阅读说明：本技术 压印模板及其制备方法 (Imprint template and preparation method thereof ) 是由 刘震 张笑 郭康 谷新 于 2020-06-16 设计创作，主要内容包括：本发明实施例提供了一种压印模板及其制备方法。压印模板的制备方法包括：在基底上依次形成牺牲层和压印胶层；将由母模板翻制出来的软模板压印在所述压印胶层上,在所述压印胶层上形成位于图案区的压印图案和位于段差区的段差图案；去除所述段差区的压印胶层和牺牲层。在由软模板制备压印模板过程中,本发明实施例通过去除由软模板带来的段差图案,解决了现有小尺寸母模板复制成大尺寸压印模板过程中存在段差不良等问题,可以实现从小尺寸母模板向大尺寸压印机使用大尺寸压印模板的图案准确转移。(The embodiment of the invention provides an imprinting template and a preparation method thereof. The preparation method of the imprinting template comprises the following steps: sequentially forming a sacrificial layer and an imprinting adhesive layer on a substrate; the soft template copied by the mother template is pressed on the imprinting adhesive layer, and an imprinting pattern located in the pattern area and a section difference pattern located in the section difference area are formed on the imprinting adhesive layer; and removing the imprinting glue layer and the sacrificial layer in the segment difference region. In the process of preparing the stamping template by the soft template, the embodiment of the invention solves the problems of poor section difference and the like in the process of duplicating the existing small-size mother template into the large-size stamping template by removing the section difference pattern from the soft template, and can realize the accurate pattern transfer from the small-size mother template to the large-size stamping machine by using the large-size stamping template.)

1. A method of making an imprint template, comprising:

sequentially forming a sacrificial layer and an imprinting adhesive layer on a substrate;

the soft template copied by the mother template is pressed on the imprinting adhesive layer, and an imprinting pattern located in the pattern area and a section difference pattern located in the section difference area are formed on the imprinting adhesive layer;

and removing the imprinting glue layer and the sacrificial layer in the segment difference region.

2. The method of making an imprint template of claim 1, further comprising:

providing a mother template, wherein the mother template comprises an original pattern;

forming a soft template including a transfer pattern and a defective pattern using the master template; the transfer pattern is a complementary pattern of an original pattern on the mother template, and the bad pattern comprises a pattern formed on the upper edge of the mother template in the process of forming the soft template.

3. The method of claim 2, wherein the imprint pattern on the imprint glue layer is a complementary pattern to the transfer pattern, and the step difference pattern on the imprint glue layer is a complementary pattern to the undesired pattern.

4. A method of preparing an imprint template according to claim 2, wherein the master template comprises a single crystal silicon wafer, quartz or glass, and the shape of the master template comprises a square, rectangle, circle or oval.

5. The method of fabricating an imprint template according to claim 2, wherein the master template includes an active area where the original pattern is disposed and an edge area, and an area of the pattern area of the imprint template is smaller than or equal to an area of the active area of the master template.

6. The method for preparing the imprinting template according to any one of claims 1 to 5, wherein the removing of the imprinting glue layer and the sacrificial layer of the segment difference region comprises:

forming a photoresist layer on the imprinting glue layer, carrying out exposure treatment on the photoresist layer by adopting a mask plate, forming an unexposed area in the pattern area, forming a complete exposure area in the segment difference area, removing the photoresist layer of the complete exposure area through development, and reserving the photoresist layer covering the imprinting pattern;

removing part of the imprinting adhesive layer of the segment difference region through first treatment;

removing the sacrificial layer and the residual imprinting glue layer in the segment difference region through second treatment;

and removing the photoresist layer in the pattern area through a third treatment.

7. The imprint template preparation method of claim 6, wherein removing the portion of the imprint glue layer of the segment difference region by a first process comprises: and etching the imprinting adhesive layer in the segment difference region by adopting a reactive ion etching process or an inductive coupling type plasma etching process for 60-200 seconds, wherein the sacrificial layer at a part of the segment difference region is exposed, and the sacrificial layers at other positions are covered with imprinting adhesive blocks.

8. The imprint template preparation method of claim 7, wherein the removing of the sacrificial layer and the remaining imprint glue layer of the segment difference region by the second process comprises: and etching the sacrificial layer exposed out of the segment difference region by adopting a wet etching process, wherein the etching time is 60-200 seconds, and removing the sacrificial layer and the imprinting rubber block in the segment difference region.

9. The imprint template preparation method of claim 8, wherein removing the photoresist layer of the pattern region by a third process includes: and stripping the photoresist layer of the pattern area by adopting a photoresist wet stripping process, wherein the stripping time is 60-300 seconds.

10. The method of claim 6, wherein the sacrificial layer has a thickness of 20nm to 40nm and the photoresist layer has a thickness of 2 μm to 8 μm.

11. The method of fabricating an imprint template according to claim 6, wherein an area of the unexposed region is less than or equal to an area of the pattern region.

12. The method of making an imprint template according to claim 11, wherein a boundary of an orthographic projection of the unexposed area on the substrate is within a boundary of an orthographic projection of the pattern area on the substrate, and a distance between the boundary of the orthographic projection of the unexposed area on the substrate and the boundary of the orthographic projection of the pattern area on the substrate is 2mm to 20 mm.

