KR20110093428A - Method for selective patterning of polyethyleneimine and a semiconductor device manufactured by using the same - Google Patents

Abstract

PURPOSE: A method for selectively patterning polyethyleneimine and a semiconductor device which is manufactured by the same are provided to use existing photo processing equipment, thereby reducing processing costs and processing time. CONSTITUTION: A photoresist resin film pattern is formed on a substrate(1). A polyethyleneimine solution is applied on the substrate. The applied polyethyleneimine solution is dried. A photosensitive resin film is eliminated by a solvent and an ultrasound wave.

Description

Method for selective patterning of polyethyleneimine and a semiconductor device manufactured using the same {Method for selective patterning of polyethyleneimine and a semiconductor device manufactured by using the same}

The present invention relates to a selective patterning method of polyethyleneimine and a semiconductor device manufactured using the same, and more specifically, to selectively pattern a polyethyleneimine thin film, which is an organic polymer thin film, using a photo-lithography method. The present invention relates to a semiconductor device in which polyethyleneimine is patterned.

The photo-lithography method spin-coates a photoresist on a flat substrate to form a thin film (e.g., AZ5214 creates a 1.4 micrometer thick film under normal conditions). After attaching a photomask, the method of producing a photosensitive resin film pattern on a board | substrate is performed by irradiating light of a suitable wavelength for a predetermined time, and selectively leaving or removing a photosensitive resin film. Generally, a thin metal material is deposited on the photosensitive resin film pattern, and then the photosensitive resin film is removed to selectively leave the metal material only in a place where the photosensitive resin film pattern is not used, thereby manufacturing the metal pattern on the substrate. have.

As such, there have been efforts to use the photolithography method, which has been mainly used to fabricate metal patterns, to fabricate organic polymer patterns. However, few examples have been successfully introduced due to various technical limitations in introducing photolithography to fabricate organic polymer patterns.

The first limitation is that the organic solvent that melts the organic polymer to be applied to the pattern often melts the photosensitive resin film. AZ5214, which is used as a general photosensitive resin film, is soluble not only in organic solvents such as acetone but also in alcoholic organic solvents such as ethanol and methanol. As such, the organic solvent used for removing the photosensitive resin film must satisfy the condition that the photosensitive resin film is melted and the organic polymer to be patterned is not melted.

In addition, the bonding force between the organic polymer and the organic polymer and the substrate should be less than. When the force between the organic polymers is greater, the entire organic polymer may be separated and lifted off from the substrate during the removal of the photosensitive resin film, thereby causing a problem that the organic polymer pattern does not remain on the actual substrate.

Since it is difficult to solve these technical limitations at the same time, conventionally, the organic polymer is coated with a method such as reactive ion etching (RIE), or the organic polymer is coated with the entire nanoimprint lithography. The organic polymer pattern was produced using the method and the like.

In order to use the reactive ion etching method, expensive equipment must be used, and conditions such as the type and pressure of the gas used, and the etching rate (rate) must be determined.

In addition, in order to use a method such as nanoimprint lithography, a master substrate is fabricated on an Si (silicon) substrate using e-beam lithography, photolithography, and various etching methods. It is inconvenient to use a method of surface modification, such as a self-assembly monolayer, to produce a polymer stamp, and to use it on a organic polymer. This method is convenient for producing a pattern that is repeated in a large area, but it is not yet applicable to the alignment (align) process has a fatal disadvantage that can not be applied to the manufacture of a multi-layer semiconductor device.

The fabrication of organic polymer patterns on substrates by photolithography is very demanding and limited in itself, resulting in no such attempts, nor in the applications of conventional semiconductor processes.

However, according to recent research results, it is necessary to dope a single-walled carbon nanotube, which is intrinsically p-type, with n-type in order to device and apply a single-walled carbon nanotube (SWCNT) ( Shim) et al . , J. Am. Chem. Soc. 2001, 123 , 11512), this approach has opened up the possibility of fabricating complementary metal oxide semiconductors (CMOS, CMOS) and the most basic ring oscillators of logic devices.

To achieve this goal, there is a need to pattern a doping material, such as polyethyleneimine, via selective coating. If the coating is carried out without selectivity, the characteristics of the device cannot be expected due to the difficulty of removing polyethyleneimine. This method of selective patterning can be achieved only by using a technology capable of an alignment process.

In this regard, the above method of nanoimprint lithography is not suitable because the alignment itself is impossible. Therefore, there is an urgent need for a process capable of aligning and selectively doping polyethyleneimine.

Under these technical backgrounds, the present inventors have completed the present invention as a result of intensive efforts to apply the conventional photolithography method to the patterning of organic polymers, especially polyethyleneimine.

After all, it is an object of the present invention to provide a method for selectively patterning polyethyleneimine through a simplified process without the need for expensive equipment through the development of optimized photolithography process.

Still another object of the present invention is to provide a semiconductor device manufactured using the method of selectively patterning the polyethyleneimine.

