CN102556951A - Silicon substrate impending metal nanometer pinhole and processing method thereof - Google Patents
Silicon substrate impending metal nanometer pinhole and processing method thereof Download PDFInfo
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- CN102556951A CN102556951A CN2012100270938A CN201210027093A CN102556951A CN 102556951 A CN102556951 A CN 102556951A CN 2012100270938 A CN2012100270938 A CN 2012100270938A CN 201210027093 A CN201210027093 A CN 201210027093A CN 102556951 A CN102556951 A CN 102556951A
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Abstract
The invention provides a silicon substrate impending metal nanometer pinhole and a processing method of the nanometer pinhole. The nanometer pinhole is prepared on silicon substrate impending metal film. The preparing process comprises the following steps: selecting a twin polished silicon wafer, depositing metal film on an upper surface of the silicon wafer and then respectively depositing silicon nitride film on two surfaces of the silicon wafer; then coating a photoresist on the upper surface of the silicon wafer for photoetching and etching the silicon nitride layer and the metal layer to obtain a coarse positioning logo pattern; coating the photoresist on the lower surface of the silicon wafer for photoetching, etching the silicon nitride layer and wetly etching bulk silicon to obtain the silicon substrate impending metal film; and finally preparing a fine alignment logo and the nanometer pinhole on the silicon substrate impending metal film by adopting a focused ion beam. In the processing method, the nanometer pinhole is directly processed on the metal film by utilizing the flexible and effective focused ion beam with high precision, the operation of nanometer precision is realized, precise alignment of a incident point and the nanometer hole is realized at the same time, and the cockamamie processes of electron beam photoetching and pattern transferring are avoided. The processing method has the advantages of a simple process and high precision.
Description
Technical field
The present invention relates to a kind of preparation method of metal nano pin hole; Be particularly related to a kind of metal pin hole that adopts silica-based unsettled metal film of body silicon wet etching fabrication techniques and focused ion beam technology to make nanoscale, belong to the micronano optical element and make and technical field of micro and nano fabrication.
Background technology
Along with the development of photoetching technique, the wavelength of light source is also shorter and shorter in the etching system.Deep ultraviolet even extreme ultraviolet have been developed into by visible light.Shorter and shorter wavelength also has higher requirement for optical system.For example for extreme ultraviolet photolithographic, in order to reach the resolution ratio of diffraction limit performance, the RMS wave aberration of optical system should be less than 1nm.In this case, the detection of optical element such as lens just needs high precision in the system, is difficult to meet the demands with general detection method.At present widely used is point-diffraction interferometer.
The characteristics of point-diffraction interferometer are to use the ideal ball ground roll of pin hole diffraction generation as the benchmark corrugated, realize the high-acruracy survey of wave aberration, often are used to the high-acruracy survey of photoetching projection objective lens optical element and system's wave aberration.Because point-diffraction interferometer is to produce desirable spherical wave as the measuring basis corrugated through convergent beam illumination pin hole, pin hole just becomes one of critical component of interferometer.The factors such as thickness of its caliber size, perforate circularity, peritreme and hole surface roughness, rete and substrate all will influence the quality of the spherical wave of diffraction generation.Defective in the pin hole processing can make the deviant spherical wave of diffraction light, and then the result of influence measurement.So in point-diffraction interferometer, the precision that pin hole is processed has proposed very high requirement.
In addition in optical system, in order to improve beam quality, the filtering link that is absolutely necessary.Filtering uses the yardstick of pin hole relevant with wavelength.At deep ultraviolet, extreme ultraviolet waveband, the pin hole yardstick that filtering is used is hundreds of even tens nanometers.Parameters such as the size of pin hole, shape, roughness also can produce very big influence to the effect of filtering, and the precision of its processing directly influences beam quality.
It is thus clear that high-precision pin hole has become an important devices in the modern lithography systems.For visible light, the yardstick of pin hole is at micron order, and above-mentioned requirements reaches easily; And for ultraviolet band, the pin hole yardstick is a nanoscale, and difficulty of processing greatly increases.The pin hole of beamwriter lithography processes commonly used is not all reaching requirement aspect size, circularity and the roughness.For the unit nanostructured figure of small size, FIB be a kind of flexibly effectively, micro-nano preparation method that precision is high, can be on any material direct processing and fabricating nanostructured figure.Because it has microscopic observation and function of processing simultaneously, can better realize the operation of nano-precision, be to make metal nano pin hole effective technical means the most.Therefore need design feature and requirement, propose the high-precision processing method and the technology that are suitable for to the nanometer pin hole.In addition, because the aperture of nano-pore is very little, if direct penetrating metal film of aperture and substrate, the design function of not only processing difficulties, and nano-pore also can't be realized.Desirable scheme is to use certain process, makes nano-pore and interior among a small circle metal film thereof be in vacant state on every side, and the spherical wave that is gone out by the nano-pore diffraction so just can not be affected.
