KR102177472B1 - Source for depositing graphene oxide and method of forming graphene oxide thin film using the same - Google Patents

Abstract

A source for depositing graphene oxide capable of forming a graphene oxide thin film having excellent electrical properties and a method of forming a graphene oxide thin film using the same are disclosed.
The source for depositing graphene oxide according to the present invention further includes a material other than a hydrocarbon-based compound. The method of forming a graphene oxide thin film according to the present invention is performed by a PECVD method, and preferably, a cyclic process is performed.

Description

Graphene oxide deposition source and graphene oxide thin film formation method using the same {SOURCE FOR DEPOSITING GRAPHENE OXIDE AND METHOD OF FORMING GRAPHENE OXIDE THIN FILM USING THE SAME}

The present invention relates to a source for deposition of graphene oxide.

In addition, the present invention relates to a method of forming a graphene oxide thin film having excellent electrical properties by using the source as a plasma enhanced chemical vapor deposition (Plasma Enhanced Chemical Vapor Deposition; hereinafter referred to as PECVD) method. .

Graphene has the advantage of showing excellent electrical properties compared to other carbon materials such as carbon black, and is expected to be used in various fields such as semiconductors and displays.

The graphene thin film can be manufactured by various methods, and can be largely classified into a graphite peeling method and a chemical vapor deposition method.

First, a graphite peeling method for manufacturing a graphene thin film includes an oxidation/reduction method and an ultrasonic peeling method.

In the oxidation/reduction method, graphite is oxidized to form graphite oxide, peeled off to obtain graphene oxide, and then reduced to prepare graphene. In the case of the graphene manufacturing method using the oxidation/reduction method, it is possible to manufacture graphene in large quantities using inexpensive graphite as a raw material, and has the advantage that a solution process using a graphene dispersion is possible. However, in the case of this method, due to the presence of chemical and structural defects in graphene produced as carbon crystals are destroyed during the oxidation process of graphite, the electrical properties of graphene are poor, that is, the electrical resistance value is high and the electrical mobility is There is a low problem.

In the ultrasonic peeling method, graphene is prepared by directly peeling graphite by applying ultrasonic waves to a solution in which graphite is dispersed in a solvent. In the case of this method, since the oxidation/reduction process is not involved, graphene with few defects can be manufactured, and excellent electrical properties can be secured. However, in the case of the ultrasonic peeling method, the production rate of graphene is low due to the limitation of the peeling efficiency of graphite, and it is difficult to mass-produce it.

In addition, a chemical vapor deposition method for preparing a graphene thin film is typically a method using a chemical vapor deposition (CVD) method. The method is a method of thermally decomposing a source (C _x H _y ) containing carbon (C) and hydrogen (H) in a CVD apparatus to deposit a graphene thin film on a catalyst metal such as Ni or Cu. Although this method has the advantage of being able to form graphene directly on the substrate, there is a disadvantage that it is expensive to manufacture graphene according to the high-temperature process, and the electrical properties of the produced graphene thin film are poor. .

As described above, methods for preparing graphene thin films known to date have to undergo various processes such as oxidation, peeling, dispersion, and reduction, and have limitations in large-area synthesis and are difficult to commercial use.

Korean Patent Application Publication No. 10-2014-0128952 (published on November 6, 2014)

One object of the present invention is to provide a source for deposition of graphene oxide.

Another object of the present invention is to provide a method of forming a graphene oxide thin film having excellent electrical properties by PECVD using the above source.

A source for depositing graphene oxide according to an embodiment of the present invention for achieving the above one object includes a compound containing carbon, hydrogen and oxygen; And it characterized in that it comprises a pin oxide.

Through such a source, it is possible to form a graphene oxide thin film having excellent electrical properties by a CVD method, particularly a PECVD method, as compared to the case of using a conventional hydrocarbon-based compound alone source.

In the source, the graphene oxide may be contained in an amount of 0.1 to 0.2% by weight.

In addition, the oxygen-containing hydrocarbon-based compound may be in a liquid state.

The oxygen-containing hydrocarbon-based compound is among ketone-based compounds such as cyclohexanone, acetone, and methyl ethyl ketone, ether-based compounds such as diethyl ether and methyl ethyl ether, and alcohol-based compounds such as methyl alcohol, ethyl alcohol, and isopropyl alcohol. It may contain one or more. These compounds can act as a dispersing solvent while also serving as a carbon and oxygen source.