In the present invention to achieve the above object

Forming a photosensitive resin film pattern on the substrate; Applying an aqueous polyethyleneimine solution to a thickness of 80% or less of the photosensitive resin film pattern thickness; Drying the applied aqueous polyethyleneimine solution; And removing the photosensitive resin film by treating an ultrasonic wave with a solvent capable of selectively removing the photosensitive resin film, thereby providing a selective patterning method of polyethyleneimine.

According to one embodiment of the method for the selective patterning of polyethyleneimine according to the present invention, the aqueous polyethyleneimine solution may range from 1: 1 to 125 polyethyleneimine: distilled water.

According to one embodiment of the method for the selective patterning of polyethyleneimine according to the present invention, the aqueous polyethyleneimine solution may be in the range of 1: 5 to 25 polyethyleneimine: distilled water.

According to one embodiment of the method for the selective patterning of polyethyleneimine according to the present invention, the application of the polyethyleneimine may be made by spin coating for 25 to 40 seconds at 1000 ~ 2000 rpm.

According to one embodiment of the selective patterning method of polyethyleneimine according to the present invention, the application of the polyethyleneimine may be made by spin coating for 5 seconds at 500 rpm, then spin coating for 25-40 seconds at 1000 ~ 2000 rpm.

According to one embodiment of the method for the selective patterning of polyethyleneimine according to the present invention, before the step of applying the polyethyleneimine aqueous solution to a thickness of 80% or less of the photosensitive resin film thickness, 1 ~ 2μl on the substrate / 1mm ² It may be characterized in that it further comprises the step of spraying so that the aqueous solution of polyethyleneimine is formed.

According to one embodiment of the selective patterning method of polyethyleneimine according to the present invention, the drying of the aqueous polyethyleneimine solution may be performed at 65 ~ 100 ℃.

According to one embodiment of the selective patterning method of polyethyleneimine according to the present invention, the removing of the photosensitive resin film may be performed by treating ultrasonic waves of 100 to 200W intensity for 2 to 10 minutes.

According to one embodiment of the selective patterning method of polyethyleneimine according to the present invention, the solvent capable of selectively removing the photosensitive resin film may be acetone.

According to one embodiment of the method for the selective patterning of polyethyleneimine according to the present invention, the selective patterning of the polyethyleneimine may be characterized in that it is suitable for manufacturing a multi-layer semiconductor device.

According to another aspect of the present invention, a semiconductor device including a substrate on which polyethyleneimine is selectively patterned according to the above method may be provided.

According to another aspect of the invention, the substrate; Carbon nanotubes arranged on the substrate; Electrodes formed at predetermined intervals in contact with the carbon nanotubes; And a polyethyleneimine layer selectively coated on the carbon nanotubes connecting the electrodes according to the above-described method.

According to a preferred embodiment of the semiconductor device according to the present invention, the semiconductor device may be a semiconductor device in which the polyethyleneimine layer is selectively coated so that the essential p-type semiconductor properties of the carbon nanotubes are converted to the n-type.

According to a preferred embodiment of the semiconductor device according to the invention, the carbon nanotubes may be a semiconductor device, characterized in that the single-walled carbon nanotubes.

The present invention can be selectively patterned polyethylene imine using the existing photo process equipment as it is very efficient in terms of process cost and time required. In addition, it is possible to align a very precise pattern of the polymer is possible, in one embodiment it has a great advantage and effects, such as to convert the electric field properties of carbon nanotubes to manufacture a semiconductor device. According to the present invention, various devices (touch screen, PMOLED, etc) using various logic circuits and passive matrix (PM) can be manufactured.

