TW200424805A - Inorganic nanoporous membranes and methods to form same - Google Patents

Abstract

The invention provides a method of forming an inorganic porous membrane that includes forming an inorganic membrane material on a substrate, forming a porous self-assembled material on the inorganic membrane material, and patterning the membrane material using the porous self-assembled material as a mask.

Description

200424805 发明 Description of the invention: [Technical field to which the invention belongs] The present invention generally relates to porous inorganic thin films, and more specifically, to an improved method for manufacturing inorganic thin films, which uses self-polymerizing materials as Sacrifice template material during the manufacturing process. [Prior art] Filtration of objects (e.g., molecules, proteins, nanocrystals, viruses) with a size of about 5-1000 nanometers is a biosensor, biomedical winter application, and other fields. needs. There are currently several different types of porous membranes for different types of applications, including polymeric films, silicon micromachined membranes, ion-track etched membranes, and anodically etched films. Several factors affect the technical applicability of a type of film. For example, because a porous film works by allowing an object of a particular size to pass through 'while excluding any larger objects, an advantage associated with the shape is the uniformity of the pore size of the film. In addition, the ability to control and adjust the size of the pores in a thin film manufacturing process allows flexibility in the choice of thin film applications. Higher pore density increases the throughput of the membrane filter. The porous thin film material itself is important both for its compatibility with the transmitted material 'and its compatibility with the environment in which the film is used. This issue is particularly relevant to biological applications. Ideally, these types of membrane filters can be manufactured with minimal complexity and at the lowest cost, allowing them to be used as disposable devices. [Summary of the Invention]

O: \ 88 \ 88956.DOC The invention provides a nanoporous film structure, which uses a self-polymerizing material as a sacrificial layer to define the pore size and pore density of the film. As described in more detail below, the properties of self-polymerizing materials are densely arranged in domains of uniform size, and the present invention applies this material property to inorganic porous films. As mentioned above, both pore density and uniformity improve film filter operation. More specifically, the present invention provides a method for manufacturing an inorganic porous film, comprising: manufacturing an inorganic film material on a substrate; manufacturing a porous self-polymerizing material on the inorganic film material; and using the same A porous self-polymerizing material is used as a mask to pattern the film material. In an embodiment, in order to manufacture the mask, the present invention manufactures a first material on the film material (the first material includes self-polymerizing particles), and removes the particles to leave a plurality of particles on the first material. hole. The film mask basically comprises a modified multi-stage copolymer layer, wherein the modified multi-stage copolymer layer is modified such that the -type block copolymer is removed. The openings at the previous position of this type of back-stage copolymer make up the holes in the mask. In the present invention, before removing the particles, they are oriented to the -material: face. In this example, the particles can include multi-block copolymers, and the multi-block copolymers can be processed by applying a solvent. Or removed by applying radiation. In alternative embodiments, the self-supporting 5 material includes anodizing | Lu film or chemically synthesized nano particle layer (the gap between the nano particles ㈣em mountaines) to form a multi-layer in the porous self-polymerizing material. Holes). The generated inorganic porous film includes a substrate support having a gap (㈣). The inorganic film is suspended in the gap of the substrate. The inorganic film includes a row of pores.

O: \ 88 \ 88956.DOC 2004248 05 column, where the pores have a pore diameter of less than 30 nm and a pore diameter distribution of less than 20%. The pores have a density greater than iow. By using self-polymerizing materials to define the size of the pores, the present invention teaches that there may be a regular arrangement of dense pores with a diameter of less than 30 nanometers (having an approximate pore size distribution). In addition, because the self-polymerizing material may not be suitable for thin-film applications per se, the present invention teaches that the self-polymerizing material is used as a template to pattern the underlying thin-film material. In this way, many types of materials can be manufactured, each of which has the characteristic dimensions of the self-polymerizing (model) material. The present invention also provides a method for manufacturing a nanoporous film, which uses a self-polymerizing material as a template to transfer the nanoscale pattern to the underlying material. [Embodiment] In the present In the invention, a self-polymerizing material is used as a sacrificial layer in the production of a nanoporous inorganic thin film, and the nanoporous inorganic thin film can be particularly used for molecular filtration or molecular sensing. Figure 丨 Eight-⑴ shows this function Schematic diagram of nano-porous film 150 (manufactured on substrate 154), illustrating its use to separate two different-sized particles 151, 152 (shown as spheres in the figure, which can represent molecules with different sizes) Purpose. More specifically, FIG. 1B illustrates particles ^ 15 and 152—located on one side of the porous membrane 150. FIG. ⑴ illustrates that the membrane filter 150 allows only smaller particles 152 to pass through and the larger The particles 151 are isolated on one side. In addition, the pores of the film 153 may be chemically reacted (fUnCnOHz) to allow or deny the passage of the particles 151, 152 based on the chemical composition. this Ming from polymeric materials for use

