KR101977366B1 - Method for manufacturing resistive oxide thin film and method of manufacturing bolometer - Google Patents

Abstract

The method for preparing an oxide-resistant thin film according to the present invention comprises: preparing a plurality of pre-precursor solutions by dissolving a plurality of metal oxide organic compounds in a first organic solvent; Mixing each of the precursor precursor solutions at a preset ratio to prepare a mixed solution; Diluting the mixed solution with a second organic solvent different from the first organic solvent to prepare a precursor solution; Forming a precursor layer on the substrate by a liquid phase process using the precursor solution; And a step of converting the precursor layer into an oxide layer by performing a subsequent heat treatment in an oxidizing atmosphere.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing an oxide-

The present invention relates to a method for producing an oxide-resistant thin film and a method for manufacturing a bolometer, and more particularly, to a method for manufacturing an oxide-resistant thin film using a precursor solution prepared as a different organic solvent and a method for manufacturing a bolometer.

Generally, a precursor solution applied on a substrate to form a resistive thin film is prepared by dissolving any precursor in a predetermined organic solvent, and the prepared precursor solution can be applied onto the substrate.

Metal oxide organic compounds having a carboxylate group are generally used most often in the preparation of precursor solutions. Metal oxide organic compounds having hydrophobicity due to a long chain length are not well soluble in polar solvents. Although the precursor solution can be prepared by dissolving it in a nonpolar solvent, there is a problem in that adhesion with the substrate and wettability are poor. That is, when a precursor solution is prepared using one organic solvent, the metal oxide organic compound is not dissolved in the organic solvent or the adhesion to the substrate is poor.

In addition, the bolometer is an infrared detector, the oxide resistive thin film used in the bolometer should have a characteristic with a high resistance temperature coefficient, a low resistivity and a low 1 / f noise, and a complementary metal oxide semiconductor process And the heat treatment temperature of 450 ° C or less should be satisfied so that the ROIC circuit is not damaged during the bolometer manufacturing process.

However, vanadium oxide (VO _x ), which is often used in oxide thin films, has a large number of intermediate states such as VO ₂ , V ₂ O ₃ , and V ₂ O ₅ . And it is difficult to obtain reproducibility because it is difficult to obtain reproducibility. In order to deposit a stable film, expensive special equipment such as a sputtering apparatus and problems to be manufactured at a high temperature of 500 ° C or more are required.

A liquid phase process can be utilized to form an oxide thin film at a low heat treatment temperature. Metal organic decomposition, which is one of the liquid phase processes, is a wet chemical thin film production method using a mixed solution of a metal compound dissolved in a stable organic solvent. It is possible to maintain the ratio, and it is advantageous in that an oxide resistive thin film can be manufactured quickly on a large-area substrate without a vacuum device and a simple process.

The optimal heat treatment temperature for the oxide thin film deposited by the metal organic decomposition method may be 450 ° C or higher. If the heat treatment is performed at a temperature higher than 450 ° C, the temperature of the heat sensitive material for forming the oxide thin film is damaged Lt; / RTI > Accordingly, a material such as single crystal can not be used for the oxide-resistive thin film, thereby limiting the selection of various temperature sensing materials.

In addition, when forming a bolometer, an organic material sacrificial layer such as polyimide (PI) may be formed on a substrate. When an oxide thin film formed at a heat treatment temperature of 450 ° C or higher is applied to an actual thin film of a bolometer oxide, A bubbling problem occurs in which organic matter boils due to a high heat treatment temperature.

In addition, uncooled infrared detectors have a problem in that the electrical characteristics of the bolometer are degraded as in the case of very high resistivity due to the presence of noise due to heat as compared with the cooling type infrared detectors.

Therefore, there is a demand for an oxide thin film which can produce an oxide thin film having a low resistivity at a heat treatment temperature lower than a heat treatment temperature of 450 캜.

Korean Patent Publication No. 10-2016-0149889

The present invention provides a method for producing an oxide-resistant thin film and a method for manufacturing a bolometer using a precursor solution prepared using different organic solvents.

