Nanoimprint mold for enhancing impact resistance based on polyurea and manufacturing method of nanoimprint mold

Abstract

According to the manufacturing method of the nanoimprint mold based on the polyurea for enhancing the impact resistance, the polyurea film is deposited on the structural layer of the nanoimprint mold in a molecular layer deposition mode, the surface of the structural layer of the nanoimprint mold is evenly coated with the polyurea film in a conformal mode, and therefore impact generated in the nanoimprint process is resisted through the polyurea film, and the impact resistance of the nanoimprint mold is improved. The impact force borne by the imprinting mold is reduced, the mold is prevented from generating cracks or fractures and other defects in the imprinting process, the impact resistance of the nanoimprinting mold is enhanced, the service life of the nanoimprinting mold is prolonged, and the cost is reduced. According to the prepared nanoimprint mold based on polyurea enhanced impact resistance, the thickness of the polyurea coated with the structural layer is uniform, and compared with mold materials such as Si, SiO2 or Ni, the polyurea has higher hydrophobicity, adhesion between the mold and imprint glue during demolding can be reduced, and the quality and precision of a structure or device obtained through imprint can be ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of nanoimprinting, and in particular relates to a nanoimprinting mold based on polyurea to enhance impact resistance and a manufacturing method thereof. Background Art

[0002] Nanoimprint technology is a low-cost and fast method to obtain replica structures at the micro-nano scale. This technology can replicate the structure on the template onto a large surface as required, and then perform conventional etching, stripping and other process flows to finally process nanostructures or devices. Nanoimprint technology has technical advantages such as large-scale, high repeatability, ultra-high resolution, and low cost. It is considered to be a processing method that is expected to replace existing UV lithography, X-ray lithography, and electron beam lithography. It has been widely used in semiconductors, biomedicine, optical device micro-nano manufacturing and other fields.

[0003] The quality and precision of the nanoimprint mold directly affect the quality and precision of the imprinted structure or device. Imprint molds can be divided into two categories: hard molds and soft molds. Compared with soft molds, the quality and precision of the structure or device imprinted by the hard mold are higher, but defects such as mold cracks or breakage are prone to occur during the imprinting process, which affects the quality and precision of the imprinted structure or device, and requires repeated replacement of the mold, increasing manufacturing costs. In some existing implementation schemes, a lower-cost sub-mold is manufactured based on the nanoimprint mold for subsequent imprinting, but this method may still cause mold damage during the imprinting of the sub-mold. In addition, the imprinting of the sub-mold will cause distortion of the imprinted structure and is not suitable for high-precision structure imprinting.

[0004] Based on this, developing a method to improve the impact resistance of nanoimprint molds to improve the impact resistance of nanoimprint molds, prevent defects such as cracks or breakage during the imprinting process, increase service life, and reduce the manufacturing cost of nanoimprint technology is a technical problem that needs to be solved urgently. Summary of the invention

[0005] One of the purposes of the present invention is to provide a method for manufacturing a nanoimprint mold based on polyurea with enhanced impact resistance, which can improve the impact resistance of the nanoimprint mold, prevent defects such as cracks or breakage during the imprinting process, extend the service life, and reduce the manufacturing cost of the nanoimprint technology.

[0006] The second object of the present invention is to provide a nanoimprint mold based on polyurea with enhanced impact resistance, which has good impact resistance and long service life.

[0007] The technical solution adopted by the present invention to achieve one of the purposes is: to provide a method for manufacturing a nanoimprint mold based on polyurea to enhance impact resistance, comprising the following steps: S1, preparing a nanoimprint mold structure layer, and transferring the nanoimprint mold to a deposition chamber; S2, introducing diisocyanate as a first precursor into the deposition chamber through a carrier gas, and then introducing a purge gas to purge excess first precursor; S3, introducing a diamine precursor as a second precursor into the chamber through a carrier gas, and then introducing a purge gas to purge excess second precursor and reaction byproducts; S4, repeating steps S2-S3 for multiple times to deposit a polyurea film of a certain thickness on the surface of the structural layer, thereby obtaining a nanoimprint mold with enhanced impact resistance based on polyurea.

[0008] In the present invention, in order to conformally coat the polyurea to the structural layer of the nanoimprint mold, after a lot of research and exploration, a solution of coating the polyurea film on the structural layer of the nanoimprint mold by molecular layer deposition was determined. Compared with other deposition methods, on the one hand, the self-limited growth characteristics of molecular layer deposition ensure excellent thickness consistency; on the other hand, in molecular layer deposition, by selecting specific precursors and utilizing the mutual reaction between functional groups, it is possible to precisely adjust the chemical composition, thereby in-situ preparing a high-performance, uniformly coated nanoscale polyurea film on the surface of the nanoimprint mold structural layer, thereby improving the impact resistance of the structural layer.

