CN101210979A - Photon crystal tunable filter and its manufacture method - Google Patents

Abstract

The invention relates to the technical field of thermo-optical tuned filter, and discloses a photon crystal tunable filter, comprising a lower reflector, a separation wall and an upper reflector on the silicon on an insulation layer (SOI) and air ports through the upper reflector, the separation wall, the lower reflector and the top silicon of SOI. The invention also discloses a preparation method for the photon crystal tunable filter. With the method, the invention can reduce the uneven film temperature from the traditional heating of film resistance, lift the limit of the minimum size of input light spot caused by the diffraction loss, lower the consumption and the power of the tunable filter and accelerate the tuning speed of the tunable filter.

Description

A kind of photon crystal tunable filter and preparation method thereof

Technical field

The present invention relates to thermo-optical tunability wave filter technology field, relate in particular to a kind of photon crystal tunable filter and preparation method thereof.This photon crystal tunable filter is a kind of subminiature three-D photon crystal thermo-optical tunability wave filter, utilizes the mode of light heating to realize thermo-optical tunability.

Background technology

Along with the active demand to high speed, high capacity communication network such as the access of internet, high-quality picture transmission, multimedia technology, dense wave division multipurpose (DWDM) system is the best solution of communication network bandwidth rapid growth, therefore become important techniques in the present point to point network, simultaneously narrower frequency interval and more multipling channel also are the targets of people's unremitting pursue always.

In this jumbo dwdm system, if adopt the fixing optical filter of centre wavelength, the requirement of wavelength accuracy and stability has increased the difficulty of making.And if adopt a kind of optically filtering device that can select frequency, the making of this system just can be simplified.Therefore tunable optical filter has become the Primary Component of dwdm system, and it has important role for the development all-optical network.

In optical communication network, tunable optic filter is used for constituting various demodulation multiplexers, and multiplexing light is together made a distinction; This tunable filtering technology is applied on laser instrument and the detector can realizes tunable optical source important among the DWDM and receiver; The Primary Component light top and bottom path device (OADM) of a new generation's all-optical network also can be made of this wave filter.This shows that tunable optic filter becomes indispensable important devices in all-optical network and the dwdm system.

According to the prediction of world-renowned CIR company, but the whole world will reach more than 100% based on the rate of growth in produce market every year of conditioning technology, will reach 1,300,000,000 dollars by 2005, wherein the market capacity of tunable optic filter will reach 400,000,000 dollars.As one of basic device in the full photokinesis optical-fiber network, the development of tunable optic filter is the focus that people pay close attention to always.

The method that can realize wavelength tuning has a lot, and it is tuning etc. for example to change grating passage length, mechanical stress, acoustooptic effect, electrooptical effect, thermo-optic effect, Control of Voltage, micromechanics.Wherein the mode of thermo-optical tunability is simple and enjoy people's attention with it.

But traditional thermo-optical tunability wave filter is the defective photonic crystal by one dimension to be constituted, and just usually said multilayer thin-film-filter adopts sheet resistance as the Electric heating that adds heat medium.Because this type of heating tends to make the non-uniform temperature of film, and the meeting introducing thermal stress that do not match of thermal conductance between sheet resistance and the material below it and mechanical property, produce stress birefrin, cause significant polarization dependent loss.In addition, the conduction loss from the film heating also is the part of thermal losses.Therefore, removing sheet resistance and adopt other type of heating completely is a kind of good selection.

At present, the existing report that utilizes the mode that adopts the light heating to realize the photon crystal filter of thermo-optical tunability.At document T.Asano et al.Dynamic wavelength tuning of channel-dropdevice in two-dimensional photonic crystal slab.Electronics Letters, described a kind of among the 2005:41 (1) based on road device about the tunable passage of photonic crystal panel.This path filter up and down is to be made of a linear defect wave-guide and near a point defect chamber it, and when the chamber mould resonance frequency in light frequency of transmitting in the line defect and the point defect chamber was mated, luminous energy was coupled in the chamber, is radiated free space then.The size of entire device is 250 μ m.(the GaN laser instrument 406nm) is radiated from the direction perpendicular to flat board as control light and causes the point defect chamber that temperature increases, and the spot radius of control light is about 2.5 μ m to utilize a blue laser.Utilize the light source of a tunable semiconductor CW laser instrument, incide the linear defect wave-guide from the edge as flashlight.When changing the signal light wavelength, just obtained time road spectrum by the light intensity that the point defect chamber is transmitted into free space by measurement.When the luminous power that absorbs was 2.1mW, maximum wavelength moved and has reached 4.5nm.The tuning response time is 20 μ s.

