JP4786867B2 - Method for forming a fine pattern on a substrate using capillary force - Google Patents

Description

  The present invention relates to a method for forming a fine pattern on a substrate such as a silicon, ceramic, metal, or polymer layer, and more particularly, to an integrated circuit, an electronic device, an optical device, a surface acoustic wave (SAW). The present invention relates to a method of forming an ultrafine pattern having a size in a range of 1 μm to several tens of nm using capillary force when manufacturing a filter or the like.

  It is a well-known fact that a fine pattern is formed on a substrate in order to manufacture a semiconductor, an electronic device, a photoelectric device, a magnetic display device, or the like. One of the existing fine pattern forming methods is a photolithography method using light.

  In the photolithography method, a polymer material (for example, a photoresist) having reactivity to light is applied on a substrate on which a material to be patterned is laminated or deposited. Thereafter, the polymeric material is exposed to light irradiated through a reticle designed to have a desired pattern. Thereafter, the exposed polymer material is removed through a development process, and a pattern mask or an etching mask having a target pattern is formed on the material to be patterned. Thereafter, an etching process using a pattern mask is performed to pattern the material deposited or stacked on the substrate so as to form a desired pattern.

  In the existing photolithography method, the circuit line width and the pattern line width are determined by the wavelength of light irradiated on the polymer material during the exposure process. Therefore, it is difficult to produce an ultrafine pattern of, for example, 100 nm or less on a substrate using a photolithography method at the current technical level in the related field.

  As another fine pattern forming method using light, there is a method of forming a three-dimensional pattern on a substrate having a large area through a multi-step process. However, this multi-step process requires a considerable amount of time and is complicated because it requires various steps including patterning, etching, and cleaning. Therefore, there is a possibility that the manufacturing price is high and the productivity is low.

  Furthermore, the existing fine pattern forming method using light has a defect that the process becomes extremely complicated due to light reflection, diffraction, and change in intensity when the surface of the substrate on which the pattern is formed is not flat. Yes.

  In order to improve such a defect, a method for forming an ultrafine pattern of 100 nm or less has been developed. As a new method of this kind, a micro-contact printing method and an imprinting method are well known.

  In the microcontact printing process, a polymer template having a target pattern is stamped on a substrate in order to obtain a desired pattern. A polymer template (eg, polydimethylsiloxane (PDMS) stamp) inked with a suitable solution such as alkanethiol is brought into contact with the surface of the substrate and the ink molecules are transferred to the portion of the substrate that contacts the stamp. . Thereafter, an etching or vapor deposition process is performed to obtain a desired pattern. Such a conventional microcontact printing process has an advantage that no special external force is required. However, since a chemical etching process is used for the last procedure, a rough pattern is obtained. As a result, a desired fine pattern may not be obtained.

  On the other hand, in the imprinting method, a physical pattern is applied to a hard mold having a target pattern to transfer the fine pattern to the polymer layer by a reactive ion etching method or the like, and the fine pattern is formed on the polymer layer. It is a method of forming. However, with conventional imprinting methods, the polymer layer or substrate can be easily deformed and even broken by the high pressures involved.

  This invention is made | formed in view of the said situation, The place made into the objective is to provide the fine pattern formation method which can form a desired fine pattern easily using capillary force.

  In order to achieve the above object, according to a first embodiment of the present invention, there is provided a method for forming a fine pattern on a substrate using a mold having a predetermined pattern structure, wherein the method includes a concave portion and a convex portion. A step of preparing a mold having a predetermined pattern structure including a portion, a step of depositing a polymer material on the substrate, a step of bringing a convex portion of the mold into contact with the polymer material, and a capillary force. A step of flowing the polymer material in contact with the convex portion of the mold into an empty space in the concave portion of the mold to remove the polymer material in contact with the convex portion of the mold; removing the mold; and Forming a polymer fine pattern on the substrate by exposing a part of the upper surface of the substrate.

