A nanoimprint mold based on polyurea-reinforced impact resistance and its manufacturing method

Abstract

This invention provides a method for manufacturing a polyurea-reinforced impact-resistant nanoimprint mold. A polyurea film is deposited on the structural layer of the nanoimprint mold via molecular layer deposition, ensuring a uniform and conformal coating of the polyurea film on the surface of the structural layer. This polyurea film resists impacts generated during nanoimprinting, reducing the impact force on the mold and preventing defects such as cracks or breakage during the imprinting process. This enhances the impact resistance of the nanoimprint mold, extends its service life, and reduces costs. The polyurea-reinforced impact-resistant nanoimprint mold obtained by this invention has a uniform thickness of polyurea coating on the structural layer and exhibits stronger hydrophobicity compared to mold materials such as Si, SiO2, or Ni. This helps reduce adhesion between the mold and the imprinting adhesive during demolding, ensuring the quality and precision of the imprinted structure or device.

Description

Technical Field

[0001] This invention belongs to the field of nanoimprinting technology, specifically relating to a nanoimprinting mold based on polyurea-enhanced impact resistance and its manufacturing method. Background Technology

[0002] Nanoimprint lithography is a low-cost and rapid method for replicating structures at the micro- and nanoscale. This technology can replicate structures from a template onto large surfaces as needed, followed by conventional etching, lift-off, and other processes to ultimately fabricate nanostructures or devices. Nanoimprint lithography offers advantages such as high-volume production, high repeatability, ultra-high resolution, and low cost, and is considered a promising alternative to existing technologies such as UV lithography, X-ray lithography, and electron beam lithography. It has found widespread application in semiconductor, biomedical, and micro / nano fabrication of optical devices.

[0003] The quality and precision of nanoimprint dies directly affect the quality and precision of the imprinted structures or devices. Imprint dies can be broadly classified into hard dies and soft dies. Compared to soft dies, hard dies produce structures or devices with higher quality and precision, but they are prone to defects such as cracks or breaks during the imprinting process. This affects the quality and precision of the imprinted structure or device and necessitates repeated die replacements, increasing manufacturing costs. Some existing implementations use lower-cost sub-dies manufactured based on nanoimprint dies for subsequent imprinting, but this method may still cause die damage during the imprinting process of the sub-dies. Furthermore, imprinting with sub-dies can cause distortion of the imprinted structure, making it unsuitable for high-precision structure imprinting.

[0004] Therefore, developing a method to improve the impact resistance of nanoimprint dies, thereby enhancing their impact resistance, preventing defects such as cracks or breaks during the imprinting process, increasing their service life, and reducing the manufacturing cost of nanoimprint technology, is an urgent technical problem to be solved. Summary of the Invention

[0005] One of the objectives of this invention is to provide a method for manufacturing a nanoimprint mold based on polyurea-reinforced impact resistance, which can improve the impact resistance of nanoimprint molds, prevent defects such as cracks or breaks during the imprinting process, extend their service life, and reduce the manufacturing cost of nanoimprint technology.

[0006] The second objective of this invention is to provide a polyurea-reinforced nanoimprint mold with good impact resistance and long service life.

[0007] One of the technical solutions adopted to achieve the objective of this invention is: to provide a method for manufacturing a nanoimprint mold based on polyurea-reinforced impact resistance, comprising the following steps:

[0008] S1. Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold to the deposition chamber;

[0009] S2. Diisocyanate is introduced into the deposition chamber as a first precursor through carrier gas, and then purge gas is introduced to remove excess first precursor.

[0010] S3. A diamine precursor is introduced into the chamber as a second precursor through a carrier gas, and then a purge gas is introduced to remove excess second precursor and reaction byproducts.

[0011] S4. Repeat steps S2-S3 multiple times to deposit a polyurea film of a certain thickness on the surface of the structural layer, thus obtaining a nanoimprint mold based on polyurea-enhanced impact resistance.

[0012] In this invention, to conformally coat polyurea onto the structural layer of a nanoimprint mold, extensive research and exploration led to the determination of a method using molecular layer deposition (MLD) to coat the structural layer of the nanoimprint mold with a polyurea film. Compared to other deposition methods, MLD offers several advantages. First, the self-limiting growth characteristics of MLD ensure excellent thickness consistency. Second, by selecting specific precursors and utilizing the interactions between functional groups, precise adjustment of the chemical composition becomes possible during MLD. This allows for the in-situ preparation of a high-performance, uniformly coated nanoscale polyurea film on the surface of the nanoimprint mold structural layer, thereby enhancing the impact resistance of the structural layer.

