KR0144627B1 - Manufacturing method for diamond phase film containing transition metal - Google Patents

Abstract

A method for producing a transition metal-containing diamond-like thin film using an alloy target of transition metal-carbon is described. Method for producing a transition metal diamond-like thin film of the present invention comprises the steps of installing a target holder (4) capable of rotating and linear movement in the vacuum chamber (10); Installing an alloy target (3) of transition metal-carbon in the target holder; Injecting a reaction gas including hydrogen into the vacuum chamber (10); Operating the pulsed laser (1) to generate a laser beam; Focusing the laser beam on the alloy target through an optical system (2); The focused laser beam impinges on a target to form a plume; A part of the formed plume is rapidly solidified on the substrate 7 toward the substrate 7 to form a diamond-like thin film.

According to the method for producing a transition metal diamond-like thin film of the present invention, it is possible to manufacture the transition metal-containing diamond-like thin film in which the adhesion between the lower metal cathode and the thin film layer is firmly maintained. In addition, graphitization does not occur even at a high temperature during vacuum packing, and thus, deterioration of electron emission characteristics is prevented, and resistance of the diamond-like thin film can be easily controlled by changing the content of the transition metal, thereby controlling electron emission characteristics.

It is another feature of the present invention that the diamond-like thin film produced by the method of the present invention is used for one of the conductive substrate or the transition metal, and is applicable to the manufacture of the emitter for the field emission type display device.

Description

Method for producing diamond-containing diamond-like thin film.

1 is a block diagram of a pulse laser deposition device for transition metal-containing diamond phase thin film deposition of the present invention.

* Explanation of symbols for main parts of the drawings

1: pulse laser 2: optical system

3: target 4: target holder

5: plum 6: reactive gas inlet

7: Substrate 8: Substrate Holder

9: vacuum pump 10: vacuum

The present invention relates to a diamond-like thin film manufacturing method, specifically, the adhesion between the diamond thin film and the lower cathode layer using a pulse laser and a transition metal is good and graphite at high temperature process in the field emission display device manufacturing The present invention relates to a method for producing a transition metal-containing diamond-like thin film that is stable even at a high temperature at which no frosting occurs.

Diamond-like carbon thin films exhibit high electron emission characteristics even under low electric fields, and are suitable for use as emitter materials for field emission display devices. Conventional methods for obtaining such a diamond-like carbon thin film are largely chemical vapor deposition (CVD) and physical vapor deposition (PVD). In chemical vapor deposition, gas such as carbon-containing methane or ethane, and mixed gas such as hydrogen gas and argon gas are used, and are mainly used for hot filament and microwave plasma as energy sources for activating or decomposing these gases. And RF plasma. In addition, physical vapor deposition includes a sputtering method and a laser ablation method using a laser. High frequency (RF) or direct current (DC) sputtering method uses graphite as a target, and the ions formed in the discharge space are accelerated by the electric field and collide with the atoms, and the target atoms pop out by the momentum exchange to form carbon atoms in the gaseous state. They solidify on the substrate to form a thin film. In the case of adding a reaction gas containing hydrogen, methane, or the like, the reaction gas is decomposed to be incorporated into the diamond-like carbon thin film to form a hydrogen-containing diamond-like thin film. At this time, the effect of hydrogenation is known to play a role of increasing the diamond bond component ratio to the graphite bond and to stabilize the diamond phase. In the pulse laser deposition method, a high energy of the pulse laser is used to vaporize a target to form a thin film.

However, the prior arts have the following problems. In other words, the hot filament chemical bonding method or the microwave plasma chemical bonding method can obtain a high quality diamond phase thin film having a higher component ratio of the diamond bonding phase to the graphite bonding phase than any other manufacturing method. Since the substrate material to be used is maintained at about -1000 ° C, such as glass, it cannot be used, and since it is a high temperature process, there are many problems in terms of process time and energy efficiency during mass production.

On the other hand, although it is possible to produce amorphous diamond phase carbon depletion at room temperature by RF plasma CVD method, the thin film produced by this method is likely to peel off between the substrate and the thin film depending on the substrate used due to the high residual stress. There is a problem. In addition, it is possible to produce a diamond-like carbon thin film at room temperature by the RF sputtering method, but the thin film prepared by this method has a problem that it is difficult to obtain a high quality diamond-like carbon thin film compared to the RF plasma CVD method.

