WO2018196319A1 - Carbon nano-dot photoresist with fluorescent effect, and imaging method thereof - Google Patents

Abstract

A carbon nano-dot photoresist with a fluorescent effect, and an imaging method thereof, the photosensitive resin being a sugar-containing polymer, the controllable carbonisation and self-crosslinking effect of same in a certain electron beam exposure dose range being used to prepare carbon nano-dots having nano-scale precision positioning, and the fluorescent properties of same under illumination of specific wavelengths being used to implement fluorescence development and other applications. Water is the only solvent used, having the characteristic of being environmentally friendly, and fluorescent carbon nano-dots with any nano pattern can be formed at any specified position, resolving the two problems of fluorescent particle preparation and nano-scale precision positioning, and having wide scope for application in semiconductor manufacturing and the biological field.

Description

Carbon nano-dot photoresist with fluorescence effect and imaging method thereof Technical field

The invention relates to the field of photoresist, in particular to a carbon nano-dot photoresist with fluorescence effect and an imaging method thereof.

Background technique

With the development of optoelectronic technology, the device size has been gradually reduced, and nano-sized quantum dots can be used as a good base material in the next few decades. The synthesis and localization of quantum dots in this field has always been a very important issue. In most cases, these two problems are handled separately. The synthesis of quantum dots is mainly divided into two types: "top-down method" and "bottom-up method", that is, large-sized materials are ground, or small molecules are used as precursors. However, in the fields of scientific research and industrial manufacturing, the positioning and laying of quantum dots play a more important role in the realization of functions. For example, the construction of three-dimensional quantum dots in quantum computers, the accurate analysis of surface plasmons and the frequency-selective properties of photonic crystals depend on the precise positioning and ordering of quantum dots. At the nanoscale, precise placement of a single or a series of quantum dots at any location would be a revolutionary breakthrough in the field. A large amount of research is currently focused on how to accurately lay out prepared quantum dots, but still has great challenges for precise control of quantum dot dose and position. The self-assembly of quantum dots is the main positioning method currently reported. The optical and electroosmotic microfluidic control also plays a significant role in the precise positioning of the microparticles. However, since the optical gradient is attenuated as the volume of the particle becomes smaller, it is more difficult to accurately position the smaller-sized nanoparticles through the pupil. Also, due to the obvious Brownian motion of nanoparticles, electroosmotic microfluidic control technology is more suitable in micrometer-scale control. Then we propose a completely different method of quantum dot preparation and localization, which combines two traditional discrete steps, namely precise control, to generate quantum dots in situ. A related example is the introduction of point defects in the wide bandgap material to achieve the luminescence of the diamond color center, and related reports have been implemented in diamond and silicon carbide materials. And with the development of laser direct writing technology, spatial resolution can exceed the optical diffraction limit. However, this method has not been applied to the preparation of quantum dots.

Summary of the invention

The object of the invention is to provide a carbon nano-dot photoresist with fluorescence effect and an imaging method thereof, and to complete the preparation and laying of quantum dots by one-step method, to break the bottleneck of precise positioning of quantum dots, and to solve the precise control of quantum dot positioning and configuration. The problem is completed in one step.

One technical solution of the present invention is: a carbon nano-dot photoresist having a fluorescent effect, comprising:

a, a sugar-containing polymer for self-crosslinking under an electron beam, the side chain of which has a sugar ring;

b, solvent: water.

Further, the sugar-containing polymer is any one of a glucose homopolymer, a mannose homopolymer, a copolymer of glucose and methacrylic acid, and a copolymer of glucose and sodium p-styrenesulfonate.

Further, the mass ratio of the sugar-containing polymer to water is 1:10 to 1,000,000.

Further, the sugar-containing polymer has a molecular weight of 800 to 1,000,000.