1 is a schematic diagram of a selective patterning process of polyethyleneimine according to the present invention. FIG. 1A shows a pattern on a photosensitive resin film after spin coating a photosensitive resin film 2 on a substrate 1. (B) shows a solution of polyethyleneimine solution (3) lower than the height of the photosensitive resin film on the photosensitive resin film pattern, and (c) shows a solvent for removing the photosensitive resin film. It is the state of the finished polyethyleneimine pattern after the treatment.
2 is When coating polyethyleneimine using a spin coater, polyethyleneimine gets wet and is made into a desired pattern. FIG. 2A is an optical micrograph corresponding to FIG. 1A, and FIG. 2B is a coating method of FIG. 1B immediately after applying polyethyleneimine to an appropriate thickness using a spin coater. (C) is an optical micrograph after the polyethyleneimine coated in FIG. 2 (B) is filled with a pattern while it is wet.
Figure 3 shows an optical microscope picture filled with a pattern after dropping an appropriate amount of polyethyleneimine aqueous solution by a tilted drop casting (Tilt drop casting) method.
4 is an optical micrograph obtained after the process of Figure 1 (c). 4A is an example of a pattern correctly manufactured according to Example 5, and the photographs on the right side (b) and (c) are examples prepared according to Comparative Example 1 (b) and Comparative Example 2 (c). .
Figure 5 shows an example of the application using the carbon nanotubes of the present invention. 5A is a scanning electron microscope (SEM) photograph taken after growing horizontally aligned single-walled carbon nanotubes, and (B) is a scanning microscope (SEM) photograph of an actual device made of (A) material (C) is an optical micrograph of the metal electrode and polyethyleneimine pattern aligned on (b), and (d) is an enlarged optical micrograph of a part of (c).
FIG. 6 is a schematic diagram for explaining the FIG. 5D in more detail. 6A shows electrodes 2 and 3 arranged on the substrate 1 and carbon nanotubes 4 connecting thereto, and B shows polyethyleneimine on the carbon nanotubes of (A). (5) shows the selectively patterned appearance. In the figure, identification number 4 is a region showing carbon nanotubes having p-type semiconductor device characteristics because the polyethyleneimine is not coated, and identification number 5 is a region showing semiconductor device characteristics converted to n-type due to the coating of polyethyleneimine. (C) is a cross-sectional view of area (B) identification number 4, showing the appearance of carbon nanotubes only on the substrate, and (D) is a cross-sectional view of area (B) identification number 5 As seen from the figure, the carbon nanotubes on the substrate are coated with polyethyleneimine.
Figure 7 shows an embodiment of (a) npn-type semiconductor device, (b) pnp-type semiconductor device prepared by the selective patterning of polyethyleneimine according to the present invention.
FIG. 8 illustrates a process of manufacturing the structure (a) of FIG. 6 in which a source electrode and a drain electrode are connected by carbon nanotubes in the manufacture of a carbon nanotube semiconductor device according to an exemplary embodiment of the present invention.
Figure 9 (a) is a single-wall carbon nanotube intrinsic properties (line labeled 'Intrinsic'), polyethyleneimine as a whole after coating (line labeled 'PEI coated'), the electrical properties after proper heat treatment of the device ( A line denoted as 'Annealed', and FIG. 9B shows electrical characteristics of the device shown in FIG.

The present invention provides a method for selectively patterning polyethyleneimine and a semiconductor device manufactured therefrom.

Polyethylenimine is a water-soluble cationic polymer composed of high density amine groups, and is used as various research materials in the fields of BT, NT, etc. as well as industries such as adhesives, fiber treatment agents, water treatment agents, and enzyme fixatives. One of the most commonly used materials in a variety of ways.

Since single-walled carbon nanotubes (SWCNT) were discovered by Iijima, it is no exaggeration to say that single-walled carbon nanotubes are at the center of nanotechnology. Many researchers have looked at the potential of single-walled carbon nanotubes and much research has been done. Among them, since the Smally Group saw the possibility of converting single-walled carbon nanotubes from p-type to n-type in alkali metals (very unstable in air) in 1997 ( Lee et al. , Nature 1997, 388 , 255), 2001 in the simmunseop Dr hongji die group may be by coating the polymer on the SWNT transform the characteristics of the initial p-type to n-type (Shim et al . , J. Am. Chem. Soc. 2001, 123 , 11512.) At this time, the material used was polyethyleneimine, and in particular, the polyethyleneimine coating showed stable n-type properties in the air.

Since then, many researchers have reported that single-walled carbon nanotubes, which are essentially p-types, can be converted to n-types with polyethyleneimine as well as various polymeric materials. This research continues to this day, and that contributor is essentially a logical pair of p-type materials paired with p, not only as a logic gate, but also as a single-walled carbon nanomaterial in other materials. This is because the advantage of converting to type n with simple doping, rather than finding pairs of tubes, is very large. In addition to pn diodes ( Zhou et al. , Nano Letters 2004, 4 , 2031.), p-MOS and n-MOS logic gates have been demonstrated using horizontally aligned single-walled carbon nanotubes ( Kang). et al . , Nature Nanotechnology 2007, 2 , 230.).

However, this method shows the possibility of the device by patterning PMMA on the device channel by e-beam lithography and spin-coating polyethyleneimine as a whole or coating and connecting polyethyleneimine as a whole. PMMA patterning using two-beam lithography, which is not applicable in the process, or logic gate fabrication through selective patterning is limited.

The present invention provides a pattern fabrication method that can be applied in an actual semiconductor process and can be aligned (including positioning), and thus can be applied to fabrication of a multilayer semiconductor device.

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

In the selective patterning method of polyethyleneimine according to the present invention, forming a photosensitive resin film pattern on a substrate; Applying an aqueous polyethyleneimine solution to a thickness of 80% or less of the photosensitive resin film pattern thickness; Drying the applied aqueous polyethyleneimine solution; And removing the photosensitive resin film by treating ultrasonic waves with a solvent capable of selectively removing the photosensitive resin film.

The kind of the photosensitive resin that can be used in the method for selective patterning of polyethyleneimine according to the present invention may be used as long as it is possible to select a solvent capable of dissolving polyethyleneimine but not the photosensitive resin.

In the embodiment of the present invention, AZ5214E (purchased from Kirin reagent company (Seoul)) which is soluble in acetone is used as the photosensitive resin. Spary, TI Plating, TI xLift, AZnLOF2000, AZ Mir 701, AZ ECI 3000 and the like can be used, and these photosensitive resins are all soluble in acetone, and acetone can be used as a solvent for dissolving the photosensitive resin. In addition, the AZ 100 Remover (purchased from Kirin reagent company (Seoul)), which is commercially available, may be used to increase the efficiency of the photoresist resin.