[0009] Furthermore, in step S1, the nanoimprint mold structure layer is obtained by electron beam or laser beam etching. Specifically, the electron beam or laser beam etching process includes the steps of photoresist coating, laser direct writing, etching, cleaning and de-bonding.

[0010] Furthermore, in step S1, before transferring the nanoimprint mold to the deposition chamber, the nanoimprint mold structure layer is plasma cleaned to obtain a clean surface. Preferably, the gas source for plasma cleaning is argon gas, the gas flow rate is 10-30 sccm, and the plasma power density is 1-20 W / cm 2 Appropriate gas flow rate and power can not only avoid damage to the surface of the nanoimprint mold during the cleaning process, but also ensure a thorough cleaning effect.

[0011] Furthermore, in step S1, the material of the nanoimprint mold includes Si, SiO 2 In the process of preparing the nanoimprint mold structure layer, the energy parameters of the electron beam or laser beam are selected and determined by the etched mold material.

[0012] Furthermore, the temperature of the deposition chamber is 25-120°C. Studies have shown that the temperature of the deposition chamber determines the effect of polyurea film deposition. When the temperature is lower than the above range, the deposition range of the film is insufficient and it is difficult to completely cover the surface, affecting the impact resistance of the mold; and when the temperature is higher than the above range, the film deposition thickness is too large, affecting the morphology and precision of the imprinted structure, and causing problems such as thermal expansion, thermal deformation and surface stress in the mold.

[0013] Furthermore, the carrier gas includes one of nitrogen, helium and argon. It has been found that when the flow rate of the carrier gas is too low, the area far from the gas inlet cannot be deposited, while the deposition thickness of the area near the gas inlet is too large; and when the flow rate of the carrier gas is too high, the precursor cannot be attached to the substrate in time, resulting in deposition failure. Preferably, in steps S2 and S3, the flow rate of the carrier gas is controlled to be 25-100 sccm.

[0014] Preferably, the sweep gas can be the same type of gas as the carrier gas and have the same flow rate to facilitate practical operation.

[0015] Furthermore, in step S3, the diamine precursor includes one or more combinations of 1,2-ethylenediamine, N(2-aminoethyl)-1,2-ethylenediamine, and N,N-di(2-aminoethyl)-1,2-ethylenediamine.

[0016] Furthermore, the ratio of the time of the first precursor and the second precursor to be introduced at the same carrier gas flow rate is 1:1-2:1. Preferably, in a single cycle, the intake time of the first precursor is 200-300s, the purge time is 100-200s, and the intake time of the second precursor is 100-300s.

[0017] In the present invention, by reasonably controlling the reaction temperature, gas flow rate and reaction time in the deposition chamber, the uniformity of polyurea film deposition is promoted, which is conducive to obtaining a nanoimprint mold with a better coating effect and higher precision and an impact-resistant layer.

[0018] Furthermore, in step S4, the number of cycles is 6-10 times, and the number of cycles determines the thickness of the polyurea film. The thickness of the polyurea film prepared by the present invention is 3-5 nm. When the thickness is lower than the above range, the improvement of the impact resistance of the nanoimprint mold is insufficient, and if the thickness is too high, it will affect the shape of the structural layer and reduce the precision of the imprint.

[0019] The technical solution adopted by the present invention to achieve the second purpose is: to provide a nanoimprint mold based on polyurea to enhance impact resistance, which is made by the manufacturing method according to one of the purposes of the present invention.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a method for manufacturing a nanoimprint mold based on polyurea to enhance impact resistance. A polyurea film is deposited on the structural layer of the nanoimprint mold. The polyurea film is used to resist the impact generated during the imprinting process, thereby preventing defects such as cracks or breakages in the mold during the imprinting process, thereby enhancing the impact resistance of the nanoimprint mold, increasing the service life of the nanoimprint mold, and reducing costs.

[0021] (2) The method for manufacturing a nanoimprint mold based on polyurea with enhanced impact resistance provided by the present invention has a more uniform thickness of the polyurea film obtained by molecular layer deposition, thereby preventing the mold imprinting accuracy from being affected.