Further, the structure of the sugar-containing polymer is as follows:

Wherein, R ₁ :H, ─CH ₃ ;

R ₂ or R ₃ : H, ─CH ₃ ,

R ₄ : a sugar ring (glucose ring, galactose ring, mannose ring and other polyhydroxy compounds conforming to the sugar definition);

X: O, C, -CO-, -CO-N-, -Ph-O-,

R ₅ : H, ─CH ₃ ;

R ₆ or R ₇ : H, ─CH ₃ ,

R ₈ :─COOH, ─Ph ^- SO ^3- Na ⁺ .

Another technical solution of the present invention is: an imaging method of a carbon nano-dot photoresist having a fluorescent effect, comprising the steps of: (1) dissolving a sugar-containing polymer in water to obtain a saccharide-containing polymer lithography a glue solution; (2) depositing the photoresist solution on the surface of the substrate to be processed to form an electron beam resist film; (3) performing electron beam exposure, and self-crosslinking occurs in the exposed region under the action of the electron beam , causing the sugar-containing polymer in the exposed region to be cross-linked and insoluble in water; and forming nano-scale carbon dots at the position of electron beam exposure; (4) placing it under a wavelength light source in the wavelength range of 300-800 nm, Has a fluorescent effect.

Further, in the step (1), the concentration of the sugar-containing polymer photoresist solution is 0.1 mg/L to 100 g/L.

Further, in the step (2), the method of coating the photoresist solution on the surface of the substrate to be processed is any one of a spin coating method and a dropping coating method, wherein the substrate is a silicon wafer, an ITO glass, and the surface has A gold plated quartz plate and a SiO ₂ plate having a silver film plating on its surface.

Further, in the step (3), the electron beam exposure conditions are: a voltage of 5 kV to 30 kV, a working distance of 5 mm to 20 mm, an aperture of 5 μm to 30 μm, and an exposure measurement of 1000 to 100,000 μC/cm ² .

Further, in the step (4), the sugar-containing polymer film forms carbon nano-dots at the exposure point, and the carbon nano-dots have a corresponding quantum fluorescence effect, and the fluorescence is generated under the excitation of the corresponding wavelength ultraviolet or visible light.

The advantages of the invention are:

(1) Dissolving a water-soluble polymer having a sugar ring side chain in water to form a photoresist solution, and forming a photoresist film on the substrate to be processed, thereby eliminating the conventional photoresist solution from chlorobenzene or Irritating and unstable by ethyl lactate as a solvent;

(2) In the later stage, water is used as the developing solution instead of methyl isobutyl ketone or isopropyl alcohol, and no fixing is required, and a developed image can be obtained after washing with water;

(3) The whole process involves only water-soluble polymer and water, and it is environmentally friendly and pollution-free;

(4) The position of the carbon nano-dots in the photoresist can be precisely positioned by the electron beam;

(5) The carbon dots are combined into an arbitrary pattern by electron beam exposure, and the exposed region has blue fluorescence under excitation of a specific wavelength.

(6) Two problems of fluorescence particle preparation and nano-scale precise positioning are solved in one step by electron beam irradiation of sugar-containing polymer photoresist.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention, Those skilled in the art can also obtain other drawings based on these drawings without paying any inventive labor. among them,

1 is a schematic view showing the steps of an image forming method of a carbon nano-dot photoresist having a fluorescent effect;

2 is an AFM characterization diagram of a carbon nano-dot photoresist pattern having a fluorescent effect of the present invention;

Figure 3 is a precise map of the carbon nanodots with fluorescence effect of the present invention (SEM image and optical diagram at 405 nm excitation);

4 is a block array fluorescence confocal diagram based on a sugar-containing polymer carbon dot of the present invention, and an ultraviolet absorption spectrum thereof and a fluorescence emission spectrum thereof.