The method of forming a graphene oxide thin film according to the present invention for achieving the other object is a method of forming a graphene oxide thin film through PECVD. More specifically, a method of forming a graphene oxide thin film according to an embodiment of the present invention includes the steps of: (a) arranging a substrate in a PECVD apparatus and heating the substrate; (b) vaporizing a source including an oxygen-containing hydrocarbon-based compound containing carbon, hydrogen and oxygen and graphene oxide, and introducing it into the PECVD apparatus; (c) decomposing the source by applying RF power to the PECVD device to form a plasma in the PECVD device to deposit graphene oxide on the substrate; And (d) purging the inside of the PECVD apparatus.

At this time, the substrate is preferably heated to 600 ℃ ~ 700 ℃. However, even when the substrate is heated to 400° C. to 600° C. and the source is introduced at a flow rate of 300 sccm (standard cubic centimeter per minute) or less, a graphene oxide thin film having excellent electrical properties can be formed.

Further, it is more preferable that the internal pressure of the PECVD apparatus is 7.5 Torr or more.

Preferably, the method of forming the graphene oxide thin film may be performed by a cyclic process.

In the case of the PECVD graphene oxide thin film formation method using a source additionally containing graphene oxide to a compound containing carbon, hydrogen and oxygen according to the present invention, a conventional compound containing carbon, hydrogen and oxygen is used as a source. Compared to the case, a graphene oxide thin film having excellent electrical properties can be prepared. That is, in the case of the method of forming a PECVD graphene oxide thin film using the source according to the present invention, a graphene oxide thin film having a low sheet resistance of 10,000 Ω/sq or less, and a few hundred Ω/sq or less under certain conditions can be prepared.

Accordingly, the graphene oxide thin film manufactured by the method according to the present invention has excellent electrical properties as described above, even without performing a separate reduction process, semiconductor material, biomaterial, solar cell, OLED, touch It can be variously applied to a panel (touch panel), a secondary battery, a gas and a bio sensor.

Meanwhile, the graphene oxide thin film prepared as needed may be converted into a reduced graphene oxide (RGO) thin film through a reduction process.

1 shows an example of a PECVD apparatus that can be applied to the method for forming a graphene oxide thin film according to the present invention.
Figure 2 schematically shows a method of forming a graphene oxide thin film by the PECVD method according to the present invention.
3A schematically shows an example in which the PECVD method of FIG. 2 is applied as a cyclic process.
3B schematically shows another example in which the PECVD method of FIG. 2 is applied as a cyclic process.
4 shows the thin film Raman peak according to the thickness of the graphene oxide thin film deposited by the PECVD method under the same conditions (substrate temperature 600°C, source flow rate 1400 sccm).

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments and drawings described below in detail. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, only these embodiments are intended to complete the disclosure of the present invention, and are common in the technical field to which the present invention pertains. It is provided to fully inform the knowledgeable person of the scope of the invention, and the invention is only defined by the scope of the claims.

Hereinafter, a source for depositing graphene oxide according to the present invention and a method of forming a graphene oxide thin film using the same will be described in detail with reference to the accompanying drawings.

In order to solve the problems of the above-described graphite peeling method and chemical vapor deposition method, recently, a graphene deposition method using a so-called PECVD method in which plasma is introduced into a CVD apparatus to lower the process temperature has been studied. In addition, a method of depositing a graphene oxide thin film using a CVD method or PECVD method using a source containing carbon (C), hydrogen (H) and oxygen (O) and then reducing it to a graphene thin film was also studied. . However, even in the case of a graphene oxide thin film or a graphene thin film prepared by applying these methods, there is a limit to the degree of improvement of electrical properties.

Accordingly, the inventor of the present invention was able to manufacture a graphene oxide thin film having remarkably improved electrical properties as a result of changing the source for preparing a graphene oxide thin film.

The source for depositing graphene oxide according to an embodiment of the present invention includes an oxygen-containing hydrocarbon-based compound including carbon, hydrogen and oxygen, and graphene oxide.

A typical source for depositing graphene oxide is an oxygen-containing hydrocarbon-based compound such as alcohol, but in the case of the present invention, graphene oxide is additionally included in the oxygen-containing hydrocarbon-based compound.

Through such a source, a graphene oxide thin film having excellent electrical properties can be formed by a CVD method, particularly a PECVD method. At this time, the excellent electrical properties of the graphene oxide thin film means that the graphene oxide thin film has a low electrical resistance value or a high electrical mobility.