As seen, adopt the mode of light heating not only to reduce size of devices, and reduced device power consumption, improved tuned speed.Therefore but this tunable optic filter is to utilize the filtering of photonic band gap effects tuning from structure, constitutes airport small-sized of photonic crystal, thereby has increased manufacture difficulty.

Summary of the invention

(1) technical matters that will solve

In view of this, one object of the present invention is to provide a kind of photon crystal tunable filter, to reduce the restriction of the input hot spot minimum dimension that film temperature unevenness that the heating of traditional sheet resistance brings and diffraction loss causes, reduce the loss and the power consumption of tunable optic filter, improve the tuned speed of tunable optic filter.

Another object of the present invention is to provide a kind of method for making of photon crystal tunable filter, to reduce the restriction of the input hot spot minimum dimension that film temperature unevenness that the heating of traditional sheet resistance brings and diffraction loss causes, reduce the loss and the power consumption of tunable optic filter, improve the tuned speed of tunable optic filter.

(2) technical scheme

For reaching an above-mentioned purpose, the invention provides a kind of photon crystal tunable filter, this photon crystal tunable filter is by following catoptron, wall and the upper reflector of growing successively on silicon on the insulation course (SOI) substrate, and the airport formation that runs through upper reflector, wall, following catoptron and SOI substrate top layer silicon.

Described upper reflector and following catoptron are by multilayer Si/SiO ₂Deielectric-coating constitutes, and described wall is Si.

The thickness of Si is in described upper reflector and the following catoptron

SiO ₂Thickness be Described space layer is

Wherein λ is a vacuum wavelength, n _SiBe the refractive index of Si, n _SiO2Be SiO ₂Refractive index, m is the interference level in chamber.

Described upper reflector is by 7 layers of Si/SiO ₂Deielectric-coating constitutes, and described catoptron down is by 9 layers of Si/SiO ₂Deielectric-coating constitutes.

The diameter of described airport and the ratio in cycle satisfy the requirement of single mode transport.

The cycle of described airport is 3 μ m, and the diameter of airport and the ratio in cycle are smaller or equal to 0.15.

Described photonic crystal is the single-point defect sturcture, and the point defect place is a single mode waveguide.

For reaching above-mentioned another purpose, the invention provides a kind of method for making of photon crystal tunable filter, this method comprises:

A, at catoptron, wall and upper reflector under the growth successively on the SOI substrate;

B, go out dorsal pore at the back-etching of SOI substrate, this dorsal pore runs through the bottom Si and the oxygen buried layer SiO of SOI substrate ₂

C, in upper reflector surface spin coating electron beam adhesive, preceding baking;

D, the electron beam adhesive of spin coating is carried out electron beam exposure, development and photographic fixing, on electron beam adhesive, form the photonic crystal pattern of triangular crystal lattice, the back baking;

E, etching run through upper reflector, wall, the airport of catoptron and SOI substrate top layer silicon down, with the photonic crystal design transfer in multilayer dielectric film;

F, remove photoresist, finish the making of photon crystal tunable filter.

Growth described in the steps A adopts electron beam evaporation or magnetically controlled sputter method to carry out;

Going out dorsal pore at the back-etching of SOI substrate described in the step B comprises: go out dorsal pore in the chemical corrosion of the back side of SOI substrate, the oxygen buried layer of SOI substrate as corrosion from stopping layer, by the oxygen buried layer of HF corrosion SOI substrate;

Electron beam adhesive in upper reflector surface spin coating described in the step C is PMMA, and thickness is 400nm;

Baking comprises before described in the step C: toasted 10 minutes down at 180 ℃, the solvent among the volatilization electron beam adhesive PMMA strengthens adhering to of glue and material surface;

When described in the step D electron beam adhesive of spin coating being carried out electron beam exposure, development and photographic fixing, developer solution adopts MIBK: IPA=1: 3, and stop bath adopts IPA, develops and fixing time is 15 seconds;

Back baking described in the step D comprises: 90 ℃ of bakings 30 minutes down, the developer solution on volatilization electron beam adhesive surface is stablized the figure of photonic crystal;

Etching described in the step e adopts the inductively coupled plasma etching method;

Remove photoresist described in the step F and comprise: adopt 80 ℃ of heating of acetone, ethanol, washed with de-ionized water, remove remaining electron beam adhesive.