detailed description

The present invention provides a carbon nano-dot photoresist having a fluorescent effect, comprising a, a sugar-containing polymer for self-crosslinking under electron beam, a side chain having a sugar ring; b, a solvent: water. The sugar-containing polymer is any one of a glucose homopolymer, a mannose homopolymer, a copolymer of glucose and methacrylic acid, and a copolymer of glucose and sodium p-styrenesulfonate. The mass ratio of the sugar-containing polymer to water is 1:10 to 1,000,000, and the structure of the sugar-containing polymer is as follows:

Wherein, R ₁ :H, ─CH ₃ ;

R ₂ or R ₃ : H, ─CH ₃ ,

R ₄ : a sugar ring (glucose ring, galactose ring, mannose ring and other polyhydroxy compounds conforming to the sugar definition);

X: O, C, -CO-, -CO-N-, -Ph-O-,

R ₅ : H, ─CH ₃ ;

R ₆ or R ₇ : H, ─CH ₃ ,

R ₈ :─COOH, ─Ph ^- SO ^3- Na ⁺ .

It should be noted that the first structural formula is a sugar-containing homopolymer, and the second structural formula is a sugar-containing copolymer. The unlabeled portions (both ends) of the two structural formulas are chain end groups, and the polymerization methods used are different. The group may be a RAFT chain transfer agent or other group such as an ATRP initiator. m, n are the number of repeating units of the polymer.

The above described objects, features and advantages of the present invention will become more apparent from the detailed description.

Please refer to FIG. 1. FIG. 1 is a schematic diagram showing the steps of an imaging method for a carbon nano-dots photoresist having a fluorescent effect. As shown in FIG. 1, the imaging method of the carbon nano-dot photoresist having a fluorescent effect comprises:

Step 1: dissolving the sugar-containing polymer in water to obtain a sugar-containing polymer photoresist solution;

In one embodiment, the step may be specifically carried out by dissolving the sugar-containing polymer in water to prepare a sugar-containing polymer photoresist solution having a concentration of from 0.1 mg/L to 100 g/L.

Step 2: depositing the photoresist solution on the surface of the substrate to be processed to form an electron beam photoresist film;

In one embodiment, the step may be performed by depositing the photoresist solution on the surface of the substrate to be processed to form an electron beam photoresist film, wherein the photoresist solution is deposited on the substrate to be processed. The surface method is any one of a spin coating method and a drop coating method, and the substrate is any one of a silicon wafer, an ITO glass, a quartz sheet having a gold film plating layer on the surface, and a SiO ₂ sheet having a silver film plating layer on its surface. .

Step 3: performing electron beam exposure, under the action of the electron beam, self-crosslinking occurs in the exposed region, so that the sugar-containing polymer in the exposed region is cross-linked and insoluble in water; and nano-scale is formed at the position of electron beam exposure. Carbon point

In one embodiment, the step may be specifically performed by electron beam exposure using an electron beam having a voltage of 5 kV to 30 kV, a working distance of 5 mm to 20 mm, a pupil of 5 μm to 30 μm, and an exposure measurement of 100 to 10000 μC/cm ² . The exposed region is self-crosslinked, so that the water-soluble polymer in the exposed region is crosslinked and insoluble in water.

Step 4: Place it under a wavelength source of 300-800 nm wavelength range, which has a fluorescent effect.

In one embodiment, the step may be specifically performed as follows: the sugar-containing polymer film forms carbon nano-dots at the exposure point, and the carbon nano-dots of a specific size have a corresponding quantum fluorescence effect, under the excitation of the corresponding wavelength ultraviolet or visible light , producing fluorescence.