  According to a second embodiment of the present invention, there is provided a method for forming a fine pattern on a substrate using a mold having a predetermined pattern structure, wherein the method includes a predetermined pattern structure including a concave portion and a convex portion. Providing a casting mold, depositing a thin film layer on the substrate, forming a polymer material on the entire surface of the thin film layer, and contacting a convex portion of the mold with the polymeric material. In order to remove the polymer substance that has contacted the convex part of the mold with the step, the polymer substance that has contacted the convex part of the mold using capillary force is allowed to flow into the empty space in the concave part of the mold, Forming a polymer pattern having a predetermined shape; etching the thin film layer using the polymer pattern as a mask; and selectively removing a portion of the thin film layer; and And removed by, characterized in that it comprises the steps of forming a desired thin film fine pattern.

  The technical central idea of the present invention is to use capillary force to form a fine pattern on a substrate. First, a polymer template having a desired pattern is prepared. Thereafter, the polymer template is brought into contact with the polymer material coated on the substrate, and the capillary material is used to flow the polymer material into an empty space of the polymer template, that is, into the recess, so that the target fine pattern is formed on the substrate. A pattern is formed.

  Various fine pattern forming methods using capillary force according to the present invention will be described.

  First, if the polymer material (eg, polystyrene) on the substrate is fluid, the polymer template is brought into contact with the polymer material provided on the substrate to induce capillary forces and To form a target pattern.

  Second, when the polymer material is a non-flowable material, the polymer template is brought into contact with the polymer material, and then the polymer material is subjected to heat treatment (for example, heating) in a predetermined temperature range to obtain a capillary tube. A force is induced to form a desired pattern on the substrate.

Third, when the polymer material is not fluid, a solvent (eg, propylene glycol monoether acetate PGMEA) is permeated or absorbed into the polymer material provided on the substrate to impart fluidity to the polymer material. Thereafter, the polymer template is brought into contact with the polymer material to induce capillary forces and obtain a target fine pattern. Instead of the polymer template (polydimethylsiloxane PDMS polymer template), an inorganic template such as a SiO ₂ template can be used.

  1A through 1I illustrate steps of a method for forming a thin film fine pattern on a substrate using capillary force according to a first embodiment of the present invention.

  As shown in FIG. 1A, the silicon substrate 104 is ultrasonically cleaned in a container 100 containing a trichloroethylene (TCE) solution 102 for a predetermined time (for example, 5 minutes). Thereafter, as shown in FIG. 1B, the silicon substrate 104 is placed in a container 106 containing a methanol solution, and is ultrasonically cleaned again in the container 106 for a predetermined time (for example, 5 minutes). Thereafter, the methanol-cleaned silicon substrate 104 is finally cleaned using distilled water. In this embodiment, a silicon substrate is taken as an example of the substrate to be patterned, but a substrate made of another material such as ceramic, metal, or polymer can also be used.

  Next, as shown in FIG. 1C, a polymeric material 108 '(eg, polystyrene) dissolved in toluene is applied onto the silicon substrate 104 using spin coating methods well known in the art. At this time, the thickness of the polymer material 108 ′ applied on the silicon substrate 104 is adjusted to be about 100 nm, for example.

  As shown in FIG. 1D, a polydimethylsiloxane PDMS template 110 having a desired fine pattern is contacted with the polymeric material 108 '. In FIG. 1D, 110 ′ indicates an empty space, ie, a recess, in the polydimethylsiloxane PDMS polymer template 110.

  When the polymer material 108 ′ (eg, polystyrene) formed on the silicon substrate 104 has fluidity, the polymer template 110 is in close contact with the polymer material 108 ′ while the fluidity of the polymer material is maintained. Let As a result, a capillary phenomenon appears and the polymer substance 108 ′ penetrates into the empty space 110 ′ of the polymer mold 110. As a result, the convex portion of the polymer mold 110 comes into direct contact with the silicon substrate 104. It should be noted that the empty space 110 ′ of the polymer mold 110 needs to be large enough to accept all of the polymer material formed on the silicon substrate 104.

  However, if the polymeric material 108 '(eg, a so-called novolac resin) is a non-flowable material, additional steps are required to fluidize the polymeric material to induce capillary forces. This example presents two methods for fluidizing non-flowable polymeric materials.