(3) beneficial effect

From technique scheme as can be seen, the present invention has following beneficial effect:

1, this photon crystal tunable filter provided by the invention and preparation method thereof, must not introduce extra material, only need on the basis of original 1-D photon crystal structure, to etch airport forms two dimension in side direction photon crystal structure, reduce the size of input hot spot and the unevenness of film temperature greatly, increased the tuned speed of device.

2, this photon crystal tunable filter provided by the invention and preparation method thereof, the optics active region of film filter is limited to a littler effective aperture, the zone that requirement reaches uniform temperature is reduced, not only reduced the size of device and input hot spot, and the diffraction loss of device, and reduced the thermal power that device consumes, increase the tuned speed of device.

3, this photon crystal tunable filter provided by the invention and preparation method thereof, the structural parameters of photonic crystal can flexible design can both make the side direction waveguide satisfy the condition of single mode transport, and only several lattice period just can reach good lateral limitation effect, this not only can realize miniaturization of devices, and has made things convenient for the integrated of device.

4, this photon crystal tunable filter provided by the invention and preparation method thereof, by effective refractive index being modulated waveguiding structure that side direction is provided to realize lateral limitation to active area, thereby make transverse beam profile and incident beam overlapping, the mechanism of this lateral limitation is similar to photonic crystal fiber, the 2 D photon crystal of side direction only plays the effect that smooth sea is led, and do not need to have photon band gap, the cycle of airport can be designed in micron dimension, has reduced manufacture difficulty greatly.

Description of drawings

The typical 1-D photon crystal Filter Structures synoptic diagram that Fig. 1 enumerates for the present invention;

Fig. 2 is the vertical view of photon crystal tunable filter provided by the invention;

Fig. 3 is provided by the invention in Λ=3 μ m and differences

Down, V _EffWith the normalization grating constant

The variation relation synoptic diagram;

Fig. 4 is the realization flow figure of making photon crystal tunable filter overall technological scheme provided by the invention;

Fig. 5 is a process chart of making photon crystal tunable filter according to the embodiment of the invention, comprises Fig. 5 A, Fig. 5 B, Fig. 5 C, Fig. 5 D, Fig. 5 E, Fig. 5 F, Fig. 5 G and Fig. 5 H; Wherein, 1 is the SOI substrate, and 2 is the bottom silicon among the SOI, and 3 is oxygen buried layer SiO among the SOI ₂, 4 is the top layer Si among the SOI, 5 is Si/SiO ₂Following catoptron, 6 is chamber medium Si, 7 is Si/SiO ₂ Upper reflector 8 is electron beam adhesive PMMA, and 9 is airport.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in more detail.

This photon crystal tunable filter provided by the invention is a kind of subminiature three-D photon crystal thermo-optical tunability wave filter, it is the defective photon crystal structure of on the basis of 1-D photon crystal wave filter, making two dimension, step by refractive index changes carries out lateral limitation and optics frequency-selecting, adopts the mode of light heating to realize thermo-optical tunability.

Photon crystal filter provided by the invention is by following catoptron, wall and the upper reflector of growing successively on silicon on the insulation course (SOI) substrate, and the airport formation that runs through upper reflector, wall, following catoptron and SOI substrate top layer silicon.

Wherein, described upper reflector and following catoptron are by multilayer Si/SiO ₂Deielectric-coating constitutes, and described wall is Si.The thickness of Si is in upper reflector and the following catoptron

SiO ₂Thickness be

Space layer is

Wherein λ is a vacuum wavelength, n _SiBe the refractive index of Si, n _SiO2Be SiO ₂Refractive index, m is the interference level in chamber.

Descend the reflectivity of catoptron high more good more in theory, generally up to more than 99%, because Si and SiO ₂Between refringence bigger, therefore only have severally just can reach good reflectivity to catoptron, getting upper reflector is 3.5 pairs, promptly upper reflector is by 7 layers of Si/SiO ₂Deielectric-coating constitutes; Following catoptron is 4.5 pairs, promptly descends catoptron by 9 layers of Si/SiO ₂Deielectric-coating constitutes.