13. A method of preparing an imprint template as claimed in any one of claims 1 to 5, wherein the material of the sacrificial layer includes any one or more of: the transparent conductive material comprises a metal material, a transparent conductive material and an oxide material, wherein the metal material comprises any one or more of the following materials: aluminum, molybdenum, copper, silver and titanium, the transparent conductive material comprises any one or more of the following: indium tin oxide, the oxide material including any one or more of: indium gallium zinc oxide, indium tin zinc oxide, indium gallium oxide, and indium aluminum zinc oxide.

14. The method for preparing the imprinting template according to any one of claims 1 to 5, wherein the material of the imprinting glue layer comprises a thermal curing type nano-imprinting glue or a UV curing type nano-imprinting glue.

15. An imprint master prepared by the imprint template preparation method of any one of claims 1 to 14, comprising:

a substrate;

a sacrificial layer disposed on the substrate;

the stamping glue layer is arranged on the sacrificial layer, an stamping pattern is formed on the surface of the stamping glue layer, which is far away from one side of the substrate, and the orthographic projection of the stamping glue layer on the substrate is completely overlapped with the orthographic projection of the sacrificial layer on the substrate.

Technical Field

The invention relates to the technical field of semiconductors, in particular to an imprinting template and a preparation method thereof.

Background

The nano imprinting technology (NIL) is a film patterning technology, mainly comprises hot imprinting, ultraviolet imprinting and micro-contact imprinting, and has the characteristics of high resolution, low cost, high yield, large-scale production and the like. The patterning principle of hot embossing and ultraviolet embossing is as follows: under the irradiation of heat or ultraviolet, pressing the imprinting template with the pre-made pattern on the imprinting glue, and making the pattern complementary with the imprinting template through the processes of demoulding, etching the excess glue, etching, removing the glue and the like. Currently, the nanoimprint technology is mainly applied to a film patterning process in the fields of biosensing, light efficiency improvement of Light Emitting Diodes (LEDs), light path control, virtual reality/augmented reality (AR/VR), and the like.

With the increasing demand for large-size and low-cost display technologies, the manufacture of medium-size or large-size display devices gradually starts to adopt the nanoimprint technology. The nanoimprint process flow applied to the display technology field generally includes: firstly preparing an imprinting template, then preparing a working template used by a large-size imprinting machine according to the imprinting template, and patterning a film on a display substrate by using the working template. However, the inventor of the present application has found that the conventional imprint template has a problem of poor step.

Disclosure of Invention

The embodiment of the invention aims to solve the technical problem of providing an imprinting template and a preparation method thereof, and solving the problem of poor section difference of the existing imprinting template. .

In order to solve the technical problem, an embodiment of the present invention provides a method for preparing an imprint template, including:

sequentially forming a sacrificial layer and an imprinting adhesive layer on a substrate;

the soft template copied by the mother template is pressed on the imprinting adhesive layer, and an imprinting pattern located in the pattern area and a section difference pattern located in the section difference area are formed on the imprinting adhesive layer;

and removing the imprinting glue layer and the sacrificial layer in the segment difference region.

Optionally, the method further comprises:

providing a mother template, wherein the mother template comprises an original pattern;

forming a soft template including a transfer pattern and a defective pattern using the master template; the transfer pattern is a complementary pattern of an original pattern on the mother template, and the bad pattern comprises a pattern formed on the upper edge of the mother template in the process of forming the soft template.

Optionally, the imprinted pattern on the imprinted glue layer is a complementary pattern of the transfer pattern, and the level difference pattern on the imprinted glue layer is a complementary pattern of the poor pattern.

Optionally, the mother template comprises a monocrystalline silicon wafer, quartz or glass, and the shape of the mother template comprises a square, a rectangle, a circle or an ellipse.

Optionally, the master template comprises an active area and an edge area, the original pattern is disposed in the active area, and the pattern area of the imprint template is smaller than or equal to the active area of the master template.

Optionally, removing the imprint glue layer and the sacrificial layer of the segment difference region includes:

forming a photoresist layer on the imprinting glue layer, carrying out exposure treatment on the photoresist layer by adopting a mask plate, forming an unexposed area in the pattern area, forming a complete exposure area in the segment difference area, removing the photoresist layer of the complete exposure area through development, and reserving the photoresist layer covering the imprinting pattern;

removing part of the imprinting adhesive layer of the segment difference region through first treatment;

removing the sacrificial layer and the residual imprinting glue layer in the segment difference region through second treatment;

and removing the photoresist layer in the pattern area through a third treatment.

Optionally, removing part of the imprinting glue layer of the segment difference region by a first treatment includes: and etching the imprinting adhesive layer in the segment difference region by adopting a reactive ion etching process or an inductive coupling type plasma etching process for 60-200 seconds, wherein the sacrificial layer at a part of the segment difference region is exposed, and the sacrificial layers at other positions are covered with imprinting adhesive blocks.

Optionally, removing the sacrificial layer and the remaining imprinting glue layer in the step difference region by a second process, including: and etching the sacrificial layer exposed out of the segment difference region by adopting a wet etching process, wherein the etching time is 60-200 seconds, and removing the sacrificial layer and the imprinting rubber block in the segment difference region.

Optionally, removing the photoresist layer of the pattern region by a third process, including: and stripping the photoresist layer of the pattern area by adopting a photoresist wet stripping process, wherein the stripping time is 60-300 seconds.

