WO2012060576A2

WO2012060576A2 - Method for processing a nano fine electrode within a biochemical analysis chip

Info

Publication number: WO2012060576A2
Application number: PCT/KR2011/008084
Authority: WO
Inventors: 이상현
Original assignee: Lee Sanghyun
Priority date: 2010-11-02
Filing date: 2011-10-27
Publication date: 2012-05-10
Also published as: KR20120046392A; KR101201106B1; WO2012060576A3

Abstract

The present invention relates to a method for processing a nano fine electrode within a biochemical analysis chip. More particularly, a metal pattern is formed within a mother material, and then the mother material and the metal pattern are processed at the same time using a femtosecond laser to precisely and finely form a fine electrode in a fine channel. Also, only the metal pattern is additionally processed through a femtosecond laser nano surface processing method to obtain a more precise metal pattern on a nano scale level. As a result, a nano scale fine electrode having a size less than about 100 nanometers may be obtained. Also, accuracy of a nanometer level between the fine electrode and the fine channel may be secured, and the processing process may be simplified.

Description

Nano-microelectrode processing method inside biochemical analysis chip

The present invention relates to a nano-electrode processing method inside the biochemical analysis chip. More specifically, by forming a metal pattern inside the base material and simultaneously processing the base material and the metal pattern using a femtosecond laser, the microelectrode can be accurately and precisely formed in the microchannel, and only the metal pattern is femtosecond laser nanosurface By further processing with the machining method, a more precise nanoscale metal pattern can be obtained, which can result in nanoscale microelectrodes of less than 100 nanometers, and nanometer accuracy between microelectrodes and microchannels. The present invention relates to a nanoelectrode processing method inside a biochemical analysis chip that can simplify the processing process.

Thanks to the remarkable developments in the fields of biotechnology, electrical and electronics, and nanoprocessing, research on biochemical analysis chips for analyzing biomaterials is being actively conducted. Biochemical analysis chips are generally manufactured by forming metal patterns on glass substrates and bonding top plates.

In order to form such a metal pattern, a lithography process widely used in a semiconductor process is used. However, when the lithography process is used to manufacture a biochemical analysis chip, unlike the general semiconductor manufacturing process, it requires additional processes such as physically bonding two or more layers to form microchannels. Forming inside the biochemical chip is a very difficult task.

When a metal pattern is formed by a lithography process and processed into a microelectrode, the thickness of the microelectrode and the microchannel may be controlled at a nanoscale, but the microelectrode having a microscopic width or length is formed. This is because mask making and exposure are performed at the micro level.

As such, the lithography method is fundamentally limited to the processing of three-dimensional structures, which can be solved to some extent through multi-layered structures, but unlike semiconductors, there is a limit that cannot meet the needs of the biochemical analysis field that requires a true three-dimensional structure. have.

Meanwhile, femtosecond laser processing has recently attracted attention as one method for overcoming the limitations of three-dimensional structure fabrication. With femtosecond laser processing, three-dimensional structures can be created inside the substrate along the path of the laser's focus.

However, these three-dimensional nanostructures without microelectrodes alone have limitations in performing effective electrokinetic flow control, analysis, and measurement, thus limiting the development of full-scale biochemical analysis chips. In order to overcome this limitation, the necessity of developing a processing method for simultaneously forming a microelectrode in a three-dimensional nanostructure is emerging.

The present invention has been made to solve the above problems, in particular, the micro-electrode can be accurately and precisely formed in the micro-channel, and by obtaining a more sophisticated nano-scale metal pattern of less than 100 nanometers It is possible to obtain nanoscale microelectrodes, to form various types of microelectrodes on the walls of microchannels, to increase the number of microelectrodes, and to control the positional relationship between microelectrodes and microchannels, An object of the present invention is to provide a method for processing nano-electrodes inside a biochemical analysis chip that can widen the contact surface of the chip.

Nano-electrode processing method inside the biochemical analysis chip according to the present invention devised to achieve the above object comprises the steps of (a) forming a metal pattern on the surface of the first base material; (b) coupling a second base material to an upper portion of the first base material on which the metal pattern is formed; And (c) forming a microchannel and a microelectrode by simultaneously processing the metal pattern and the base material with a femtosecond laser.

