KR101444991B1 - Membrane having cylinderical penetration channel and method of manufacturing the same - Google Patents

Abstract

A separation membrane having a cylindrical permeable channel and a method of making the same are disclosed. The separator according to the present invention includes a support substrate having a plurality of pores formed therein and a transmissive layer formed on the support substrate, wherein the transmissive layer includes a plurality of cylindrical transmissive channels of uniform size passing through the transmissive layer, The permeability and the separation efficiency are increased. A method of manufacturing a separation membrane having a cylindrical transmission channel according to the present invention includes the steps of providing a structure in which a sacrificial substrate, a sacrificial layer and a permeable layer are sequentially laminated, forming a resist film on the permeable layer, Exposing and developing the mask layer to form a mask pattern on the transmissive layer, etching the transmissive layer to form a cylindrical transmissive channel, removing the sacrificial layer to separate the transmissive layer, And a step of forming a separation membrane by transferring the separation membrane to a support substrate, thereby making it possible to easily manufacture a separation membrane having a uniformly sized cylindrical transmission channel by utilizing a semiconductor process including a lithography process and an etching process, You can control the size.

Description

[0001] The present invention relates to a membrane having a cylindrical permeable channel and a method of manufacturing the membrane.

The present invention relates to a separation membrane having a cylindrical transmission channel and a manufacturing method thereof, and more particularly, to a separation membrane having a plurality of cylindrical transmission channels formed in a uniform size and a semiconductor process including a lithography process and an etching process And a method for producing the separator.

Membranes are mechanical filters that can selectively permeate or exclude specific materials in a mixture and are used to provide product or process purity in the pharmaceutical, microelectronics, chemical, and food industries. The separation membrane is typically included in an apparatus designed to be inserted into a fluid stream, and is used to remove particles, microorganisms or solutes from the process fluid. Therefore, an ideal separator requires a high transmittance and a high separation efficiency, that is, a high selective transmittance characteristic.

Various types of polymer membranes with excellent permeability and selective permeability have been developed by long - term studies. However, polymer membranes are limited in their use due to problems such as low thermal stability, decomposition resistance of a low membrane by a solvent or a microorganism, membrane degradation due to high pressure, and high membrane internal resistance.

As means for solving the above problems, separators using inorganic materials which have high thermal, chemical, mechanical and biological stability and can be used without decomposition of the membrane and deformation of the microstructure are being researched and developed. However, most of the inorganic materials are expensive compared to conventional polymer materials, and the process is complicated. Accordingly, the possibility of utilizing a silicon-based separator which is easy to process by a semiconductor process and is relatively competitive in price is attracting attention.

In order to use silicon as a separation membrane, it is necessary to form a pore of a certain size on a silicon substrate. It is very important to increase the selectivity of the material to be separated by forming controllable pores with a uniform size because the pores are separated by a size that excludes a substance larger than the pore size. In addition, the internal resistance of the separation membrane should be minimized so that high permeability can be obtained even with a small driving force (pressure, concentration, etc.).

A method of enlarging the pore size to increase the permeability of the silicon-based separator, a method of increasing the pore size of the silicon substrate by forming the pores more densely, and a method of reducing the thickness of the separator membrane to minimize the resistance . However, there is a limitation that the pore size can not be larger than the substance to be excluded. When the porosity is 50% or more or the thickness is less than 10 nm, the strength of the separation membrane is lowered, Lt; / RTI > Thus, there is a need for a technique for forming optimized pores with high permeability while maintaining the strength available for the process under pressure.

In order to increase the selective transmittance, it is necessary to control the pore size. Since it is technically very difficult to form the pore size of 1 to 10 μm or less in the silicon substrate, It is practically impossible to filter fine particles in the unit of a meter (nm), and the pore size is uneven, so that the separation efficiency, that is, the selective permeability, is reduced. In order to solve this problem, there have been reported methods of preparing heat-treated copolymers by using polymeric polymers. However, these methods have problems in that the pore size is uneven, the porosity is very low, and the manufacturing process is complicated. Therefore, a technique for forming a uniform nano-sized pore is still required.

Accordingly, it is a first object of the present invention to provide a separation membrane capable of increasing the permeability through a cylindrical permeation channel having a uniform size of nanometer unit.

It is a second object of the present invention to provide a method of manufacturing a separation membrane which can easily and easily form a cylindrical transmission channel by utilizing a semiconductor process, and can accurately control a uniform size.

According to an aspect of the present invention, there is provided a semiconductor device comprising: a support substrate on which a plurality of pores are formed; and a transmissive layer formed on the support substrate, wherein the transmissive layer includes a plurality of cylindrical transmissive channels .

