CN102621610B - Manufacturing method of high-resolution super-diffraction focusing structure lens - Google Patents

Abstract

The invention provides a method for manufacturing a high-resolution super-diffraction focusing structure lens, which comprises the steps of selecting a proper substrate material, evaporating or sputtering a layer of metal film on the substrate, and enabling monochromatic light in a certain polarization state to be incident vertical to the upper surface of the metal film; selecting a central point of the upper surface of the metal film as a coordinate origin, wherein coordinate axes passing through the central point are an x axis and a y axis respectively, and a connecting line of the central points vertical to the metal film is a z axis; calculating the position of each Fresnel ring band of the metal film according to an aplanatic principle; and (3) forming nano small holes in each ring belt area of the metal film by utilizing the existing nano processing technology. The periodic or non-periodic arrangement position of the nano-pores in the ring belt region is determined by the polarization state of incident light; and then alternately evaporating or sputtering to deposit a metal and dielectric planar multilayer film structure with nanometer thickness. The lens designed by the invention has a simple structure, can be used for nano lithography and data storage, greatly improves the integration level of electronic devices, and has a wide development prospect.

Description

The method for making of the super diffraction focusing structure of a kind of high resolution lens

Technical field

The present invention relates to the technical field of the super diffraction limit focusing of metal nano-void array, be particularly related to the method for making of the super diffraction focusing structure of a kind of high resolution lens, it can produce the metal film of a kind of wavestrips at different levels zone open interior and the resolving power enhancement mode lens of alternating deposit metal and dielectric multi-layered membrane structure combination.

Background technology

In recent years, the development of nanofabrication technique, increasing researcher carries out the research of nanophotonics.Nanophotonics has important application prospect in single-molecule detection, plasmon, super-resolution focus and imaging in fields such as nano-photoetchings.Conventional wave strap and microtechnic are owing to focusing in air, and focal beam spot is all diffraction limited usually.Although traditional phase-contrast technique and immersion oil technology can improve resolving power to a certain extent.Higher requirement has proposed a new difficult problem for the researcher yet people are for optical resolution.

Summary of the invention

The technical problem to be solved in the present invention is: the deficiency that overcomes conventional wave strap and microtechnic diffraction limited, utilize the evanescent wave of endless belt nanometer open-porous metal membrane structures generations at different levels and the evanescent wave propagates ability that nano thickness replaces metal and dielectric multi-layered membrane structure, realize that the super diffraction limit in far field of high resolution focuses on, the convenient super diffraction focusing structure of a kind of high resolution lens that are used for nano-photoetching and high capacity data memory storage.

The present invention solves the problems of the technologies described above the technical scheme that adopts: the method for making of the super diffraction focusing structure of a kind of high resolution lens is characterized in that step is as follows:

Step (1) is selected the operation wavelength λ of incident light, according to its wavelength select can printing opacity base material;

Step (2) is the shading metal film of d at substrate surface evaporation thickness, and the monochromatic light of the operation wavelength λ of certain polarization state is perpendicular to the incident of shading metal film upper surface;

Step (3) is calculated the skin depth of the incident glistening light of waves in the shading metal film of getting according to formula (1):

$d_F=\frac{\mathrm{\λ}}{2\mathrm{\π}}{\left(\frac{{\mathrm{\ϵ}}_1+{\mathrm{\ϵ}}_2}{{{\mathrm{\ϵ}}_1}^2}\right)}^{1/2}---\left(1\right)$

D wherein _FThe expression skin depth, ε ₁The real part of the specific inductive capacity of expression shading metal, ε ₂The specific inductive capacity of expression shading metal surrounding medium;

It is the z axle that step (4) is got the center of vertically passing the shading metal film, supposes that z axle and shading metal film upper surface intersection location are true origin, crosses shading metal film upper surface central point line and is respectively x axle and y axle.Sample in shading metallic film surface (x-y plane), foundation

The first order position of Fresnel wavestrip should be selected apart from initial point

So m=0 substitution formula (2), (3) are calculated, can obtain the radial width w of the first endless belt _2m+1=| r _2m+1-r _2m|,

