CN102608862A - Method for producing device in structure with large height-to-width ratio - Google Patents
Method for producing device in structure with large height-to-width ratio Download PDFInfo
- Publication number
- CN102608862A CN102608862A CN2011100213409A CN201110021340A CN102608862A CN 102608862 A CN102608862 A CN 102608862A CN 2011100213409 A CN2011100213409 A CN 2011100213409A CN 201110021340 A CN201110021340 A CN 201110021340A CN 102608862 A CN102608862 A CN 102608862A
- Authority
- CN
- China
- Prior art keywords
- mask plate
- semi
- height
- graph layer
- manufacture
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Preparing Plates And Mask In Photomechanical Process (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
Abstract
The invention discloses a method for producing a device in a structure with a large height-to-width ratio. According to the method, a method for depositing a diagram layer by a plurality of times is used, and the height-to-width ratio is controlled by controlling times of depositing a diagram and the height-to-width of the deposited diagram per time, so that the successful rate of producing the device with the very large height-to-width ratio is improved, and the production cost is reduced. Furthermore, the device in the structure with the large height-to-width ratio can be produced by the method disclosed by the invention through using primary electronic beam direct-writing and primary X-ray exposure, so that the method disclosed by the invention has wide application prospect in the field of rays with very high energy.
Description
Technical field
The present invention relates to microelectronics and optical technical field, relate in particular to a kind of method for preparing the large ratio of height to width structure devices.
Background technology
In the very high ray field of energy, have only the thickness of absorber to reach certain value and just can absorb corresponding ray, so it is significant to make the diffraction optical element of large ratio of height to width.Under normal conditions, depth-width ratio can be called the large ratio of height to width structure devices greater than 4 structure.What the diffraction optical element of made was common at present has zone plate, photon screen, grating like Fig. 1, Fig. 2, shown in Figure 3, and along with development of science and technology, more and more littler to the characteristic dimension requirement of these devices, the requirement that has reaches tens nanometers.
Tradition large ratio of height to width structure graph manufacturing process mainly may further comprise the steps:
Step S002 makes public on the substrate of gluing;
Step S004 develops to the photoresist of spin coating;
Step S006 develops after the completion, from developer solution, takes out substrate in the process that dries up, and the figure photoresist that depth-width ratio is very big receives the capillary influence of developer solution easily and collapses.
In realizing process of the present invention, the inventor recognizes that there is following defective in prior art: in the preparation process, because that the photoresist post is influenced by the tension force of developer solution is very big, be easy to collapse, be difficult to prepare the diffraction optical element of large ratio of height to width.
Summary of the invention
The technical matters that (one) will solve
For addressing the aforementioned drawbacks, the invention provides a kind of method for preparing the large ratio of height to width structure devices, to overcome the defective that the photoresist post collapses easily under big the ratio of width to height situation.
(2) technical scheme
According to an aspect of the present invention, a kind of method for preparing the large ratio of height to width structure devices is provided.This method comprises: prepare figure is identical, alignment mark is arranged mask plate A and semi-manufacture mask plate B, semi-manufacture mask plate B is fabricated into and removes before the ground floor photoresist; Spin coating second layer photoresist on semi-manufacture mask plate B; According to alignment mark, be mask with mask plate A, semi-manufacture mask plate B is carried out the exposure second time and development, original first graph layer is gone up up to semi-manufacture mask plate B in the space that the back of developing forms; On semi-manufacture mask plate B, develop in the space that forms, deposit the second graph layer, the second graph layer and first graph layer are combined closely; And remove mask plate B and go up all photoresists, form the large ratio of height to width structure devices.
Preferably, in the present technique scheme, in the step of preparation mask plate A and semi-manufacture mask plate B, adopt electron beam exposure technology and material depositing operation to form first graph layer; With mask plate A is mask, and semi-manufacture mask plate B is carried out in the step of exposing second time, adopts X ray exposure technology and material depositing operation to form the second graph layer.