For the experimental results obtained in the above steps, please refer to FIG. 2 to FIG. 4. FIG. 2 is an AFM characterization diagram of a carbon nano-dot photoresist pattern having a fluorescent effect according to the present invention. As can be seen from FIG. 2, an enlarged scan of the exposed region can be found. The surface contains dense nano-sized lattices (carbon dots). Figure 3 is a precise map of the carbon nanodots with fluorescence effect of the present invention (SEM image and 405 nm excitation) Under the optical map). Wherein, a: Au point (coated with a sugar film, the same below) SEM photograph, b: optical image of Au point (405 nm excitation, dark color), c: SEM of the sugar-containing polymer carbon spot positioned at the lower right corner of the Au point Photograph, d: Optical image of the sugar-containing polymer carbon spot positioned at the lower right corner of the Au spot (excitation at 405 nm, bright color at the lower right corner). It can be seen from Fig. 3 that an SEM photograph (Fig. 3a) on an ITO sheet (with gold dots) spin-coated with PMAG is used to position the carbon dots in the lower right corner of the gold dots with an electron beam (Fig. 3c) at 405 nm in a super-resolution microscope. Under light excitation, it is obvious that the position (lower right corner) of the electron beam exposure emits light, that is, fluorescence (Fig. 3d). It is indicated that the precise positioning operation of carbon quantum dots can be directly realized by electron beam exposure. 4 is a block array fluorescence confocal diagram based on a sugar-containing polymer carbon dot of the present invention, and an ultraviolet absorption spectrum thereof and a fluorescence emission spectrum thereof. Among them, a: Confocal fluorescence pattern excited by 405nm wavelength light (this picture is not developed by ion water in the past, the gray point is the blue fluorescent area, which is the electron beam exposure area, and the rest is not exposed by electron beam) b: The ultraviolet absorption spectrum of the sugar polymer carbon dots (c line) and the fluorescence emission spectrum (d line 405 nm excitation), as shown in Fig. 4, the sample was placed in an ultraviolet-visible absorption spectrometer for testing, and the ultraviolet absorption of the film was obtained. Spectrogram (c-line), we found a strong UV absorption peak at 360 nm. On this basis, we conducted a confocal microscope test, and excitation with a wavelength of 405 nm light showed that the exposed film region could emit blue fluorescence (Fig. 4a). At the same time, under the confocal microscope, the region was subjected to fluorescence emission spectroscopy to obtain a fluorescence emission spectrum (d line) with a maximum fluorescence emission peak at 480 nm.

The above described objects, features and advantages of the present invention will become more apparent from the aspects of the appended claims. However, the invention is not limited to the embodiments shown, but also includes any other known changes within the scope of the claims.

First, "an embodiment" or "an embodiment" as used herein refers to a particular feature, structure, or characteristic that can be included in at least one implementation of the invention. The appearances of the "in one embodiment", "a" or "an"

The present invention will be described in detail with reference to the accompanying drawings and the like. The scope. In addition, the actual production should include three-dimensional space of length, width and depth.

In addition, the abbreviations of the letters mentioned in the present invention are fixed abbreviations in the field, and some of them are letters. The text is explained as follows: SEM image: electronic scanning imaging; AFM image: atomic force microscopy.

Embodiment 1

Film formation and preparation method of carbon nano-dot photoresist with fluorescence effect: preparing poly(methacrylamide) glucose polymer (PMAG) aqueous solution with mass ratio of 1:10 as water-soluble negative electron beam lithography The paste was spin-coated on the surface of the ITO glass at a speed of 3000 rpm with a film thickness of about 60 nm. Then, it was exposed by an electron beam, and the working voltage was 20 kV, the working distance was 10 mm, the aperture was 30 μm, and the exposure measurement was 10000 μC/cm ² . After the end, the substrate was fully immersed in deionized water to develop an image with a single point resolution of <20 nm. Under a confocal microscope, excitation with a wavelength of 405 nm light has a blue fluorescence in the exposed region.

Embodiment 2

Film formation and preparation method of carbon nano-dot photoresist with fluorescence effect: preparing poly(acrylamide-based) glucose polymer aqueous solution (PAGA) with a mass ratio of 1:100 as a water-soluble negative electron beam photoresist, The photoresist was spin-coated on the surface of the silicon wafer at a speed of 2000 rpm to a film thickness of about 40 nm. Then, it was exposed by electron beam, and the working voltage was 20 kV, the working distance was 10 mm, the aperture was 15 μm, and the exposure measurement was 2000 μC/cm 2 . After the end, the substrate was fully immersed in deionized water to develop an image with a single point resolution of <20 nm. Under a confocal microscope, excitation with 400 nm wavelength light, the exposed region has blue fluorescence.