In addition, in the step (c), the processing direction of the microchannel may be a horizontal direction with respect to the metal pattern.

In addition, by adjusting the processing height of the femtosecond laser in the step (c) it can be processed so that the microelectrode is placed at any one of the top, center, and bottom of the microchannel.

The method may further include selectively processing only the metal pattern using the femtosecond laser (a1) between the step (a) and the step (b).

In addition, by asymmetrically processing the width of both ends of the metal pattern in the step (a1), the width of the microelectrode formed on both sides of the microchannel in the step (c) may be different from each other.

In addition, in the step (c), the processing direction of the microchannel may be perpendicular to the metal pattern.

Further, in the step (c), the processing direction of the microchannel may be inclined at an angle with respect to the metal pattern.

In addition, in the step (c), the microchannel may be processed so that the microchannel penetrates the metal pattern a plurality of times.

In addition, in step (c), the microchannels may be processed in a U-shape to form a plurality of microelectrodes.

Further, after the step (c), (d) further processing the microchannel and the microelectrode to selectively expand the inner diameter of the microchannel, thereby allowing the microelectrode to protrude into the microchannel. can do.

According to the present invention, by forming a metal pattern inside the base material and simultaneously processing the base material and the metal pattern using a femtosecond laser, there is an effect that the fine electrode can be accurately and precisely formed in the microchannel.

In addition, according to the present invention, by further processing only the metal pattern by the femtosecond laser nanosurface method, a more precise nanoscale metal pattern can be obtained, and through this, a nanoscale microelectrode of less than 100 nanometers can be obtained, Not only can nanometer-level accuracy be achieved between microchannels, but the process is very simple.

In addition, according to the present invention by varying the processing direction of the femtosecond laser focus can be formed on the wall of the microchannels of various types, there is an effect that can increase the number of microelectrodes.

In addition, according to the present invention, the positional relationship between the microelectrode and the microchannel can be controlled by adjusting the processing height of the femtosecond laser, and after contacting the preprocessed microelectrode and the microchannel to form an internally projecting microelectrode, the contact surface between the electrode and the fluid is formed. It is effective to widen the.

1 is a cross-sectional view showing a process of forming a metal pattern inside the base material using a lithography process,

2 is a view for explaining a metal pattern additional processing method using a femtosecond laser according to an embodiment of the present invention,

3 is a view for explaining a microchannel and a microelectrode processing method using a femtosecond laser according to an embodiment of the present invention,

4 is a view for explaining a microchannel and a microelectrode processing method using a femtosecond laser according to another embodiment of the present invention,

5 is a view for explaining a microchannel and microelectrode processing method using a femtosecond laser according to another embodiment of the present invention,

Fig. 6 is a diagram showing an example of forming the protruding microelectrode by further processing.

(a) forming a metal pattern on the surface of the first base material;

(b) coupling a second base material to an upper portion of the first base material on which the metal pattern is formed; And

(c) The nano-electrode processing method inside the biochemical analysis chip including the step of forming the microchannel and the microelectrode by simultaneously processing the metal pattern and the base material with a femtosecond laser is the best form for the practice of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the following will describe a preferred embodiment of the present invention, but the technical idea of the present invention is not limited thereto and may be variously modified and modified by those skilled in the art.

A femtosecond laser is a type of pulsed laser that is a very short wavelength laser having a pulse width in the femtosecond ( ^10-15 seconds) region. According to the processing method using the femtosecond laser, the microstructure is processed to the material with the resolution from micrometer to hundreds of nanometers by using the femtosecond laser, and free three-dimensional processing is possible. The process is unnecessary.

In order to perform essential functions such as electrokinetic fluid driving and electrochemical sensing in bioanalysis needle or lab-on-a-chip manufacturing, it is necessary to install electrodes at predetermined positions inside the chip.

In order to form such a microelectrode, it is common to use a lithography method as shown in FIG. However, according to the general lithography method, the electrode becomes difficult to accumulate rapidly in a microstructure having a channel size of 1 micrometer or less, and thus, there is a technical difficulty. .