[0013] Further, in step S1, a nanoimprint mold structure layer is obtained by etching with an electron beam or laser beam. Specifically, the electron beam or laser beam etching process includes steps such as photoresist coating, laser direct writing, etching, and cleaning to remove the photoresist.

[0014] Furthermore, in step S1, before transferring the nanoimprint mold into the deposition chamber, the nanoimprint mold structural layer is subjected to plasma cleaning to obtain a clean surface. Preferably, the gas source for plasma cleaning is argon, the gas flow rate is 10-30 sccm, and the plasma power density is 1-20 W / cm². 2 Appropriate gas flow rate and power can both avoid damage to the surface of the nanoimprint mold during the cleaning process and ensure a thorough cleaning effect.

[0015] Furthermore, in step S1, the material of the nanoimprint mold includes one of Si, SiO2, and Ni. During the preparation of the nanoimprint mold structure layer, the energy parameters of the electron beam or laser beam are selected and determined by the mold material being etched.

[0016] Furthermore, the temperature of the deposition chamber is 25-120℃. Studies have found that the temperature of the deposition chamber determines the effect of polyurea film deposition. When the temperature is below the above range, the deposition area of ​​the film is insufficient, making it difficult to completely cover the surface and affecting the impact resistance of the mold. When the temperature is above the above range, the film deposition thickness is too large, which affects the morphology and precision of the imprint structure and can also cause problems such as thermal expansion, thermal deformation and surface stress in the mold.

[0017] Furthermore, the carrier gas includes one of nitrogen, helium, and argon. Studies have found that when the carrier gas flow rate is too low, areas far from the inlet cannot deposit, while areas closer to the inlet have excessively thick deposits; conversely, when the carrier gas flow rate is too high, the precursor cannot adhere to the substrate in time, leading to deposition failure. Preferably, in steps S2 and S3, the carrier gas flow rate is controlled to be 25-100 sccm.

[0018] Preferably, the purge gas can be the same type of gas as the carrier gas and maintain the same flow rate for ease of operation.

[0019] Further, 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.

[0020] Furthermore, the ratio of the introduction time of the first precursor and the second precursor under the same carrier gas flow rate is 1:1 to 2:1. Preferably, in a single cycle, the intake time of the first precursor is 200-300s, the purging time is 100-200s, and the intake time of the second precursor is 100-300s.

[0021] In this 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 beneficial to obtaining a nanoimprint mold with a better coating effect and higher precision and an impact-resistant layer.

[0022] Furthermore, in step S4, the number of cycles is 6-10, and the number of cycles determines the thickness of the polyurea film. The polyurea film obtained by this invention has a thickness of 3-5 nm. When the thickness is less than the above range, the improvement in the impact resistance of the nanoimprint mold is insufficient, while if the thickness is too high, it will affect the shape of the structural layer and reduce the imprinting accuracy.

[0023] The second objective of this invention is achieved by providing a nanoimprint mold based on polyurea-enhanced impact resistance, which is manufactured by the manufacturing method described in one of the objectives of this invention.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) The present invention provides a method for manufacturing a nanoimprint mold based on polyurea-enhanced impact resistance, wherein a polyurea film is deposited in the structural layer of the nanoimprint mold, and the polyurea film is used to resist the impact generated during the imprinting process, preventing defects such as cracks or breaks in the mold during the imprinting process, enhancing the impact resistance of the nanoimprint mold, improving the service life of the nanoimprint mold, and reducing costs.

[0026] (2) The manufacturing method of the nanoimprint mold based on polyurea-enhanced impact resistance provided by the present invention obtains a more uniform polyurea film thickness through molecular layer deposition, which prevents the impact on the imprinting accuracy of the mold.

[0027] (3) The nanoimprint mold based on polyurea-enhanced impact resistance prepared by the present invention has a stronger hydrophobicity than mold materials such as Si, SiO2 or Ni, which helps to reduce the adhesion between the mold and the imprinting adhesive when the mold is demolded, and ensures the quality and accuracy of the imprinted structure or device. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the imprinting process of the nanoimprint mold based on polyurea-reinforced impact resistance obtained in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the impact load region of one of the periodic structures of the polyurea-reinforced impact-resistant nanoimprint mold prepared according to an embodiment of the present invention during the imprinting process;

[0030] Figure 3 This is a comparison diagram of the impact loads on the embossing mold provided in the comparative example and Example 1 of this invention before and after being coated with polyurea.