In order to selectively pattern polyethyleneimine according to the present invention, a step of preparing a photosensitive resin pattern on a substrate in advance to an appropriate thickness is required, which is performed by spin coating or otherwise coating a photosensitive resin film on a substrate using a conventional photolithography patterning method. After application through the method of drying and drying, it can be carried out by placing a photo mask on the aligner and irradiating UV.

The aqueous solution of polyethyleneimine is applied to the substrate on which the photosensitive resin pattern is formed to have a thickness of 80% or less of the thickness of the photosensitive resin film.

Before the step of applying the polyethyleneimine aqueous solution to a thickness of 80% or less of the thickness of the photosensitive resin film, the step of spraying to form a 1 ~ 2μ / 1mm ² polyethyleneimine aqueous solution layer on the substrate It is desirable to.

The polyethyleneimine aqueous solution used in the present invention may be diluted in a ratio of polyethyleneimine: distilled water 1: 1 to 125, preferably 1: 5 to 25. More preferably, an aqueous solution of polyethyleneimine diluted in distilled water at 1: 5 may be used.

If the ratio of polyethyleneimine: distilled water is less than 1: 125, the polyethyleneimine component formed is so thin that the properties of the compound itself do not appear, which is not preferable.If the content of polyethyleneimine increases beyond 1: 1, the viscosity becomes high. In the case of spin coating, the polyethyleneimine aqueous solution flies away from each other. In this case, the amount of the polyethyleneimine aqueous solution is too small in the pattern of a part of the substrate, and thus the polyethyleneimine aqueous solution cannot be uniformly distributed.

Evenly spraying the polyethyleneimine aqueous solution is preferably so that 1 ~ 2μl of polyethyleneimine aqueous solution layer is uniformly formed per 1mm ² area of the entire substrate. This is sprinkled with a Hamiltonian syringe and soaked again, or the prepared photosensitive resin film sample is inclined, the diluted polyethyleneimine aqueous solution is sprayed on the top of the photosensitive resin film, and the bottom of the sample is coated with gauze to absorb water well. It may also be carried out through the method of leaving at room temperature in a tilted state. These methods control the amount of polyethyleneimine that remains on the substrate.

As described above, when the polyethyleneimine is sprayed so that 1 ~ 2 μl of polyethyleneimine solution per 1 mm ² is evenly spread, the polyethyleneimine aqueous solution having excellent polarity on the photosensitive resin film can be maintained at a thickness of 150˜200 μm. The thickness of the aqueous solution of polyethyleneimine to be sprayed is also related to the thickness and quality of the polyethyleneimine layer to be produced through processes including spin coating.

That is, when the polyethyleneimine aqueous solution is sprayed less than 1 μl per 1 mm ² area of the substrate, the polyethyleneimine aqueous solution starts to locally aggregate, and in some areas, the problem of disappearing the aqueous polyethyleneimine solution is not preferable.

When the aqueous polyethyleneimine solution is sprayed more than ² μl per 1 mm ² area of the substrate, the polyethyleneimine layer is formed too thick to cover all of the photosensitive resin layers even after a subsequent spin coating and drying process. In this case, since the solvent is not accessible to the photosensitive resin film, the photosensitive resin film cannot be removed, which is not preferable.

As described above, the sample sprayed with a suitable thickness of polyethyleneimine solution is preferably spin-coated for 25 to 40 seconds at 1000 to 2000 rpm.

When the spin speed is performed at 1000 rpm or less, the polyethyleneimine aqueous solution appears to be spin coated with a uniform thickness on the naked eye. Afterwards, the polyethyleneimine aqueous solution is agglomerated into the middle during the drying process, and the polyethyleneimine lump is agglomerated at the center. The entire pattern will be covered. In this case, the polyethyleneimine pattern will not be made clean even if the process is further processed under optimal conditions. This is because the polyethyleneimine layer is formed too thick locally so that the photosensitive resin film and acetone cannot come into contact with each other. That is, it is because acetone cannot penetrate a polyethyleneimine film and melt | dissolve a photosensitive resin film.

In this case, the outer region of the substrate is too low in polyethyleneimine to produce the pattern originally intended. That is, even if a suitable amount of aqueous polyethyleneimine solution is applied to spin coating at a low speed such as 1000 rpm or less, even if the aqueous polyethyleneimine solution appears to be uniformly applied at first, the aqueous polyethyleneimine solution starts to agglomerate locally in the center of the substrate. In the region, the problem of disappearing the aqueous solution of polyethyleneimine occurs, which is not preferable.

In this case, even when the spin coating is performed at 2000 rpm or more, it is not preferable because the polyethyleneimine aqueous solution is blown away from each other.

In a preferred embodiment according to the present invention may further comprise the step of slightly spin coating for 5 seconds at 500 rpm before the spin coating as described above.