  In the first method, the silicon substrate 104 that is in contact with the polymer mold 110 is heat-treated in a heat treatment furnace, for example, at about 110 ° C. for about 3 hours, as shown in FIG. 1E. The material can be fluidized and flow into the empty space 110 ′ of the polymer mold 110.

  As is well known in the art, most polymeric materials and the like have inherent glass transition temperatures. When heated above the glass transition temperature, the polymeric material fluidizes. Therefore, when a template having a shape capable of pulling up the polymer material is brought into close contact with the polymer material, the polymer material moves to an empty space of the polymer template.

  FIG. 3 shows that the fluidized material is infiltrated into the polymer material on the substrate provided in the sealed container to acquire the fluidity of the polymer material. At this time, the container filled with the fluidized material is placed in the sealed container. It is the schematic which shows the state included in.

  In FIG. 3, a fluidizing material (e.g., a solvent such as propylene glycol monoether acetate PGMEA) is sealed in a sealed container to infiltrate the fluidizing material into the non-flowable polymeric material 108 'formed on the substrate 104. Place in container 302 in 300. When the fluidizing material evaporated from the container 302 is absorbed by the polymer material 108 ', the polymer material 108' has fluidity. As a result, the polymeric material 108 'fluidizes.

  Although not shown in FIG. 3, a container may be used to facilitate evaporation of the fluidized material from the fluidized material contained in the container 302 and to improve the absorption of the fluidized material by the polymeric material 108 ′. A heating device for heating 302 is further included in the sealed container 300. Thus, the time required to provide fluidity to the polymeric material 108 'can be significantly reduced, thereby reducing the overall process time required to pattern the substrate.

  As described above, the polymer material 108 'can flow into the empty space 110' of the polymer template 110 using capillary forces induced by the various methods described above.

  When the polymer material 108 ′ has completely flowed into the empty space 110 ′ of the polymer template 110 using capillary force, the polymer template 110 is removed, and a desired polymer pattern 108, that is, a fine pattern is formed on the silicon substrate 104. As shown in FIG. 1F.

  Using the polymer pattern thus obtained, for example, a fine pattern of metal wiring can be provided on the substrate.

  For example, as shown in FIG. 1G, a silicon substrate 104 having a polymer pattern 108 formed on the substrate is placed in a reactor 120 containing an electroless plating solution 112. As a result, as shown in FIG. 1H, a thin film fine pattern 114 ′ made of, for example, Al or Cu having a desired thickness or more is grown on a predetermined portion of the silicon substrate 104 where the polymer pattern is not left.

  Thereafter, the polymer pattern 108 on the silicon substrate 104 is removed using a solvent. Thereafter, the silicon substrate 104 is dried by nitrogen gas blown into the substrate, thereby forming a target thin film fine pattern on the substrate made of, for example, a conductor, an insulator, a semiconductor, or an organic substance.

  Therefore, unlike the conventional microcontact printing method and imprinting method, according to the present invention, a desired fine pattern can be easily and accurately formed on a substrate by a simple process using capillary force. .

  2A to 2F are diagrams illustrating method steps for forming a thin film fine pattern on a substrate using capillary force according to a second embodiment of the present invention.

  In the first embodiment, a thin film fine pattern is obtained by forming a polymer pattern on a silicon substrate using a polymer template and capillary force having a desired pattern. A thin film layer is grown on a predetermined portion of the substrate surface where the polymer pattern is not formed, and then the polymer pattern is removed from the substrate.

  On the other hand, in the second embodiment of the present invention, a desired fine pattern is formed on a silicon substrate by forming a polymer pattern on the silicon substrate using a polymer template having a desired pattern and capillary force. Thereafter, an etching process is performed using a desired fine pattern as an etching mask.

  In the fine pattern forming method according to the second embodiment of the present invention, the silicon substrate cleaning process and the like are substantially the same as those performed in the first embodiment as shown in FIGS. 1A to 1B.