[0031] Among them, 1-structural layer; 2-polyurea film; 3-imprint adhesive; 4-impact load analysis area. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] 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.

[0034] This invention provides a method for manufacturing a polyurea-reinforced impact-resistant nanoimprint mold, comprising the following steps:

[0035] Step 1: Prepare the nanoimprint mold structure layer. The nanoimprint mold material includes one of Si, SiO2, or Ni. The structure layer is etched by an electron beam or laser beam. The processing includes photoresist coating, laser direct writing, etching, and cleaning to remove the photoresist. The energy parameters of the electron beam or laser beam are determined by the selected mold material. The nanoimprint mold structure layer is then subjected to plasma cleaning (argon gas source, gas flow rate of 10-30 sccm, plasma power density of 1-20 W / cm). 2 To obtain a clean surface, the nanoimprint mold is then transferred to the deposition chamber, and the temperature of the deposition chamber is set to 25-120℃.

[0036] Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor using a carrier gas, followed by a purge gas to remove excess first precursor. The carrier gas is selected from nitrogen, helium, and argon, and its flow rate is 25-100 sccm. The inlet time of the first precursor diisocyanate is 200-300 s, and the purge time is 100-200 s. The purge gas and the carrier gas are the same type and flow rate.

[0037] Step 3: A diamine precursor is introduced into the chamber as a second precursor using a carrier gas, followed by a purge gas to remove excess second precursor and reaction byproducts. The carrier gas is selected from nitrogen, helium, and argon, and its flow rate is 25-100 sccm. 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. The introduction time of the diamine precursor is 100-300 s. The purge gas is the same type and flow rate as the carrier gas.

[0038] Step 4: Repeat steps 2 and 3 6-10 times to coat the surface of the structural layer with a polyurea film with a thickness of 3-5 nm, thus obtaining a nanoimprint mold based on polyurea-enhanced impact resistance.

[0039] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the scope of the invention.

[0040] The main parameters and variables involved in each embodiment of the present invention are shown in Table 1 below.

[0041] Table 1

[0042]

[0043] Example 1

[0044] This embodiment provides a polyurea-reinforced impact-resistant nanoimprint mold, the manufacturing method of which includes the following steps:

[0045] Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold into the deposition chamber; the raw material for the nanoimprint mold is Si, and the laser direct writing exposure dose is 100 mJ / cm². 2 The etching gas used was either SF6 or O2, with a source power of 600W and a bias power of 30W. The etching time was 30 seconds. The etched structural layer was then subjected to plasma cleaning to obtain a clean surface. The nanoimprint mold was then transferred to the deposition chamber, and the temperature of the deposition chamber was set to 100℃.

[0046] Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor using carrier gas, followed by purge gas to remove excess first precursor; the carrier gas is N2, and the flow rate is 50 sccm; the inlet time of the first precursor diisocyanate is 250s, and the purge time is 150s; the purge gas and the carrier gas are the same type and flow rate.

[0047] Step 3: Introduce 1,2-ethylenediamine as the second precursor into the chamber using a carrier gas, followed by the introduction of a purge gas to remove excess second precursor and reaction byproducts; wherein, the carrier gas is N2, the flow rate of the carrier gas is 50 sccm; the inlet time of the diamine precursor is 200s; the purge gas is the same type and flow rate as the carrier gas.

[0048] Step 4: Repeat steps 2 and 3 6 times to coat the surface of the structural layer with a polyurea film with a thickness of 3nm, thus obtaining a nanoimprint mold based on polyurea-enhanced impact resistance.

[0049] Example 2

[0050] This embodiment provides a polyurea-reinforced impact-resistant nanoimprint mold, the manufacturing method of which includes the following steps:

[0051] Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold into the deposition chamber; the raw material for the nanoimprint mold is Si, and the laser direct writing exposure dose is 100 mJ / cm². 2 The etching gas used was either SF6 or O2, with a source power of 600 W and a bias power of 30 W. The etching time was 30 s. The etched structural layer was then subjected to plasma cleaning to obtain a clean surface. The nanoimprint mold was then transferred to the deposition chamber, and the temperature of the deposition chamber was set to 25°C.