The source for forming a graphene oxide thin film by the conventional CVD method or PECVD method is mainly a hydrocarbon-based compound containing carbon and hydrogen (in this case, evaporation is performed in an atmosphere containing oxygen) or containing oxygen containing oxygen such as alcohol. It was a hydrocarbon-based compound. However, in the case of using these sources, in the case of deposited graphene oxide, the sheet resistance was very high, over tens of thousands of Ω/sq.

By the way, as a source for producing a graphene oxide thin film, as a result of including graphene oxide in an oxygen-containing hydrocarbon-based compound containing carbon, hydrogen and oxygen, 10,000 Ω/sq or less, under certain conditions several hundred Ω/sq or less It was possible to prepare a graphene oxide thin film having a low sheet resistance of. This is due to the fact that graphene oxide and oxygen-containing hydrocarbon-based compounds are included in the source as opposed to using only oxygen-containing hydrocarbon-based compounds as a source. The properties of the graphene oxide having the SP2 structure and the properties of the oxygen-containing hydrocarbon compound in which the SP2 structure and the SP3 structure are mixed are mixed, so that the SP2 structure is relatively increased, so that the thin film characteristics can be improved.

It is preferable that the source contains graphene oxide in an amount of 1.0% by weight or less based on the total weight. As the graphene oxide content in the source increases, the effect of contributing to the improvement of the electrical properties of the deposited graphene oxide may increase, but when the graphene oxide content in the source exceeds 1.0% by weight, a precipitation problem may occur. On the other hand, when the graphene oxide content in the source is too low, such as less than 0.1% by weight, the effect of contributing to the improvement of electrical properties of the deposited graphene oxide may not be significant. Accordingly, it is preferable that 0.1 to 1.0% by weight of graphene oxide is included in the source, and more preferably 0.1 to 0.2% by weight of graphene oxide is included. All components other than graphene oxide in the source may be oxygen-containing hydrocarbon-based compounds. Further, in the source, components other than graphene oxide may be water or organic solvents together with oxygen-containing hydrocarbon-based compounds.

In addition, the oxygen-containing hydrocarbon-based compound may be in a liquid state. When the oxygen-containing hydrocarbon-based compound is in a solid state, an organic solvent capable of dispersing it or a dispersion solvent such as water (H ₂ O) is separately required. In this case, it is not preferable to lower the relative content of the graphene oxide source. Consequently, it is more preferable that the compound is in a liquid state in that it can serve as a dispersion solvent while also serving as a carbon and oxygen source. However, the present invention does not exclude that the oxygen-containing hydrocarbon-based compound is in a solid state.

As the oxygen-containing hydrocarbon-based compound, a ketone-based compound, an ether-based compound, and an alcohol-based compound may be presented. As a ketone compound, cyclohexanone, acetone, methyl ethyl ketone, and the like can be presented. As the ether compound, diethyl ether, methyl ethyl ether, and the like can be presented. As the alcohol-based compound, methyl alcohol, ethyl alcohol, isopropyl alcohol, and the like can be presented. These oxygen-containing hydrocarbon-based compounds can serve as a dispersion solvent while also serving as a carbon and oxygen source.

In addition, the source according to the present invention may further include an organic solvent such as water (H ₂ O) or N-methylprrolidone (NMP). This can be applied mainly when the oxygen-containing hydrocarbon-based compound is in a solid state, but is also applicable when the oxygen-containing hydrocarbon-based compound is in a liquid state. However, in the case of mixing an oxygen-containing hydrocarbon-based compound with another material (for example, a solvent), in order to prepare a pure graphene oxide thin film or a graphene thin film, a hydrocarbon material of the same series as the oxygen-containing hydrocarbon-based compound (for example, For example, it is preferable to mix a hydrocarbon solvent).

Hereinafter, as an example of the PECVD apparatus shown in FIG. 1, a method of forming a graphene oxide thin film according to the present invention will be described.

1 shows an example of a PECVD apparatus that can be applied to the method for forming a graphene oxide thin film according to the present invention.

Briefly explaining the PECVD apparatus shown in FIG. 1, the PECVD apparatus 1 includes a reaction chamber 2, a showerhead 3, a substrate support 4, an RF power supply 5, and an electrode 6. .

The reaction chamber 2 has a substrate disposed therein, and provides a reaction space.