In order to leave the pattern formed through the photosensitive resin film after the polyethyleneimine has been applied, the polyethyleneimine layer to be applied must be thin enough. If the polyethyleneimine layer is thicker than the photosensitive resin film, the organic solvent used for removing the photosensitive resin film is the photosensitive resin. This is because the reaction cannot be reached because the membrane cannot be reached (see (b) and (c) of FIG. 1).

Therefore, the present invention includes applying a polyethyleneimine aqueous solution to a thickness of 80% or less of the thickness of the photosensitive resin film.

When the process of applying polyethyleneimine under the above conditions, the aqueous polyethyleneimine solution is applied to a thickness of 80% or less of the thickness of the photosensitive resin film. Fig. 1B is a schematic diagram showing such a shape. In this case, when the polyethyleneimine is applied with a thickness exceeding 80% of the thickness of the photosensitive resin film, the photosensitive resin film may not be exposed to the outside due to the surface tension acting between the edges of the photosensitive resin film and the polyethyleneimine. In this case, even if the subsequent process is subjected to the optimum conditions, the polyethyleneimine layer is formed too thick, so that the solvent which can dissolve the photosensitive resin film is not accessible.

The selective patterning method of polyethyleneimine according to the present invention includes the step of drying the applied aqueous polyethyleneimine solution.

The spin-coated sample is preferably dried for 12 to 48 hours using a drying oven at a temperature of 65-100 ° C. in which the horizontal state is maintained using a level gauge to remove water. At this time, when the temperature is lower than 65 ℃, or the treatment time is shorter than 12 hours it is not preferable to take too much time for drying, and when treated at a temperature of 100 ℃ or more or 48 hours or more is excessive drying and formation Deformation of the polyethyleneimine layer may occur, which is undesirable.

Selective patterning method of polyethyleneimine according to the present invention includes the step of removing the photosensitive resin film by ultrasonic treatment with a solvent capable of selectively removing the photosensitive resin film.

Preferably, the substrate having the polyethyleneimine layer dried is soaked in a beaker filled with a solvent capable of selectively removing the photosensitive resin film, and then placed in a bath-type ultrasonic sonicator for 2 to 10 minutes at an intensity of 100 to 200 W. The efficiency of removing the photosensitive resin film is increased.

Acetone is used in the embodiment according to the present invention as a solvent for removing the photosensitive resin film without affecting polyethyleneimine. Instead of acetone, the solvent is changed to an alcohol such as methanol or ethanol and ultrasonic waves under the same conditions as the acetone treatment are used. In the case of the treatment, polyethyleneimine is partially dissolved and adhered to the substrate as shown in FIG. 4B. Acetone may be used as a solvent for dissolving the photosensitive resin in the present invention, and in order to dissolve the photosensitive resin, the efficiency may be improved by using a commercially available AZ 100 Remover (purchased from Kirin reagent company, Seoul).

At this time, when the intensity of the ultrasonic wave is less than 100 W, it is not preferable because the removal of the photosensitive resin film is not performed cleanly. When acetone is treated without ultrasonic waves using a washing bottle or the like, it may be possible to obtain a neat result as shown in (c) of FIG. 4. When the intensity of the ultrasonic waves exceeds 200W, an unnecessary amount of energy is applied to the substrate to be manufactured, which increases the mechanical fatigue.

If the treatment time of the ultrasonic wave is shorter than 2 minutes, the photosensitive resin film may not be removed cleanly, which is not preferable. If the treatment is performed for more than 10 minutes, the mechanical fatigue on the substrate is also increased. Even if a big improvement is not found, it is unnecessary.

Through the above process, the photosensitive resin pattern is dissolved and removed in a solvent, and only polyethyleneimine remains on the substrate, thereby producing a pattern as shown in FIG. Depending on the shape of the photosensitive resin film, it may be manufactured in various forms in addition to (a) of FIG. 4.

The present invention can provide a semiconductor device manufactured using a substrate on which a pattern is formed through the above method.

5 shows an example of a semiconductor device that can be fabricated using selective patterning of polyethyleneimine in accordance with the present invention. 5 (c) shows a sample in which an electrode pattern and a line pattern are aligned with an aligner (Mask Aligner MA150CC, SUSS), showing that the method according to the present invention can be aligned in an actual process. It also shows that polyethyleneimine can be well formed on the metallic electrode pattern.

6 shows a schematic diagram of the single-walled carbon nanotube semiconductor device of FIG. 5 (D) according to the present invention.

6A shows electrodes 2 and 3 arranged on the substrate 1 and carbon nanotubes 4 connecting thereto, and B shows polyethyleneimine on the carbon nanotubes of (A). (5) shows the selectively patterned appearance. In the figure, identification number 4 is an area where carbon nanotubes are p-type semiconductor device characteristics because the polyethyleneimine is not coated, and identification number 5 is an area where semiconductor device characteristics are converted to n-type due to the coating of polyethyleneimine.