In addition, the conventional pulsed laser deposition method can produce a high-quality diamond-like carbon thin film having a simpler manufacturing method and a higher ratio of diamond bonding components than the conventional diamond-like carbon thin film manufacturing method described above. It is problematic in high temperature stability such as graphitization and deterioration of electron emission characteristics in the high temperature process, and because of insufficient adhesion to the substrate and difficulty in controlling the concentration of impurities for controlling electrical and mechanical properties, There have been many difficulties in application to the manufacture of display devices.

In addition, in order to apply a diamond thin film to a field emitter for a field emission type display device, a diamond thin film must be deposited on a substrate on which a conductive thin film of a uniform shape is deposited. In particular, a strong adhesion between the cathode layer and the diamond thin film layer is required. do. In the conventional pulsed laser deposition method, a diamond-like carbon thin film is manufactured in high vacuum by targeting graphite, loucite, or the like. However, such a pulse laser deposition method has a problem that it is impossible to firmly adhere the above-described cathode layer to the diamond thin film layer.

The present invention, in order to solve the above-mentioned problems of the prior art, by using a transition target metal and carbon alloy target by a conventional pulse laser deposition method, the transition metal containing the metal metal and the adhesion of the thin film layer is maintained firmly even at room temperature It is for providing a method for producing a diamond-like thin film.

Further, another object of the present invention is to provide a method for producing a transition metal-containing diamond-like thin film in which graphitization does not occur even at a high temperature during vacuum packing.

Another object of the present invention is to provide a method for producing a transition metal-containing diamond phase thin film which can easily control the electron emission characteristics by controlling the resistance of the diamond phase thin film according to the transition metal content change.

Another object of the present invention is to use a diamond-like thin film manufactured by the method of the present invention on an electrically conductive substrate such as ITO (Indium Tin Oxide) or a metal of one of transition metals. It is for application to manufacture.

In order to achieve the above object, the method for producing a transition metal-containing diamond-like thin film of the present invention comprises the steps of installing a target holder capable of rotating and linear movement in a vacuum chamber; Installing an alloy target of transition metal-carbon in the target holder; Injecting a reaction gas containing hydrogen into the vacuum chamber; Operating the pulsed laser to generate a laser beam; Focusing the laser beam on the alloy target through an optical system; The focused laser beam impinges on a target to form a plume; Part of the formed plume is rapidly solidified on the substrate toward the substrate to form a diamond-like thin film comprising the step of forming a diamond-like thin film.

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

1 shows a deposition apparatus for manufacturing a transition metal-containing diamond thin film of the present invention using a conventional pulsed laser. The target holder 4 and the substrate holder 8 are provided on opposite side walls of the vacuum chamber 10. The target holder 4 and the substrate holder 8 are rotatable and linear in movement, and the target 3 and the substrate 7 are attached, respectively. In a preferred embodiment of the present invention, the target 3 used is an alloy target of transition metal-carbon, and the content of the transition metal is a multilayer diamond phase having different transition metal contents by changing the alloy composition ratio of the alloy target. Thin film production is possible.

One of the opposing side walls of the vacuum chamber 10 is provided with a pulse laser 1 for generating a pulse laser beam of high energy density outside the side walls. In front of the pulse laser 1, an optical system 2 is installed to transfer a pulse laser beam output from the pulse laser 1 to a target 3 to form a full room, which is a mixture of ions, atoms, molecules, and electrons. It is.

On the other hand, the reaction gas injection unit 6 is provided on one sidewall of the vacuum chamber 10 to inject the reaction gas for adjusting the hydrogen content in the vacuum chamber 10 into the vacuum chamber 10. In a preferred embodiment of the present invention, the reaction gas is a hydrogen gas or a mixed gas such as methane or ethane containing hydrogen. One of the characteristics of the present invention is that by periodically changing the flow rate of the gas containing hydrogen, it is possible to obtain a multilayer thin film of two or more layers in which the hydrogen-containing composition of the diamond-like thin film formed on the substrate 7 is periodically changed. to be. That is, the flow rate of the hydrogen containing gas can be adjusted by adjusting the gas partial pressure of hydrogen gas, hydrogen containing methane, ethane, etc. in the vacuum chamber 10, and therefore the content of hydrogen in the diamond thin film can be adjusted.

The laser beam output from the pulse laser 1 passes through the optical system 2 and is focused on the target 3. The focused laser beam collides with the target 3 atoms to form a plume 5 consisting of a mixture of atoms, molecules, ions and electrons of transition metals, carbon and hydrogen. Part of the reaction gas is mixed into the plume 5, and part of the reaction gas is adsorbed to the diamond-like thin film being formed. That is, the formed plume 5 spreads into the space in the vacuum chamber 10 at a high speed while reacting with a part of the reaction gas in the vacuum chamber 10, and a portion of the plume is directed toward the substrate 7 on the substrate 7. Is deposited.