The method for preparing an oxide-resistant thin film according to an embodiment of the present invention includes: preparing a plurality of pre-precursor solutions in which a plurality of metal oxide organic compounds are respectively dissolved in a first organic solvent; Mixing each of the precursor precursor solutions at a preset ratio to prepare a mixed solution; Diluting the mixed solution with a second organic solvent different from the first organic solvent to prepare a precursor solution; Forming a precursor layer on the substrate by a liquid phase process using the precursor solution; And a step of converting the precursor layer into an oxide layer by performing a subsequent heat treatment in an oxidizing atmosphere.

The first organic solvent may be an aromatic hydrocarbon-based organic solvent.

The second organic solvent may be acetic ester-based organic solvent.

The molar concentration of the plurality of the metal oxides relative to the second organic solvent may be 0.1M to 0.4M.

The precursor layer may be formed by a metal organic decomposition method.

The subsequent heat treatment may be performed at a temperature ranging from 300 ° C to 400 ° C.

The metal oxide may include nickel oxide, manganese oxide, copper oxide, and chromium oxide.

The method may further include forming a metal layer including at least one of the metals of the metal oxide organic compound on the substrate prior to the step of forming the precursor layer.

The metal layer may be formed by physical vapor deposition.

The method may further include a step of preheating the metal layer at a temperature lower than the temperature of the next heat treatment to form the oxide seed layer before forming the metal layer and forming the precursor layer.

The oxide layer has a cubic spinel crystal structure and may have a composition of a compound represented by the following formula (1). [Formula 1] [(Ni _y Mn _{1 -y- x} Cr _x ) Cu] ₃ O ₄ , wherein x is 0.04? X?

The oxide resistive thin film may have a resistivity at room temperature of less than 2? 占. M.

According to another aspect of the present invention, there is provided a method of manufacturing a bolometer, including: providing a substrate on which a signal processing circuit is formed; Forming a plurality of metal pads spaced apart from the upper surface of the substrate to transmit an electric signal of the signal processing circuit; Forming an organic sacrificial layer on the substrate; Forming an oxide resistive thin film on the organic sacrificial layer by the method of any one of claims 1 to 11; And patterning the organic sacrificial layer and the oxide resistive thin film.

And forming a support member having one side connected to the metal pad and the other side connected to the oxide resistive thin film.

And removing the organic sacrificial layer.

In the present invention, by producing the precursor solution coated on the substrate using different first and second organic solvents, it is possible to effectively dissolve the metal oxide organic compound having a low polarity and to exhibit hydrophobicity and to improve the wettability, The bonding property between the resistive thin film and the substrate can be improved. That is, by dissolving the metal oxide organic compound having a long chain length in the first organic solvent having no polarity, it is possible to dissolve the metal oxide organic compound more easily than the polar solvent, and the mixed solution can be dissolved in the second organic solvent different from the first organic solvent, By diluting, the adhesion with the substrate can be improved.

In addition, since the metal ions contributing to crystallization can be increased by controlling the molar concentration of the precursor solution, crystal grain growth of the oxide-resistant thin film can be induced. That is, since the metal ions can easily contribute to crystallization as the molar concentration increases, the subsequent heat treatment temperature required for crystallization can be lowered to 400 ° C or lower, so that the oxide thin film can be stably produced without heat treatment at a high temperature. In addition, by controlling the molar concentration, the microstructure of the film and the electrical characteristics due to crystal growth can be improved.

By forming an oxide seed layer serving as a crystal nucleus between the substrate and the oxide layer, it is possible to induce crystal growth of the oxide layer to improve the crystal structure of the oxide-resistant thin film, and an oxide-resistant thin film having a spinel crystal structure It is possible to form a resistor for a bolometer having a low resistivity characteristic, thereby improving the electrical characteristics of the bolometer.

Therefore, the oxide thin film formed at a low heat treatment temperature of 400 ° C or less can have a very low resistivity of 2? · Cm or less. Therefore, when applied to a resistive thin film for an actual bolometer, damage to the signal processing circuit and bubbling of the organic sacrificial layer And a resistor having excellent electrical characteristics can be formed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart showing a method for manufacturing an oxide-resistive thin film according to an embodiment of the present invention. FIG.
2 is a cross-sectional view showing a structure of a spin coater according to an embodiment of the present invention;
3 is a graph showing the sheet resistance according to the molar concentration according to an embodiment of the present invention.
4 is a graph showing the resistivity according to the molar concentration according to the embodiment of the present invention.
5 is a photograph showing the grain size according to the molar concentration according to the embodiment of the present invention.
6 is a sectional view showing a manufacturing process of a bolometer according to another embodiment of the present invention;

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. To illustrate the invention in detail, the drawings may be exaggerated and the same reference numbers refer to the same elements in the figures.