6 (c) is a cross-sectional view of region (B) identification number 4 showing an intrinsic p-type semiconductor device characteristic of carbon nanotubes in which only carbon nanotubes exist on a substrate. (See FIG. 9A).

Figure 6 (D) is a cross-sectional view of the area (B) identification number 5, carbon nanotubes (n type semiconductor device characteristics, shown in Figure 9 (a)) coated with polyethyleneimine on the substrate Indicates the shape of.

Figure 7 (a) is an n-p-n type semiconductor device manufactured by the selective patterning of polyethyleneimine according to the present invention, (b) shows an embodiment of the p-n-p type semiconductor device (b).

FIG. 8 illustrates a process of manufacturing the structure (a) of FIG. 6 in which a source electrode and a drain electrode are connected by carbon nanotubes in the manufacture of a carbon nanotube semiconductor device according to an exemplary embodiment of the present invention.

Figure 9 (a) is a graph showing the intrinsic characteristics of single-wall carbon nanotubes (PE) coated with polyethyleneimine as a whole (PEI coated), the electrical characteristics (Annealed) after proper heat treatment of the device, (B) shows the electrical characteristics of the element shown to (d) of FIG.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, these Examples are only for illustrating the present invention, and the scope of the present invention will not be construed as being limited by these Examples.

Example  1: photosensitive Resinous  Produce

Two types of wafer substrates: 5mm x 5mm and 10mm x 10mm (SiO ₂ (300nm, thermally grown) / Si (orientation: <100>, heavily boron doped (p-type), 525 +/- 25 μm, resistivity 0.010 ~ 0.020 , AZ5214 photosensitive resin film was turned at 500rpm for 5 seconds on the Silicon Technology Coporation, and applied at a spin speed of 35 seconds at a speed of 3500 revolutions per minute, and then the substrate coated with AZ5214 on a hot plate set at 100 ° C. The AZ5214 (Clant Company) was dried up. Then, the photomask was placed on the substrate and UV (= 350 nm) was irradiated for 9 seconds to prepare a photosensitive resin film patterned as shown in FIG. 1. The photosensitive resin film prepared under these conditions has a thickness of 1.4 ~ 1.5㎛.

Example  2: application of polyethyleneimine by spin coating (5) mm  x 5 mm )

A 5 mm x 5 mm sample of the photosensitive resin film pattern coated substrate prepared in the above process was placed on a spin coater, and then diluted 1: 5 (polyethylenimine: aqueous solution) using a Hamiltonia syringe. 30 μl of an aqueous polyethyleneimine solution was evenly spread over the entire substrate, and 26 μl was again sucked into a Hamiltonian syringe. After such a process, polyethyleneimine was applied to the photosensitive resin film with a thickness of approximately 160 μm, and spin-coated at 500 rpm for 5 seconds and 1500 rpm for 30 seconds to obtain a result as shown in FIG. 2.

Example  3: application of polyethyleneimine by spin coating (10) mm  x 10 mm )

After placing the substrate on which the 10 mm x 10 mm photosensitive resin film pattern formed in the same manner as in Example 1 was formed on a spin coater, 100 µl of the whole substrate was evenly sprayed with a Hamiltonian syringe and 80-85 µl was sucked again. A polyethyleneimine membrane of about 200 μm thick was formed. This was spin-coated at 500 rpm for 5 seconds and 1500 rpm for 30 seconds to obtain a result as shown in FIG. 2.

Example  4: Tilted  Drop casting ( Tilted drop casting Application of Polyethylenimine by

The 10 mm x 10 mm photosensitive resin film sample prepared in the same manner as in Example 1 was inclined at 45 degrees, and 1 ml of 5: 1 diluted polyethylenimine was sprinkled on top of the resin film to absorb water well on the bottom. The sample was left at room temperature for 2-3 minutes while the sample was inclined at about 80 degrees or more, and then spin-coated for 5 seconds at 500 rpm and 30 seconds at 1500 rpm to obtain a result as shown in FIG. 4. .

Example  5: photosensitive with acetone Resinous  remove

The sample prepared in Example 3 was dried in a drying oven at 70 ° C. for 24 hours in a horizontal oven using a horizontal gauge to remove the water, and then filled with an appropriate amount of acetone in a beaker. , Was put in a bath-type ultrasonic treatment (JAC Ultrasonic 1505 KODO, the frequency is 40kHz), and then ultrasonicated for 5 minutes at an intensity of 150W. Through this, the photosensitive pattern was dissolved and removed in a solvent, and only polyethyleneimine remained on the substrate, thereby producing a pattern as shown in FIG.

Comparative example  One: Alcohol  Photosensitive Resinous  remove

The same method as in Example 5 was applied, but the lift-off process using methanol instead of acetone as a solvent showed that polyethyleneimine was partially dissolved and adhered to the substrate as shown in FIG.

Comparative example  2: photosensitive with only solvent treatment without sonication Resinous  remove

And when acetone is treated with a general washing bottle without ultrasonic waves instead of the ultrasonic cleaning of Example 5, a neat result is obtained as shown in FIG.