In the present invention, in the diamond-like thin film formed on the substrate 7, the atomic% of the composition ratio of the atoms is represented by the following equation.

Cx-Hy-Mz (C; carbon, H; hydrogen, M; Cr, Mo, W, V, Nb, Ta, Ti, Zr, Hf, at least one of transition metals, such as 60≤x≤100, 0≤y≤40, 0z≤40 and x + y + z = 100)

Is displayed. As shown in the above formula, the carbon atoms of the transition metal-containing diamond-like thin film must be at least 60 atomic% in carbon (C) sms atomic%. The reason is that when the composition ratio of hydrogen (H) or transition metal (M), which is an element other than carbon (C), is 40 atomic% or more, the property of the diamond is likely to be lost. As an example, when hydrogen is 40 atom% or more, the emphasis and adhesion of the thin film are remarkably inferior, and when the metal component is too large, the properties of the thin film become closer to the metal. At this time, the ratio of hydrogen or transition metal may change within 40 atomic%.

In a preferred embodiment of the present invention, even in the case of a multilayer thin film having different transition metals and / or hydrogen contents in the diamond-like thin film, an average atomic ratio of the multilayer thin film is applied.

According to the present invention, by using an alloy target containing a transition metal, the stress of the diamond-like thin film formed on the substrate is reduced, the adhesion to the lower cathode layer is improved, and the transition metal is added to the diamond-like thin film. The resistance of the thin film can be easily adjusted to control electron emission characteristics. In addition, the diamond-like thin film may maintain the firm adhesion with the substrate even after the high temperature heat treatment at about 500 ° C., and also suppress the graphitization of the diamond to prevent deterioration of electron emission characteristics.

In addition, the diamond-like thin film produced by the method of the present invention can be applied to the production of an emitter for a low-cost field emission display device.

In the above, the technical content of this invention was described in detail. However, various modifications and changes may be made by those skilled in the art without departing from the scope of the invention described above. Accordingly, the invention is not limited to only the above-described embodiments or drawings, but only by the claims.

Claims (8)

Installing a target holder (4) capable of rotating and linear movement in the vacuum chamber (10); Installing an alloy target (3) of transition metal-carbon in the target holder; Injecting a reaction gas containing hydrogen into the vacuum chamber (10); Operating the pulsed laser (1) to generate a laser beam; Focusing the laser beam on the alloy target through an optical system (2); The focused laser beam impinges on a target to form a plume (5); And forming a diamond-like thin film by rapidly solidifying a portion of the formed plume toward the substrate (7) to form a diamond-like thin film. The method of claim 1, wherein the atomic ratio of the formed diamond-like thin film is given by the formula Cx-Hy-Mz in atomic%, wherein C is carbon, H is hydrogen, and M is at least one of transition metals. And x, y, and z are 60 ≦ x ≦ 100, 0 ≦ y ≦ 40, 0z ≦ 40, and x + y + z = 100, respectively. . According to claim 1, wherein the transition metal-carbon alloy target is a diamond-like thin film formed using two or more transition metal-carbon alloy targets having different compositional ratios of transition metals and carbon is 2 different transition metal composition ratios A method for producing a transition metal-containing diamond-like thin film, comprising a multilayer thin film of more than one layer. The diamond-like transition thin film according to claim 1, wherein the diamond-like thin film formed by periodically changing the flow rate of the reaction gas containing hydrogen comprises two or more multilayer thin films whose composition ratio of hydrogen is periodically changed. Dephase thin film manufacturing method. The method of claim 1, wherein the transition metal-carbon alloy target uses two or more transition metal-carbon alloy targets having different compositional ratios of the transition metal and carbon, and at the same time periodically changes the flow rate of the reaction gas containing hydrogen. Wherein the formed diamond-like thin film comprises two or more multi-layered thin films having different transition metal composition ratios and periodically changing hydrogen composition ratios. The method according to claim 5, wherein the average constituent atomic ratio of the formed diamond-like multilayer thin film is given by the formula Cx-Hy-Mz in atomic%, wherein C is carbon, H is hydrogen, and M is a transition metal. At least one element, wherein x, y, and z are 60 ≦ x ≦ 100, 0 ≦ y ≦ 40, 0z ≦ 40, and x + y + z = 100, respectively. Manufacturing method. A field emission emitter manufactured by using a diamond-like thin film produced by the method of any one of claims 2 to 6 on a conductive substrate. A field emission emitter prepared by using a diamond-like thin film prepared by the method of any one of claims 2 to 6 on a metal belonging to a transition metal.