing a large area stamper in a method for manufacturing a stamper for lithography according to an embodiment of the present invention.

First, a large area stamper substrate 41 having both surfaces polished is provided (Fig. 6 (a)).

Subsequently, a thin film 43 is deposited on the substrate 41 (FIG. 6B). In this case, both the metal and the nonmetal may be used for the thin film 43, which is preferably matched with the material of the substrate 41. For example, when the substrate 41 is a metal, the thin film 43 may also be deposited by a metal material. When the substrate 41 is a non-metal material, the thin film 43 may also be deposited by a non-metal material. In this case, when the thin film 43 is a metal, aluminum (Al), silver (Ag), chromium (Cr), or the like may be used.

Next, the polymer 45 is coated on the deposited thin film 43, and then a plurality of pre-equipped small area stampers 47 are aligned on the coated polymer 45, and then the plurality of aligned small The foil 49 is covered over the area stamper 47 (FIG. 6C). At this time, the size of the foil 49 should be able to include the plurality of small area stamper.

Subsequently, the substrate 41 is heated above the glass transition temperature of the coated polymer 45 to cure the coated polymer 45 while applying gas pressure to the plurality of small area stampers 47 to give the polymer. Imprinted at 45 (Fig. 6 (d)). At this time, the foil 49 covered on the plurality of small area stampers 47 by the gas pressure is deformed and encloses the plurality of small area stampers 47 so that the plurality of small area stampers at a uniform pressure ( 47), thereby allowing the polymer 45 to be subjected to a uniform pressure. The foil 49 is provided with a plurality of small area stampers 47 arranged on the substrate 41 to have different plan views, and thus, a plurality of small area stampers 47 having different plan views. When the gas pressure is applied, the degree to which the plurality of small area stampers 47 presses the polymer 45 is different from each other. That is, when gas pressure is applied to the foil 49, the foil 49 is wrapped around each small area stamper 47 so that each small area stamper 47 presses the polymer 45 at a uniform pressure. Therefore, the polymer 45 is subjected to a uniform pressure to form a uniform pattern.

Next, the substrate 41 is cooled to a temperature below a predetermined temperature, and then the imprinted plurality of small area stampers 47 are separated from the polymer 45 so that the shape of the plurality of small area stampers 47 is transferred. The polymer 45 pattern is formed (FIG. 6 (e)).

Subsequently, dry etching is performed on the patterned polymer 45 until the thin film 43 is exposed to remove the remaining polymer (FIG. 6 (f)).

As such, when the remaining polymer is removed, the thin film 43 is etched using the polymer 45 pattern as an etching mask until the substrate 41 is exposed (Fig. 6 (g)).

And finally, by removing the patterned polymer 45 remaining on the thin film 43, the large area stamper 40 is completed (Fig. 6 (h)).

7 (a) to 7 (h) is a view showing a method for manufacturing a large area stamper in a method for manufacturing a stamper for lithography according to another preferred embodiment of the present invention.

First, a large area stamper substrate 51 having both surfaces polished is provided (Fig. 7 (a)).

Subsequently, a thin film 53 is deposited on the substrate 51 (FIG. 7B). In this case, both the metal and the nonmetal may be used for the thin film 53, and it is preferable to match the material of the substrate 51. For example, when the substrate 51 is a metal, the thin film 53 may also be deposited using a metal material. When the substrate 51 is a nonmetal, the thin film 53 may also be deposited using a nonmetal material. In this case, when the thin film 53 is a metal, aluminum (Al), silver (Ag), chromium (Cr), or the like may be used.

Next, the polymer 55 is coated on the deposited thin film 53, and then a plurality of small area stampers 57 provided in advance are aligned on the coated polymer 55, and then the plurality of small aligned The foil 59 is covered over the area stamper 57 (FIG. 7C). At this time, the size of the foil 59 should include the plurality of small area stamper (57). In addition, the plurality of small area stampers 57 and the foils 59 may be made of a transparent material that can transmit ultraviolet rays.

Subsequently, ultraviolet rays are irradiated while the polymer 55 is imprinted with the plurality of small area stampers 57 to cure the polymer 55 (Fig. 7 (d)). In this case, the foil 59 covered on the plurality of small area stampers 57 by the gas pressure is deformed and surrounds the plurality of small area stampers 57, and thus the plurality of small area stampers at a uniform pressure ( 57), thereby allowing the polymer 55 to be subjected to a uniform pressure. The foil 59 is provided with a plurality of small area stampers 57 arranged on the substrate 51 to have different plan views, and thus, a plurality of small area stampers 57 having different plan views. When the gas pressure is applied, the degree to which the plurality of small area stampers 57 presses the polymer 55 is different from each other. That is, when gas pressure is applied to the foil 59, the foil 59 surrounds each small area stamper 57 so that each small area stamper 57 presses the polymer 55 at a uniform pressure. Therefore, the polymer 55 is subjected to a uniform pressure to form a uniform pattern.