  As shown in FIG. 2A, a thin film layer 204 'having a predetermined thickness is formed on the silicon substrate 202 by a vapor deposition process. Thereafter, as shown in FIG. 2B, a polymer material 206 'having a predetermined thickness is applied on the entire surface of the thin film layer 204' using, for example, a spin coating method. In the second embodiment, silicon is exemplified as the silicon substrate, but it should be noted that the present invention can be applied to a substrate made of ceramic, metal, polymer, or the like.

  Thereafter, when the polymer material 206 'has fluidity, the polymer template 208 is brought into intimate contact with the polymer material 206'. Otherwise, the polymer material may be heat treated as described in the first embodiment to provide fluidity to the polymer material before the polymer material is in intimate contact with the polymer template 208. And other processes such as the solvent penetration stage and the solvent penetration stage. Thereafter, the polymer material 206 ′ is poured into the empty space 208 ′ of the polymer mold 208.

  At this time, by adjusting the thickness of the polymer material 206 ′, all the polymer material 206 ′ can be poured into the empty space 208 ′ of the polymer mold 208, and a part of the polymer material 206 ′ can be part of the thin film layer. It can also be left on 204 ′.

  A part of the polymer material 206 ′ is left on the thin film layer 204 ′ without flowing into the empty space 208 ′ of the polymer mold 208, and the etching rate is controlled in an etching process described later.

  After all or part of the polymer material 206 ′ is poured into the empty space 208 ′ of the polymer template 208, the polymer template 208 is separated from the thin film layer 204 ′ on the substrate 202 to have a desired pattern structure. A polymer pattern 206 is formed on the thin film layer 204 ′. Thereafter, an etching process is performed using the polymer pattern 206 as an etching mask. Therefore, as shown in FIG. 2E, a specific portion of the thin film layer 204 ′ is selectively removed, thereby selectively exposing a predetermined portion of the silicon substrate 202.

  Thereafter, the polymer pattern 206 formed on the thin film layer 204 ′ is removed using a solvent, and nitrogen gas is blown into the silicon substrate 202 having the thin film layer 204 ′ to dry it. A fine pattern 204 made of a conductor, an insulator, a semiconductor, or an organic material is finally obtained on the silicon substrate 202.

  Accordingly, the fine pattern forming method according to the second embodiment of the present invention can achieve the same effect as the first embodiment.

  As described above, unlike the conventional microcontact printing method and imprinting method, according to the present invention, a polymer fine pattern can be easily formed by a simple process using a polymer template (or inorganic template) and capillary force. In addition, it can be formed on the substrate accurately. Furthermore, by using the polymer fine pattern provided on the substrate as a thin film layer growth suppression layer or etching mask, for example, the target fine pattern can be successfully formed on the substrate made of silicon, ceramic, metal, polymer, etc. Can do.

  While preferred embodiments of the present invention have been described above, those skilled in the art will be able to make various modifications without departing from the scope of the claims of the present invention.

The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 1st Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 1st Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 1st Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 1st Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 1st Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 1st Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 1st Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 1st Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 1st Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 2nd Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 2nd Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 2nd Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 2nd Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 2nd Example of this invention. The figure which shows the step of the process for forming a thin film fine pattern on a board | substrate using capillary force by 2nd Example of this invention. The fluidized material penetrates into the polymer material on the substrate provided in the sealed container to acquire the fluidity of the polymer material, and at this time, the container containing the fluidized material is included in the sealed container. FIG.

Claims (21)