Optionally, the thickness of the sacrificial layer is 20nm to 40nm, and the thickness of the photoresist layer is 2 μm to 8 μm.

Optionally, the area of the unexposed region is smaller than or equal to the area of the pattern region.

Optionally, the boundary of the orthographic projection of the unexposed area on the substrate is positioned in the boundary range of the orthographic projection of the pattern area on the substrate, and the distance between the boundary of the orthographic projection of the unexposed area on the substrate and the boundary of the orthographic projection of the pattern area on the substrate is 2 mm-20 mm.

Optionally, the material of the sacrificial layer comprises any one or more of the following: the transparent conductive material comprises a metal material, a transparent conductive material and an oxide material, wherein the metal material comprises any one or more of the following materials: aluminum, molybdenum, copper, silver and titanium, the transparent conductive material comprises any one or more of the following: indium tin oxide, the oxide material including any one or more of: indium gallium zinc oxide, indium tin zinc oxide, indium gallium oxide, and indium aluminum zinc oxide.

Optionally, the material of the imprinting glue layer 30 includes a thermal curing type nanoimprint glue or a UV curing type nanoimprint glue.

In order to solve the above technical problem, an embodiment of the present invention further provides an imprint template prepared by the foregoing imprint template preparation method, including:

a substrate;

a sacrificial layer disposed on the substrate;

the stamping glue layer is arranged on the sacrificial layer, an stamping pattern is formed on the surface of the stamping glue layer, which is far away from one side of the substrate, and the orthographic projection of the stamping glue layer on the substrate is completely overlapped with the orthographic projection of the sacrificial layer on the substrate.

The embodiment of the invention provides an imprinting template and a preparation method thereof, and solves the problems of poor section difference and the like in the process of duplicating the existing small-size mother template into a large-size imprinting template by removing the section difference patterns brought by a soft template in the process of preparing the imprinting template by the soft template, and can realize the accurate pattern transfer from the small-size mother template to the large-size imprinting machine by using the large-size imprinting template.

Of course, not all of the advantages described above need to be achieved at the same time in the practice of any one product or method of the invention. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the embodiments of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosed embodiments and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the example serve to explain the principles of the disclosure and not to limit the disclosure. The shapes and sizes of the various elements in the drawings are not to be considered as true proportions, but are merely intended to illustrate the present disclosure.

FIG. 1 is a schematic view of an 8-inch wafer;

FIG. 2 is a schematic diagram of a stepped difference existing on an imprinting master;

FIG. 3 is a flow chart of a method of fabricating an imprint master according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a soft template formed by a manufacturing process according to an embodiment of the invention;

FIG. 5 is a schematic view of a process for forming an imprinting adhesive layer according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a process for forming an imprinting glue pattern according to an embodiment of the present invention;

FIG. 7 is a schematic view of a process for forming a photoresist layer according to one embodiment of the present invention;

FIG. 8 is a schematic view of a photoresist pattern formed by one embodiment of the process;

FIG. 9 is a schematic representation of a first pass of a process according to an embodiment of the present invention;

FIG. 10 is a schematic representation of a second processing step of a process according to an embodiment of the present invention;

FIG. 11 is a schematic representation of a third processing step of a process according to an embodiment of the present invention;

FIG. 12 is a schematic view of a pattern area after wet etching according to one embodiment of the present invention;

FIG. 13 is a schematic illustration of a post-wet etch treatment segment difference zone in accordance with an embodiment of the present invention;

FIG. 14 is a schematic illustration of another fabrication process for forming a soft template according to an embodiment of the present invention;

FIG. 15 is a schematic view of an alternative process for forming an imprinting layer according to embodiments of the present invention;

FIG. 16 is a schematic view of another alternative process for forming an imprint resist pattern according to embodiments of the present invention;

FIG. 17 is a schematic view of another alternative process for forming a photoresist layer in accordance with an embodiment of the present invention;

FIG. 18 is a schematic view of another alternative fabrication process in accordance with an embodiment of the present invention after formation of a photoresist pattern;

FIG. 19 is a schematic representation of another alternate embodiment of the present invention after a first pass;

FIG. 20 is a schematic representation of another alternate embodiment of the present invention after a second pass;

FIG. 21 is a schematic representation of another alternate embodiment of the present invention after a third treatment.

Description of reference numerals:

10-a substrate; 20-a sacrificial layer; 30-imprinting the adhesive layer;

31-stamping a rubber block; 40-a photoresist layer; 100-a wafer;

200-a tray; 201-groove; 300-soft template.

Detailed Description

The embodiments herein may be embodied in many different forms. Those skilled in the art can readily appreciate the fact that the present implementations and teachings can be modified into a variety of forms without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure should not be construed as being limited to the contents described in the following embodiments. The embodiments and features of the embodiments in the present disclosure may be arbitrarily combined with each other without conflict.