[0022] (3) The nanoimprint mold based on polyurea for enhanced impact resistance prepared by the present invention has a polyurea film uniformly coated on the surface of the structural layer, which is more 2 Or Ni and other mold materials have stronger hydrophobicity, which helps to reduce the adhesion of the mold to the imprinting glue during demolding, ensuring the quality and accuracy of the imprinted structure or device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the imprinting of a nanoimprint mold based on polyurea to enhance impact resistance prepared in an embodiment of the present invention; Figure 2 It is a schematic diagram of an impact load region of one of the periodic structures in a nanoimprint mold with enhanced impact resistance based on polyurea prepared in an embodiment of the present invention during an imprint process; Figure 3 It is a comparison chart of the impact loads on the imprinting mold provided in the comparative example of the present invention and Example 1 before and after being coated with polyurea.

[0024] Among them, 1-structural layer; 2-polyurea film; 3-embossing glue; 4-impact load analysis area. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0027] The present invention provides a method for manufacturing a nanoimprint mold based on polyurea to enhance impact resistance, comprising the following steps: Step 1: Prepare the nanoimprint mold structure layer. The nanoimprint mold raw materials include Si, SiO 2or Ni, and the structure layer is etched out by electron beam or laser beam. The processing process includes photoresist coating, laser direct writing, etching, cleaning and degumming, etc. The energy parameters of the electron beam or laser beam are determined by the selected mold material; the nanoimprint mold structure layer is plasma cleaned (the gas source is argon, the gas flow rate is 10-30 sccm, and the plasma power density is 1-20W / cm 2 ) to obtain a clean surface; then the nanoimprint mold is transferred to a deposition chamber, and the temperature of the deposition chamber is set to 25-120°C; Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor through a carrier gas, and then a purge gas is introduced to purge excess first precursor; the carrier gas is selected from one of nitrogen, helium, and argon, and the flow rate of the carrier gas is 25-100 sccm; the intake time of the first precursor diisocyanate is 200-300 seconds, and the purge time is 100-200 seconds; the purge gas and the carrier gas use the same type and flow rate of gas; Step 3: A diamine precursor is introduced into the chamber as a second precursor through a carrier gas, and then a purge gas is introduced to purge excess second precursor and reaction byproducts; wherein the carrier gas is selected from one of nitrogen, helium, and argon, and the flow rate of the carrier gas is 25-100 sccm; the diamine precursor includes a combination of one or more of 1,2-ethylenediamine, N (2-aminoethyl) -1,2-ethylenediamine, and N, N-di (2-aminoethyl) -1,2-ethylenediamine; the intake time of the diamine precursor is 100-300s; the purge gas and the carrier gas are of the same type and flow rate; Step 4: Cycle steps 2 and 3 for 6-10 times, and coat the surface of the structural layer with a polyurea film having a thickness of 3-5 nm, thereby obtaining a nanoimprint mold based on polyurea with enhanced impact resistance.

[0028] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0029] The main parameters and variables involved in each embodiment of the present invention are shown in Table 1 below.

[0030] Table 1

[0031] Example 1 This embodiment provides a nanoimprint mold based on polyurea to enhance impact resistance, and the manufacturing method thereof comprises the following steps: Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold to the deposition chamber; the raw material of the nanoimprint mold is Si, and the laser direct writing exposure dose is 100mJ / cm 2 , etching gas selection SF 6 or2 , the source power used was 600 W, the bias power was 30 W, and the etching was 30 s. The etched structure layer was plasma cleaned to obtain a clean surface, and then the nanoimprint mold was transferred to the deposition chamber, and the temperature of the deposition chamber was set to 100 °C; Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor through a carrier gas, and then a purge gas is introduced to purge excess first precursor; the carrier gas is N 2 , the flow rate of the carrier gas is 50 sccm; the intake time of the first precursor diisocyanate is 250s, and the purge time is 150s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 3: 1,2-ethylenediamine is introduced into the chamber as the second precursor through a carrier gas, and then a purge gas is introduced to purge excess second precursor and reaction byproducts; wherein the carrier gas is N 2 , the flow rate of the carrier gas is 50 sccm; the intake time of the diamine precursor is 200s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 4: Steps 2 and 3 are cycled for 6 times to coat the surface of the structural layer with a polyurea film having a thickness of 3 nm, thereby obtaining a nanoimprint mold based on polyurea with enhanced impact resistance.