Example  6: polyethyleneimine is optionally Patterned Single Wall Carbon Nanotubes Fabrication of Semiconductor Devices

First, (a) of FIG. 5 shows a scanning electron micrograph of a horizontally aligned single wall carbon nanotube (SWCNT) on a quartz substrate.

First, a semiconductor device was manufactured using single-walled carbon nanotubes. After depositing 100 nm thick gold on single-walled carbon nanotubes, the gold is removed using a thermal tape (Nitto Denko, No. 3198M / 3198MS or No. 3195M / 3198MS). Attached to and separated from the quartz substrate, and the tape is placed on a SiO ₂ (300 nm, thermally grown) / p ++ Si (500 μm, heavily boron doped substrate, resistivity of 0.010 to 0.020 ohm cm) substrate, Treat to the appropriate temperature.

The thermal tape used loses its adhesive ability at 120 ° C. When the thermal tape is treated with a hot plate maintained at 125 ° C, only the thermal tape dries and falls off. More specifically, first, the substrate is raised and then heated to 120 ° C., and upon reaching 120 ° C., the temperature is set to 125 ° C. again and the temperature is raised to 125 ° C., thereby visually confirming that the thermal tape and Au are completely removed, and then picking up the thermal tape. After passing through, a single-walled carbon nanotube / Au layer is left on the substrate. This was etched with gold (Au) etchant (Gold Etch TFA, Transene Company, INC.) So that only horizontally aligned single-walled carbon nanotubes remained on the substrate. ((B) of FIG. 5)

Then, as shown in FIG. 8, Au was deposited on the substrate on which the single-walled carbon nanotubes were manufactured to form source and drain electrodes. In this case, instead of Au, metals such as Au / Ti, Pd, Pd / Ti, or Cr may also be used.

The electrode is formed by depositing a metal material on single-walled carbon nanotubes using an E-beam evaporator. In the case of a poor adhesion metal, a Ti adhesive layer having a thickness of 1 nm is deposited first. The metal electrode is then deposited over 30 nm.

In the present invention, after depositing Au, the acetone-filled beaker was sonicated, and then acetone> IPA> methanol> ethanol> distilled water was repeated three times for 1 minute each to remove the photoresist to form a metal electrode. .

Then, a cover pattern is made on the electrode as shown by identification number 4 of FIG. 8 (b). The cover pattern is a pattern for channel defining channels of single-walled carbon nanotubes, and refers to a pattern formed of a photoresist between electrodes in order to isolate the device.

Then, O ₂ -RIE treatment (20 sccm / 100 W / 5 (5 ~ 20) mtorr / 30 sec) to remove all the single-walled carbon nanotubes exposed outside the cover pattern and the electrode pattern to the ).

Thereafter, an electrical break-down process is performed. In other words, when a strong positive voltage is applied to the bottom gate, the p-type single-walled carbon nanotube having semiconductor properties no longer functions as a channel, and all currents are metallic single-walled carbon nano. It will flow along the tube. Therefore, if a voltage is applied to the drain-source electrode to the extent that the metallic single-walled carbon nanotubes cannot withstand, the metallic single-walled carbon nanotubes are broken, and only the semiconducting single-walled carbon nanotubes remain on the channel. It is preferable to apply Vg of 40 V or more and Vds of 40 V or more, which may vary depending on the channel. In this example, Vg is set to 40 V, Vds is raised from 0 V to 40 volts at 2 V intervals, the boosting time is increased at 0.2 second intervals, and Vg is taken from 40 V to 45 V and the voltage is increased at 1 volt intervals. As soon as it is finished, the voltage is increased and the voltage is continuously increased until just before the moment when the current level drops sharply. If the current level does not drop sharply at this stage, increase Vg and Vds by 5 V again and repeat this process. In this process, the current level is suddenly dropped, which is caused by the overcurrent being caught by metallic single-walled carbon nanotubes, which is called an electrical crushing process. Through this, only metallic carbon nanotubes were selectively removed.

Polyethyleneimine was selectively patterned as described in Examples 1 to 5 in the single-walled carbon nanotube semiconductor device fabricated as described above.

 When the photosensitive resin film is removed under the same conditions as in Example 5, the same results as in FIG. 5 (C), (D) and FIG. 6 (B) shown in the photograph can be obtained. Through this, the manufactured single-walled carbon nanotube semiconductor device exhibited n-type electrical characteristics such as PEI coated in the graph of FIG.

 The reason why the single-walled carbon nanotubes are not visible in (c) and (d) of FIG. 5 is that they have a fine diameter of about 1 nm. In addition to the above process was carried out for 10 minutes at 150 ℃ to produce a device having a complete n-type electrical properties indicated as annealed in Fig. 9 (a).