The inventor of the application finds that the existing stamping template has the problems of poor section difference and the like and is caused by the edge chamfer of the small-size mother template. Taking an 8-inch wafer (8inches wafer) as an example of the master template, a process for preparing an imprint template by using a wafer in the prior art comprises the following steps: (1) a tray is provided, and grooves are formed in the tray, wherein the shape and the size of the grooves are the same as those of the 8-inch wafer. (2) And placing the 8-inch wafer in a groove of a tray, coating template glue on the surface of the tray, and transferring the pattern of the 8-inch wafer on the template glue to form a soft template with the pattern. (3) Providing a substrate, arranging imprinting glue on the substrate, and imprinting a pattern on the imprinting glue by using a soft template to form an imprinting template. Generally, a wafer (wafer) as a master template is prepared by the following steps: the photoresist is exposed and developed to form a design pattern by using an electron beam lithography technique or a focused ion beam lithography technique, and then the photoresist pattern is transferred to a silicon (Si) substrate by using a dry etching process. In order to improve the mechanical strength of the silicon substrate and prevent the edge of the silicon substrate from cracking or chipping during subsequent processing, the sharp edge of the cut silicon substrate is usually trimmed to a prescribed shape, such as a circular arc chamfer, with a diamond grinding wheel or other means. In the process of preparing the soft template by using the round crystal, the template glue is filled in the edge chamfer of the wafer, so that a poor pattern with the segment difference of dozens of micrometers or even millimeter level appears on the soft template. In the process of preparing the imprinting template by using the soft template, the poor-section patterns on the soft template form poor-section patterns on the imprinting template, so that the imprinting template has poor section differences.

Fig. 1 is a schematic view of an 8-inch wafer, and fig. 2 is a schematic view of a step defect existing on a soft template. Due to the poor section difference on the surface of the soft template, the poor section difference exists on the stamping template prepared by the soft template, and the poor section difference also exists on the working template prepared by the stamping template. In the subsequent film patterning process, the poor step differences cause that the working template can not effectively contact the substrate, the exhaust is insufficient, and the accuracy of the patterning process is seriously influenced. In practical use, the problem of poor step can also exist when the pattern of the small-size master template is directly transferred to the large-size imprinting template.

In order to solve the problems of poor section difference and the like of the existing imprint template, the embodiment of the invention provides a preparation method of the imprint template. FIG. 3 is a flow chart of a method of fabricating an imprint template according to an embodiment of the present invention. As shown in fig. 3, in an exemplary embodiment, a method of preparing an imprint template may include:

s1, sequentially forming a sacrificial layer and an imprinting adhesive layer on the substrate;

s2, stamping the soft template copied by the mother template on the stamping adhesive layer, and forming a stamping pattern in the pattern area and a step difference pattern in the step difference area on the stamping adhesive layer;

and S3, removing the imprinting glue layer and the sacrificial layer of the segment difference region.

In an exemplary embodiment, step S1 may be preceded by the step of forming a soft template.

In an exemplary embodiment, the step of forming the soft template may include:

providing a mother template, wherein the mother template comprises an original pattern;

forming a soft template including a transfer pattern and a defective pattern using the master template; the transfer pattern is a complementary pattern of an original pattern on the mother template, and the bad pattern comprises a pattern formed on the upper edge of the mother template in the process of forming the soft template.

In an exemplary embodiment, the embossed pattern on the embossed glue layer is a complementary pattern to the transfer pattern, and the level difference pattern on the embossed glue layer is a complementary pattern to the defective pattern.

In an exemplary embodiment, the mother substrate includes a single crystal silicon wafer, quartz, or glass, and the shape of the mother substrate includes a square, a rectangle, a circle, or an ellipse.

In an exemplary embodiment, removing the imprinting glue layer and the sacrificial layer of the step difference region includes:

forming a photoresist layer on the imprinting adhesive layer, carrying out exposure treatment on the photoresist layer by adopting a mask plate, removing the photoresist layer in the section difference area after development, and covering the photoresist layer in the pattern area;

removing part of the imprinting adhesive layer of the segment difference region through first treatment;

removing the sacrificial layer and the residual imprinting glue layer in the segment difference region through second treatment;

and removing the photoresist layer in the pattern area through a third treatment.

In an exemplary embodiment, removing the portion of the imprinting glue layer of the segment difference region by a first process includes: and etching the imprinting adhesive layer in the segment difference region by adopting a reactive ion etching process or an inductive coupling type plasma etching process for 60-200 seconds, wherein the sacrificial layer at a part of the segment difference region is exposed, and the sacrificial layers at other positions are covered with imprinting adhesive blocks.

In an exemplary embodiment, removing the sacrificial layer and the remaining imprinting glue layer of the segment difference region by a second process includes: and etching the sacrificial layer exposed out of the segment difference region by adopting a wet etching process, wherein the etching time is 60-200 seconds, and removing the sacrificial layer and the imprinting rubber block in the segment difference region.

In an exemplary embodiment, the removing the photoresist layer of the pattern region by a third process includes: and stripping the photoresist layer of the pattern area by adopting a photoresist wet stripping process, wherein the stripping time is 60-300 seconds.

In an exemplary embodiment, the sacrificial layer has a thickness of 20nm to 40nm, and the photoresist layer has a thickness of 2 μm to 8 μm.

In an exemplary embodiment, the material of the sacrificial layer includes any one or more of: the transparent conductive material comprises a metal material, a transparent conductive material and an oxide material, wherein the metal material comprises any one or more of the following materials: aluminum, molybdenum, copper, silver and titanium, the transparent conductive material comprises any one or more of the following: indium tin oxide, the oxide material including any one or more of: indium gallium zinc oxide, indium tin zinc oxide, indium gallium oxide, and indium aluminum zinc oxide.