Next, when the polymer 55 is cured to a certain extent, the imprinted plurality of small area stampers 57 are separated from the polymer 55, whereby the shape of the plurality of small area stampers 57 is transferred. 55) A pattern is formed (Fig. 7 (e)).

Subsequently, dry etching is performed on the patterned polymer 55 to remove the remaining polymer until the thin film 53 is exposed (FIG. 7 (f)).

As such, when the remaining polymer is removed, the thin film 53 is etched using the polymer pattern 55 as an etching mask until the substrate 51 is exposed (Fig. 7 (g)).

And finally, by removing the patterned polymer 55 remaining on the thin film 53, a large area stamper 50 is completed (Fig. 7 (h)).

Large area nanodevices can be manufactured at a time using the large area stamper manufactured as described above.

Therefore, the present invention is to manufacture a large area stamper using a plurality of small area stamper provided in advance to form a large area pattern on a large area nano device at a time, thereby repeatedly using a small area stamper as in the prior art. Forming a pattern on the nano-device while moving the can significantly shorten the process cost and time generated.

As described above, according to the method of manufacturing a stamper for imprint lithography of the present invention, by forming a pattern on a large-area nano device at a time by using a large-area stamper, an effect that can significantly shorten the process cost and time is expected. do.

1 (a) to 1 (d) is a view showing a nano imprint process using a thermosetting method.

Figure 2 (a) to 2 (d) is a view showing a nano imprint process using the ultraviolet curing method.

Figure 3 (a) to Figure 3 (d) is a view briefly illustrating a step repeat imprint lithography process using a conventional ultraviolet curing method.

Figure 4 is a flow chart briefly showing a method of manufacturing a stamper for imprint lithography according to an embodiment of the present invention.

5 (a) to 5 (d) schematically show a process of manufacturing a small area stamper in a method for manufacturing a stamper for lithography according to an embodiment of the present invention.

Figure 6 (a) to Figure 6 (h) is a view showing a method for manufacturing a large area stamper in a method for manufacturing a stamper for lithography according to an embodiment of the present invention.

Figure 7 (a) to Figure 7 (h) is a view showing a method for manufacturing a large area stamper in a method for manufacturing a stamper for lithography according to another preferred embodiment of the present invention.

Claims (10)

In the method for manufacturing a stamper for imprint lithography, Continuously forming a thin film and a polymer on the substrate; Forming a pattern on the polymer using a thermosetting method based on a plurality of small area stampers provided in advance; Etching the thin film using the patterned polymer as an etching mask; And Removing the patterned polymer to complete a large area stamper Imprint lithography stamper manufacturing method comprising a. The method of claim 1, wherein forming a pattern on the polymer comprises: Aligning the plurality of small area stampers on the polymer; Imprinting the cured polymer with the plurality of small area stampers while heating the substrate to a predetermined temperature or more to cure the polymer; And Cooling the substrate, and then separating the imprinted plurality of small area stampers from the polymer. 3. The method of claim 2, further comprising covering a foil over the aligned plurality of small area stampers. The method of claim 2, wherein the predetermined temperature is the glass transition temperature of the coated polymer. In the method for manufacturing a stamper for imprint lithography, Continuously forming a thin film and a polymer on the substrate; Forming a pattern on the polymer using an ultraviolet curing method based on a plurality of small area stampers provided in advance; Etching the thin film using the patterned polymer as an etching mask; And Removing the patterned polymer to complete a large area stamper comprising a stamper manufacturing method for imprint lithography. The method of claim 5, wherein forming a pattern on the polymer comprises: Aligning the plurality of small area stampers on the polymer; Irradiating ultraviolet light to cure the polymer while imprinting the polymer with the plurality of small area stampers; And When the polymer is cured to some extent, separating the imprinted plurality of small area stampers from the polymer Imprint lithography stamper manufacturing method comprising a. 7. The method of claim 6, further comprising covering a foil over the aligned plurality of small area stampers. The method according to claim 1 or 5, The substrate is used both metal and non-metal material, when the UV curing method is used, the substrate is a transparent material is used for manufacturing a stamper for imprint lithography. The method according to claim 1 or 5, The material of the thin film is used both metal and non-metal material, the metal material is aluminum (Al), silver (Ag), chromium (Cr) one of the stamper manufacturing method for an imprint lithography, characterized in that used. The method according to claim 1 or 5, The method of manufacturing a stamper for imprint lithography further comprising the step of removing the remaining polymer by etching until the thin film is exposed to the patterned polymer.