Summary of the invention
The technical problem that the present invention will solve is: existing electric lithography is made metal structure to be needed to develop through electron beam exposure earlier; After forming figure on the photoresist; Dry etching or lift-off technology are delivered to figure on the metallic diaphragm again; This technological process is numerous and diverse, obtain the nanostructured precision of needs, and technical difficulty is higher.Therefore to requirements such as the high accuracy of existing nanometer pin hole processing, small-bore, perforate circularity, hole depths; Propose a kind of body silicon wet etching technology of utilizing and obtain silica-based unsettled metal film, and adopt focused ion beam technology on metal film, directly to prepare the method for contraposition sign and nanometer pin hole.It is simple that this method has technology, can realize the advantage of nano-precision processing.
The technical solution adopted for the present invention to solve the technical problems is:
A kind of processing method of silica-based unsettled metal nano pin hole, this method may further comprise the steps:
The silicon chip that step (1) is chosen twin polishing is as substrate;
Step (2) adopts magnetron sputtering or vacuum ionic coating technology, is the metal film of 100～300nm at the upper surface deposit thickness of silicon chip;
Step (3) adopt chemical vapour deposition (CVD) or magnetron sputtering technique on metallic diaphragm with the lower surface of silicon chip respectively deposit thickness be the silicon nitride film of 100～200nm;
Step (4) deposits the surface-coated photoresist of metal film and silicon nitride film at silicon chip, through preceding baking, photoetching, developing process, obtains coarse positioning sign photoresist figure;
Step (5) is masking layer with the photoresist, adopts dry etching technology etch silicon nitride layer;
Step (6) is masking layer with the silicon nitride, adopts wet etching technology corroding metal layer;
Step (7) deposits the surface-coated photoresist of silicon nitride film at silicon chip, through preceding baking, double-sided alignment photoetching, development, dry etching silicon nitride technology, obtains body silicon perforate figure;
Step (8) is masking layer with the silicon nitride, adopts the anisotropic wet corrosion technology, carries out the perforate of body silicon wet etching, and corrosive liquid is that concentration is 20%～40% potassium hydroxide solution;
Step (9) is utilized wet etching, removes the silicon nitride film layer in the structure after above-mentioned steps (8) is accomplished;
Step (10) adopts focused ion beam technology on the metal film of the aperture area of body silicon, to make fine alignment sign and nanometer pin hole.
Silicon chip crystal orientation in the said step (1) is < 100 >, and thickness is 0.25～0.35mm;
Metal in the said step (2) can be chromium, gold, aluminium and alloy film layer material thereof;
Photoresist thickness in the said step (4) is 200～600nm;
Dry etching in the said step (5) can be reactive ion etching, ion beam etching, inductance coupling high ion etching;
Etching depth in the said step (5) is the silicon nitride film layer thickness;
The wet etching degree of depth in the said step (6) is a metallic diaphragm thickness;
Photoresist thickness in the said step (7) is 200～600nm, and etching depth is the silicon nitride film layer thickness;
Dry etching in the said step (7) can be reactive ion etching, ion beam etching, inductance coupling high ion etching;
The bulk silicon etching degree of depth in the said step (8) is a silicon wafer thickness;
The wet etching silicon nitride degree of depth in the said step (9) is the silicon nitride film layer thickness;
Metal nano pin hole bore in the said step (10) is φ 100～300nm.
A kind of silica-based unsettled metal nano pin hole, this metal nano pin hole is processed into by above-mentioned method.
The advantage that the present invention is compared with prior art had:
The groove structure that the present invention adopts body silicon wet etching fabrication techniques to go out to need obtains silica-based unsettled metallic film, has reduced the degree of depth of metal nano pin hole to greatest extent, has improved the spherical wave quality through the aperture outgoing; Utilize the FIB effective flexibly, that precision is high on metal film, directly to process the nanometer pin hole, realize the operation of nano-precision, technology is simple, the loaded down with trivial details technological process of having avoided electric lithography and figure to transmit.