A method of forming a fine pattern on a substrate using a mold having a predetermined pattern structure, the method comprising:
a) having a predetermined pattern structure including concave and convex portions, and providing an elastic mold;
b) depositing a polymeric material on the substrate;
c) contacting the convex portion of the mold with the polymeric material;
c1) performing a heat treatment on the polymer material in a predetermined temperature range;
d) using capillary force to flow the polymer material in contact with the convex portion of the mold into an empty space in the concave portion of the mold to remove the polymer material in contact with the convex portion of the mold;
e) removing the mold to expose a portion of the upper surface of the substrate to form a polymer micropattern on the substrate. A method of forming a fine pattern on a substrate using a mold having a predetermined pattern structure, the method comprising:
a) having a predetermined pattern structure including concave and convex portions, and providing an elastic mold;
b) depositing a polymeric material on the substrate;
b1) impregnating the polymeric material with a fluidizing material to impart fluidity to the polymeric material;
c) contacting the convex portion of the mold with the polymeric material;
d) using capillary force to flow the polymer material in contact with the convex portion of the mold into an empty space in the concave portion of the mold to remove the polymer material in contact with the convex portion of the mold;
e) removing the mold to expose a portion of the upper surface of the substrate to form a polymer micropattern on the substrate. The method according to claim 1 , wherein the template is a polymer template. The method of claim 1 or 2 , wherein the polymeric material is formed on the substrate using a spin coating method. The method
f) depositing a thin film layer on the exposed portion of the upper surface of the substrate;
The method according to claim 1 , further comprising: g) forming a desired thin film micropattern by removing the polymer micropattern. Wherein step b1), in order to facilitate the evaporation of the fluidizing agent, and heating the claim 2, characterized in that it comprises a step of enhancing the penetration into the polymeric material of the fluidized material The method described in 1. The method according to claim 5 , wherein the polymer fine pattern is removed using a solvent. 6. The method of claim 5 , wherein the substrate is selected from the group consisting of a conductor film, an insulating film, a semiconductor film, and an organic film. The method of claim 6 , wherein the polymer material is a novolak resin and the fluidizing material is propylene glycol mono ether acetate (PGMEA). A method of forming a fine pattern on a substrate using a mold having a predetermined pattern structure, the method comprising:
a) having a predetermined pattern structure including concave and convex portions, and providing an elastic mold;
b) depositing a thin film layer on the substrate;
c) forming a polymeric material on the entire surface of the thin film layer;
d) contacting the convex portion of the mold with the polymeric material;
h) heat treating the polymeric material at a predetermined temperature range;
e) In order to remove the polymer substance that has contacted the convex part of the mold, the polymer substance that has contacted the convex part of the mold is caused to flow into the empty space of the concave part of the mold by using capillary force. Forming a polymer pattern of the following shape:
f) etching the thin film layer using the polymer pattern as a mask to selectively remove a portion of the thin film layer;
g) removing the polymer pattern to form a desired thin film fine pattern. A method of forming a fine pattern on a substrate using a mold having a predetermined pattern structure, the method comprising:
a) having a predetermined pattern structure including concave and convex portions, and providing an elastic mold;
b) depositing a thin film layer on the substrate;
c) forming a polymeric material on the entire surface of the thin film layer;
h) impregnating the polymeric material with a fluidized material to impart fluidity to the polymeric material prior to contacting the template with the polymeric material;
d) contacting the convex portion of the mold with the polymeric material;
e) In order to remove the polymer substance that has contacted the convex part of the mold, the polymer substance that has contacted the convex part of the mold is caused to flow into the empty space of the concave part of the mold by using capillary force. Forming a polymer pattern of the following shape:
f) etching the thin film layer using the polymer pattern as a mask to selectively remove a portion of the thin film layer;
g) removing the polymer pattern to form a desired thin film fine pattern. The method according to claim 10 or 11 , wherein the template is a polymer template. 12. The method according to claim 10 , wherein the polymer material is formed on the substrate using a spin coating method. The method according to claim 10 or 11 , wherein the polymer pattern is removed using a solvent. 12. The method according to claim 10 or 11 , wherein the substrate is selected from the group consisting of a conductor film, an insulating film, a semiconductor film, and an organic film. 11. The method of claim 10 , wherein a portion of the polymer material is allowed to flow into an empty space of the mold by the heat treatment, thereby leaving a remaining portion of the polymer material on the thin film layer. It said step h), in order to facilitate the evaporation of the fluidizing agent, claim 11, characterized in that by heating it, comprising the step of enhancing the penetration into the polymeric material of the fluidized material The method described in 1. 14. The method of claim 13 , wherein the polymeric material is a novolac resin and the fluidizing material is propylene glycol mono ether acetate (PGMEA). The method of claim 16 , wherein the remaining portion of the polymer material left on the thin film layer is removed by an etching process. The method according to claim 1 or 2 , wherein the elastic mold is PDMS. The method according to claim 10 or 11 , wherein the elastic mold is PDMS.

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