Preferably, in the present technique scheme, the step of preparation mask plate A and semi-manufacture mask plate B comprises: plating seed layer on substrate; The spin coating electron beam resist carries out beamwriter lithography, development; Utilize plasma to etch and electroplate required electrode window through ray, etch the plating additional window at opposite side simultaneously in substrate one side; In electron beam develops formed space, utilize and electroplate growth first graph layer, the consistency of thickness of first graph layer and electron beam resist for semi-manufacture mask plate B, finishes; For mask plate A, remove remaining electron beam resist, finish.
Preferably, in the present technique scheme, comprise in the step of spin coating second layer photoresist on the semi-manufacture mask plate B: spin coating X-ray resist on semi-manufacture mask plate B, the thickness of X-ray resist is greater than the thickness of electron beam resist.Semi-manufacture mask plate B is carried out second time step of exposing to be comprised: semi-manufacture mask plate B is carried out the X ray exposure.On semi-manufacture mask plate B, develop in the space that forms, the step of deposition second graph layer comprises: utilize plasma etching to go out to electroplate required electrode window through ray in substrate etching; In the formed space of photoresist developing, utilize and electroplate growth second graph layer.
(3) beneficial effect
The present invention adopts the method for gradation deposition pattern layer, comes to control expeditiously depth-width ratio through the number of times of control deposition pattern and the depth-width ratio of each deposition pattern, has improved the success ratio of making the very big device of depth-width ratio, has reduced production cost.And the present invention adopts once electron beam directly to write with primary X-ray exposure can make the device with large ratio of height to width structure, and the ray field very high at energy has broad application prospects.
Description of drawings
Fig. 1 is the structural representation of zone plate in the prior art of the present invention;
Fig. 2 is the structural representation of photon screen in the prior art of the present invention;
Fig. 3 is the structural representation of grating in the prior art of the present invention;
Fig. 4 is the preparation method's of embodiment of the invention large ratio of height to width structure devices a process flow diagram;
Fig. 5 is the sectional view of embodiment of the invention semi-manufacture mask plate B;
Fig. 6 is the sectional view of embodiment of the invention mask plate A;
Fig. 7 is the diagrammatic cross-section that mask makes public to semi-manufacture mask plate B for the embodiment of the invention with mask A;
Fig. 8 is the diagrammatic cross-section of development after the embodiment of the invention is made public to semi-manufacture mask plate B, photographic fixing;
Fig. 9 carries out the diagrammatic cross-section of second time electroplating on mask plate C for the embodiment of the invention;
Figure 10 is the diagrammatic cross-section of the device D of the large ratio of height to width structure of embodiment of the invention preparation.
Embodiment
For making the object of the invention, technical scheme and advantage clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, to further explain of the present invention.
In exemplary embodiment of the present invention, a kind of method for preparing the large ratio of height to width structure devices is provided.Fig. 4 is the preparation method's of embodiment of the invention large ratio of height to width structure devices a process flow diagram.As shown in Figure 4, this method comprises:
Step S402: prepare figure is identical, alignment mark is arranged mask plate A and semi-manufacture mask plate B, semi-manufacture mask plate B is fabricated into and removes before the ground floor photoresist;
Step S404: spin coating second layer photoresist on semi-manufacture mask plate B;
Step S406: according to alignment mark, be mask with mask plate A, semi-manufacture mask plate B is carried out the exposure second time and development, original first graph layer is gone up up to semi-manufacture mask plate B in the space that the back of developing forms;
Step S408: in the space that forms of on semi-manufacture mask plate B, developing, deposition second graph layer, the second graph layer and first graph layer are combined closely;
Step S410: remove mask plate B and go up all photoresists, form the large ratio of height to width structure devices.
In the present embodiment, deposited two-layer graph layer, but in fact, can repeated execution of steps S404-S408, reach preset thickness until graph layer, remove all photoresists again, to form the large ratio of height to width structure devices.
Present embodiment adopts the method for gradation deposition pattern layer, thereby the depth-width ratio of figure is not very big in each process of developing, thereby can guarantee that the figure photoresist receives the effect of surface tension of developer solution little, also just is not easy to collapse.Present embodiment can be controlled depth-width ratio expeditiously, improves the success ratio of making the very big device of depth-width ratio, reduces production costs.