The nano-electrode processing method inside the biochemical analysis chip according to the present invention is made through the following process.

First, a metal pattern is formed on the surface of the first base material (“first step”), and second, only a metal pattern is selectively processed using a femtosecond laser (“second step”). Third, after the second base material is bonded to the first base material on which the metal pattern is formed ("third step"), and fourth, the microchannel and the microelectrode are formed by simultaneously processing the metal pattern and the base material with a femtosecond laser ("fourth step) "). It is noted here that the second step may be omitted as necessary.

First, the first step and the third step will be described with reference to FIG. 1.

1 is a cross-sectional view illustrating a process of forming a metal pattern inside a base material using a lithography process. Hereinafter, the glass-based base material has been described as an example, but is not limited thereto.

The metal layer 1 is formed on the glass-based base material 2 by chemical vapor deposition, or the like, and the

metal patterns

4 and 5 having a desired shape are formed by using the mask 3, and then the upper base material 6 is formed. It will go through the process of combining. In forming the metal pattern, a method such as wet etching may be used, but is not limited thereto. In this process, since the fabrication and exposure of the mask is difficult to be made at the nano level, an additional special process is required to make the width or length of the metal pattern at the nano level. As a method for solving this, the second step will be described with reference to FIG. 2.

2 is a view for explaining a metal pattern additional processing method using a femtosecond laser according to an embodiment of the present invention.

Femtosecond laser processing has the characteristic of nonlinear optical destruction and cutting of the material in the laser focus regardless of the type of material when the energy intensity of the laser focus exceeds the band gap of the material. Fine processing is possible. By using the lithography-based processing method, the metal pattern is pre-formed into the desired design inside the base material, and only the metal pattern is selectively processed using a femtosecond laser. By processing the microelectrode can be accurately and precisely formed in the microchannel.

After the metal pattern is formed on the surface of the base material through the first step, the metal pattern formed on the lithography base is further processed by femtosecond laser nanosurface processing to further process the metal pattern at the nano-level resolution. A metal pattern of a level can be obtained (second step).

The femtosecond laser can be used to selectively process only the metal pattern because of the difference in the band gap between the metal and the glass. In order to selectively process only a metal pattern by using a band gap difference between metal and glass, it is necessary to adjust the intensity of the femtosecond laser. More specifically, by controlling the intensity of the femtosecond laser so that the glass having a much larger bandgap than the metal is processed, only the metal, the base metal is not processed, and only the metal pattern is selectively processed.

According to the femtosecond laser nanosurface processing method, a surface processing resolution of less than 100 nanometers can be obtained, and thus nanoscale patterns that are difficult to obtain in the lithography process can be easily realized.

However, when the nano-level metal pattern is not required, the second step may be omitted and the micro-level metal pattern may be manufactured.

Referring to FIG. 2A, a metal pattern 12 having a level of about 10 micrometers is formed on the base material 10. In order to further improve the resolution of the metal pattern, more precise masks and exposure and alignment techniques have to be applied, but in addition to technical problems, manufacturing cost is greatly affected.

Alternatively, the nanocomb electrode 14 may be easily processed at a resolution of about 100 nanometers or less by using a femtosecond laser nanosurface machining method as shown in FIG. 2 (b). In addition, the nano-electrode pair 16 formed to face each other with a pointed tip as shown in Figure 2 (c) may be processed at a resolution of about 100 nanometers or less.

In this way, since fine precision additional processing is possible using the femtosecond laser processing method, the metal pattern of about 100 nanometers can be easily manufactured by applying the lithography technique and the femtosecond laser nanosurface processing method.

The metal substrate may be directly integrated into the chip by combining the upper base material on the nano metal electrode patterns thus formed, but by further processing nanoscale microchannels having a three-dimensional shape by using femtosecond laser nanomachining, It is possible to implement a fusion type nano-microelectrode and nano-microchannels with utilization and added value.

Next, a fourth step will be described with reference to FIGS. 3 to 5.

