CN111240150A

CN111240150A - Nano graph transfer printing method assisted by sacrificial layer

Info

Publication number: CN111240150A
Application number: CN202010053496.4A
Authority: CN
Inventors: 刘军山; 胡小光; 庞博; 张之昊; 杨馥瑞; 张思琪
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2020-01-17
Filing date: 2020-01-17
Publication date: 2020-06-05
Anticipated expiration: 2040-01-17
Also published as: CN111240150B

Abstract

The invention discloses a sacrificial layer assisted nano pattern transfer printing method, and belongs to the technical field of Micro Electro Mechanical Systems (MEMS) and micro-nano processing. Firstly, a sacrificial layer is deposited on the surface of a donor substrate, and a nano pattern to be transferred is manufactured on the surface of the sacrificial layer. And secondly, attaching the stamp to the surface of the donor substrate, then peeling off the donor substrate from the surface of the donor substrate to transfer the nano pattern and the sacrificial layer to the surface of the stamp together, and removing the sacrificial layer on the surface of the stamp by adopting a wet etching process. Finally, after the stamp is attached to the surface of the receiver substrate, the stamp is peeled off from the surface of the receiver substrate, so that the nano pattern is transferred to the surface of the receiver substrate. The nano pattern transfer printing method provided by the invention does not need to carry out any processing on the surface of the stamp and any chemical treatment on the surface of the receiver substrate, and has no limitation on the material of the transfer printing pattern, simple process and good universality.

Description

Nano graph transfer printing method assisted by sacrificial layer

Technical Field

The invention belongs to the technical field of Micro Electro Mechanical Systems (MEMS) and micro-nano processing, and particularly relates to a sacrificial layer assisted nano pattern transfer printing method.

Technical Field

Transfer printing refers to a technology of transferring a pattern made on a donor substrate (Donorsubrate) to a receiver substrate (receiver substrate) by means of a stamp (stamp), and is widely applied to the fields of flexible wearable electronics, flexible display and the like because of the advantages of strong compatibility, normal-temperature operation and the like. At present, researchers have invented a variety of transfer methods, but most of the transfer methods can only transfer micro patterns, and only a few of the transfer methods can transfer nano patterns. However, the existing methods for transferring nano patterns are complex in process and poor in universality. For example, the nano pattern transfer method proposed by the teaching group of Rogers of the northwest university of america requires processing a complex micro-nano structure on the surface of a stamp, and requires specific chemical treatment of the surface of a receptor substrate for different transfer pattern materials; for another example, the nano-transfer printing method proposed by the teaching group of whitesis of the university of harvard in the united states requires a thiol-ene film to be formed on the surface of a stamp by using extrusion and ultraviolet curing processes, the thiol-ene film needs to be removed by oxygen plasma etching after the pattern transfer is completed, and the nano-transfer printing method can only realize the transfer printing of a metal pattern.

Disclosure of Invention

The invention provides a sacrificial layer assisted nano pattern transfer printing method, which does not need to process the surface of a stamp or chemically process the surface of a receiver substrate, has no limitation on the material of a transfer printing pattern, and has simple process and good universality compared with the previously reported nano pattern transfer printing method.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for transferring nano patterns assisted by a sacrificial layer comprises the following steps:

(1) a sacrificial layer is deposited on the donor substrate surface with weak adhesion to it. When the donor substrate material is polymethyl methacrylate (PMMA), a copper film or a gold film may be selected as the sacrificial layer; when the donor substrate material is silicon, a copper film or a gold film may also be selected as the sacrificial layer.

(2) And manufacturing a nano pattern to be transferred on the surface of the sacrificial layer. The nano-pattern can be made by selecting a photoetching technology or an electric spraying printing technology.

(3) The stamp is attached to the donor substrate surface and then peeled from the donor substrate surface such that the nanopattern and the sacrificial layer are transferred together to the stamp surface. When Polydimethylsiloxane (PDMS) is selected as the stamp material, PMMA or silicon is selected as the donor substrate material, the bonding pressure between the stamp and the donor substrate should be greater than or equal to 6kPa, and the peeling speed of the stamp from the donor substrate surface should be greater than or equal to 5 mm/s.

(4) And removing the sacrificial layer on the surface of the stamp by using a wet etching process. When the sacrificial layer is a copper film, HNO with the mass fraction of 2.5 percent can be adopted₃Corroding the solution; when the sacrificial layer is a gold thin film, a mixed solution of iodine, potassium iodide and water (the mixing ratio of the three is 1g:5g:50mL) can be used for etching.

(5) The stamp is attached to the surface of the recipient substrate. When PDMS is selected as the stamp material, the bonding pressure between the stamp and the receptor substrate should be greater than or equal to 6 kPa.

(6) The stamp is slowly peeled from the surface of the recipient substrate so that the nano-pattern is transferred to the surface of the recipient substrate. When PDMS is selected as the stamp material, the peeling speed of the stamp from the surface of the receiver substrate should be 5mm/s or less.