In an exemplary embodiment, the material of the imprinting glue layer 30 includes a thermal-curing type nanoimprint glue or a UV-curing type nanoimprint glue.

The technical solution of the present embodiment is further described below by the manufacturing process of the imprint master. The "patterning process" referred to in this disclosure includes processes of depositing a film layer, coating a photoresist, mask exposing, developing, etching, stripping a photoresist, and the like. The deposition can be any one or more of sputtering, evaporation and chemical vapor deposition, the coating can be any one or more of spraying and spin coating, and the etching can be any one or more of dry etching and wet etching, and the disclosure is not limited. "thin film" refers to a layer of a material deposited or otherwise formed on a substrate. The "thin film" may also be referred to as a "layer" if it does not require a patterning process throughout the fabrication process. If the "thin film" requires a patterning process during the entire fabrication process, it is referred to as a "thin film" before the patterning process and a "layer" after the patterning process. The "layer" after the patterning process includes at least one "pattern".

In an exemplary embodiment, the imprint template preparation process may include the following operations.

(1) Forming the soft template. In an exemplary embodiment, forming the soft template may include: providing a wafer 100 and a tray 200, wherein the original pattern A is prepared on the wafer 100 as a master template, the tray 200 is provided with a groove 201, the shape of the groove 201 is basically the same as that of the wafer 100, and the size of the groove 201 is basically the same as that of the wafer 100. In an exemplary embodiment, the shape of the groove 201 and the wafer 100 are both circular, the diameter of the groove 201 is the same as the diameter of the wafer 100, and the depth of the groove 201 is the same as the thickness of the wafer 100. Placing the wafer 100 in the groove 201 of the tray 200, coating template glue on the surface of the tray 200 provided with the groove 201 and the surface of the wafer 100, copying the original pattern A on the wafer 100 on the template glue, and arranging the template glue with the transfer pattern B on a soft substrate to form the soft template 300. Since the wafer 100 has the edge chamfer, the template paste fills the edge chamfer of the wafer 100, and thus the prepared soft template 300 has not only the transfer pattern B but also the defective pattern C, the transfer pattern B of the template 300 is a complementary pattern to the original pattern a of the wafer 100, and the defective pattern C of the template 300 is a pattern formed by the edge chamfer of the wafer 100, as shown in fig. 4.

(2) And forming an imprinting glue layer of the imprinting template. In an exemplary embodiment, forming the imprint glue layer of the imprint template may include: a substrate 10 is provided, a sacrificial layer 20 is formed on the substrate 10, and then an imprint glue layer 30 is formed on the sacrificial layer 20, as shown in fig. 5. In an exemplary embodiment, the substrate 10 may be made of glass, quartz, or hard plastic, and the substrate 10 has the same size as the soft mold 300, and may form a large-sized imprint template, such as a G2.5 size (370mm × 470 mm). In an exemplary embodiment, the sacrificial layer 20 may employ a metal material, a transparent conductive material, and an oxide material. In an exemplary embodiment, the metallic material may include any one or more of: aluminum (Al), molybdenum (Mo), copper (Cu), silver (Ag), and titanium (Ti), or an alloy material of the above metals, such as aluminum neodymium alloy (AlNd) or molybdenum niobium alloy (MoNb), may be a single-layer structure, or a multi-layer composite structure, such as Ti/Al/Ti, or the like. The transparent conductive material may include Indium Tin Oxide (ITO). The oxide material may include any one or more of: indium Gallium Zinc Oxide (IGZO), Indium Tin Zinc Oxide (ITZO), Indium Zinc Oxide (IZO), Indium Gallium Oxide (IGO), and Indium Aluminum Zinc Oxide (IAZO).

In an exemplary embodiment, the sacrificial layer 20 may be deposited by magnetron sputtering (Sputter), and the thickness of the sacrificial layer 20 may be about 20nm to 40 nm. In some possible implementations, the thickness of the sacrificial layer 20 may be about 20nm to 25 nm. In an exemplary embodiment, the imprinting glue layer 30 may employ a thermal curing type nanoimprint glue or a UV curing type nanoimprint glue. In some possible implementations, the imprinting adhesive layer 30 may be a UV-curable nanoimprint adhesive, which has a high pattern resolution and can prepare a pattern with a line width and a line distance of several tens of nanometers. In an exemplary embodiment, the imprinting glue layer 30 may be formed by spraying, spin coating, or inkjet printing, and the like, and the thickness of the imprinting glue layer 30 may be determined according to the structure of the original pattern a on the wafer 100, and the thickness of the imprinting glue layer 30 is not lower than the height of the original pattern a on the wafer 100 in principle.

(3) Forming an imprint resist pattern. In an exemplary embodiment, forming the imprinting paste pattern may include: the soft template 300 including the transferred pattern B and the bad pattern C is pressed on the imprinting glue layer 30 of the imprinting template, and an imprinting glue pattern is formed on the surface of the imprinting glue layer 30 on the side away from the substrate 10, where the imprinting glue pattern includes an imprinting pattern D located in the pattern region and a step difference pattern E located in the step difference region, and the step difference region is located at the periphery of the pattern region, as shown in fig. 6. In an exemplary embodiment, the imprint pattern D on the imprint master and the transfer pattern B on the soft template 300 are complementary patterns, and the level difference pattern E on the imprint master and the defective pattern C on the soft template 300 are complementary patterns, i.e., the imprint pattern D on the imprint template is the same as the original pattern a on the wafer 100, and the level difference pattern E is a level difference defective pattern caused by the edge chamfering of the wafer 100. In an exemplary embodiment, the wafer 100 (master template) includes an active area where the original pattern a is disposed and an edge area, and the pattern area of the imprint template corresponds to the active area of the wafer 100, and the area of the pattern area of the imprint template is smaller than or equal to the area of the active area of the master template. In an exemplary embodiment, the pattern area may be designed by retracting each side of the active area such that the area of the pattern area of the imprint template is smaller than the area of the active area of the master template.