3 is a view for explaining a microchannel and a microelectrode processing method using a femtosecond laser according to an embodiment of the present invention. 3 illustrates an example in which the processing direction of the microchannel is in a horizontal direction with respect to the metal pattern. 3 (a) to 3 (c), the upper three views are plan views, and the lower three views are vertical sectional views.

After the nanoscale metal pattern is formed inside the base material through the first to third steps, the base material and the metal pattern are simultaneously processed by the femtosecond laser processing method on the base material including the metal pattern to form microchannels and microelectrodes. There are four steps.

When the prepared base material is processed by femtosecond laser processing, metal and glass are processed at the same time, so that various nano-level microelectrodes can be manufactured in a fused form to microchannels.

Referring to FIG. 3A, a relatively narrow metal pattern 22, a relatively wide metal pattern 24, and an asymmetric metal pattern 26 at both ends are formed in the base material 20. An example is shown. In this case, as described above, in the case of the metal pattern 22 having a relatively narrow width and the metal pattern 26 having different widths at both ends, the metal pattern 26 may be formed in the nanoscale using the processing method of the second step.

For convenience, the lower side of FIG. 3 (a) is typically illustrated as a narrow metal pattern 22, but may be equally applied to the wide metal pattern 24 and the asymmetric metal pattern 26. To reveal. When the asymmetric metal patterns 26 having different widths on the left and right sides are formed, microelectrode pairs having different widths of the left and right microelectrodes are formed.

Referring to FIG. 3 (b), an outline 28 of cutting a base material and a metal pattern using a femtosecond laser processing method to form a microchannel is illustrated.

Referring to FIG. 3 (c), the microstructure formed when the base material 20 and the

metal patterns

22, 24, and 26 are simultaneously processed using the femtosecond laser processing method along the outline 28 of FIG. 3 (b). The shapes of the

channels

30, 32, 34 and microelectrodes are shown. In FIG. 3C, fine electrodes are formed at both ends of the

microchannels

30, 32, and 34.

Also, by adjusting the processing height of the femtosecond laser, it is possible to adjust the positional relationship between the microelectrode and the microchannel. For example, as shown in FIG. 3C, the microelectrode may be processed to be positioned at the center of the microchannel 30, and the microelectrode may be processed to be positioned below the microchannel 32, or the microelectrode may be disposed at the bottom of the microchannel 32. It may be processed to be located above the fine channel 34.

The final shape of the microelectrode may be variously determined according to the shape of the metal pattern formed inside the base material, the energy distribution and intensity of the femtosecond laser focus, the direction and angle at which the focal passes through the metal patterns, and the like. As such, processing the base material and the metal pattern at the same time not only ensures nanometer accuracy between the microelectrode and the microchannel, but also has the advantage of making the processing process very simple.

4 is a view for explaining a microchannel and a microelectrode processing method using a femtosecond laser according to another embodiment of the present invention. 4 shows an example in which the processing direction of the microchannel is perpendicular to the metal pattern.

Referring to FIG. 4, the microchannel 44 is perpendicular to the metal pattern 42. As a result, a circular ring-shaped microelectrode 42 is formed on the wall surface of the microchannel 44. That is, when the femtosecond laser focus penetrates the metal pattern vertically, a ring-shaped microelectrode may be formed.

5 is a view for explaining a microchannel and a microelectrode processing method using a femtosecond laser according to another embodiment of the present invention. 5 illustrates an embodiment in which two or more circular microelectrodes are formed along a microchannel (FIGS. 5A and 5B) and an embodiment in which an elliptical microelectrode is formed along a microchannel (FIG. 5C). ) Is shown.

By processing the microchannels so that the microchannels penetrate the metal pattern a plurality of times, a plurality of microelectrodes can be obtained.

As illustrated in FIG. 5A, when the microchannel 50 is processed by stacking the metal patterns 52 in multiple layers, a plurality of circular microelectrodes may be formed along the microchannel 50. However, there are limitations in technically and economically difficult to process a multilayer laminate using a lithography process.

As shown in FIG. 5 (b), when the plurality of metal patterns 56 are formed in the horizontal direction, and the microchannels 54 are formed in a U-shape using a three-dimensional femtosecond laser processing method, the plurality of ring-shaped microelectrodes are formed in the microchannels. Can be installed accordingly. In FIG. 5 (b), for the sake of convenience, the U-shaped microchannel is illustrated as an example, but any type of microchannel may be used as long as the processing direction of the microchannel is changed.