[0032] Example 2 This embodiment provides a nanoimprint mold based on polyurea to enhance impact resistance, and the manufacturing method thereof comprises the following steps: Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold to the deposition chamber; the raw material of the nanoimprint mold is Si, and the laser direct writing exposure dose is 100 mJ / cm 2 , etching gas selection SF 6 or 2 , the source power used was 600 W, the bias power was 30 W, and the etching was 30 s. The etched structure layer was plasma cleaned to obtain a clean surface, and then the nanoimprint mold was transferred to the deposition chamber, and the temperature of the deposition chamber was set to 25 °C; Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor through a carrier gas, and then a purge gas is introduced to purge excess first precursor; the carrier gas is N 2 , the flow rate of the carrier gas is 100 sccm; the intake time of the first precursor diisocyanate is 200 s, and the purge time is 100 s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 3: N (2-aminoethyl)-1,2-ethylenediamine is introduced into the chamber as the second precursor through a carrier gas, and then a purge gas is introduced to purge excess second precursor and reaction byproducts; wherein the carrier gas is N 2, the flow rate of the carrier gas is 100 sccm; the intake time of the diamine precursor is 150 s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 4: Steps 2 and 3 are cycled for 8 times to coat the surface of the structural layer with a polyurea film having a thickness of 4 nm, thereby obtaining a nanoimprint mold based on polyurea with enhanced impact resistance.

[0033] Example 3 This embodiment provides a nanoimprint mold based on polyurea to enhance impact resistance, and the manufacturing method thereof comprises the following steps: Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold to the deposition chamber; the raw material of the nanoimprint mold is Si, and the laser direct writing exposure dose is 100 mJ / cm 2 , etching gas selection SF 6 or 2 , the source power used was 600 W, the bias power was 30 W, and the etching was performed for 30 s. The etched structure layer was plasma cleaned to obtain a clean surface, and then the nanoimprint mold was transferred to the deposition chamber, and the temperature of the deposition chamber was set to 50 °C; Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor through a carrier gas, and then a purge gas is introduced to purge excess first precursor; the carrier gas is N 2 , the flow rate of the carrier gas is 75 sccm; the intake time of the first precursor diisocyanate is 250s, and the purge time is 100s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 3: N,N-bis(2-aminoethyl)-1,2-ethylenediamine is introduced into the chamber as the second precursor through a carrier gas, and then a purge gas is introduced to purge excess second precursor and reaction byproducts; wherein the carrier gas is N 2 , the flow rate of the carrier gas is 75 sccm; the intake time of the diamine precursor is 150s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 4: Steps 2 and 3 are cycled 10 times to coat the surface of the structural layer with a polyurea film having a thickness of 5 nm, thereby obtaining a nanoimprint mold based on polyurea with enhanced impact resistance.

[0034] Example 4 This embodiment provides a nanoimprint mold based on polyurea to enhance impact resistance, and the manufacturing method thereof comprises the following steps: Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold to the deposition chamber; the raw material of the nanoimprint mold is Si, and the laser direct writing exposure dose is 100 mJ / cm 2 , etching gas selection SF 6 or 2, the source power used was 600 W, the bias power was 30 W, and the etching was performed for 30 s. The etched structure layer was plasma cleaned to obtain a clean surface, and then the nanoimprint mold was transferred to the deposition chamber, and the temperature of the deposition chamber was set to 100 °C; Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor through a carrier gas, and then a purge gas is introduced to purge excess first precursor; the carrier gas is N 2 , the flow rate of the carrier gas is 75 sccm; the intake time of the first precursor diisocyanate is 200s, and the purge time is 100s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 3: 1,2-ethylenediamine is introduced into the chamber as the second precursor through a carrier gas, and then a purge gas is introduced to purge excess second precursor and reaction byproducts; wherein the carrier gas is N 2 , the flow rate of the carrier gas is 75 sccm; the intake time of the diamine precursor is 150s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 4: Steps 2 and 3 are cycled for 8 times to coat the surface of the structural layer with a polyurea film having a thickness of 4 nm, thereby obtaining a nanoimprint mold based on polyurea with enhanced impact resistance.

[0035] Example 5 This embodiment provides a nanoimprint mold based on polyurea to enhance impact resistance, and the manufacturing method thereof comprises the following steps: Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold to the deposition chamber; the raw material of the nanoimprint mold is Ni, and the laser direct writing exposure dose is 100 mJ / cm 2 , etching gas selection SF 6 or 2 , the source power used was 600 W, the bias power was 30 W, and the etching was performed for 30 s. The etched structure layer was plasma cleaned to obtain a clean surface, and then the nanoimprint mold was transferred to the deposition chamber, and the temperature of the deposition chamber was set to 120°C; Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor through a carrier gas, and then a purge gas is introduced to purge excess first precursor; the carrier gas is N 2 , the flow rate of the carrier gas is 50 sccm; the intake time of the first precursor diisocyanate is 300 s, and the purge time is 150 s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 3: 1,2-ethylenediamine is introduced into the chamber as the second precursor through a carrier gas, and then a purge gas is introduced to purge excess second precursor and reaction byproducts; wherein the carrier gas is N 2, the flow rate of the carrier gas is 75 sccm; the intake time of the diamine precursor is 100 s; the purge gas and the carrier gas use the same type and flow rate of gas; Step 4: Steps 2 and 3 are cycled 10 times to coat the surface of the structural layer with a polyurea film having a thickness of 5 nm, thereby obtaining a nanoimprint mold based on polyurea with enhanced impact resistance.