Photon crystal tunable filter provided by the invention, photonic crystal are the single-point defect sturcture, and the point defect place is a single mode waveguide.The upper and lower catoptron Si/SiO that is constituting by multilayer dielectric film ₂And on the one dimension defective photon crystal filter (typical structure as shown in Figure 1) that the wall (Si) between the catoptron forms up and down, form the single-point defective photon crystal structure of two dimension in conjunction with etching airport array by electron beam exposure and inductively coupled plasma etching technology.The hole depth of etching passes whole film.The synoptic diagram of this structure as shown in Figure 2.

For the 1-D photon crystal wave filter, Si and SiO in the catoptron up and down ₂The thickness of layer should be respectively

The thickness of Si wall is

Wherein, λ is a vacuum wavelength; n _Si, nSiO ₂Be respectively Si and SiO ₂Refractive index; M is the interference level in chamber.When λ=1.55 μ m, get n _Si=3.5, n _SiO2=1.45, ${\mathrm{<figure-callout\; id="2"\; label="n\; SiO"\; filenames="A20061017166500201.png,A20061017166500203.png"\; state="\{\{state\}\}">n</figure-callout>}}_{{\mathrm{SiO}}_{}}=1.45,$ Then Si and SiO ₂The thickness of layer is respectively 110.7nm and 267.2nm, and the thickness of Si wall is 221.4m (nm), and wherein m represents chamber mode step number.Because this structure is a sandwich construction, if when the structural parameters of design photonic crystal, each layer of detailed consideration will be very complicated.So we are one deck with this sandwich construction equivalence, its refractive index replaces with an equivalent refractive index.Because wall is Si, be high refractive index layer, so its equivalent refractive index can be with following formulate, that is,

$n_{\mathrm{equ}}=n_H\sqrt{\frac{m-(m-1)(n_L/n_H)}{(m-1)-(m-1)(n_L/n_H)+(n_H/n_L)}},$ N wherein _HAnd n _LThe refractive index of representing high index of refraction and low-index layer in the catoptron respectively, and m still represents the interference level in chamber.When getting m=1, top formula becomes: $n_{\mathrm{equ}}=\sqrt{n_H{n}_L},$ Here, n _H=3.5, n _L=1.45, therefore, n _Equ≈ 2.25, and the thickness that obtains the Si wall is 221.4nm.

Then we represent the refractive index of whole one dimension defective photon crystal filter with this equivalent refractive index, and the two-dimensional photon crystal structure of making on it is designed.Because we introduce the purpose of the photon crystal structure of two dimension is to reach the restriction of side direction by horizontal index modulation, rather than obtains real band gap.The photonic crystal fiber of this and full-internal reflection type machine-processed similar.Therefore the cycle of airport can be very big, easier realization on technology.

As everyone knows, for common waveguiding structure, the parameter of a key is a normalized frequency V parameter, and it is used for estimating the guided mode quantity that comprises in the waveguide.V=2.405 is the cutoff frequency of first high-order mode, so the waveguide of V＜2.405 is considered to single mode waveguide.Equally, in a lateral wave guide structure that is made of the single-point defective photonic crystal of two dimension, effectively the V parameter can be expressed as: $V_{\mathrm{eff}}=\frac{2\mathrm{\&pi;R}}{\mathrm{\&lambda;}}\sqrt{n_{\mathrm{equ}}^2-{\mathrm{<figure-callout\; id="2"\; label="n\; eff"\; filenames="A20061017166500201.png,A20061017166500203.png"\; state="\{\{state\}\}">n</figure-callout>}}_{\mathrm{eff}}^{}},$ Wherein, λ is an operation wavelength, and R is equivalent defective radius, n _EquBe the effective refractive index of whole multilayer thin-film-filter when not having 2 D photon crystal to exist, promptly introduce the effective refractive index of two-dimensional photon crystal structure back cavity, n _EffIt is the effective refractive index of covering behind the introducing two-dimensional photon crystal structure.In certain wavelength and bore dia scope, we have calculated V _EffSuppose that grating constant is Λ, the diameter of airport is d.For single defect cavity, can think R ≈ Λ.With Λ=3 μ m is example, the relative opening diameter

Be increased to 0.35, the V that calculates from 0.01 _EffWith the normalization grating constant

Variation relation as shown in Figure 3.