O: \ 88 \ 88956.DOC 2004248 05 is a sacrificial layer to rude _. Holes on the substrate, wire can be cut or made by other villages /. The self-polymerizing material is used as a template to pattern the substrate. In the present invention, a nano-film is manufactured from a material that is not porous beforehand. The size, homogeneity, and density of the film binding holes depend on the characteristic size of the self-polymerizing material. For the purposes of the present invention, the term, self-polymerizing material "refers to a specific type of material 'which, under appropriate conditions, will be organized into a uniform nanometer-scale domain with a slightly wide range arrangement (々adegreeoflonger_range_rder). Generally, 忒The self-aggregating domain will arrange itself into a hexagonal grid, but there are also several specific systems that combine into an oblique or square grid. The usual domain size is small and can be down in the appropriate material system. Adjusted to only a few nanometers. In these materials, 'the "domain size" is the basic characteristic of the material, so the size uniformity of the domain may have an error (self-average) of less than 10%. Examples of self-polymerizing materials (the use of which in this application will be further described) are bi-segmented copolymers, homo-sized nanocrystals, anodized film, and, · field surface layer (S-layer), and other systems. Self-polymerization provides a precise, effective, and straightforward method for making nanostructures with a size "below the decomposition limit achievable by conventional techniques", and makes such nanostructures suitable for thin film applications. Attractive choice of cowl. By using a self-polymerizing material, the field size of the present invention provides a way to achieve a uniform film pore size density exceeding and as high as 10 12 / cm2. In a preferred embodiment of this issue H +, a double-segment polymer material is used to generate a mask comprising a dense array of nanoscale domains. A possible choice of diblock copolymer material is "polystyrene-polymethylmethacrylate" O: \ 88 \ 88956.doc 200424805 (polystyrene-polymethylmethacrylate, PS..PMMA). By appropriately selecting the ratio of the molecular weight of the polymer to the molecular weight of the polymer block, the diblock copolymer film can be self-polymerized into a hexagonal compression arrangement of PMMa cylinders in a polystyrene matrix. By diluting (in addition to other known methods) the diluted polymer solution (the polymer is diluted in toluene or other suitable solvents) onto the substrate 'and annealing the resulting film, the The PMma cylinder is oriented perpendicular to the plane of the film. These PMma cylinders can then be removed, as appropriate, by exposure to electron beam or UV light, and dissolution in acetic acid or other effective solvents. Depending on the molecular weight of the polymer selected, the resulting film typically has pores of about 20 nanometers in diameter that are compressed hexagonally. By controlling the molecular weight and the ratio of these two polymer blocks, we can control the hole size range from about 2 nm to up to about 100 nm (for example, from about 10 to about 50 nm) ' The spacing of the holes is controlled from about 2 nanometers up to about 100 nanometers (for example, from about 10 to about 50 nanometers). This self-polymerization process is simple, cheap and fast. The size of the pores / domains can also be adjusted (in the range of about 10 to > 100 nanometers) using a molecular weight scale (the molecular weight of the polymer) that depends on the basic molecular length scale. The size of the holes is tightly distributed. Although the above embodiment of the present invention uses a diblock copolymer composed of polystyrene and polymethyl methacrylate, many other types of diblock copolymers can be used. Some examples of other diblock copolymers include: polyethylene oxide-polyisoprene 'polyethylene oxide_polybutadiene, polyethylene oxide-polystyrene, polyethylene oxide- Polyfluorenyl acrylate, polystyrene_polyvinyl. Pyridine, polystyrene_polyisoprene, polystyrene_polybutadiene, butadiene-polyvinyl ° ratio, and polyisoprene-polymethylpropionate