FIG. 1 is a flow chart showing a method of manufacturing an oxide-resistive thin film according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a structure of a spin coater according to an embodiment of the present invention.

Referring to FIGS. 1 and 2, a method of fabricating an oxide-resistive thin film 340 according to an embodiment of the present invention includes: preparing a plurality of preliminary precursor solutions in which a plurality of metal oxide organic compounds are respectively dissolved in a first organic solvent; Mixing each of the precursor precursor solutions at a preset ratio to prepare a mixed solution; Preparing a precursor solution 110 by diluting the mixed solution with a second organic solvent different from the first organic solvent; Forming a precursor layer (120) on a substrate (100) by a liquid phase process using the precursor solution (110); And subsequent heat treatment of the precursor layer 120 in an oxidizing atmosphere to change into the oxide layer 125.

First, a plurality of preliminary precursor solutions can be prepared by dissolving a plurality of metal oxide organic compounds in the first organic solvent (S100, FIG. 2A). At this time, the first organic solvent may be an aromatic hydrocarbon-based organic solvent.

A plurality of pre-precursor solutions can be prepared by dissolving a plurality of metal oxide organic compounds in the first organic solvent. The first organic solvent for dissolving each of the plurality of metal oxide organic compounds is benzene (C ₆ H ₆ ), toluene (C ₆ H ₅ CH ₃ ), xylene (C ₆ H ₄ (CH ₃ ) ₂ ), naphthalene (C ₁₀ H ₈ ) and anthracene (C ₁₄ H ₁₀ ).

In general, the metal oxide organic compound having a carboxylate group may be a nonpolar material that does not dissolve in a polar solvent such as water and may have a long chain length.

Materials with long chain or complex hydrocarbon (CH) chains, such as carbon compounds, have non-polar and hydrophobic properties that are insoluble in polar solvents. As the chain length increases, hydrophobic properties increase. Since the solubility is reduced, it is soluble in a polar solvent when it has a short chain, whereas it is not well soluble in a polar solvent when it has a long chain.

Therefore, the metal oxide organic compound having a small polarity due to its long chain length is more soluble in a non-polar solvent such as benzene, toluene, xylene and the like than a polar solvent due to its hydrophobic property, so that a plurality of pre- Can be prepared by dissolving each metal oxide organic compound in the first organic solvent, which is an aromatic hydrocarbon organic solvent, and the metal oxide organic compound can be more effectively dissolved in the first organic solvent as described above, The molar concentration of the solution, that is, the molar concentration of each composition can be easily controlled, and a precursor solution having a desired composition can be easily obtained.

After preparing a plurality of precursor precursor solutions, the precursor precursor precursor solutions may be mixed at a preset ratio to produce a mixed solution (S200, FIG. 2A).

In the present invention, in one embodiment, the oxide layer 125 is [(Ni _y Mn _{1- y x} Cr _x ) Cu] ₃ O ₄ (x = 0.08). Details regarding the composition of the oxide layer 125 will be described later.

After the mixed solution is prepared, the precursor solution 110 may be prepared by diluting the mixed solution with a second organic solvent different from the first organic solvent (S300, FIG. 2B). At this time, the second organic solvent may be acetic acid ester-based organic solvent.

The precursor solution 110 to be coated on the substrate 100 may be prepared by diluting the mixed solution with a second organic solvent different from the first organic solvent. The second organic solvent may be ethyl acetate (C ₄ H ₈ O ₂ ) , Acetic acid esters such as butyl acetate (C ₆ H ₁₂ O ₂ ), methyl acetate (C ₃ H ₆ O ₂ ), cellosolve acetate (C ₆ H ₁₂ O ₃ ), and carbitol acetate (C ₁₀ H ₂₀ O ₄ ) It can be used daily for organic.