The showerhead 3 is provided on the upper side of the reaction chamber 2 and distributes and injects the source injected through the source supply line S connected to the source supply unit outside the reaction chamber into the reaction chamber below the showerhead.

The source is vaporized in a vaporization unit such as a bubbler to which an indirect injection method is applied or a vaporizer to which a direct injection method is applied, before being supplied to the reaction chamber 2, and is supplied to the reaction chamber 2 at a temperature of about 120°C or higher. I can. To this end, a temperature maintaining means such as a heating jacket for maintaining the temperature of the vaporized source may be disposed in the source supply line S.

The electrode 6 is electrically connected to the high frequency power source 5 and is used as an electrode for plasma discharge. In the case of the example shown in FIG. 1, the shower head 3 is electrically connected to the first electrode 6 through the connection part 3a and functions as a single electrode together with the electrode 6. In this case, the RF power of 13.56 MHz generated from the RF power supply unit 5 is applied to the showerhead 3 into the reaction chamber 2. RF power is applied from the RF power supply unit 5, and plasma is formed in the reaction chamber 2 between the showerhead 3 and the substrate support 4.

A substrate support 4 supporting a substrate W to be deposited with graphene oxide is disposed below the reaction chamber 2. The substrate support 4 is provided with a temperature control means such as a hot wire, so that the substrate is in a heated state during the deposition process. Further, the substrate support 4 may function as a ground electrode.

As the PECVD apparatus that can be used in the present invention, not only the exemplary apparatus shown in FIG. 1 but also various types of known PECVD apparatuses can be used.

Figure 2 schematically shows a method of forming a graphene oxide thin film by the PECVD method according to the present invention.

A method of forming a graphene oxide thin film according to an embodiment of the present invention is a method of forming a graphene oxide thin film through PECVD. More specifically, the method includes the following steps.

First, a substrate is placed on a substrate support in a reaction chamber of a PECVD apparatus as shown in FIG. 1, and the substrate is heated through the substrate support (S210). The substrate may be a metal substrate or a semiconductor substrate such as a silicon wafer. Further, the substrate may be a substrate on which a film such as SiOx is formed on a silicon wafer. In addition, a catalyst metal such as Ni or Cu may be present on the surface of the semiconductor substrate or on the surface of the substrate on which a film of a different material is formed on the semiconductor substrate.

Next, an oxygen-containing hydrocarbon-based compound (C _x H _y O _z ) containing carbon, hydrogen and oxygen and a source containing graphene oxide are vaporized using a bubbler or the like, and introduced into the PECVD apparatus ( S220). In this case, the source may be introduced into the PECVD apparatus together with an inert gas such as He, Ar, or a carrier gas such as oxygen gas. The supply of the source may also be performed in the plasma deposition step described later.

Next, by applying an RF power of about 400 to 2400 W into the PECVD apparatus, plasma is formed between the showerhead and the substrate to decompose the supplied source to deposit graphene oxide on the substrate (S230).

After the graphene oxide is deposited, the inside of the PECD device is purged using a purge gas such as nitrogen gas (S240).

At this time, the substrate is preferably heated to 400 ℃ or more, preferably 600 ~ 700 ℃. There are various factors that affect the electrical properties of the deposited graphene oxide, such as substrate temperature, pressure in the reaction chamber, source supply flow rate, and deposition thickness. Among them, it can be confirmed that a very low sheet resistance is exhibited when the substrate temperature is over 600℃. there was. However, as can be seen in Tables 3 and 4 of Examples to be described later, even when the substrate temperature is less than 600 °C, when the source supply flow rate is relatively low as 300 sccm or less, or the RF power is relatively low as 400 to 600 W The deposited graphene oxide thin film showed a somewhat low sheet resistance. Accordingly, when the substrate temperature is 400° C. to 600° C., lowering the source flow rate or lowering the RF power can form a graphene oxide thin film having excellent electrical properties.

In addition, referring to Table 1 of Examples to be described later, the thickness of the deposited graphene oxide thin film does not significantly affect, but as the thickness of the graphene oxide thin film increases, for example, in the case of a silicon substrate, it is relatively more It showed good electrical properties. This can also be confirmed from the Raman Peak of the thin film when only the deposition thickness of graphene oxide was changed under the same conditions.

Further, referring to Table 6 of Examples to be described later, the internal pressure of the PECVD apparatus may be 7.5 Torr or more. In general, when a vacuum is applied in the CVD method or the PECVD method, a high vacuum of 1 Torr or less is generally applied, but when the source of the present invention is used, the sheet resistance is lower at 7.5 Torr or more. Depending on the process conditions, the internal pressure of the PECVD apparatus may be 10 Torr or more.