In the further embodiment of the present invention, comprise two big steps, that is: the step (A) of preparation mask plate A and semi-manufacture mask plate B and on semi-manufacture mask plate B, prepare the step (B) of large ratio of height to width structure devices.Wherein
The steps A of preparation mask plate A and semi-manufacture mask plate B comprises:
Steps A 1: plating seed layer on substrate;
Steps A 2: the spin coating electron beam resist, carry out beamwriter lithography, development;
Steps A 3: utilize plasma to etch and electroplate required electrode window through ray, etch the plating additional window at opposite side simultaneously in substrate one side;
Steps A 4: in electron beam develops formed space, utilize and electroplate growth first graph layer, the consistency of thickness of first graph layer and electron beam resist for semi-manufacture mask plate B, finishes;
Steps A 5: for mask plate A, remove remaining electron beam resist, finish.
And after having prepared mask plate A and mask plate B, the method that on mask plate B, prepares the large ratio of height to width structure devices comprises:
Step B1: spin coating X-ray resist on semi-manufacture mask plate B, the thickness of X-ray resist is greater than the thickness of electron beam resist;
Step B2: according to alignment mark, be mask with mask plate A, semi-manufacture mask plate B is carried out X ray exposure and development, original first graph layer is gone up up to semi-manufacture mask plate B in the space that the back of developing forms;
Step B3: utilize plasma etching to go out to electroplate required electrode window through ray in substrate etching; In the formed space of photoresist developing, utilize and electroplate growth second graph layer, the second graph layer and first graph layer are combined closely;
Step B4: remove mask plate B and go up all photoresists, form the large ratio of height to width structure devices.
Technology with respect to traditional making large ratio of height to width device; Present embodiment adopts once electron beam directly to write with primary X-ray exposure can make the device with large ratio of height to width structure; Method for making is simple, and the ray field very high at energy has broad application prospects.In addition; Be that example describes with the plating in the present embodiment, but those of ordinary skill in the art should know, also can adopt other physics or chemical deposition; For example magnetron sputtering, CVD etc. also can reach the requirement of some steps among the present invention then with the method for lift-off.The key of present embodiment is to have utilized the precision of electron beam exposure high, but speed is slow, and the precision of X ray exposure is low, but penetration capacity is strong, speed fast, be usually used in making the advantage of large ratio of height to width structure.
Through foregoing description, whole introduced the method that the present invention prepares the large ratio of height to width structure devices.Below will the present invention be described, but each characteristic of following examples does not constitute the restriction to protection domain of the present invention with concrete embodiment.Following order according to preparation, divide three parts that the present invention is specified:
One, electron-beam direct writing is made mask plate A, B:
1, on 2 inches (100) silicon chips of single-sided polishing, the spin-on polyimide precursor solution forms the thick film of 0.5-2 μ m, Kapton is heat-treated to curing, to carry graph layer;
2, adopt isotropic wet etching; The silicon at the Kapton back side is eroded; Be that mask plate A, B are last completion of silicon chip (film of hollow out) after corrosion, when doing electron beam lithography, can well reduce the adverse effect that electron scattering causes like this.；
3, in positive deposited by electron beam evaporation less than the conduction chromium of 20nm gold layer as plating seed layer;
4, spin coating electron beam resist (photoresist ZEP 520 or PMMA), and heat-treat, carry out beamwriter lithography, development then, and remove cull with plasma etching;
5, utilize plasma etching to etch the required electrode window through ray of plating, etch the plating additional window at opposite side simultaneously in a side (side on the electroplate liquid liquid level) of substrate;
6, in electron beam resist develops formed space, utilize and electroplate the golden absorber of growth, note the height and the photoresist consistency of thickness of the gold of plating; Accomplished the making of semi-manufacture mask plate B this moment; In this step, need to prove, because the glue of electron beam ability etching is thinner; So the corresponding metal layer thickness of electroplating is also little, Fig. 5 is the sectional view of embodiment of the invention semi-manufacture mask plate B;
7, after completion is electroplated, remove the photoresist as template, and use plasma etching to remove the photoresist of remained on surface, accomplished the making of mask plate A, Fig. 6 is the sectional view of embodiment of the invention mask plate A.