[0036] Comparative Example This comparative example provides a nanoimprint mold, which is different from Example 1 in that no polyurea film is deposited on the surface of the nanoimprint mold structure layer.

[0037] The raw material of the nanoimprint mold is Si, the laser direct writing exposure dose is 100, and the etching gas is SF 6 or 2 The source power used was 600 W, the bias power was 30 W, and the etching was performed for 30 s. The etched structure layer was plasma cleaned to obtain a clean surface, thereby obtaining a nanoimprint mold.

[0038] Application performance testing like Figure 1 As shown, the polyurea-based nanoimprint mold with enhanced impact resistance prepared in Example 1 was used to imprint the imprint glue, and the nanoimprint mold prepared in the comparative example was used for comparison. One of the periodic structures at the same position was selected for impact load analysis, as shown in FIG. Figure 2 As shown in the figure, the thick line part is the main area of ​​the nanoimprint mold subjected to impact load, that is, the selected impact load analysis area. The impact load performance of other periodic structures should be the same. Figure 2 The region remains consistent.

[0039] Figure 3 The figure shows the impact load comparison of the same position of the nanoimprint mold and the impact-resistant nanoimprint mold before and after polyurea coating. The positive and negative values ​​indicate compression or tension. Figure 3 It can be seen that the impact load on the impact-resistant nanoimprint mold coated with polyurea provided in Example 1 is greatly reduced. Under the same conditions, the peak value of the impact load on the uncoated nanoimprint mold provided in the comparative example is 771.4 MPa, and the average is 167.2 MPa. The peak value of the impact load on the polyurea film coated in Example 1 is 451.8 MPa, and the average is 70.9 MPa, which are 41.4% and 57.6% lower than those before coating, respectively. The impact resistance of the mold is greatly improved.

[0040] In summary, the nanoimprint mold based on polyurea enhanced impact resistance provided by the present invention can effectively prevent defects such as cracks or breakages in the mold during the imprinting process, enhance the impact resistance of the nanoimprint mold, increase the service life of the nanoimprint mold, reduce manufacturing costs, and has promotion prospects and application value.

[0041] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of the specification of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a nanoimprint mold based on polyurea to enhance impact resistance, characterized in that: The following steps are involved: S1, preparing a nanoimprint mold structure layer, and transferring the nanoimprint mold to a deposition chamber; S2, introducing diisocyanate as a first precursor into the deposition chamber through a carrier gas, and then introducing a purge gas to purge excess first precursor; S3, introducing a diamine precursor as a second precursor into the chamber through a carrier gas, and then introducing a purge gas to purge excess second precursor and reaction byproducts; S4, repeating steps S2-S3 for multiple times to deposit a polyurea film of a certain thickness on the surface of the structural layer, thereby obtaining a nanoimprint mold with enhanced impact resistance based on polyurea.

2. The manufacturing method according to claim 1, characterized in that: In step S1, a nanoimprint mold structure layer is obtained by electron beam or laser beam etching.

3. The manufacturing method according to claim 1, characterized in that: In step S1, the material of the nanoimprint mold includes one of Si, SiO2, and Ni.

4. The manufacturing method according to claim 1, characterized in that: The temperature of the deposition chamber is 25-120°C.

5. The manufacturing method according to claim 1, characterized in that The carrier gas includes one of nitrogen, helium and argon, and the flow rate of the carrier gas is 25-100 sccm.

6. The manufacturing method according to claim 1, characterized in that: In step S3, the diamine precursor includes one or more combinations of 1,2-ethylenediamine, N(2-aminoethyl)-1,2-ethylenediamine, and N,N-di(2-aminoethyl)-1,2-ethylenediamine.

7. The manufacturing method according to claim 1, characterized in that: Under the same carrier gas flow rate condition, the ratio of the time of introduction of the first precursor and the second precursor is 1:1-2:

1.

8. The manufacturing method according to claim 7, characterized in that: In a single cycle, the intake time of the first precursor is 200-300s, the purge time is 100-200s, and the intake time of the second precursor is 100-300s.

9. The manufacturing method according to claim 1, characterized in that: In step S4, the number of cycles is 6-10 times, and the thickness of the polyurea film is 3-5 nm.

10. A nanoimprint mold based on polyurea to enhance impact resistance, characterized in that: The method is prepared according to any one of claims 1 to 9.

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