[0052] Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor using carrier gas, followed by purge gas to remove excess first precursor; the carrier gas is N2, and the flow rate is 100 sccm; the inlet time of the first precursor diisocyanate is 200s, and the purge time is 100s; the purge gas and the carrier gas are the same type and flow rate.

[0053] Step 3: N(2-aminoethyl)-1,2-ethylenediamine is introduced into the chamber as a second precursor via a carrier gas, followed by the introduction of a purge gas to remove excess second precursor and reaction byproducts; wherein, the carrier gas is N2, the flow rate of the carrier gas is 100 sccm; the inlet time of the diamine precursor is 150 s; the purge gas is the same type and flow rate as the carrier gas;

[0054] Step 4: Repeat steps 2 and 3 8 times to coat the surface of the structural layer with a polyurea film with a thickness of 4nm, thus obtaining a nanoimprint mold based on polyurea-enhanced impact resistance.

[0055] Example 3

[0056] This embodiment provides a polyurea-reinforced impact-resistant nanoimprint mold, the manufacturing method of which includes the following steps:

[0057] Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold into the deposition chamber; the raw material for the nanoimprint mold is Si, and the laser direct writing exposure dose is 100 mJ / cm². 2 The etching gas used was either SF6 or O2, with a source power of 600 W and a bias power of 30 W. The etching time was 30 s. The etched structural layer was then subjected to plasma cleaning to obtain a clean surface. The nanoimprint mold was then transferred to the deposition chamber, and the temperature of the deposition chamber was set to 50°C.

[0058] Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor using carrier gas, followed by purge gas to remove excess first precursor; the carrier gas is N2, and the flow rate is 75 sccm; the inlet time of the first precursor diisocyanate is 250s, and the purge time is 100s; the purge gas and the carrier gas are the same type and flow rate.

[0059] Step 3: N,N-di(2-aminoethyl)-1,2-ethylenediamine is introduced into the chamber as a second precursor via a carrier gas, followed by the introduction of a purge gas to remove excess second precursor and reaction byproducts; wherein, the carrier gas is N2, the flow rate of the carrier gas is 75 sccm; the inlet time of the diamine precursor is 150s; the purge gas is the same type and flow rate as the carrier gas;

[0060] Step 4: Repeat steps 2 and 3 10 times to coat the surface of the structural layer with a 5nm thick polyurea film, thus obtaining a nanoimprint mold based on polyurea-enhanced impact resistance.

[0061] Example 4

[0062] This embodiment provides a polyurea-reinforced impact-resistant nanoimprint mold, the manufacturing method of which includes the following steps:

[0063] Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold into the deposition chamber; the raw material for the nanoimprint mold is Si, and the laser direct writing exposure dose is 100 mJ / cm². 2 The etching gas used was either SF6 or O2, with a source power of 600 W and a bias power of 30 W. The etching time was 30 s. The etched structural layer was then subjected to plasma cleaning to obtain a clean surface. The nanoimprint mold was then transferred to the deposition chamber, and the temperature of the deposition chamber was set to 100℃.

[0064] Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor using carrier gas, followed by purge gas to remove excess first precursor; the carrier gas is N2, and the flow rate is 75 sccm; the inlet time of the first precursor diisocyanate is 200s, and the purge time is 100s; the purge gas and the carrier gas are the same type and flow rate.

[0065] Step 3: Introduce 1,2-ethylenediamine as the second precursor into the chamber using a carrier gas, followed by the introduction of a purge gas to remove excess second precursor and reaction byproducts; wherein, the carrier gas is N2, the flow rate of the carrier gas is 75 sccm; the inlet time of the diamine precursor is 150s; the purge gas is the same type and flow rate as the carrier gas.

[0066] Step 4: Repeat steps 2 and 3 8 times to coat the surface of the structural layer with a polyurea film with a thickness of 4nm, thus obtaining a nanoimprint mold based on polyurea-enhanced impact resistance.

[0067] Example 5

[0068] This embodiment provides a polyurea-reinforced impact-resistant nanoimprint mold, the manufacturing method of which includes the following steps:

[0069] Step 1: Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold into the deposition chamber; the raw material for the nanoimprint mold is Ni, and the laser direct writing exposure dose is 100 mJ / cm². 2The etching gas used was either SF6 or O2, with a source power of 600 W and a bias power of 30 W. The etching time was 30 s. The etched structural layer was then subjected to plasma cleaning to obtain a clean surface. The nanoimprint mold was then transferred to the deposition chamber, and the temperature of the deposition chamber was set to 120℃.