Compared with the prior art, the invention has the beneficial effects that: the sacrificial layer assisted nano pattern transfer printing method does not need any processing on the surface of a stamp or any chemical treatment on the surface of a receiver substrate, and has no limitation on the material of the transfer printing pattern, simple process and good universality.

Drawings

FIG. 1 is a schematic illustration of the deposition of a sacrificial layer on a donor substrate surface;

FIG. 2 is a schematic diagram of a nano-pattern formed on the surface of a sacrificial layer;

FIG. 3 is a schematic view of the transfer of a nanopattern and a sacrificial layer from a donor substrate surface to a stamp surface;

FIG. 4 is a schematic view of removing a sacrificial layer from the surface of a stamp;

FIG. 5 is a schematic view of attaching a stamp to a surface of a recipient substrate;

FIG. 6 is a schematic view of the transfer of a nanopattern to a surface of a recipient substrate;

FIG. 7 is a scanning electron micrograph of gold nanopatterns transferred to the polyimide surface.

In the figure: 1 donor substrate, 2 sacrificial layers, 3 nanometer patterns, 4 stamps and 5 acceptor substrates.

Detailed Description

The following describes embodiments of the present invention in detail with reference to the drawings.

step 1: a copper sacrificial layer 2 with a thickness of 70nm is magnetron sputtered on the surface of a polymethyl methacrylate (PMMA) donor substrate 1, as shown in figure 1.

Step 2: firstly, spin-coating a 400nm positive photoresist with the type AZMIR-703 on the surface of a copper sacrificial layer 2 by using a spin coater, and sequentially carrying out pre-baking, exposure, development and post-baking treatment on the photoresist; then, performing magnetron sputtering on the surface of the photoresist pattern to form a gold film with the thickness of 100 nm; then, a gold nanopattern 3 is fabricated by a sputter etching process, as shown in fig. 2.

And step 3: attaching a Polydimethylsiloxane (PDMS) stamp 4 with the thickness of 1mm to the surface of a PMMA donor substrate 1, wherein the attaching pressure between the PDMS stamp and the PMMA donor substrate is 6 kPa; the PDMS stamp 4 was then peeled off from the surface of the PMMA donor substrate 1 at a rate of 5mm/s and the gold nanopattern 3 and the copper sacrificial layer 2 were transferred to the surface of the PDMS stamp 4 as shown in FIG. 3.

And 4, step 4: the mass fraction is 2.5%HNO of (2)₃The solution etches away the copper sacrificial layer 2 on the surface of the PDMS stamp 4 for 30s, as shown in FIG. 4.

And 5: the PDMS stamp 4 was attached to the surface of a Polyimide (PI) thin film receiver substrate 5 having a thickness of 75 μm under a pressure of 6kPa, as shown in FIG. 5.

Step 6: the PDMS stamp 4 was peeled off from the surface of the PI thin film receptor substrate 5 at a speed of 5mm/s, and the gold nanopattern 3 was transferred to the surface of the PI thin film receptor substrate 5, as shown in FIG. 6.

The gold nanopattern 3 transferred to the surface of the PI thin film receptor substrate 5, as shown in fig. 7, has a width of 47nm ± 3nm and a length of 4 mm.

The above-mentioned embodiments only express the embodiments of the present invention, but not should be understood as the limitation of the scope of the invention patent, it should be noted that, for those skilled in the art, many variations and modifications can be made without departing from the concept of the present invention, and these all fall into the protection scope of the present invention.

Claims

1. A sacrificial layer assisted nano pattern transfer printing method is characterized by comprising the following steps:

(1) depositing a sacrificial layer on the surface of the donor substrate;

(2) manufacturing a nano pattern to be transferred on the surface of the sacrificial layer;

(3) attaching the stamp to the surface of a donor substrate, and then peeling the stamp from the surface of the donor substrate so that the nano pattern and the sacrificial layer are transferred to the surface of the stamp together;

(4) removing the sacrificial layer on the surface of the stamp by using a wet etching process;

(5) attaching a stamp to a surface of a recipient substrate;

(6) the stamp is slowly peeled from the surface of the recipient substrate so that the nano-pattern is transferred to the surface of the recipient substrate.

2. The method of claim 1, wherein in step (1), when the donor substrate is polymethyl methacrylate or silicon, a copper film or a gold film is selected as the sacrificial layer.

3. The method for transferring nano patterns assisted by a sacrificial layer as claimed in claim 1, wherein in the step (2), the nano patterns are formed by photolithography or electrospray printing.

4. The method according to claim 1, wherein in step (3), the stamp material is polydimethylsiloxane.

5. The method of claim 1, wherein in step (3), the bonding pressure between the stamp and the donor substrate is greater than or equal to 6kPa, and the peeling speed of the stamp from the donor substrate surface is greater than or equal to 5 mm/s.

6. The method for sacrificial layer assisted nanopattern transfer printing as claimed in claim 1, wherein in step (5), the bonding pressure between the stamp and the receptor substrate is greater than or equal to 6 kPa.

7. The method for sacrificial layer assisted nanopattern transfer printing as claimed in claim 1, wherein in step (6), the speed of peeling the stamp from the surface of the receiver substrate is less than or equal to 5 mm/s.