Two, X-ray lithography part
1, the negative photoresist HSQ of spin coating X ray or other X-ray resist on incomplete mask plate B obtain the egative film that will make public.In this step, X-ray resist can be positive glue or negative glue, and because X ray can make public thicker glue, this place's X-ray lithography can be thicker, can be coated with several microns, thereby lay the foundation for the structure of doing large ratio of height to width later on;
2, the mask A that makes with the first step does mask, egative film is carried out X ray aim at exposure, notices that A this moment, B will aim at, and Fig. 7 is the diagrammatic cross-section that mask makes public to semi-manufacture mask plate B for the embodiment of the invention with mask A;
3, develop after semi-manufacture mask plate B is made public, photographic fixing obtains mask plate C, Fig. 8 is for the embodiment of the invention is developed after semi-manufacture mask plate B is made public, the diagrammatic cross-section of photographic fixing.
Three, the plating of mask plate C, remove photoresist
Can on original gold layer basis, continue to electroplate after mask plate C develop to accomplish, because passed through registration process exposure the time, this time electroplating be on original electrogilding lines, to carry out; As shown in Figure 9; Because the glue of the usefulness of making public specifically is very thick,, all remove all glue at last with organic solvent so electroplated metal is also very high; Obtain the device D of large ratio of height to width structure, shown in figure 10.
In sum, the present invention has following beneficial effect:
1, the present invention adopts the deposition pattern layer twice, can control depth-width ratio expeditiously, thereby can better make phase-type or amplitude type device, such as phase-type zone plate, photon screen etc., all has good prospect;
2, the present invention makes the success ratio height of the very big device of depth-width ratio, greatly reduces production cost, has wide practical use;
3, with respect to the technology of traditional making large ratio of height to width device; The present invention adopts once electron beam directly to write with primary X-ray exposure can make the device with large ratio of height to width structure; Method for making is simple, and the ray field very high at energy has bigger application prospect.
Above-described specific embodiment; The object of the invention, technical scheme and beneficial effect have been carried out further explain, and institute it should be understood that the above is merely specific embodiment of the present invention; Be not limited to the present invention; All within spirit of the present invention and principle, 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. a method for preparing the large ratio of height to width structure devices is characterized in that, this method comprises:
Prepare figure is identical, alignment mark is arranged mask plate A and semi-manufacture mask plate B, said semi-manufacture mask plate B is fabricated into and removes before the ground floor photoresist;
Spin coating second layer photoresist on said semi-manufacture mask plate B;
According to said alignment mark, be mask with said mask plate A, said semi-manufacture mask plate B is carried out the exposure second time and development, original first graph layer is gone up up to said semi-manufacture mask plate B in the space that the said back of developing forms;
On said semi-manufacture mask plate B, develop in the space that forms, deposit the second graph layer, said second graph layer and said first graph layer are combined closely; And
Remove said mask plate B and go up all photoresists, form the large ratio of height to width structure devices.
2. the method for preparing the large ratio of height to width structure devices according to claim 1 is characterized in that, in the step of said preparation mask plate A and semi-manufacture mask plate B, adopts electron beam exposure technology and material depositing operation to form first graph layer; Said is mask with mask plate A, and semi-manufacture mask plate B is carried out in the step of exposing second time, adopts X ray exposure technology and material depositing operation to form the second graph layer.
3. the method for preparing the large ratio of height to width structure devices according to claim 2 is characterized in that, the step of said preparation mask plate A and semi-manufacture mask plate B comprises:
Plating seed layer on substrate;
The spin coating electron beam resist carries out beamwriter lithography, development;
Utilize plasma to etch and electroplate required electrode window through ray, etch the plating additional window at opposite side simultaneously in substrate one side;
In electron beam develops formed space, utilize and electroplate growth first graph layer, the consistency of thickness of said first graph layer and said electron beam resist for semi-manufacture mask plate B, finishes;
For mask plate A, remove remaining electron beam resist, finish.