O: \ 88 \ 88956.DOC -10- 200424805 " In addition, the 'self-polymerizing film may be made of a block copolymer (for example, a triblock or multiblock copolymer) containing more than two blocks. Finally, the morphology of the self-polymerizing diblock copolymer film can be adjusted by the relative molecular weight ratio of the two polymer blocks constituting the diblock copolymer. For a ratio greater than about 80:20, the diblock copolymer is combined into a sphere state. For a ratio between about 60:40 and 80:20, the diblock copolymer is combined into a cylindrical state. For a ratio between about 50 ·· 50 and 6 (^ 40), the film exhibits a thin layer state. In a second embodiment of the present invention, the self-polymerizing material is used as a masking material, To produce thin film pores containing anodized aluminum. It is well known that anodization of an aluminum film under appropriate conditions will produce an aluminum oxide film that contains a uniform, dense, and neat array of pores. By anodizing conditions (Such as anodizing voltage and electrolyte), the pore size and density can be controlled from about 5 nm to about 300 nm. As in the above-mentioned embodiment of the diblock copolymerized material, the oxide film can be used Used as a template for the underlying substrate material, and then removed. By the method outlined below, the templated underlying material will eventually become a porous film structure. In another embodiment of the invention, it is used as The self-polymerizing material used as the base substrate template is made of a single layer of "chemically synthesized nano particles." Various existing chemical methods can be used to produce "having a diameter of about 2 nanometers to about 20 nanometers, having Less than 5% of diameter points "Nano particles (of a variety of materials). By using nano particles with a sufficiently uniform size, they can be assembled into a neat hexagonal arrangement on the substrate. By using the voids of the nano particle array as holes' The single nanoparticle layer can then be used as a surface

O: \ 88 \ 88956.DOC -11-2004248 05. In this embodiment, the size and spacing of the holes in the self-polymerizing mask are made by selecting the size of the nanoparticle. 2. Although three embodiments of self-polymerizing materials are described above, the self-polymerizing human puppets can be used as a sacrificial material layer to pattern the underlying substrate into a multi-film, film, but the existence of plutonium can be handled in the same way. Many other materials used. Figure 2A-2C shows the process of using a self-polymerizing material as a template to pattern the underlying inorganic substrate, which will eventually become a thin film. More specifically, FIG. 2A illustrates a substrate 20 and a nanoporous self-polymerizing material 21 including pores 22 of uniform size. It should be noted that the material 21 may be any two of the above-mentioned list 'or other self-polymerizing materials that can produce a uniform-sized, densely arranged array of pores below the size of a nanometer. In FIG. 2Bf, a portion of the substrate 20 only in the porous region of the self-polymerizing material 21 is removed by a process called, for example, 'reactive ion etching, chemical etching, or ion beam etching.' In Fig. 2C ', the self-polymerizing material 21 is removed 24, leaving the nanoporous pattern reproduced in the substrate. FIG. 3 illustrates a flowchart of a manufacturing process of the inorganic nanoporous film. In item 300, a self-polymerizing material is manufactured on a substrate. It should be noted that this step includes the entire procedure necessary to manufacture the self-polymerizing material. In the case of double-stage copolymers, this includes any copolymer annealing step and chemical development. In the case of anodized aluminum, this includes aluminum film deposition and proper aluminum anodic oxidation. For nanoparticle layers, this includes solution deposition and solvent evaporation. Next, 'in item 302', the present invention transfers the nanoscale pattern of the self-polymerizing material to the underlying substrate (which will eventually form an inorganic thin film). The present invention removes the sacrificial self-polymerizing material in the project. In item 306, the invention