According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device, including: providing a structure in which a sacrificial substrate, a sacrificial layer, and a transmissive layer are sequentially laminated; forming a resist film on the transmissive layer; Forming a mask pattern on the transmissive layer, etching the transmissive layer to form a cylindrical transmissive channel, removing the sacrificial layer to separate the transmissive layer, and removing the separated transmissive layer to a support substrate And forming a separation membrane by transferring.

The separation membrane having the cylindrical transmission channel according to the present invention has a cylindrical transmission channel having a uniform size of nanometer unit, thereby reducing the fluid resistance in the separation membrane, thereby increasing the permeability and separation efficiency.

In addition, the method of manufacturing a separation membrane having a cylindrical transmission channel according to the present invention can easily control the size of a transmission channel by using a semiconductor process including a lithography process and an etching process, There is an effect that can be formed.

Figures 1a, 2a, 3a, 4a, and 5a are cross-sectional views illustrating a method for fabricating a silicon-based separator according to one embodiment of the present invention.
FIGS. 1B, 2B, 3B, 4B and 5B are plan views illustrating a method of manufacturing a silicon-based separator according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thicknesses of the layers and regions are exaggerated for clarity. Like reference numerals designate like elements throughout the specification.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figures 1a, 2a, 3a, 4a, and 5a are cross-sectional views illustrating a method for fabricating a silicon-based separator according to one embodiment of the present invention.

FIGS. 1B, 2B, 3B, 4B and 5B are plan views illustrating a method of manufacturing a silicon-based separator according to an embodiment of the present invention.

Referring to FIGS. 1A and 1B, a sacrificial substrate 100, a sacrificial layer 200, and a transmissive layer 300 are sequentially stacked. The sacrificial substrate 100 may be a silicon substrate, and the sacrificial layer 200 may be silicon nitride including SiN _x or silicon oxide including SiO _x . Also, the transmissive layer 300 may be silicon or silicon oxide.

The structure in which the sacrificial substrate 100, the sacrificial layer 200, and the transmissive layer 300 are sequentially stacked may be a silicon on insulator (SOI) substrate composed of a silicon substrate / a silicon oxide / silicon layer. The SOI substrate may be manufactured by a known technique such as a technique of ion-implanting oxygen at a high concentration into a silicon substrate, followed by heat treatment, or a technique of bonding two silicon substrates having an oxide film on their surfaces.

The sacrificial substrate 100 positioned at the lowermost part serves to support the structure in a lithography process and an etching process, which will be described later, and is separated from the transparent layer 300 having a plurality of cylindrical transmission channels formed therein after the etching process. The sacrificial layer 200 located on the sacrificial substrate 100 serves as an etch stopper for preventing the sacrificial substrate 100 from being etched and is formed of a plurality of through- Layer 300 as shown in FIG.

The transmissive layer 300 located on the sacrificial layer 200 may include a plurality of cylindrical transmissive channels having a uniform size therein through a lithographic process and an etching process. At this time, the thickness of the transmissive layer 300 may be within a range of 50 nm to 500 nm. This is an increased thickness compared to conventional silicon-based membranes, which can be used in separation processes where pressure is applied.

Referring to FIGS. 2A and 2B, a resist film 400 is formed on the transparent layer 300. The resist film 400 is patterned through a circular mask (not shown) having a predetermined gap, and the diameter of a cylindrical transmission channel to be described later is determined according to the shape of the mask. The diameter of the circle in the pattern shape may be in the range of 30 nm to 100 nm.

A mask pattern is formed on the transmission layer 300 by exposing and developing the same through a lithography process. This can be performed, for example, by a photolithography process in which a photomask is placed and exposed to ultraviolet (UV) light, then immersed in a developing solution and developed. The resist film 400 may be a silicon oxide film or a silicon nitride film, and may be formed on the transparent layer 300 through chemical vapor deposition (CVD).

3A and 3B, the exposed portion of the transmissive layer 300 having the resist film 400 formed thereon is etched to form a cylindrical transmissive channel 300a in the transmissive layer 300. Referring to FIG. The etching can be achieved by reactive ion etching (RIE) using, for example, a mixed gas of Cl ₂ / HBr / CF ₄ as a reaction gas. The etch proceeds perpendicularly to the surface of the transmissive layer 300 to form a cylindrical transmissive channel 300a. When the permeable channel having the cylindrical shape is formed as described above, the resistance of the fluid passing through the channel is reduced, and the slip effect is generated between the wall of the channel and the fluid, thereby increasing the permeability. The diameter of the cylindrical transmission channel 300a can be formed within a range of 30 nm to 100 nm, which is caused by being manufactured through a semiconductor process. At this time, the sacrificial layer 200 formed under the transmissive layer 300 serves as an etch stopper for preventing the sacrificial substrate 100 from being etched.