(4) And forming a photoresist layer. In an exemplary embodiment, forming the photoresist layer may include: a photoresist wet film is coated on the imprint template on which the aforementioned pattern is formed, and a photoresist layer 40 covering the imprint pattern D and the step pattern E is formed, as shown in fig. 7. In an exemplary embodiment, the photoresist layer 40 may employ a UV type positive photoresist, and the photoresist layer 40 has a thickness of about 2 μm to 8 μm. In an exemplary embodiment, after the photoresist wet film is coated, the solvent in the photoresist film layer is removed by pre-baking at a temperature of about 80 ℃ to 140 ℃ for about 15 seconds to 360 seconds. In some possible implementations, the photoresist layer 40 has a thickness of about 4 μm to about 5 μm, a pre-bake temperature of about 100 ℃ to about 120 ℃, and a pre-bake time of 270 seconds to 330 seconds.

(5) A photoresist pattern is formed. In an exemplary embodiment, forming the photoresist pattern may include: firstly, a mask plate is used for carrying out exposure treatment on the photoresist layer, an unexposed area is formed in the pattern area, and a complete exposed area is formed in the section difference area. The photoresist layer 40 in the completely exposed region is then removed by development, so that the step pattern E in the step region is exposed, while the photoresist layer 40 in the unexposed region remains, and the imprint pattern D in the pattern region is still covered by the photoresist layer 40, forming a photoresist pattern, as shown in fig. 8. In an exemplary embodiment, the exposure amount in the exposure process may be about 60mj/cm²～400mj/cm²An alkaline developer, such as potassium hydroxide (KOH) solution, may be used, and the development time may be about 60 seconds to 180 seconds. In some possible implementations, the exposure amount in the exposure process may be about 200mj/cm²～300mj/cm²A potassium hydroxide (KOH) solution may be used, and the development time may be about 80 seconds to about 120 seconds. In an exemplary embodiment, in the exposure process using a mask, an area where an unexposed area (a protection area) is formed may be equal to an area of a pattern area, or may be appropriately smaller than the area of the pattern area. In an exemplary embodiment, the unexposed area may be designed by recessing each edge of the pattern area. In an exemplary embodiment, the boundary of the orthographic projection of the unexposed area on the substrate is within the boundary of the orthographic projection of the pattern area on the substrate, and the distance between the boundary of the orthographic projection of the unexposed area on the substrate and the boundary of the orthographic projection of the pattern area on the substrate may be 2mm to 20 mm. In some possible implementations, the distance between the boundary of the orthographic projection of the unexposed area on the substrate and the boundary of the orthographic projection of the pattern area on the substrate may be 4mm to 6 mm.

(6) And (5) carrying out first treatment. In an exemplary embodiment, the first processing may includeComprises the following steps: by using Reactive Ion Etching (RIE) or Inductively Coupled Plasma (ICP) processes, a portion of the imprint glue layer 30 in the step area is removed, so that the sacrificial layer 20 at a portion of the step area is exposed, and the imprint glue blocks 31 cover the sacrificial layer 20 at other portions of the step area, as shown in fig. 9. In an exemplary embodiment, the first process is referred to as an ashing process, and an oxidizing gas, such as oxygen O, may be used₂Or sulfur hexafluoride SF₆And the treatment time is about 60 seconds to 200 seconds. In some possible implementations, the processing time is about 120 seconds to 140 seconds. In an exemplary embodiment, the positions where the sacrificial layer 20 is exposed include at least the positions where the segment difference region is adjacent to the pattern region.

In an exemplary embodiment, considering that the photoresist in the pattern region is also etched during the ashing process, for example, the imprint glue layer 30 in the step region is completely removed, a longer ashing time is required, and a thicker photoresist layer 40 needs to be formed in advance to protect the imprint pattern D in the pattern region, which is not beneficial to the manufacturing efficiency and the manufacturing cost, so the ashing process according to the embodiment of the present invention does not need to completely remove the imprint glue layer 30 in the step region, and the imprint glue blocks 31 remaining in the step region are removed by using a subsequent process, thereby improving the manufacturing efficiency and reducing the manufacturing cost.

(7) And (5) carrying out secondary treatment. In an exemplary embodiment, the second processing may include: and etching the sacrificial layer 20 in the segment difference region by using a wet etching process, removing the sacrificial layer 20 in the segment difference region, and removing the residual imprint glue blocks 31 in the segment difference region along with the removal of the sacrificial layer 20 in the segment difference region, so that the surface of the substrate 10 is exposed in the segment difference region, and the imprint patterns D in the pattern region and the photoresist layer 40 are remained, as shown in fig. 10. In an exemplary embodiment, the second treatment is referred to as a wet etching treatment, and the etching solution used may include a mixed acid solution of sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, acetic acid, and the like, mixed at a certain ratio and concentration, and the etching time may be about 60 seconds to 200 seconds. In some possible implementations, the etch time may be about 100 seconds to 130 seconds.