As seen: when $\frac{d}{\mathrm{\&Lambda;}}\&le;0.15$ The time, in the normalization grating constant $\frac{\mathrm{\&Lambda;}}{\mathrm{\&lambda;}}\&le;20$ In the scope, V _Eff＜2.405, a single point defect state has played the effect of single mode waveguide.Therefore, if design Λ=3 μ m, d≤0.45 μ m for the light of λ 〉=0.15 mum wavelength scope, all can realize single mode transport.But because undersized airport is made and is difficult to, for the difficulty that reduces to make, we choose d=0.45 μ m.In summary, for we research λ=1.55 mum wavelengths near light, the structural parameters of photonic crystal can be elected Λ=3 μ m, d=0.45 μ m as.At this moment, the ratio in the diameter of airport and cycle satisfies the requirement of single mode transport.The cycle of airport is 3 μ m, and the diameter of airport and the ratio in cycle are smaller or equal to 0.15.When light entered the 1-D photon crystal resonant cavity, because the interference effect of resonant cavity, the light that satisfies the particular phases condition was by wave filter, and other light is suppressed, thereby had wavelength selection effect.The 2 D photon crystal defect cavity of side direction constitutes the restriction of single mode waveguide realization lateral light simultaneously.Just can effectively heat when incident illumination is mapped to defect area, thereby reach the purpose of wavelength tuning film.

Based on the structural representation of photon crystal tunable filter illustrated in figures 1 and 2, Fig. 4 shows the realization flow figure of making photon crystal tunable filter overall technological scheme provided by the invention, and this method may further comprise the steps:

Step 401: catoptron, wall and upper reflector under growing successively on the SOI substrate;

Step 402: the back-etching at the SOI substrate goes out dorsal pore, and this dorsal pore runs through the bottom Si and the oxygen buried layer SiO of SOI substrate ₂

Step 403: in upper reflector surface spin coating electron beam adhesive, preceding baking;

Step 404: the electron beam adhesive to spin coating is carried out electron beam exposure, development and photographic fixing, forms the photonic crystal pattern of triangular crystal lattice on electron beam adhesive, the back baking;

Step 405: etching runs through upper reflector, wall, the airport of catoptron and SOI substrate top layer silicon down, with the photonic crystal design transfer in multilayer dielectric film;

Step 406: remove photoresist, finish the making of photon crystal tunable filter.

Below in conjunction with accompanying drawing tunable photonic crystal filtering device structure of the present invention is described in detail.With reference to Fig. 5.Fig. 5 is a process chart of making photon crystal tunable filter according to the embodiment of the invention, comprises Fig. 5 A, Fig. 5 B, Fig. 5 C, Fig. 5 D, Fig. 5 E, Fig. 5 F, Fig. 5 G and Fig. 5 H; Wherein, 1 is the SOI substrate, and 2 is the bottom silicon among the SOI, and 3 is oxygen buried layer SiO among the SOI ₂, 4 is the top layer Si among the SOI, 5 is Si/SiO ₂Following catoptron, 6 is chamber medium Si, 7 is Si/SiO ₂Upper reflector 8 is electron beam adhesive PMMA, and 9 is airport.

At first, shown in Fig. 5 A, adopt electron beam evaporation or the magnetron sputtering 4.5 couples of Si/SiO that grow successively ₂Following catoptron 5,6,3.5 couples of Si/SiO of Si wall ₂Upper reflector 7.

Behind the growth ending, shown in Fig. 5 B, go out dorsal pore in the chemical corrosion of the back side of wafer, buried oxide layer layer 3 from stopping layer, erodes oxide skin(coating) 3 by HF as corrosion again.

Then, shown in Fig. 5 C, at upper reflector 7 surperficial spin coating PMMA 8,400nm is thick.

Then, shown in Fig. 5 D, toast the solvent evaporates of impelling among the PMMA 8 in 10 minutes down, strengthen adhering to of glue and material surface at 180 ℃.

Then, shown in Fig. 5 E, utilize electron beam exposure, develop, photographic fixing, the photonic crystal pattern of formation triangular crystal lattice on PMMA 8.Wherein, developer solution adopts MIBK: IPA=1: 3, and stop bath adopts IPA.Development and fixing time are 15s.

Then, shown in Fig. 5 F, toasted 30 minutes down so that the developer solution of sheet sub-surface volatilizees rapidly and the figure of stable photonic crystal at 90 ℃.

Afterwards, shown in Fig. 5 G, adopt inductively coupled plasma etching to go out the top layer Si 4 that airport 9 penetrates SOI, be about to the photonic crystal design transfer in multilayer dielectric film.

At last, shown in Fig. 5 H, utilize 80 ℃ of heating of acetone, ethanol, washed with de-ionized water, to remove remaining PMMA glue 8.