The second organic solvent may be an acetate-based organic solvent containing oxygen atoms different from the first organic solvent in consideration of the contact angle or wettability with the substrate 100 when the prepared precursor solution 110 is coated on the substrate Such a second organic solvent can increase the wettability of the substrate 100 and increase the surface energy so that effective adhesion with the substrate 100 can occur. In other words, when the precursor solution 110 using the second organic solvent containing oxygen atoms is applied on the substrate 100, the contact angle with the substrate 100 is minimized to improve the wettability of the precursor solution 110, It is possible to effectively improve the adhesion with the adhesive layer 100.

Therefore, by using the second organic solvent having oxygen atoms different from the first organic solvent in the preparation of the precursor solution, the substrate 100 can be prevented from being damaged by oxygen plasma treatment in order to impart adhesiveness and hydrophilicity to the surface of the substrate 100. [ And the oxide-resistance thin film 340 can be improved.

In the present invention, precursor solution (110) is not prepared using one organic solvent, and precursor solution (110) is prepared in two stages using different first organic solvent and second organic solvent, Can be more effectively dissolved and the adhesion with the substrate 100 can be improved. When the precursor solution 110 is prepared by dissolving the metal oxide organic compound in the second organic solvent without dissolving it in the first organic solvent, adhesion with the substrate 100 can be improved. However, 2 organic solvent is a polar solvent, the metal oxide organic compound having a long chain length is not dissolved well and the oxide-resistant thin film 340 may not be produced.

Therefore, by dissolving the metal oxide organic compound having a long chain length in the first organic solvent, which is a non-polar solvent, it is possible to dissolve the metal oxide organic compound more easily than the second organic solvent which is a polar solvent, The bonding property between the substrate 100 and the oxide resistance thin film 340 can be improved by diluting the substrate with the solvent.

FIG. 3 is a graph showing the sheet resistance according to the molar concentration according to the embodiment of the present invention, FIG. 4 is a graph showing the resistivity according to the molar concentration according to the embodiment of the present invention, This is a photograph showing the grain size according to the molar concentration.

3 to 5, the molar concentration of the plurality of metal oxides with respect to the second organic solvent may be 0.1M to 0.4M.

The present invention can control the microstructure and electrical properties of the oxide-resistive thin film 340 by controlling the molar concentration of the precursor solution 110, wherein the molar concentration of the precursor solution 110 is a multiple of Is the molar concentration of the whole metal oxide. Also, as the molar concentration (M or mol / L) is increased, the grain size of the resistive film 340 increases and the resistivity decreases and the microstructure of the resistive film 340 can be improved.

5, when the molar concentration is 0.1 M, the crystal growth occurs locally, but when the molar concentration is increased to 0.4 M, it can be seen that the crystal growth is uniformly performed as a whole .

As the molar concentration of the precursor solution 110 increases, the metal ions to be coated on the substrate 100 increase, so that the metal ions serving as crystal nuclei can be uniformly distributed and thus the spinel crystal structure is formed Crystal nucleation is promoted, and grain growth can occur due to reduction of interfacial energy per unit volume. As the grain size of the resistive thin film 340 increases due to the increase of the molar concentration, the number of grains decreases and the grain boundaries decrease. When the grain boundaries decrease, the energy barrier that hinders the dislocation movement decreases and the electron conduction can be facilitated Therefore, as the molar concentration increases, the grain size of the resistive thin film 340 may increase, and the resistivity may be reduced due to the reduction of the energy barrier.

Since the resistivity of the resistive thin film 340 is influenced not only by the grain size but also by the microstructure, the microstructure of the resistive thin film 340 must be uniform in order to have a low resistivity. According to the embodiment of the present invention, As the molar concentration is increased, the microstructure of the resistive thin film 340 becomes uniform, and at the same time, the crystal structure of the resistive thin film 340 can be improved, so that it can have a low resistivity. That is, as the molar concentration increases, the uniform distribution of the metal ions increases the uniformity of the resistive thin film 340 and decreases the roughness, so that the crystal structure of the resistive thin film 340 can be improved.