φ _2m+1-φ _2m＝π(2)

${\mathrm{\&phi;}}_{2m+1}=2\mathrm{\&pi;}\sqrt{{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="xy\; f"\; filenames="HDA0000152893680000011.png,HDA0000152893680000012.png"\; state="\{\{state\}\}">xy</figure-callout>}}{f}^{}{}^2+{\mathrm{\&epsiv;}}_{\mathrm{zz}}({x_{2m+1}}^2+{y_{2m+1}}^2)}/\mathrm{\&lambda;}---\left(3\right)$

Wherein, λ is the wavelength of incident light in free space, ε _xyAnd ε _zzBe respectively alternately noble metal and the horizontal and vertical effective dielectric constant of dielectric multilayer-film of evaporation nano thickness of shading metal film below, f is the focal length of design condenser lens, w _2m+1It is the radial width of 2m+1 endless belt;

Step (5) is in order to make all endless belt on the shading metal film just have and contribute focal beam spot, and the phase differential between each endless belt should be 2m π.With m=1 substitution formula (2), (3), the position of the 3rd endless belt and radial width are represented by (4), (5), (6) formula as can be known

$r_{2m}=\sqrt{{x_{2\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="HDA0000152893680000011.png,HDA0000152893680000012.png"\; state="\{\{state\}\}">m</figure-callout>}}}^2+{y_{2\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="HDA0000152893680000011.png,HDA0000152893680000012.png"\; state="\{\{state\}\}">m</figure-callout>}}}^2}=\sqrt{({\left(2m\right)}^2{\mathrm{\&lambda;}}^2/4+\left(2m\right)\mathrm{\&lambda;}\sqrt{{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="xy\; f"\; filenames="HDA0000152893680000011.png,HDA0000152893680000012.png"\; state="\{\{state\}\}">xy</figure-callout>}}{f}^{}{}^2+{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="0"\; label="zz\; r"\; filenames="HDA0000152893680000021.png"\; state="\{\{state\}\}">zz</figure-callout>}}{r_{}}^{}{{}_0}^2})/{\mathrm{\&epsiv;}}_{\mathrm{zz}}+{{\mathrm{<figure-callout\; id="0"\; label="r"\; filenames="HDA0000152893680000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_0}^2}---\left(4\right)$

$r_{2m+1}=\sqrt{{x_{2m+1}}^2+{y_{2m+1}}^2}=\sqrt{({(2m+1)}^2{\mathrm{\&lambda;}}^2/4+(2m+1)\mathrm{\&lambda;}\sqrt{{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="xy\; f"\; filenames="HDA0000152893680000011.png,HDA0000152893680000012.png"\; state="\{\{state\}\}">xy</figure-callout>}}{f}^{}{}^2+{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="0"\; label="zz\; r"\; filenames="HDA0000152893680000021.png"\; state="\{\{state\}\}">zz</figure-callout>}}{r_{}}^{}{{}_0}^2})/{\mathrm{\&epsiv;}}_{\mathrm{zz}}+{{\mathrm{<figure-callout\; id="0"\; label="r"\; filenames="HDA0000152893680000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_0}^2}---\left(5\right)$

w _2m+1＝|r _2m+1-r _2m|(6)

Utilize the aplanatism principle, by (4), (5), (6) formula, can obtain position and the endless belt width of the 3rd endless belt (m=1) on the mask metal film;

Step (6) in like manner, calculates locus and the endless belt width of 2m+1 (m＞1) endless belt by repeating step (5), thereby obtain the endless belt of Fresnel wavestrip on the shading metal film, arrange;

Step (7), according to the locus of each endless belt of above-mentioned design gained, utilizes existing process technology to make, and each endless belt is carried out perforate process;

Step (8) nanometer aperture determines in size, shape and the distribution of endless belt at different levels deviation state by incident light;

After step (9) is processed the endless belt at different levels position punching of suprabasil shading metal film, replace noble metal and the dielectric multi-layered membrane structure of evaporation nano thickness.The thickness of deposit multilayer film is the focal distance f of the super diffraction focusing structure lens of setting.

Incident light in described step (2) can be linear polarization, circular polarization, elliptic polarization and natural polarized light.