So far, finish the making of photon crystal tunable filter spare.Wherein, the pattern of photonic crystal designs when drawing the electron beam exposure domain, only needs to remove in complete airport lattice the airport of center, just can obtain corresponding single-point defect cavity structure.

Disclosed manufacture craft can have been removed the step of evaporated film resistance in the thermo-optical tunability wave filter in the past from, only need rayed just can effectively be heated film at defect area, thereby reach the purpose of wavelength tuning, this has simplified manufacture craft greatly.

Above-described specific embodiment; purpose of the present invention, technical scheme and beneficial effect are further described; institute is understood that; the above only is specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any modification of being made, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (9)

1. photon crystal tunable filter, it is characterized in that, this photon crystal tunable filter is by following catoptron, wall and the upper reflector of growing successively on silicon SOI substrate on the insulation course, and the airport formation that runs through upper reflector, wall, following catoptron and SOI substrate top layer silicon.

2. photon crystal tunable filter according to claim 1 is characterized in that, described upper reflector and following catoptron are by multilayer Si/SiO ₂Deielectric-coating constitutes, and described wall is Si.

3. photon crystal tunable filter according to claim 2 is characterized in that, the thickness of Si is in described upper reflector and the following catoptron

SiO ₂Thickness be Described space layer is

Wherein λ is a vacuum wavelength, n _SiBe the refractive index of Si, n _SiO2Be SiO ₂Refractive index, m is the interference level in chamber.

4. according to claim 2 or 3 described photon crystal tunable filters, it is characterized in that described upper reflector is by 7 layers of Si/SiO ₂Deielectric-coating constitutes, and described catoptron down is by 9 layers of Si/SiO ₂Deielectric-coating constitutes.

5. photon crystal tunable filter according to claim 1 is characterized in that, the diameter of described airport and the ratio in cycle satisfy the requirement of single mode transport.

6. photon crystal tunable filter according to claim 5 is characterized in that, the cycle of described airport is 3 μ m, and the diameter of airport and the ratio in cycle are smaller or equal to 0.15.

7. photon crystal tunable filter according to claim 1 is characterized in that, described photonic crystal is the single-point defect sturcture, and the point defect place is a single mode waveguide.

8. the method for making of a photon crystal tunable filter is characterized in that, this method comprises:

A, at catoptron, wall and upper reflector under the growth successively on the SOI substrate;

B, go out dorsal pore at the back-etching of SOI substrate, this dorsal pore runs through the bottom Si and the oxygen buried layer SiO of SOI substrate ₂

C, in upper reflector surface spin coating electron beam adhesive, preceding baking;

D, the electron beam adhesive of spin coating is carried out electron beam exposure, development and photographic fixing, on electron beam adhesive, form the photonic crystal pattern of triangular crystal lattice, the back baking;

E, etching run through upper reflector, wall, the airport of catoptron and SOI substrate top layer silicon down, with the photonic crystal design transfer in multilayer dielectric film;

F, remove photoresist, finish the making of photon crystal tunable filter.

9. the method for making of photon crystal tunable filter according to claim 8 is characterized in that,

Growth described in the steps A adopts electron beam evaporation or magnetically controlled sputter method to carry out;

Going out dorsal pore at the back-etching of SOI substrate described in the step B comprises: go out dorsal pore in the chemical corrosion of the back side of SOI substrate, the oxygen buried layer of SOI substrate as corrosion from stopping layer, by the oxygen buried layer of HF corrosion SOI substrate;

Electron beam adhesive in upper reflector surface spin coating described in the step C is PMMA, and thickness is 400nm;

Baking comprises before described in the step C: toasted 10 minutes down at 180 ℃, the solvent among the volatilization electron beam adhesive PMMA strengthens adhering to of glue and material surface;

When described in the step D electron beam adhesive of spin coating being carried out electron beam exposure, development and photographic fixing, developer solution adopts MIBK: IPA=1: 3, and stop bath adopts IPA, develops and fixing time is 15 seconds;

Back baking described in the step D comprises: 90 ℃ of bakings 30 minutes down, the developer solution on volatilization electron beam adhesive surface is stablized the figure of photonic crystal;

Etching described in the step e adopts the inductively coupled plasma etching method;

Remove photoresist described in the step F and comprise: adopt 80 ℃ of heating of acetone, ethanol, washed with de-ionized water, remove remaining electron beam adhesive.

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