The precursor solution 110 may have a molar concentration of 0.1 M to 0.4 M. When the molar concentration of the precursor solution 110 becomes lower than 0.1 M, the viscosity of the precursor solution 110 due to the molar concentration becomes too low, The thickness becomes thinner and the amount of metal ions to be applied can be reduced. That is, the crystal nuclei (or metal ions) for forming the spinel crystal structure are reduced, and crystal growth becomes difficult, and it becomes impossible to measure the electrical characteristics such as the resistivity of the resistive thin film. On the other hand, if the molar concentration of the precursor solution 110 becomes larger than 0.4M, the viscosity increases with an increase in the molar concentration to form a film thicker than 100 nm. If the thickness of the resistive film 340 exceeds 100 nm, There arises a problem that the adhesion with the substrate 100 is deteriorated due to the phenomenon of being eliminated without being deposited. When the thickness of the precursor layer 120 constituting the resistive thin film 340 to be described later is formed thicker than 100 nm, the very thick thickness of the resistive thin film 340 (Roughness, uniformity, and the like) are uneven due to the presence of a metal oxide, which causes a problem in that the electrical properties of the metal oxide thin film are poor.

Accordingly, the molar concentration of the precursor solution (110) of the present invention may range from 0.1M to 0.4M.

At least one of the metals of the metal oxide organic compound may be formed on the substrate 100 prior to the step of forming the precursor layer 120 with the precursor solution 110 after the precursor solution 110 is prepared. The metal layer may be formed by a physical vapor deposition method.

The formation of the metal layer by the physical vapor deposition method can be deposited by a sputtering deposition method, and the sputtering deposition method is a conventional method, so a detailed description will be omitted.

The metal layer may include at least one of metal of the metal oxide organic compound, and the metal atoms of the metal layer may be a crystal nucleus or a position (for example, site so that the resistance thin film 340 can easily grow.

Since the precursor layer 120 formed by coating the precursor solution on the metal layer (or the pre-oxide seed layer) is oxidized by the subsequent heat treatment to be changed into the oxide layer 125, the metal layer according to the present invention is a metal oxide If at least one of the organic compounds is oxidized and provided as crystal nuclei, the crystal growth of the oxide layer 125 may be easier. In other words, since the metal of the metal layer can provide crystal nuclei required when forming the resistive thin film 340 of the spinel crystal structure and can provide a position where crystals of the resistive thin film 340 can grow, The thin film 340 can easily grow.

In the plurality of metal oxide organic compounds dissolved in the first organic solvent, the metal oxide may include nickel oxide, manganese oxide, copper oxide and chromium oxide.

The plurality of metal oxide organic compounds may be metal oxide organic compounds including nickel oxide, metal oxide organic compounds including manganese oxide, metal oxide organic compounds including copper oxide, and metal oxide organic compounds including chromium oxide, A plurality of pre-precursor solutions prepared by dissolving a plurality of metal oxide organic compounds in the first organic solvent may be NiO, Mn ₂ O ₃ , CuO, Cr ₂ O ₃ in one embodiment. That is, the oxide layer 125, according to an embodiment of the present invention _{[(Ni y Mn 1-yx} Cr x) Cu] 3 O 4 composition of a plurality of metal oxide an organic compound to the (x = 0.08) of nickel oxide, Manganese oxide, copper oxide, and chromium oxide. However, it is an embodiment of the present invention, but not limited thereto, and various metal oxides can be used according to a desired composition or predetermined ratio.

The plurality of metal oxide organic compounds may be at least one selected from the group consisting of nickel oxide, manganese oxide, copper oxide, and chromium oxide such that the oxide layer 125 has a composition of [(Ni _y Mn _{1- y x} Cr _x ) Cu] ₃ O ₄ Since the metal layer may serve as a nucleus at the bottom of the oxide layer 125, the metal layer may include at least one of metals of a plurality of metal oxide organic compounds, more specifically nickel, manganese, copper, and chromium And the like.

The method may further include a step of preheating the metal layer at a temperature lower than the temperature of the next heat treatment to form the oxide seed layer 130 before forming the precursor layer 120 after forming the metal layer.

At least any one metal of nickel, manganese, copper, and chromium in the metal layer is changed to the oxide seed layer 130 to serve as a nucleus The preliminary heat treatment can be performed at a lower temperature than the subsequent heat treatment. In order to facilitate crystal growth of the oxide layer 125, a preliminary heat treatment for oxidizing the metal layer in an oxygen atmosphere or atmosphere at a lower temperature than the subsequent heat treatment is performed to change the metal layer to a preliminary oxide seed layer serving as a seed layer .

Since the pre-oxide seed layer changed by the preliminary heat treatment of the metal layer is not in a state of being coupled with the oxide layer 125 before the precursor layer 120 is changed to the oxide layer 125 through the subsequent heat treatment, But may be a pre-oxide seed layer for serving as a seed layer.