Embodiment 3

Film formation and use method of carbon nano-dot photoresist with fluorescence effect: preparing (methacrylamide-based) glucose and methacrylic acid copolymer (P(MAG-co-MAA)) aqueous solution, the mass ratio is 1: 1000, as a water-soluble negative electron beam photoresist, the photoresist was spin-coated on the surface of the ITO glass at a speed of 1000 rpm, and the film thickness was about 50 nm. Then, it was exposed by an electron beam, and the working voltage was 5 kV, the working distance was 5 mm, the aperture was 10 μm, and the exposure measurement was 5000 μC/cm ² . After the end, the substrate was fully immersed in deionized water to develop an image with a single dot resolution of <50 nm. Under a confocal microscope, it was excited with a light of 360 nm wavelength and developed with a fluorescent pattern.

Embodiment 4

Film formation and preparation method of carbon nano-dot photoresist with fluorescence effect: preparing (methacrylamide-based) glucose and sodium p-styrenesulfonate copolymer (P(MAG-co-SS)) aqueous solution, mass ratio It is 1:100,000, as a water-soluble negative electron beam photoresist, which is applied onto the surface of the silicon wafer to quickly dry the water, and the film thickness is about 80 nm. Then, it was exposed by an electron beam, and the working voltage was 30 kV, the working distance was 10 mm, the aperture was 5 μm, and the exposure was measured at 1000 μC/cm ² . After the end, the substrate was fully immersed in deionized water to develop an image with a single point resolution of <20 nm. Under a confocal microscope, excitation with a light of 390 nm wavelength, the exposed area has blue fluorescence.

Embodiment 5

Film formation and preparation method of carbon nano-dot photoresist with fluorescence effect: preparing (methacrylamide-based) mannose (PMAM) aqueous solution with a mass ratio of 1:10000 as a water-soluble negative electron beam photoresist, The photoresist was spin-coated at a speed of 2000 rpm on a quartz surface with a gold film to a film thickness of about 20 nm. Then, it was exposed by electron beam, and the working voltage was 20 kV, the working distance was 10 mm, the aperture was 30 μm, and the exposure measurement was 20000 μC/cm ² . After the end, the substrate was fully immersed in deionized water to develop an image with a single point resolution of <20 nm. Under a confocal microscope, excitation with 380 nm wavelength light, the exposed region has blue fluorescence.

Embodiment 6

Film formation and preparation method of carbon nano-dot photoresist with fluorescence effect: preparing aqueous solution of poly(acrylamide) glucose and methacrylic acid copolymer (P(AGA-co-MAA)) aqueous solution, the mass ratio is 1:1000000, as a water-soluble negative electron beam photoresist, was applied onto the surface of SiO ₂ with a silver film, and quickly dried the water to a thickness of about 80 nm. Then, it was exposed by electron beam, and the working voltage was 20 kV, the working distance was 10 mm, the aperture was 30 μm, and the exposure measurement was 50000 μC/cm ² . After the end, the substrate was fully immersed in deionized water to develop an image with a single point resolution of <20 nm. Under confocal microscopy, excitation with 375 nm wavelength light, the exposed region has blue fluorescence.

In summary, the present invention discloses a carbon nano-dot photoresist having a fluorescent effect and an image forming method thereof, which is a novel photosensitive resin based on a sugar-containing polymer and an electron beam etching technique to generate fluorescent carbon nano-dots in situ and For precise positioning, the photosensitive resin is a sugar-containing polymer, and its carbonized nano-point preparation with nanometer-scale precise positioning is realized by controlled carbonization and self-crosslinking in a certain electron beam exposure dose range. Fluorescent properties under wavelength illumination for fluorescence development and other applications. Water is the only solvent used in this patent. It has the characteristics of green environmental protection, and can form fluorescent carbon nano-dots with arbitrary nano patterns at any specified position. One step is to solve the problems of fluorescent particle preparation and nano-scale precise positioning in semiconductor manufacturing. And the biological field has broad application prospects.