Preferably, the PECVD process can be carried out in a cyclic process such as the example shown in FIGS. 3A and 3B. The cyclic process means that when the stabilization step (S410), the deposition step (S420), and the purge step (S430) are set as a unit process (one cycle) as shown in FIG. 3A, this unit process is repeated. In this case, the unit process may further include a plasma processing step S425 between the deposition step S420 and the purge step S430 as shown in FIG. 3B.

3A and 3B, the stabilization step (S410) corresponds to the source supply step (S220) of FIG. 2, the deposition step (S420) corresponds to the plasma deposition step (S230) of FIG. 2, and the purge step (S430) Corresponds to the purge step S240 of FIG. 2.

In the stabilization step (S410), the vaporized source is supplied and RF power is not applied, so that the pressure inside the PECVD apparatus is equalized to stabilize the inside of the PECVD apparatus. In the deposition step (S420), a vaporized source is supplied and RF power is applied to thereby deposit a graphene oxide thin film. In the purge step (S430), the vaporized source is not supplied, and RF power is not applied. In the purge step S430, a purge gas such as nitrogen gas is supplied into the chamber to remove residual gas and by-products in the chamber. In the plasma processing step S425, the vaporized source is not supplied, and an inert gas such as helium gas is supplied into the chamber to which RF power is applied, thereby densifying the thin film.

As shown in FIG. 3A, when the plasma processing step S425 is not included, the unit process may be performed for 0.5 to 1 second. In this case, since the deposited graphene oxide thin film is not dense, if the unit process time exceeds 1 second, the resistance value of the deposited graphene oxide thin film may increase significantly. On the other hand, as shown in the example shown in Figure 3b, when the plasma treatment step (S425) is included, the deposited graphene oxide thin film is relatively dense, so that the thin film unit process can be performed for a relatively longer time for 0.5 to 1.5 seconds. have.

As described above, when graphene oxide is deposited by PECVD using a source according to the present invention that additionally includes graphene oxide in an oxygen-containing hydrocarbon-based compound, a graphene oxide thin film having excellent electrical properties can be prepared. have.

In addition, if necessary, such as lowering the sheet resistance, the formed graphene oxide thin film may be reduced to form a reduced graphene oxide thin film.

Example

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention in any sense. Contents not described herein can be sufficiently technically inferred by those skilled in the art, and thus description thereof will be omitted.

A PECVD process was performed to form a graphene oxide thin film under the conditions of specimens 6 to 14 described in Table 1.

In the case of specimen 1, it shows the sheet resistance of a pure silicon wafer.

In the case of specimen 2, the sheet resistance when SiO ₂ is deposited on a silicon wafer is shown. The SiO ₂ film was formed using TEOS as a precursor.

In the case of specimen 3, the sheet resistance when tungsten carbide (WC) is deposited on SiO ₂ is shown.

In the case of specimens 4 to 5, it shows the sheet resistance when an amorphous carbon layer (ACL) is deposited on SiO ₂ .

In the case of specimens 6 to 12, the sheet resistance when deposited on the substrate using a source consisting of 99.8 wt% of cyclohexanone and 0.2 wt% of graphene oxide was shown.

In the case of specimens 6 to 8, it is a result of forming a graphene oxide thin film on a silicon substrate on which SiO ₂ is formed, and in the case of specimens 9 to 12, it is a result of forming a graphene oxide thin film on a silicon substrate.

[Table 1]

Referring to Table 1, in the case of forming the amorphous carbon layer, the sheet resistance was higher than the limit value (Sample 4, 5), but when the graphene oxide thin film was formed using the source according to the present invention, a silicon wafer (Sample 1 It can be seen that it shows a sheet resistance almost equal to) or lower than that of a silicon wafer (Specimens 6-12).

In addition, referring to Specimens 6 to 8, it can be seen that the larger the graphene oxide deposition thickness, the lower the sheet resistance value of the deposited graphene oxide, which showed a similar tendency in the case of Specimens 9 to 12. When referring to Table 1, the graphene oxide deposition thickness may be 40 ~ 3000Å. More preferably, when forming a graphene oxide thin film on SiO ₂ formed by using TEOS as a precursor, the deposition thickness is 1000 to 3000 Å, and when forming a graphene oxide thin film on silicon, the deposition thickness is 70 Å or more. It is preferably 300 Å, that is, 30 nm or more.