O: \ 88 \ 88956.DOC -12- 2004248 05 Use micro-motor technology (described below) to pattern the thin film structure. Finally, in the project, the diaphragm was opened and (at item 31) the diaphragm hole was chemically used for specific applications as appropriate. The fabrication and disconnection of the final thin film structure is accomplished by using technology from a micro-motor or micro-electro-mechanical system (MEMS). The following example (Figures 4A-4H and M, shows possible thin film manufacturing materials, but those skilled in the art should understand that other self-polymerizing materials can also be used. In this first example (shown in Figures 4A-4H) The final thin film material will be silicon nitride (§ίΝ). The process starts in FIG. 4A by depositing a silicon nitride film 600 on top of a sacrificial oxide 600 on a silicon substrate 600. The diblock copolymer self-polymerization process (described earlier) was performed on the top nitride film 600. As a result, a nanoporous polymer film 606 was formed on top of the silicon nitride 600 (Fig. 4b). By way of example, the pattern of the porous polymer template is transferred to the entire nitride film by the reactive ion engraving 608 (Figure 4C). Then, the remaining polymer is peeled off. Next, In FIG. 4D, the top of the wafer is protected 6 (for example, by polymer anti-money, stone dioxide or other materials), and the back of the wafer is etched by micro-shirt etching or other methods. Pattern 6 丨 4 (Figure 4E) to define the film size (multiple films can be patterned at once). See Figure 4] F and all As shown in FIG. 4H, the substrate stone is removed from the film openings by, for example, using KOH or TMAH wet etching or plasma etching. Finally, as shown in FIG. 4H, The front side protection is removed and the sacrificial oxide layer 618 is removed (eg, 'using HF'), and the film is broken. The resulting structure consists of a suspended nitride film containing a nanoscale hole / A dense arrangement of pores (defined by the self-polymerizing material). The suspended inorganic membrane may have less than 30 nanometers

O: \ 88 \ 88956.DOC -13- 2004248 05 m pore diameter, the pores in the suspended inorganic film may have a pore diameter distribution of less than 20%. The density of pores in the suspended inorganic film may be greater than 109 / cm2 (or even greater than 10u / cm2). In a second embodiment (FIG. 5A.5H), the starting substrate is cut over an insulator (SOI) wafer, which has silicon on top of silicon dioxide (702) on a silicon substrate (704). The membrane (700) is shown in Figure 5A. The diblock copolymer self-polymerization process (described earlier) is performed on top of the silicon film 700, and as a result, a nanoporous polymer film 706 is formed on the top of the silicon film 700 (Fig. 5) 3). For example, with the reactive ion surname 708 (FIG. 5C), the multi-record polymer sample pattern ^ is transferred to the entire Shi Xi film. Then, the remaining polymer is peeled off. The remaining thin film processes shown in Figures 5d_5h (meaning front side protection 712, wafer back patterning 714, transparent wafer engraving (through_wafer price 7 [6, and film break 718)) and the above examples It is the same as described in this process. This process produces a suspended Shixi film that contains a dense array of nano-sized holes. Alternatively, the manufacturing process can be reversed. The back film can be patterned and etched first, and then continued The process of self-polymerization of the diblock copolymer and the transfer of the pattern into the film material can be completed (for both the manufacture of SiN and SOC films). The self-polymerized bismuth of the present invention shown above is used. Meng Duan Qiu Qiong, "The nano-porous film prepared has a consistent use as a nanometer β, in the application of poetic biotechnology / biomedicine / biosensor. ^ By using self-polymerizing materials To define the size of the pores, the teachings of the present invention may have a regular arrangement of tightly compressed pores with a diameter of less than 30 nanometers (the pore size distribution is as large as 10%). In addition, since the self-polymerizing material itself may not

O: \ 88 \ 88956.DOC -14- 2004248 05 is suitable for use as a thin film, so the present invention teaches that the self-polymerizing material is used as a template 'to pattern the underlying thin film material. In this way, films of many materials can be made, each type having the characteristic dimensions of the self-polymerizing (model) material. The present invention also provides a method for manufacturing a nanoporous film, which uses a self-polymerizing material as a template to transfer a nanoscale pattern into the underlying material. Although the present invention has been described with several preferred embodiments, those skilled in the art should understand that the present invention can be modified within the spirit and scope of the scope of the accompanying patent application. [Brief description of the drawings] With reference to these Figures 4, a detailed description of the invention can better understand the present invention. In the drawings: Figures 1A-1C use a self-polymerizing material to pattern the underlying film material. Schematic diagram of the prepared nano-porous structure. Figures 2A-2C illustrate the use of self-polymerizing materials for patterning the underlying material layer. Figure 3 is a flowchart. Figures 4A-4H are a series of diagrams. Figures 5A-5H are A series of schematic diagrams [illustration of the representative symbols] 20 The substrate illustrates a preferred method of the present invention; 'illustrates a preferred method of the present invention; and' illustrates a preferred method of the present invention. 1 Self-polymerizing materials 22 holes 23 Last name engraving process