4. the method for preparing the large ratio of height to width structure devices according to claim 3 is characterized in that,
Said step at spin coating second layer photoresist on the semi-manufacture mask plate B comprises: spin coating X-ray resist on said semi-manufacture mask plate B, and the thickness of said X-ray resist is greater than the thickness of said electron beam resist;
Saidly semi-manufacture mask plate B is carried out second time step of exposing comprise: semi-manufacture mask plate B is carried out the X ray exposure;
In the said space that forms of on semi-manufacture mask plate B, developing, the step of deposition second graph layer comprises: utilize plasma etching to go out to electroplate required electrode window through ray in substrate etching; In the formed space of photoresist developing, utilize and electroplate growth second graph layer.
5. the method for preparing the large ratio of height to width structure devices according to claim 3 is characterized in that, said initial substrates is (100) silicon chip of single-sided polishing, saidly on substrate, also comprises before the step of plating seed layer:
On said silicon chip, the spin-on polyimide precursor solution forms the thick film of 0.5-2 μ m and heat-treats, to support graph layer; And
Adopt isotropic wet etching, the silicon at the Kapton back side is eroded;
6. according to each described method for preparing the large ratio of height to width structure devices among the claim 1-5, it is characterized in that the step that said removal mask plate B goes up all photoresists also comprises before: repeat following steps, reach preset thickness until graph layer:
Spin coating N layer photoetching glue on said semi-manufacture mask plate B;
According to said alignment mark, be mask with said mask plate A, said semi-manufacture mask plate B is carried out the N time exposure and development, original N-1 graph layer is gone up up to said semi-manufacture mask plate B in the space that the said back of developing forms; And
On said semi-manufacture mask plate B, develop in the space that forms, deposit the N graph layer, said N graph layer and said N-1 graph layer are combined closely.
7. according to each described method for preparing the large ratio of height to width structure devices among the claim 1-5; It is characterized in that; Said on semi-manufacture mask plate B in the step of spin coating second layer photoresist, said second layer photoresist is positive glue or negative glue, and its thickness is more than or equal to 1 μ m.
8. according to each described method for preparing the large ratio of height to width structure devices among the claim 1-5, it is characterized in that the material of said first graph layer and second graph layer is gold.
9. according to each described method for preparing the large ratio of height to width structure devices among the claim 1-5, it is characterized in that said large ratio of height to width structure devices is zone plate, photon screen or grating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100213409A CN102608862A (en) | 2011-01-19 | 2011-01-19 | Method for producing device in structure with large height-to-width ratio |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100213409A CN102608862A (en) | 2011-01-19 | 2011-01-19 | Method for producing device in structure with large height-to-width ratio |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102608862A true CN102608862A (en) | 2012-07-25 |
Family
ID=46526333
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011100213409A Pending CN102608862A (en) | 2011-01-19 | 2011-01-19 | Method for producing device in structure with large height-to-width ratio |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102608862A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110618482A (en) * | 2019-09-19 | 2019-12-27 | 中国科学院重庆绿色智能技术研究院 | Preparation method of polyimide film diffraction lens with high thickness uniformity |
| CN113707357A (en) * | 2021-07-08 | 2021-11-26 | 湖南大学 | Preparation method of high-aspect-ratio zone plate |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050058949A1 (en) * | 2003-09-11 | 2005-03-17 | Wood Robert L. | Systems and methods for fabricating microstructures by imaging a radiation sensitive layer sandwiched between outer layers, and microstructures fabricated thereby |