5 (c) shows an elliptical microelectrode formed by inclining at an oblique angle with respect to the metal pattern instead of making the microchannel processing direction with respect to the metal pattern horizontal (FIG. 3) or vertical (FIG. 4). An example is shown. Although not shown, unlike FIG. 5 (c), after the microchannel is formed obliquely from the upper direction to the downward direction and penetrates the metal pattern, the microchannel is elliptical when the microchannel is formed obliquely from the lower direction to the upper direction by changing the direction. A plurality of fine electrodes may be formed.

As such, by varying the processing direction of the femtosecond laser focus, various types of microelectrodes may be formed on the walls of the microchannels, and the number of microelectrodes may be increased.

When the microchannel and the microelectrode are formed through the fourth step, the microchannel and the microelectrode may be used as biochemical analysis chips. On the other hand, if the post-processing is additionally performed on the microchannel and the microelectrode after the fourth step, the shape of the microelectrode and the microchannel may be changed.

For example, referring to FIG. 6, the microchannels 62 formed in the base material 60 and the microelectrodes 64 are post-processed to selectively expand the inner diameter of the microchannels 62, thereby expanding the microchannels 66. The protrusion 68 may be implemented to protrude the microelectrode 64 into the inside. In this case, only the microchannel 62 may be selectively etched using hydrogen fluoride (HF) to form the expanded microchannel 66. Such a protruding microelectrode may be very useful when the contact surface between the electrode and the fluid needs to be wider, or when the internal protruding structure is functionally required.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. . The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

The present invention relates to a microstructure for biochemical analysis including nanometer level and a processing method for forming a microelectrode inside the analysis chip, in particular, nanosensor, nano actuator, single cell analysis platform, bio drug development, stem cell related research It can be widely applied to DNA analysis field.

Claims

(a) forming a metal pattern on the surface of the first base material;

(b) coupling a second base material to an upper portion of the first base material on which the metal pattern is formed; And

(c) forming microchannels and microelectrodes by simultaneously processing the metal pattern and the base material with a femtosecond laser;

Nano-microelectrode processing method inside the biochemical analysis chip comprising a.
The method of claim 1,

The processing method of the microchannel in the step (c) is a nano-electrode processing method inside the biochemical analysis chip, characterized in that the horizontal direction with respect to the metal pattern.
The method of claim 2,

In the step (c) by adjusting the processing height of the femtosecond laser nano-electrode inside the biochemical analysis chip, characterized in that the micro-electrode is processed to be located at any one position of the top, center, bottom of the microchannel. Processing method.
The method of claim 1, wherein the step (a) and the step (b)

(a1) A method for processing nano-electrodes inside a biochemical analysis chip, further comprising selectively processing the metal pattern using a femtosecond laser.
The method of claim 4, wherein

Biochemical analysis, characterized in that the (a) by processing the width of both ends of the metal pattern asymmetrically, so that the width of the microelectrode formed on both sides of the microchannel in the step (c) are different from each other Nano micro electrode processing method inside chip.
The method of claim 1,

The nano-electrode processing method inside the biochemical analysis chip, characterized in that in the step (c) the processing direction of the microchannel is perpendicular to the metal pattern.
The method of claim 1,

The nano-electrode processing method inside the biochemical analysis chip, characterized in that in the step (c) the processing direction of the microchannel is inclined at a predetermined angle with respect to the metal pattern.
The method of claim 1,

And processing the microchannels such that the microchannels penetrate the metal pattern a plurality of times in step (c).
The method of claim 8,

The nano-microelectrode processing method inside the biochemical analysis chip, characterized in that to form a plurality of micro-electrodes by processing the micro-channel in the step (c) in the step (c).
The method of claim 1, wherein after step (c)

(d) postprocessing the microchannels and the microelectrodes to selectively extend the inner diameter of the microchannels so that the microelectrodes protrude into the microchannels;

Nano-microelectrode processing method inside the biochemical analysis chip further comprising a.