O: \ 88 \ 88956.DOC 15- 200424805 24 The self-polymerizing material 21 is removed 150 nanometer porous film 152 smaller particles 151 larger particles 153 film 300 making self-polymerizing material on a suitable substrate 302 pattern transfer Into the substrate 304 Remove the self-polymerizing material 306 Patterned film structure 308 Thin film disconnection 310 The chemically applied film hole 604 $ 夕 substrate 602 Oxide 600 Nitrided shatter film 606 Nanoporous polymer film 608 Pattern quilt Transfer to all nitride films 612 The top of the wafer is protected 614 The back of the wafer is patterned 616 Insects 618 Remove the sacrificial oxide layer 700 Silicon film 702 Silicon dioxide 704 Broken substrate 706 Nanoporosity Polymer film O: \ 88 \ 88956.DOC -16- 708 The pattern is transferred to all silicon films 712 Front side protection 714 Wafer back patterning 716 Through wafer etching 718 Thin film disconnection O: \ 88 \ 88956.DOC- 17-

Claims (1)

Patent application scope: A method for manufacturing an inorganic porous film, comprising: manufacturing an inorganic film material; manufacturing a porous self-polymerizing material on the inorganic film material; and using the porous self-polymerizing material Operation-masking, patterning the film material 2. If the manufacture of the scope of patent application No. 1 includes: manufacturing a self-layer. A method in which the porous self-polymerizing material is polymerized into a material having a pore structure. 3. The method of claiming the scope of application for a patent application, wherein the manufacturing of the layer further includes: removing at least one from the layer Components. 4. The method according to item ^ Gugule, where the component includes a multi-block copolymer. 5. If the formula, version, and position of patent application No. 2 are included, the position is the same as that of the method, and further includes the orientation of the holes perpendicular to the plane of the layer. 6. The oldest method as claimed in the patent application, wherein the manufacturing of the porous self-polymerizing material includes manufacturing-oxidizing the film; and anodizing the oxide film. 7. The method according to item 6 of the patent application, wherein the anodization forms a porous alumina film. 8. If the scope of patent application is the first! The method of claim 1, wherein the manufacturing of the porous self-polymerizing material comprises chemically synthesizing nano particles in a layer. 9. The method as claimed in claim 8 wherein the voids between the nano particles in the layer constitute the pores in the porous self-polymerizing material. O: \ 88 \ 88956.DOC 2004248 05 10. The method according to the scope of patent application, wherein the manufacturing of the porous self-polymerizing method comprises: making a first material on the film material, wherein the first material includes Polymerize the particles; and remove the particles to leave holes in the first material. 11. A method of making a porous self-polymerizing mask, comprising: fabricating a layer comprising a material that will self-polymerize into a structure having pores. 12. The method of claiming a patent, further comprising orienting the pores to a plane perpendicular to the layer. 13. · A method of manufacturing a porous self-polymerizing mask, comprising: manufacturing an aluminum oxide film; and anodizing the aluminum oxide film. 14. The method as claimed in claim 13 wherein the anodization forms a porous alumina film. 1 5-A method for making a porous self-contained, waste mask from Yongkou, which involves chemically synthesizing nano particles in a <-layer. 16. According to item 15 of the scope of the patent application, \ ^ ^ ^ ^ ^ ^ ^ Xin Li Pan 'wherein the voids between the nano particles in the layer constitute the pores in the porous self-polymerizing mask. No. 17. A method of manufacturing a porous self-polymerizing mask, comprising: manufacturing-a first material 'wherein the first material includes self-polymerizing particles; and * n ττ Ding Bingguang. 18. The method of claim 17 in the scope of patent application, which includes: before the shift O: \ 88 \ 88956.DOC • 2 * process, orient the particles perpendicular to the first material 19. Please refer to the method of item 17 of the patent, in which the grain surface ° segment polymer. A series of inorganic porous films comprising: a substrate support having a gap; and the inorganic film includes an arrangement of inorganic film pores suspended in the gap of the substrate, wherein The pores have a pore diameter of less than 30 nm, and the pores have a pore diameter distribution of less than 20%. O: \ 88 \ 88956.DOC