(8) And (5) carrying out third treatment. In an exemplary embodiment, the third processing may include: the photoresist layer 40 of the pattern region is stripped using a photoresist wet stripping process to form an imprint template free of segment difference defects, as shown in fig. 11. In an exemplary embodiment, the third treatment is referred to as a wet stripping process, the stripping solution may include a combination of alkaline solvents such as N-methylpyrrolidone (NMP), aminoethanol (MEA), or Propylene Glycol Methyl Ether Acetate (PGMEA), and the stripping time may be about 60 seconds to 300 seconds. In some possible implementations, the stripping time may be about 120 seconds to 160 seconds.

The preparation of the imprinting template of the embodiment of the invention is completed through the process flow. In the process of transferring the pattern on the soft template to the imprinting template, the embodiment of the invention effectively eliminates the step difference defect caused by the chamfering of the edge of the wafer by removing the step difference pattern on the imprinting template, solves the problems of poor step difference and the like of the existing imprinting template, and can realize the accurate transfer of the pattern of the large-size imprinting template used by the large-size imprinting machine from the small-size mother template. The large-size imprinting template formed by the embodiment of the invention has the advantages that the pattern structure of the pattern area is complete, the sacrificial layer and the imprinting glue in the segment difference area have no residue, the whole imprinting template has no defect, and the pattern quality of the imprinting template is improved. Furthermore, the embodiment of the invention adopts a combined process of ashing and wet etching, utilizes ashing treatment to remove part of the imprinting adhesive layer in the segment difference region, and utilizes a wet etching process to remove the sacrificial layer and the rest imprinting adhesive layer in the segment difference region, thereby not only ensuring no residue in the segment difference region, but also improving the preparation efficiency and reducing the preparation cost. In addition, the preparation scheme of the embodiment of the invention can be implemented by adopting the existing process equipment, and has the advantages of good process compatibility, high process realizability, strong practicability, simple method, obvious effect and good application prospect.

FIG. 12 is a schematic view of a pattern region after wet etching according to an embodiment of the present invention, and FIG. 13 is a schematic view of a step region after wet etching according to an embodiment of the present invention. The pattern of the pattern area is a one-dimensional nano-grating structure, and fig. 12 is a cross-sectional view of a Scanning Electron Microscope (SEM) of the one-dimensional nano-grating structure of the pattern area. As shown in fig. 12, the laminated structure of the imprinting master plate includes a substrate, a sacrificial layer, and an imprinting adhesive layer forming a one-dimensional nano-grating structure pattern from bottom to top, and the photoresist layer covers the one-dimensional nano-grating structure pattern of the imprinting adhesive layer. It can be seen that the one-dimensional nano-grating structure is accurately replicated and is complete without defects. Fig. 13 illustrates a cross-sectional view of the step area SEM, which shows that no sacrificial layer and no imprint resist layer remain in the step area.

The imprinting template prepared by the preparation method provided by the embodiment of the invention comprises the following steps:

a substrate 10;

a sacrificial layer 20 disposed on the substrate;

an imprinting glue layer 30 is arranged on the sacrificial layer 20, and an imprinting pattern is formed on the surface of the imprinting glue layer 30, which is far away from the substrate 10, and the orthographic projection of the imprinting glue layer on the substrate is completely overlapped with the orthographic projection of the sacrificial layer on the substrate.

In an exemplary embodiment, the imprint pattern on the imprint glue layer 30 is obtained by imprinting through a soft template, the soft template includes a transfer pattern and a bad pattern, the transfer pattern on the soft template is obtained by wafer transfer, and the bad pattern on the soft template is caused by wafer edge chamfering.

It should be noted that the foregoing manufacturing process of forming a transfer pattern on a flexible printed circuit board is merely an exemplary process. In practical application, for a plurality of transfer patterns formed on the flexible film plate, the imprint template can be prepared by the preparation method of the embodiment of the invention.

FIGS. 14-21 are schematic views of another manufacturing process according to an embodiment of the present invention. In an exemplary embodiment, taking the example of the soft film plate having two transfer patterns formed thereon, the process of preparing the imprint template may include:

(11) forming the soft template. In an exemplary embodiment, forming the soft template may include: two wafers 100 and a tray 200 are provided, wherein the two wafers 100 are respectively prepared with an original pattern a1 and an original pattern a2, and the tray 200 is provided with two grooves 201. The two wafers 100 are respectively placed in the two grooves 201 of the tray 200, a template paste is applied, and the original patterns on the two wafers 100 are copied on the template paste, forming a soft template 300 with a transfer pattern B1 and a transfer pattern B2, as shown in fig. 14. In an exemplary embodiment, the soft template with the transfer pattern B1 and the transfer pattern B2 is referred to as a two-window soft template. Since there are edge chamfers for two wafers 100, the surface of the prepared soft template 300 has not only the transfer patterns B1 and B2 but also two defective patterns C due to the edge chamfers. In an exemplary embodiment, the sizes of the two wafers 100 may be the same or may be different, and original pattern a1 and original pattern a2 may be the same or may be different.