Nanometer aperture in described step (8) can be the aperture of circular hole, square hole or other shapes.

Nanometer aperture in described step (8) can be cycle, non-periodic or partial periodicity arrangement mode, and arrangement mode is determined by incident light polarization state and incident light direction.

The thickness of the noble metal dielectric multilayer-film in described step (9) is much smaller than lambda1-wavelength, and dispersion characteristics can be oval dispersion, hyperbolic dispersion etc.

The advantage that the present invention compared with prior art has is:

The present invention utilizes evanescent wave that the nanometer perforate of each ring belt area produces and the evanescent wave propagates ability of nano thickness metal and dielectric multi-layered membrane structure, proposes the designing and making method of the super diffraction focusing structure of high resolution lens; Compare with the conventional wave strap with super grating, the super diffraction structure lens of ring belt areas at different levels perforate can both focus on linear polarization, circular polarization, elliptic polarization and natural polarized light; The super diffraction structure lens of ring belt areas at different levels perforate have better focusing effect and less focal beam spot; Simultaneously, these lens can be realized below super diffraction limit the even focal beam spot below degree of depth diffraction limit to vertical, oblique incidence light, have broad application prospects.

Description of drawings

Fig. 1 is the sectional view of the designed super diffraction focusing structure lens of the embodiment of the present invention;

Fig. 2 is the vertical view of the designed super diffraction focusing structure lens of the embodiment of the present invention;

Fig. 3 designs the (1,3,5 of gained for the embodiment of the present invention ...) the corresponding wavestrip width in level wavestrip locus;

Fig. 4 is the section distribution map of the electric field of the designed super diffraction focusing structure lens of the embodiment of the present invention;

In figure: 1 is substrate silicon dioxide, and 2 is crome metal, and 3 is argent.

Embodiment

The present invention is described in detail below in conjunction with the drawings and the specific embodiments, but protection scope of the present invention is not limited in following embodiment, should comprise the full content in claims.

The concrete steps of the embodiment of the present invention are as follows:

(1) choosing operation wavelength λ is 442nm, and polarization mode is circular polarization, determines that the focal length of the designed super diffraction focusing structure of resolving power enhancement mode lens is f=0.8um;

(2) select silicon dioxide as base material, at the crome metal of its surperficial evaporation 50nm;

(3) allow incident light perpendicular to the incident of crome metal film upper surface, the skin depth that using formula (1) calculates light under operation wavelength is 10nm;

$d_F=\frac{\mathrm{\&lambda;}}{2\mathrm{\&pi;}}{\left(\frac{{\mathrm{\&epsiv;}}_1+{\mathrm{\&epsiv;}}_2}{{{\mathrm{\&epsiv;}}_1}^2}\right)}^{1/2}---\left(1\right)$

ε ₁The real part of the specific inductive capacity of expression crome metal, its value is-13.26, ε ₂The specific inductive capacity of expression air, its value is 1;

(4) getting the center of vertically passing metal film is the z axle, supposes that z axle and metal film upper surface intersection location are true origin, crosses metal film upper surface central point line and is respectively x axle and y axle.Sample in metallic film surface (x-y plane), foundation

The first order position r of Fresnel wavestrip ₀=470nm, r ₁=480nm can obtain the radial width w of the first endless belt _2m+1=10nm;

Wherein, ε _xy=-2.215+0.115i and ε _zz=6.4207+0.1091i is respectively alternately argent and the horizontal and vertical effective dielectric constant of silicon dioxide multilayer film of evaporation nano thickness of crome metal film below;

(5) in order to make all endless belt on metal film just have and contribute focal beam spot, the phase differential between each endless belt should be 2m π.With m=1 substitution formula (2), (3), the position of the 3rd endless belt and radial width are represented by (4), (5), (6) formula as can be known:

$r_{2m}=\sqrt{{x_{2\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="HDA0000152893680000011.png,HDA0000152893680000012.png"\; state="\{\{state\}\}">m</figure-callout>}}}^2+{y_{2\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="HDA0000152893680000011.png,HDA0000152893680000012.png"\; state="\{\{state\}\}">m</figure-callout>}}}^2}=\sqrt{({\left(2m\right)}^2{\mathrm{\&lambda;}}^2/4+\left(2m\right)\mathrm{\&lambda;}\sqrt{{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="xy\; f"\; filenames="HDA0000152893680000011.png,HDA0000152893680000012.png"\; state="\{\{state\}\}">xy</figure-callout>}}{f}^{}{}^2+{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="0"\; label="zz\; r"\; filenames="HDA0000152893680000021.png"\; state="\{\{state\}\}">zz</figure-callout>}}{r_{}}^{}{{}_0}^2})/{\mathrm{\&epsiv;}}_{\mathrm{zz}}+{{\mathrm{<figure-callout\; id="0"\; label="r"\; filenames="HDA0000152893680000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_0}^2}---\left(4\right)$

$r_{2m+1}=\sqrt{{x_{2m+1}}^2+{y_{2m+1}}^2}=\sqrt{({(2m+1)}^2{\mathrm{\&lambda;}}^2/4+(2m+1)\mathrm{\&lambda;}\sqrt{{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="xy\; f"\; filenames="HDA0000152893680000011.png,HDA0000152893680000012.png"\; state="\{\{state\}\}">xy</figure-callout>}}{f}^{}{}^2+{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="0"\; label="zz\; r"\; filenames="HDA0000152893680000021.png"\; state="\{\{state\}\}">zz</figure-callout>}}{r_{}}^{}{{}_0}^2})/{\mathrm{\&epsiv;}}_{\mathrm{zz}}+{{\mathrm{<figure-callout\; id="0"\; label="r"\; filenames="HDA0000152893680000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_0}^2}---\left(5\right)$

w _2m+1＝|r _2m+1-r _2m|(6)

Utilize the aplanatism principle, by (4), (5), (6) formula, can obtain position and the endless belt width of the 3rd endless belt (m=1) on the crome metal film;

(6) in like manner, calculate locus and the endless belt width of 2m+1 (m＞1) endless belt by repeating step (5), thereby obtain the endless belt of Fresnel wavestrip on metal film, arrange;

(7) according to the locus of each endless belt of above-mentioned design gained, utilize existing process technology to make, each endless belt is made a call to 10～20 hole, hole at the distributing position of endless belt at different levels about the metal film central point;

(8) after the endless belt at different levels position punching of suprabasil metal film is processed, replace the silverskin of 5 layer of 10 nano thickness of evaporation and the silicon dioxide multi-layer film structure of 5 layer of 10 nano thickness.

The part that the present invention does not elaborate belongs to techniques well known.

Claims (5)

1. the method for making of the super diffraction focusing structure of high resolution lens, is characterized in that comprising the following steps:

The operation wavelength λ of step (1), selection incident light, according to the base material of its wavelength selection printing opacity;

Step (2), at substrate surface evaporation or sputtering sedimentation thickness, be the shading metal film of d, the monochromatic light of the operation wavelength λ of certain polarization state is perpendicular to the incident of shading metal film upper surface;

Step (3), according to formula (1), calculate the skin depth of incident light in the shading metal film of getting:

$d_F=\frac{\mathrm{\&lambda;}}{2\mathrm{\&pi;}}{\left(\frac{{\mathrm{\&epsiv;}}_1+{\mathrm{\&epsiv;}}_2}{{\mathrm{\&epsiv;}}_1^2}\right)}^{1/2}---\left(1\right)$

D wherein _FThe expression skin depth, ε ₁The real part of the specific inductive capacity of expression shading metal, ε ₂The specific inductive capacity of expression shading metal surrounding medium;

Step (4), to get the center of vertically passing the shading metal film be the z axle, supposes that z axle and shading metal film upper surface intersection location are true origin, crosses shading metal film upper surface central point line and be respectively x axle and y axle; Sample in shading metallic film surface (x-y plane), foundation

The first order endless belt position of Fresnel wavestrip should be selected apart from initial point So m=0 substitution formula (2), (3) are calculated, can access the radial width w of first ring band _2m+1=| r _2m+1-r _2m|,