In addition, FIG. 4 shows the thin film Raman peak according to the thickness of the graphene oxide thin film deposited on the silicon substrate by the PECVD method under the same conditions (substrate temperature 600° C., source flow rate 1400 sccm). Referring to FIG. 4, it can be seen that as the deposited graphene oxide thickness increases from 4 nm to 30 nm, the thin-film disorder peak (1350 cm ^-1 ) increases.Through this, the sheet resistance increases as the graphene oxide deposition thickness increases. It can be seen that this is consistent with this decreasing trend.

In addition, a graphene oxide PECVD process was performed on a silicon wafer under the conditions shown in Tables 2 to 6 to examine the change in sheet resistance of the deposited graphene oxide thin film according to the process parameters.

[Table 2]

In the case of Table 2, only the substrate temperature and the deposition thickness were changed while the process pressure, carrier gas (Ar gas) flow rate, and source flow rate RF power were all the same.

Referring to Table 2, it can be seen that the graphene oxide thin film deposited at a substrate temperature of 600° C. has the lowest sheet resistance despite the low deposition thickness. Based on these results, the substrate temperature in the PECVD graphene oxide deposition process needs to be 600°C or higher.

[Table 3]

[Table 4]

In the case of Table 3, the source flow rate was changed while the substrate (Si) temperature, process pressure, carrier gas (Ar gas) flow rate, and RF power were all the same, and the deposition thickness was also similar. In addition, in the case of Table 4, the substrate (Si) temperature was 400°C, the process pressure, the carrier gas (Ar gas) flow rate, and the source flow rate were all the same, and the RF power was changed.

Referring to Table 3, in the case of a graphene oxide thin film deposited at a substrate temperature of 550°C, it can be seen that the sheet resistance value is low only when the source flow rate is 300 sccm. In addition, referring to Table 4, it can be seen that even when the substrate temperature is 400°C, when the RF power is low, the sheet resistance value is low. Based on the results of FIGS. 3 and 4, it can be seen that when the substrate temperature is 400 to 600° C., it is necessary to lower the source flow rate to 300 sccm or less or the RF power to 400 to 600 W.

[Table 5]

In the case of Table 5, only the RF power was changed while the substrate temperature was fixed at 600° C., the process pressure, the carrier gas flow rate, and the deposition thickness were the same or similar.

Referring to Table 5, it can be seen that the sheet resistance value relatively decreases as the RF power decreases, but excellent sheet resistance is shown in all of the specimens 22 to 26. That is, when the substrate temperature is 600° C., the electrical properties of the graphene oxide thin film manufactured according to the change in RF power do not show a significant difference.

In view of these results, when the substrate temperature is above 600°C, the degree of influence of the change in RF power on the electrical properties of the graphene oxide thin film to be manufactured is not significant, but when the substrate temperature is less than 600°C, the change in RF power It can be seen that the degree of influence on the electrical properties of the prepared graphene oxide thin film is relatively greater.

[Table 6]

In Table 6, the substrate temperature, carrier gas flow rate, source flow rate, and RF power were all the same, and the deposition thickness was similar, and only the process pressure was changed.

Referring to Table 6, it can be seen that the higher the process pressure, the lower the sheet resistance value is, and it can be seen that the sheet resistance is very low when it reaches 7.5 Torr.

Table 7 shows the characteristics of the graphene oxide thin film deposited when applying the cyclic process.

In Table 7, during the deposition step, the RF power was 400W, the substrate was a silicon substrate, and the substrate temperature was 400°C. In addition, in CYCLIC #2 of Table 6, the plasma treatment used helium gas, and the RF power applied in the deposition step was continuously applied during the plasma treatment.

[Table 7]

Referring to Table 7, when applying the cyclic process, when the plasma treatment step is not included as shown in FIG. 3A, excellent sheet resistance (Rs, Ω/sq) and specific resistance (mΩ· cm) characteristics, but showed relatively poor results when the unit process time was 1.5 seconds.

On the other hand, when the plasma treatment step is included as shown in FIG. 3B, when the unit process time is 0.5 seconds, 1.0 second, and 1.5 seconds, excellent resistance characteristics are exhibited, and excellent resistance characteristics are exhibited when the unit process time is 1.5 seconds. This means that the film exhibits the best resistance characteristics when it has a relatively thick deposition thickness in a state where the film is densified through plasma treatment.