When only a portion of polyethyleneimine patterning is possible, as shown in FIGS. 5 (c), 6 (d) and 6 (b), an intrinsic p-type region and polyethyleneimine are coated between two electrodes to n It is possible to fabricate a pn junction type device having a region converted to a type, and in this case, a device having distinct pn junction diode characteristics can be manufactured as shown in FIG. By converting only the desired channel to the n type through the coating of polyethyleneimine, or selectively coating only a portion of the channel, pn junction, or ppn type device such as npn, (b) as shown in (a) of FIG. You can make as many backs. Using this, not only a logic circuit such as a CMOS and even a ring oscillator, but also a passive matrix (PM) that is a pn junction array can be manufactured.

As described above, the present invention does not require expensive equipment, and has the advantage that it can be performed only by the equipment used in the existing photolithography process.

In addition, the polyethyleneimine disclosed in the present invention is a cationic polymer having a very rich amine group, which is water-soluble, and thus can be applied onto the photosensitive resin film without using a highly toxic solvent, and controls the dilution rate and amount of the polyethyleneimine aqueous solution. After the spin coating under a predetermined condition to dry the polyethyleneimine aqueous solution so as not to agglomerate with each other, through the acetone lift-off process it was possible to selectively produce a polyethyleneimine pattern.

The present invention enables the formation of a nanoscale selective pattern using the difference in solubility of polyethyleneimine and the photosensitive resin film during etching. In addition, the optimum amount of aqueous solution of polyethyleneimine is applied, preventing excessive aggregation and loss during spin coating, thus suggesting optimum conditions for forming a film capable of selective patterning.

The present invention can be selectively patterned polyethylene imine by utilizing the existing photo process equipment as it is very efficient in terms of process cost and time required. In addition, it is possible to align a very precise pattern of the polymer is possible, in one embodiment it has a great advantage and effects, such as to convert the electric field properties of carbon nanotubes to manufacture a semiconductor device. According to the present invention, various devices (touch screen, PMOLED, etc) using various logic circuits and PMs can be manufactured.

As described above in detail specific parts of the present invention, it is apparent to those skilled in the art that such specific descriptions are merely preferred embodiments, and thus the scope of the present invention is not limited thereto. something to do. Thus, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

1: 1 substrate, 2: photosensitive resin film, 3: polyethyleneimine.
6, 1: substrate, 2: electrode, 3: electrode, 4: carbon nanotube, 5: polyethylenimine coated on the carbon nanotube
7 (a), (b) 1: substrate, 2: electrode, 3: electrode, 4: carbon nanotube, 5: polyethyleneimine coated on the carbon nanotube
8: 1: source electrode, 2: carbon nanotube, 3: drain electrode

Claims (14)

Forming a photosensitive resin film pattern on the substrate;
Applying an aqueous polyethyleneimine solution to a thickness of 80% or less of the photosensitive resin film pattern thickness;
Drying the applied aqueous polyethyleneimine solution; And
Selective patterning method of polyethyleneimine comprising the step of removing the photosensitive resin film by ultrasonic treatment with a solvent capable of selectively removing the photosensitive resin film.
The method of claim 1, wherein the aqueous polyethylenimine solution is polyethyleneimine: distilled water ranging from 1: 1 to 125.
The method of claim 1, wherein the aqueous polyethylenimine solution is polyethyleneimine: distilled water in the range of 1: 5-25.
The method of claim 1, wherein the polyethyleneimine is applied to the selective patterning method of polyethyleneimine, characterized in that the spin coating for 25 to 40 seconds at 1000 ~ 2000 rpm.
The method of claim 1, wherein the polyethyleneimine is coated by spin coating at 500 rpm for 5 seconds and then spin coating at 1000 to 2000 rpm for 25 to 40 seconds.
The method of claim 1, wherein before the step of applying the polyethyleneimine aqueous solution to a thickness of 80% or less of the thickness of the photosensitive resin film, to form a 1 ~ 2μ / 1mm ² polyethyleneimine aqueous solution layer on the substrate Selective patterning method of polyethyleneimine further comprising the step of spraying.
The method of claim 1, wherein the drying of the aqueous polyethyleneimine solution is a selective patterning method of polyethyleneimine, characterized in that at 65 ~ 100 ℃.
The method of claim 1, wherein the removing of the photosensitive resin film is a selective patterning method of polyethyleneimine, characterized in that the treatment by ultrasonic wave of 100 ~ 200W intensity for 2 to 10 minutes.
The method of claim 1, wherein the solvent capable of selectively removing the photosensitive resin film is acetone.
The method of claim 1, wherein the selective patterning of polyethyleneimine is suitable for the manufacture of multilayer semiconductor devices.
10. A semiconductor device comprising a substrate on which polyethyleneimine is selectively patterned by the method according to claim 1.
Board; Carbon nanotubes arranged on the substrate; Electrodes formed at predetermined intervals in contact with the carbon nanotubes; And a polyethyleneimine layer selectively coated on the carbon nanotubes connecting the electrodes according to any one of claims 1 to 9.
13. The semiconductor device of claim 12, wherein the semiconductor device is selectively coated with a polyethyleneimine layer such that the intrinsic p-type semiconductor properties of the carbon nanotubes are converted to n-type.
The semiconductor device of claim 12, wherein the carbon nanotubes are single-walled carbon nanotubes.

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