(12) And forming an imprinting glue layer of the imprinting template. In an exemplary embodiment, forming the imprint glue layer of the imprint template may include: a substrate 10 is provided, a sacrificial layer 20 is formed on the substrate 10, and then an imprint glue layer 30 is formed on the sacrificial layer 20, as shown in fig. 15.

(13) Forming an imprint resist pattern. In an exemplary embodiment, forming the imprinting paste pattern may include: the soft template 300 having the transfer pattern B1, the transfer pattern B2, and the two defective patterns C is pressed against the imprinting paste layer 30 of the imprinting master, and an imprinting paste pattern is formed on the surface of the imprinting paste layer 30, the imprinting paste pattern including an imprinting pattern D1 and an imprinting pattern D2 located in the pattern region, and a step difference pattern E located in a step difference region located at the periphery of each pattern region, as shown in fig. 16. In an exemplary embodiment, the imprint pattern D1 on the imprint master and the transfer pattern B1 on the soft template 300 are complementary patterns, the imprint pattern D2 on the imprint master and the transfer pattern B2 on the soft template 300 are complementary patterns, and the step difference pattern E on the imprint master and the defective pattern C on the soft template 300 are complementary patterns, i.e., the imprint pattern D1 on the imprint master is identical to the original pattern a1 on the wafer 100, the imprint pattern D2 on the imprint master is identical to the original pattern a2 on the wafer 100, and the step difference pattern E is a step difference defective pattern caused by chamfering of the edge of the wafer 100.

(14) And forming a photoresist layer. In an exemplary embodiment, forming the photoresist layer may include: a photoresist wet film is coated on the imprinting master having the aforementioned pattern formed thereon to form a photoresist layer 40 covering the imprinting pattern D1, the imprinting pattern D2, and the step difference pattern E, as shown in fig. 17.

(15) A photoresist pattern is formed. In an exemplary embodiment, forming the photoresist pattern may include: firstly, a mask plate is used for carrying out exposure treatment on the photoresist layer, an unexposed area is formed in the pattern area, and a complete exposed area is formed in the section difference area. The photoresist layer 40 in the completely exposed region is then removed by development, exposing the step difference pattern E in the step difference region, while the photoresist layer 40 in the unexposed region remains, and the imprint patterns D1 and D2 in the pattern region remain covered with the photoresist layer 40, forming a photoresist pattern, as shown in fig. 18.

(16) And (5) carrying out first treatment. In an exemplary embodiment, the first processing may include: by using the processes of reactive ion etching or inductively coupled plasma etching, etc., part of the step pattern E in the step region is removed, part of the position of the step region is exposed out of the sacrificial layer 20, and part of the position is left with the imprint resist block 31, as shown in fig. 19.

(17) And (5) carrying out secondary treatment. In an exemplary embodiment, the second processing may include: and etching the sacrificial layer 20 in the step area by using a wet etching process, removing the sacrificial layer 20 in the step area, and removing the residual imprint resist blocks 31 in the step area along with the removal of the sacrificial layer 20 in the step area, so that the surface of the substrate 10 is exposed in the step area, and the imprint patterns D1, the imprint patterns D2 and the photoresist layer 40 in the pattern area are remained, as shown in fig. 20.

(18) And (5) carrying out third treatment. In an exemplary embodiment, the third processing may include: the photoresist layer 40 of the pattern region is stripped using a photoresist wet stripping process to form an imprint template free of segment difference defects, as shown in fig. 21.

The embodiment of the invention provides a preparation method of an imprinting template, which removes poor pattern with section difference caused by a soft template through an etching process, effectively eliminates the defect of section difference caused by chamfering of the edge of a wafer, solves the problems of poor section difference and the like of the existing imprinting template, and can realize accurate transfer of the pattern of a large-size imprinting template used by a large-size imprinting machine from a small-size mother template. The imprint template formed by the embodiment of the invention has the advantages that the pattern structure of the pattern area is complete, the sacrificial layer and the imprint glue in the segment difference area have no residue, the imprint template has no defect on the whole, and the pattern quality on the imprint template is improved.

According to the embodiment of the invention, by adopting a combined process of ashing and wet etching, part of the imprinting glue in the segment difference region is removed by ashing treatment, and the sacrificial layer in the segment difference region and the rest of the imprinting glue are removed by using a wet etching process, so that no residue in the segment difference region is ensured, the preparation efficiency is improved, and the preparation cost is reduced.

The preparation scheme of the embodiment of the invention can be implemented by adopting the existing process equipment, and has the advantages of good process compatibility, high process realizability, strong practicability, simple method, obvious effect and good application prospect.

In the description of the present disclosure, it is to be understood that the terms "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present disclosure and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present disclosure.

In the description of the present disclosure, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as being fixedly connected, or detachably connected, or integrally connected; may be a mechanical connection, or may be an electrical connection; may be directly connected, or may be indirectly connected through intervening media, or may be in communication between the two elements. The specific meaning of the above terms in the present disclosure can be understood in specific instances by those of ordinary skill in the art.

Although the embodiments disclosed in the present disclosure are described above, the descriptions are only for the convenience of understanding the present disclosure, and are not intended to limit the present disclosure. It will be understood by those skilled in the art of the present disclosure that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure, and that the scope of the present disclosure is to be limited only by the terms of the appended claims.