[0070] Step 2: Diisocyanate is introduced into the deposition chamber as the first precursor using carrier gas, followed by purge gas to remove excess first precursor; the carrier gas is N2, and the flow rate is 50 sccm; the inlet time of the first precursor diisocyanate is 300 s, and the purge time is 150 s; the purge gas and the carrier gas are the same type and flow rate.

[0071] Step 3: Introduce 1,2-ethylenediamine as the second precursor into the chamber using a carrier gas, followed by the introduction of a purge gas to remove excess second precursor and reaction byproducts; wherein, the carrier gas is N2, the flow rate of the carrier gas is 75 sccm; the inlet time of the diamine precursor is 100s; the purge gas is the same type and flow rate as the carrier gas.

[0072] Step 4: Repeat steps 2 and 3 10 times to coat the surface of the structural layer with a 5nm thick polyurea film, thus obtaining a nanoimprint mold based on polyurea-enhanced impact resistance.

[0073] Comparative Example

[0074] This comparative example provides a nanoimprint mold, which differs from Example 1 in that: no polyurea film is deposited on the surface of the nanoimprint mold structural layer.

[0075] The nanoimprint mold is made of Si, with a laser direct-write exposure dose of 100, and SF6 or O2 as the etching gas. The source power is 600 W, the bias power is 30 W, and the etching time is 30 s. The etched structural layer is then subjected to plasma cleaning to obtain a clean surface, resulting in a nanoimprint mold.

[0076] Application performance testing

[0077] like Figure 1 As shown, the nanoimprinting mold based on polyurea-reinforced impact resistance, prepared in Example 1, was used to imprint the imprinting adhesive, and a nanoimprinting mold prepared in the comparative example was used for comparison. An impact load analysis was performed on a periodic structure at the same location, as shown... Figure 2 As shown, the thick lines represent the main area of ​​impact load on the nanoimprint mold, which is also the selected impact load analysis area. The impact load performance of other periodic structures should be similar. Figure 2 The region remains consistent.

[0078] Figure 3The image shows a comparison of impact loads at the same location before and after polyurea coating, i.e., between the nanoimprint mold and the impact-resistant nanoimprint mold. The positive and negative values ​​indicate compression or tension. Figure 3 It can be seen that the impact load on the polyurea-coated impact-resistant nanoimprint mold provided in Example 1 is significantly 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 value is 167.2 MPa. The peak value of the impact load on the polyurea film-coated mold provided in Example 1 is 451.8 MPa, and the average value is 70.9 MPa, which are 41.4% and 57.6% lower than before coating, respectively, and the impact resistance of the mold is greatly improved.

[0079] In summary, the nanoimprint mold based on polyurea-enhanced impact resistance provided by this invention can effectively prevent defects such as cracks or breaks in the mold during the imprinting process, enhance the impact resistance of the nanoimprint mold, improve the service life of the nanoimprint mold, and reduce manufacturing costs, thus possessing promotional prospects and application value.

[0080] The above are merely 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 recognize that any equivalent substitutions and obvious changes made based on the content of this specification should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a nanoimprint mold based on polyurea-reinforced impact resistance, characterized in that, Includes the following steps: S1. Prepare the nanoimprint mold structure layer and transfer the nanoimprint mold to the deposition chamber; S2. Diisocyanate is introduced into the deposition chamber as a first precursor through carrier gas, and then purge gas is introduced to remove excess first precursor. S3. A diamine precursor is introduced into the chamber as a second precursor through a carrier gas, and then a purge gas is introduced to remove excess second precursor and reaction byproducts. Under the same carrier gas flow rate, the ratio of the time for the first precursor to the second precursor to be introduced is 1:1-2:1; in a single cycle, the intake time of the first precursor is 200-300s, the purging time is 100-200s, and the intake time of the second precursor is 100-300s. S4. Repeat steps S2-S3 6-10 times to deposit a polyurea film with a thickness of 3-5 nm on the surface of the structural layer, thus obtaining a nanoimprint mold based on polyurea-enhanced impact resistance.

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

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 in the deposition chamber is 25-120℃.

5. The manufacturing method according to claim 1, characterized in that, The carrier gas includes one of nitrogen, helium, or 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. A nanoimprint mold based on polyurea-reinforced impact resistance, characterized in that, It is prepared by the manufacturing method according to any one of claims 1-6.

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