It should be noted that the above embodiments are only used to explain the technical solutions of the present invention, and the present invention is not limited thereto. Although the present invention is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be Modifications or equivalents are intended to be included within the scope of the appended claims.

Claims (10)

A carbon nano-dot photoresist having a fluorescent effect, comprising: a, a sugar-containing polymer for self-crosslinking under an electron beam, the side chain of which has a sugar ring; b, solvent: water. The carbon nano-dot photoresist having a fluorescent effect according to claim 1, wherein the sugar-containing polymer is a glucose homopolymer, a mannose homopolymer, a copolymer of glucose and methacrylic acid, and glucose. Any of a copolymer with sodium p-styrene sulfonate. The carbon nano-dot photoresist having a fluorescence effect according to claim 1, wherein the mass ratio of the sugar-containing polymer to water is 1:10 to 1,000,000. The carbon nano-dot photoresist having a fluorescent effect according to claim 1, wherein the sugar-containing polymer has a molecular weight of 800 to 1,000,000. The carbon nano-dot photoresist having a fluorescent effect according to claim 1, wherein the structure of the sugar-containing polymer is as follows:

Wherein, R ₁ :H, ─CH ₃ ; R ₂ or R ₃ : H, ─CH ₃ , R ₄ : sugar ring; X: O, C, -CO-, -CO-N-, -Ph-O-,

R ₅ : H, ─CH ₃ ; R ₆ or R ₇ : H, ─CH ₃ , R ₈ :─COOH, ─Ph ^- SO ^3- Na ⁺ . The method for imaging a carbon nano-dot photoresist having a fluorescent effect according to any one of claims 1 to 5, comprising the steps of: (1) dissolving a sugar-containing polymer in water to obtain a saccharide-containing polymer lithography. a glue solution; (2) depositing the photoresist solution on the surface of the substrate to be processed to form an electron beam resist film; (3) performing electron beam exposure, and self-crosslinking occurs in the exposed region under the action of the electron beam So that the sugar-containing polymer in the exposed region is crosslinked and insoluble in water; and exposed to electron beam The position of the light forms a nano-scale carbon point; (4) it is placed under a wavelength source of the wavelength range of 300-800 nm, and has a fluorescent effect. The method for imaging a carbon nano-dot photoresist having a fluorescent effect according to claim 6, wherein in the step (1), the concentration of the sugar-containing polymer photoresist solution is 0.1 mg/L to 100 g. /L. The method for imaging a carbon nano-dot photoresist having a fluorescent effect according to claim 6, wherein in the step (2), the method of coating the photoresist solution on the surface of the substrate to be processed is a spin coating method. In any one of the dropping methods, the substrate is any one of a silicon wafer, an ITO glass, a quartz plate having a gold plating layer on its surface, and a SiO ₂ plate having a silver plating layer on its surface. The method for imaging a carbon nano-dot photoresist having a fluorescent effect according to claim 6, wherein in the step (3), the electron beam exposure conditions are: a voltage of 5 kV to 30 kV and a working distance of 5 mm. ～20 mm, the aperture is 5 μm to 30 μm, and the exposure measurement is 1000 to 100,000 μC/cm ² . The method for imaging a carbon nano-dot photoresist having a fluorescent effect according to claim 6, wherein in the step (4), the sugar-containing polymer film forms carbon nano-dots at the exposure point, and the carbon nano-dots have corresponding The quantum fluorescence effect produces fluorescence under the excitation of its corresponding wavelength ultraviolet or visible light.

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