Description of drawings
Fig. 1 is the flow chart of the inventive method;
Fig. 2 is < 100>the twin polishing silicon chip in the step 1 of the present invention;
Fig. 3 is the structural representation after silicon chip upper surface depositing metallic films is accomplished in the step 2 of the present invention;
Fig. 4 is the structural representation after metal film and the completion of silicon chip lower surface silicon nitride film in the step 3 of the present invention;
Fig. 5 is for identifying the structural representation behind the photoresist figure through photoetching, the acquisition coarse positioning that develops in the step 4 of the present invention;
Fig. 6 is etch silicon nitride in the step 5 of the present invention, 6 and the metal film structural representation after accomplishing;
Fig. 7 is the structural representation after the photoetching of process double-sided alignment, development, etch silicon nitride are accomplished in the step 7 of the present invention;
Fig. 8 is the sketch map that obtains body silicon open-celled structure after bulk silicon etching is accomplished in the step 8 of the present invention;
Fig. 9 makes fine alignment sign and nanometer pin hole for adopting FIB in the step 9 of the present invention, and removes the structural representation behind the silicon nitride film;
Figure 10 is the sketch map of a kind of silica-based unsettled metal nano pin hole of the present invention;
Drawing is explained as follows: 1 is < 100>twin polishing silicon chip; 2 is metallic diaphragm; 3 is silicon nitride film layer; 4 are the coarse positioning sign; 5 is the bulk silicon etching aperture area; 6 are the fine positioning sign; 7 is the nanometer pin hole.
The specific embodiment
The inventive method is detailed below with reference to accompanying drawings, rather than will limits the invention with this.Provided exemplary embodiment in the accompanying drawing, identical label is represented identical part in different figure.But following embodiment only limits to explain the present invention, and protection scope of the present invention should comprise the full content of claim, and promptly can realize the full content of claim of the present invention through following examples those skilled in the art.
The making flow process of this figure is as shown in Figure 1, and concrete performing step is following:
(1) choice of substrate and cleaning: get the twin polishing silicon chip of crystal orientation for < 100 >, use the acetone ultrasonic cleaning, the substrate that will clean afterwards places 160 ℃ of bakings of baking oven 15min, removes on-chip residual liquid.After accomplishing like Fig. 2.
(2) preparation of metal Al layer: adopt magnetron sputtering technique, at the one side depositing Al film of silicon chip, thickness is 200nm.After accomplishing like Fig. 3.
(3) preparation of protective layer silicon nitride film layer: adopt Low Pressure Chemical Vapor Deposition, in the lower surface difference silicon nitride film of Al film and silicon chip, thickness is 150nm.After accomplishing like Fig. 4.
(4) coating of photoresist: adopt spin-coating method, spin coating thickness is the photoresist of 560nm on the substrate after step (3) is accomplished, and toasts 100 ℃ of hot plate temperatures, stoving time 30min.
(5) making of coarse positioning sign photoresist figure: utilize contact exposure machine and coarse positioning identify mask to photoresist make public, development, post bake.Time for exposure is 35s, and developing time is 50s, and the post bake temperature is 120 ℃, time 10min.After accomplishing like Fig. 5.
(6) etch silicon nitride film and metal A l film: with the photoresist is masking layer, utilizes the reactive ion etching method, and the photoresist figure is transferred on the silicon nitride film layer; Be masking layer with the silicon nitride again, utilize the wet etching method, figure is passed on the metal A l film.After accomplishing like Fig. 6.
(7) making of body silicon aperture area; Spin coating thickness is the photoresist of 560nm on the rete that only deposits silicon nitride, and pre-bake temperature is 100 ℃ of hot plates, 30min.Utilize the double-sided alignment exposure machine, to photoresist make public, development, post bake.Time for exposure is 35s, and developing time is 50s, and the post bake temperature is 120 ℃, 10min.Be masking layer with the photoresist again, utilize the reactive ion etching machine etch silicon nitride.After accomplishing like Fig. 7.