| CN1799986A (en) * | 2004-12-30 | 2006-07-12 | 中国科学院微电子研究所 | Three-layer production process for high aspect ratio, deep submicro nanometer metal structure |
| CN1801458A (en) * | 2004-12-30 | 2006-07-12 | 中国科学院微电子研究所 | High depth-width ratio deep sub-micrometer, nanometer metal structure making process based on self-supporting thin film |
| WO2009081342A1 (en) * | 2007-12-21 | 2009-07-02 | Nxp B.V. | Low magnetic field inductor |
| CN101515110A (en) * | 2008-02-21 | 2009-08-26 | 中国科学院微电子研究所 | Photoetching mask structure for aeration of X-ray and method for preparing same |
-
2011
- 2011-01-19 CN CN2011100213409A patent/CN102608862A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050058949A1 (en) * | 2003-09-11 | 2005-03-17 | Wood Robert L. | Systems and methods for fabricating microstructures by imaging a radiation sensitive layer sandwiched between outer layers, and microstructures fabricated thereby |
| CN1799986A (en) * | 2004-12-30 | 2006-07-12 | 中国科学院微电子研究所 | Three-layer production process for high aspect ratio, deep submicro nanometer metal structure |
| CN1801458A (en) * | 2004-12-30 | 2006-07-12 | 中国科学院微电子研究所 | High depth-width ratio deep sub-micrometer, nanometer metal structure making process based on self-supporting thin film |
| WO2009081342A1 (en) * | 2007-12-21 | 2009-07-02 | Nxp B.V. | Low magnetic field inductor |
| CN101515110A (en) * | 2008-02-21 | 2009-08-26 | 中国科学院微电子研究所 | Photoetching mask structure for aeration of X-ray and method for preparing same |
Non-Patent Citations (1)
| Title |
|---|
| 朱效立等: "3333lp/mmX射线透射光栅的研制", 《光学学报》, vol. 28, 30 June 2008 (2008-06-30), pages 1026 - 1030 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110618482A (en) * | 2019-09-19 | 2019-12-27 | 中国科学院重庆绿色智能技术研究院 | Preparation method of polyimide film diffraction lens with high thickness uniformity |
| CN113707357A (en) * | 2021-07-08 | 2021-11-26 | 湖南大学 | Preparation method of high-aspect-ratio zone plate |
| CN113707357B (en) * | 2021-07-08 | 2024-05-17 | 湖南大学 | Preparation method of high-aspect-ratio zone plate |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101261331B (en) | Self-supporting transmission metal grating based on nanometer stamping technology and its preparation method | |
| CN107112212A (en) | Use grafted polymer material patterned substrate | |
| CN102568498A (en) | Block copolymer self-assembly methods and patterns formed thereby | |
| US20130059438A1 (en) | Method for forming pattern and mask pattern, and method for manufacturing semiconductor device | |
| EP0808481B1 (en) | Photolithographic structure generation process | |
| CN101566799B (en) | Method for preparing hollowed-out polyimide evaporation shadow mask | |
| JP2002303992A (en) | Method of manufacturing microstructure | |
| CN104465337A (en) | Method for manufacturing metal nanometer slit through PMMA/NEB double-layer glue | |
| CN102608687A (en) | Large height-width ratio photon sieve and preparation method thereof | |
| TWI650619B (en) | Method for preparing grating | |
| CN102608862A (en) | Method for producing device in structure with large height-to-width ratio | |
| CN109440067B (en) | Method for processing thin film structure by utilizing oblique evaporation | |
| CN101452203A (en) | Method for producing X ray exposure mask based on double-layer gum process | |
| CN101759140B (en) | Method for manufacturing silicon nano structure | |
| CN103280404A (en) | Patterned preparation method of field emission electrode on basis of vertical graphene | |
| CN102495526B (en) | Optical exposing method, and method for applying optical exposure in preparation of silicon material vertical hollow structure | |
| CN103091982B (en) | Microtube fabrication process | |
| CN102466832B (en) | Method for manufacturing photon sieve with high height-width ratio | |
| WO2019129104A1 (en) | Method for preparing film layer sleeve hole and array substrate | |
| CN102736432B (en) | Overlay method for nano-scale components | |
| CN101625522B (en) | Method for preparing dense pattern on thick negative high resolution electron beam resist HSQ | |
| CN102608864A (en) | Method for manufacturing nanoscale component with large height-width ratio | |
| US7951720B2 (en) | Method of forming a contact hole for a semiconductor device | |
| CN102608863A (en) | Method for preparing diffraction optical element with large aspect ratio | |
| CN110783263B (en) | Method for forming semiconductor structure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120725 |