Thereafter, a coating layer (not shown) may be formed on the entire surface of the plurality of cylindrical transmission channels 300a to modify the surface. Since the plurality of cylindrical transmission channels 300a are formed in a fine nano-size, the surface area is very large, and the attraction or repulsive force between the fluid and the surface of the transmission channel exerts a great influence on the total transmission. Particularly, when the fluid permeates through the separator, only the frictional force with the permeable channel acts as a resistance. Therefore, in order to obtain a good permeability, the physical / chemical characteristics of the permeable channel are very important.

For example, in the case of water permeation through which water is permeated, a phenomenon in which permeability is higher than the theoretical value can be observed due to the slip phenomenon on the surface of the permeation channel, which is caused by the contact angle and irregularity of the surface. In the case of silicon as compared to the contact angle of 50 ^o, silicon nitride (SiN _x) is 42 ^o, it is 35 ^o, amorphous carbon is 80 ^o, the carbon allotrope having a crystal structure, such as a CNT nearly 180 of silicon oxide (SiO _x) ^o have different contact angles, so they can show different water permeability.

Accordingly, various coating layers can be selected depending on the fluid to be permeated. The coating layer may be any one selected from silicon nitride, silicon oxide, and carbon isotope.

For example, the formation of the coating layer may be performed using atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), or the like.

4A and 4B, the sacrificial layer 200 interposed between the sacrificial substrate 100 and the transmissive layer 300 is removed to separate the transmissive layer 300 provided with the cylindrical transmissive channel 300a. The sacrificial layer 200 may be removed by wet etching using, for example, a BOE (Buffered Oxide Etchant) solution in which HF and NH ₄ F are mixed. Through which the transmissive layer 300 with the cylindrical transmissive channel 300a is ready to act as a separator.

5A and 5B, a transparent layer 300 having a cylindrical transmission channel 300a is transferred to a support substrate 500 or the like to complete a separation layer. The supporting substrate 500 includes a plurality of pores. For example, the support substrate 500 may be a silicon substrate having a plurality of pores. However, the present invention is not limited thereto, and it is possible to pass a fluid having a plurality of pores and to have a certain thickness and to serve as a support. Preferably, the plurality of pores have a larger diameter than the cylindrical permeable channel 300a to allow fluid to pass therethrough.

The separation membrane having the cylindrical transmission channel according to the present invention has a relatively thick thickness compared with the conventional silicon-based separation membrane, so that the overall density of the separation membrane is increased, which is advantageous for use in a separation process in which a constant pressure is applied. Also, by providing a plurality of cylindrical transmission channels having a uniform size and having a size of nanometers, the permeability is improved by the slip effect between the channel wall and the fluid, and the fluid resistance in the separation membrane is reduced to increase the separation efficiency. In addition, a method of manufacturing a separation membrane having a cylindrical transmission channel can easily form a transmission channel by utilizing a semiconductor process including a lithography process and an etching process, and can precisely control its size, There is an advantage.

100: sacrificial substrate 200: sacrificial layer
300: transmission layer 300a: cylindrical transmission channel
400: resist film 500: supporting substrate

Claims (12)

A support substrate on which a plurality of pores are formed;
And a transmissive layer formed on the support substrate,
Wherein the transmissive layer comprises a plurality of cylindrical transmissive channels through the transmissive layer,
And a coating layer is formed to cover the entire surface of the plurality of cylindrical transmission channels. The method according to claim 1,
Wherein the transmissive layer comprises silicon or silicon oxide. The method according to claim 1,
Wherein the diameter of each cylindrical transmission channel is selected within a range of 30 nm to 100 nm and is uniformly formed. delete The method according to claim 1,
Wherein the coating layer comprises any one selected from the group consisting of silicon nitride, silicon oxide, and carbon isotope. Providing a structure in which a sacrificial substrate, a sacrificial layer, and a transmissive layer are sequentially stacked;
Forming a resist film on the transmissive layer;
Exposing and developing the resist film to form a mask pattern on the transparent layer;
Etching the permeable layer to form a cylindrical permeable channel;
Removing the sacrificial layer to separate the transmissive layer; And
And transferring the separated transmissive layer to a support substrate to form a separation membrane. The method according to claim 6,
Wherein the sacrificial substrate is silicon. The method according to claim 6,
Wherein the sacrificial layer is silicon nitride or silicon oxide. The method according to claim 6,
Wherein the transparent layer is silicon or silicon oxide. The method according to claim 6,
Forming a cylindrical permeable channel by etching the permeable layer and forming a coating layer to cover the entire surface of the cylindrical permeable channel between the step of removing the sacrificial layer and the step of separating the permeable layer, Gt; 11. The method of claim 10,
Wherein the forming of the coating layer is performed by any one of atomic layer deposition, chemical vapor deposition, and physical vapor deposition. 11. The method of claim 10,
Wherein the coating layer is one selected from the group consisting of silicon nitride, silicon oxide, and carbon isotope.

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