Table 8 shows the results when a graphene oxide thin film is formed on a silicon substrate on which a silicon oxide film is formed by the PECVD method and the PEALD method to which the cyclic process shown in FIG. 3A is applied.

In the PEALD method shown in Table 8, the source gas is supplied and the source is adsorbed to the substrate without RF power applied, the first purge step, the RF power application step, and the second step. A unit process consisting of a purge step was repeated to form a graphene oxide thin film on the silicon oxide film. In Table 8, the conditions applied to the PECVD method and the PEALD method are the same except for those described in Table 1. However, in the case of the PECVD method, the source gas is supplied in the deposition step, but in the case of the PEALD method, the source gas is not supplied in the RF power application step.

[Table 8]

Referring to Table 8, when comparing the resistance characteristics of the graphene oxide thin film deposited by the PECVD method and the graphene oxide thin film deposited by the PEALD method, it can be seen that the resistance characteristics of the graphene oxide thin film deposited by the PECVD method are relatively excellent. It can be seen that in the PECVD method, as the deposition thickness increases, the resistance characteristics exhibit relatively good characteristics.

Meanwhile, since the deposition rate when depositing the graphene oxide thin film by the PECVD method is relatively faster than the deposition rate when depositing the graphene oxide thin film by the ALD method, it can be seen that the PECVD method is more preferable in terms of productivity. It can be seen that the difference in deposition rate is due to the difference in the presence or absence of source supply in each deposition step of the PECVD method and the PEALD method. In other words, in the case of the PECVD method, since the source is supplied in the deposition step, the amount of decomposed sources is large and the deposition rate is faster. However, in the case of the PEALD method, the source is not supplied in the RF power application step and the atomic layer Since adsorption is performed in units, it can be seen that the amount of decomposed sources is relatively small.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, but may be modified in various different forms, and those having ordinary knowledge in the technical field to which the present invention pertains. It will be understood that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting.

Claims (12)

As a source for graphene oxide deposition using PECVD,
Oxygen-containing hydrocarbon-based compounds containing carbon, hydrogen and oxygen; And
Including graphene oxide,
Graphene oxide deposition source, characterized in that 0.1 to 1.0% by weight of the graphene oxide is included in the source.
The method of claim 1,
The oxygen-containing hydrocarbon-based compound is a source for deposition of graphene oxide, characterized in that it comprises at least one of a ketone-based compound, an ether-based compound and an alcohol-based compound.
The method of claim 2,
The source is a graphene oxide deposition source, characterized in that it further comprises water or an organic solvent.
As a method of forming a graphene oxide thin film using PECVD,
(a) placing a substrate in a PECVD apparatus and heating the substrate;
(b) vaporizing an oxygen-containing hydrocarbon-based compound containing carbon, hydrogen and oxygen and a source containing graphene oxide, and introducing it into the PECVD apparatus;
(c) decomposing the source by applying RF power to the PECVD apparatus to form a plasma in the PECVD apparatus, and depositing graphene oxide on the substrate; And
(d) a method of forming a graphene oxide thin film comprising the step of purging the inside of the PECVD apparatus.
The method of claim 4,
Graphene oxide thin film forming method, characterized in that 0.1 to 1.0% by weight of the graphene oxide is included in the source.
The method of claim 4,
The oxygen-containing hydrocarbon-based compound is a method of forming a graphene oxide thin film comprising at least one of a ketone-based compound, an ether-based compound, and an alcohol-based compound.
The method of claim 4,
The substrate is a silicon substrate, the graphene oxide thin film forming method, characterized in that the thickness of the graphene oxide deposited in the step (c) is 30nm or more.
The method of claim 4,
Graphene oxide thin film formation method, characterized in that the unit process including the step (b) to step (d) is performed in a repeating manner.
The method of claim 8,
In the step (b), the vaporized source is supplied, but RF power is not applied,
In the step (c), a method of forming a graphene oxide thin film, characterized in that the vaporized source is supplied and RF power is also applied.
The method of claim 8,
The unit process, between the step (c) and the step (d), the graphene oxide thin film forming method, characterized in that it further comprises a plasma treatment step of treating the deposited graphene oxide with an inert gas plasma.
The method according to any one of claims 4 to 10,
Graphene oxide thin film forming method, characterized in that it further comprises the step of reducing the deposited graphene oxide. delete

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