(8) body silicon wet etching perforate: with the silicon nitride is masking layer, and wet etching silicon, etchant solution are 30% hydroxide
(9) making of fine alignment sign and nanometer pin hole; The sample that above-mentioned steps (7) is accomplished places hydrofluoric acid solution to remove silicon nitride film, and rinsed with deionized water places 100 ℃ in baking oven, 30min.Adopt FIB again, preparation fine alignment sign and bore are the nanometer pin hole of φ 200 on metal film.After accomplishing like Fig. 9.
The sketch map of being processed into a kind of silica-based unsettled metal nano pin hole for above-mentioned method shown in Figure 10.
The part that the present invention does not set forth in detail belongs to techniques well known.
Claims (13)
1. the processing method of a silica-based unsettled metal nano pin hole, it is characterized in that: this method comprises the steps:
The silicon chip that step (1) is chosen twin polishing is as substrate;
Step (2) adopts magnetron sputtering or vacuum ionic coating technology, is the metal film of 100～300nm at the upper surface deposit thickness of silicon chip;
Step (3) adopt chemical vapour deposition (CVD) or magnetron sputtering technique on metallic diaphragm with the lower surface of silicon chip respectively deposit thickness be the silicon nitride film of 100～200nm;
Step (4) deposits the surface-coated photoresist of metal film and silicon nitride film at silicon chip, through preceding baking, photoetching, developing process, obtains coarse positioning sign photoresist figure;
Step (5) is masking layer with the photoresist, adopts dry etching technology etch silicon nitride layer;
Step (6) is masking layer with the silicon nitride, adopts wet etching technology corroding metal layer;
Step (7) deposits the surface-coated photoresist of silicon nitride film at silicon chip, through preceding baking, double-sided alignment photoetching, development, dry etching silicon nitride technology, obtains body silicon perforate figure;
Step (8) is masking layer with the silicon nitride, adopts the anisotropic wet corrosion technology, carries out the perforate of body silicon wet etching, and corrosive liquid is that concentration is 20%～40% potassium hydroxide solution;
Step (9) is utilized wet etching, removes the silicon nitride film layer in the structure after above-mentioned steps (8) is accomplished;
Step (10) adopts focused ion beam technology on the metal film of the aperture area of body silicon, to make fine alignment sign and nanometer pin hole.
2. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the silicon chip crystal orientation in the said step (1) is < 100 >, and thickness is 0.25～0.35mm.
3. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the metal in the said step (2) can be chromium, gold, aluminium and alloy film layer material thereof.
4. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the photoresist thickness in the said step (4) is 200～600nm.
5. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the dry etching in the said step (5) can be reactive ion etching, ion beam etching, inductance coupling high ion etching.
6. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the etching depth in the said step (5) is the silicon nitride film layer thickness.
7. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the wet etching degree of depth in the said step (6) is a metallic diaphragm thickness.
8. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the photoresist thickness in the said step (7) is 200～600nm, and etching depth is the silicon nitride film layer thickness.
9. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the dry etching in the said step (7) can be reactive ion etching, ion beam etching, inductance coupling high ion etching.
10. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the bulk silicon etching degree of depth in the said step (8) is a silicon wafer thickness.
11. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the wet etching silicon nitride degree of depth in the said step (9) is the silicon nitride film layer thickness.
12. the processing method of silica-based unsettled metal nano pin hole according to claim 1 is characterized in that the metal nano pin hole bore in the said step (10) is φ 100～300nm.
13. a silica-based unsettled metal nano pin hole is characterized in that: this metal nano pin hole is processed into by each described method in the claim 1 to 12.
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| CN104889410A (en) * | 2015-03-26 | 2015-09-09 | 中国科学院上海微系统与信息技术研究所 | A manufacture method for controllable metal nanoparticles |
| CN110520392A (en) * | 2017-03-09 | 2019-11-29 | 康宁股份有限公司 | The method for manufacturing the metallic film supported by glass support part |
| CN111320164A (en) * | 2020-02-28 | 2020-06-23 | 南方科技大学 | Preparation method of suspended graphene structure, suspended graphene structure obtained by preparation method and application of suspended graphene structure |
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| JP2003149411A (en) * | 2001-11-13 | 2003-05-21 | Nikon Corp | Method for manufacturing optical element, the optical element, inspection device loaded with the element, and exposure device and point diffraction type interference measuring instrument provided with the inspection device |
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| CN110520392A (en) * | 2017-03-09 | 2019-11-29 | 康宁股份有限公司 | The method for manufacturing the metallic film supported by glass support part |
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Application publication date: 20120711 |