φ _2m+1-φ _2m＝π （2）

${\mathrm{\&phi;}}_{2m+1}=2\mathrm{\&pi;}\sqrt{{\mathrm{\&epsiv;}}_{\mathrm{xy}}{f}^2+{\mathrm{\&epsiv;}}_{\mathrm{zz}}({x_{2m+1}}^2+{y_{2m+1}}^2)}/\mathrm{\&lambda;}---\left(3\right)$

Wherein, λ is the wavelength of incident light in free space, ε _xyAnd ε _zzBe respectively noble metal and the horizontal and vertical effective dielectric constant of dielectric multilayer-film that shading metal film below replaces the nano thickness of evaporation or sputtering sedimentation, f is the focal length of design condenser lens, w _2m+1It is the radial width of 2m+1 endless belt;

Step (5), in order to make all endless belt on the shading metal film, focal beam spot is just had and contributes, the phase differential between each endless belt should be 2m π; With m=1 substitution formula (2), (3), the position of the 3rd endless belt and radial width are represented by (4), (5), (6) formula as can be known:

$r_{2m}=\sqrt{{x_{2m}}^2+{y_{2m}}^2}=\sqrt{({\left(2m\right)}^2{\mathrm{\&lambda;}}^2/4+\left(2m\right)\mathrm{\&lambda;}\sqrt{{\mathrm{\&epsiv;}}_{\mathrm{xy}}{f}^2+{\mathrm{\&epsiv;}}_{\mathrm{zz}}{r_0}^2})/{\mathrm{\&epsiv;}}_{\mathrm{zz}}+{r_0}^2}---\left(4\right)$

$r_{2m+1}=\sqrt{{x_{2m+1}}^2+{y_{2m+1}}^2}=\sqrt{({(2m+1)}^2{\mathrm{\&lambda;}}^2/4+(2m+1)\mathrm{\&lambda;}\sqrt{{\mathrm{\&epsiv;}}_{\mathrm{xy}}{f}^2+{\mathrm{\&epsiv;}}_{\mathrm{zz}}{r_0}^2})/{\mathrm{\&epsiv;}}_{\mathrm{zz}}+{r_0}^2}---\left(5\right)$

w _2m+1＝|r _2m+1-r _2m| （6）

Utilize the aplanatism principle, position and endless belt width in the time of accessing the 3rd endless belt and be m=1 by (4), (5), (6) formula on the mask metal film;

Step (6), in like manner, calculate locus and the endless belt width of 2m+1 endless belt, wherein m by repeating step (5)〉1, arrange thereby obtain the endless belt of Fresnel wavestrip on the shading metal film;

Step (7), according to the locus of each endless belt of above-mentioned design gained, utilize existing process technology to make, each endless belt is carried out perforate processes, obtain the nanometer aperture;

Step (8), nanometer aperture determine in size, shape and the distribution of endless belt at different levels deviation state by incident light;

After step (9), the endless belt at different levels position punching processing to suprabasil shading metal film, replace noble metal and the dielectric multi-layered membrane structure of evaporation or sputtering sedimentation nanometer grade thickness; The thickness of deposit multilayer film is the focal distance f of the super diffraction focusing structure lens of setting.

2. the method for making of the super diffraction focusing structure of a kind of high resolution according to claim 1 lens, it is characterized in that: the incident light in described step (2) is linear polarization, circular polarization or natural polarized light.

3. the method for making of the super diffraction focusing structure of a kind of high resolution according to claim 1 lens, it is characterized in that: the nanometer aperture in described step (8) is circular hole or square hole.

4. the method for making of the super diffraction focusing structure of a kind of high resolution according to claim 1 lens, it is characterized in that: the nanometer aperture in described step (8) is cycle, non-periodic or partial periodicity arrangement mode, and arrangement mode is determined by incident light polarization state and incident light direction.

5. the method for making of the super diffraction focusing structure of a kind of high resolution according to claim 1 lens, it is characterized in that: the noble metal in described step (9) and the thickness of dielectric multilayer-film are much smaller than lambda1-wavelength, and dispersion relation is oval dispersion or hyperbolic dispersion.

Images