Since the precursor layer 120 formed on the oxide seed layer 130 is transformed into the oxide layer 125 through the subsequent heat treatment, the metal layer (for example, the copper metal layer) subjected to the preliminary heat treatment is changed from Cu to CuOx, Or may be a pre-oxide seed layer that facilitates crystal growth of the oxide layer 125 that is ultimately formed on the pre-oxide seed layer, which is the oxidized metal layer, as the pre-oxide seed layer.

A precursor heat treatment for oxidizing the metal layer to the precursor seed layer is not necessarily performed and the precursor layer 120 is subjected to a subsequent heat treatment in an oxidizing atmosphere even if a preliminary heat treatment is not performed before the precursor layer 120 is formed, The oxide seed layer 130 may be formed by oxidizing the precursor layer 120 as well as the metal layer to an oxidized metal layer.

Therefore, the pre-oxide seed layer for serving as the seed layer can provide the crystal nuclei necessary for forming the resistive thin film 340 of the spinel crystal structure, and the position where the crystal of the resistive thin film 340 can grow A resistive thin film 340 having a composition of [(Ni, Mn, Cr) Cu] ₃ O ₄ can be easily grown.

The precursor layer 120 may be formed by a liquid phase process using the spin coater and the precursor solution 110 as shown in FIG. 2C on the substrate 100 after changing the metal layer to the preliminary oxide seed layer (S400, FIG. 2C ). At this time, the precursor layer 120 may be formed by a metal organic decomposition method.

The substrate 100 on which the pre-oxide seed layer (not shown) is formed is placed on the support unit 210 and the precursor solution 110 is injected onto the pre-oxide seed layer using the nozzle 220. The substrate 100 may be rotated by rotating the support unit 210 while applying the precursor solution 110 onto the pre-oxide seed layer. Thus, the precursor solution 110 may be coated so as to have a stable thickness on the pre-oxide seed layer while being evenly spread.

Since the solvent or organic residues contained in the precursor layer 120 formed by coating the precursor solution 110 may deteriorate the quality of the resistive thin film 340, the organic solvent or organic residues in the precursor layer 120 may be removed A preliminary subsequent heat treatment may be performed at a lower temperature and a faster holding time than the subsequent heat treatment before performing the subsequent heat treatment.

The metal organic decomposition method can maintain the desired stoichiometric ratio by the wet chemical thin film manufacturing method using the precursor solution 110. The metal organic decomposition method can quickly manufacture the resistive thin film 340 on the substrate 100 without a vacuum device and a simple process There is an advantage to be able to do. Although the precursor layer 120 according to the present invention is formed by the metal organic decomposition method, the present invention is not limited thereto and various liquid phase processes can be selected.

The precursor layer 120 may be subjected to a subsequent heat treatment in an oxidizing atmosphere to convert the precursor layer 120 into an oxide layer 125 by performing a preliminary subsequent heat treatment to remove the organic solvent or organic residues in the precursor layer 120 at step S500. At this time, the subsequent heat treatment may be performed at a temperature ranging from 300 ° C to 400 ° C.

The precursor layer 120 formed on the preoxidation seed layer is changed to an oxide layer 125 and improved to meet densification and crystallization or high resistance temperature coefficient, low resistivity, low 1 / f noise, excellent environmental stability The precursor layer 120 may be subjected to a subsequent heat treatment.

As the subsequent heat treatment of the precursor layer 120 formed on the pre-oxide seed layer proceeds, the precursor layer 120 turns into an oxide layer 125 where the precursor layer 120 changes into an oxide layer 125 through a subsequent heat treatment The metal oxide crystal grains of the oxide layer 125 and the metal oxide crystal grains of the preliminary oxide seed layer formed below the oxide layer 125 are coupled to each other so that the preliminary oxide seed layer provides crystal nuclei to the oxide layer 125 To the oxide seed layer 130 of the spinel crystal structure. That is, the nickel, manganese, copper, and chromium crystal grains of the oxide layer 125 may diffuse and penetrate into the pre-oxide seed layer formed under the oxide layer 125, so that the pre- And an oxide seed layer 130 made of a spinel crystal structure having a composition of [(Ni, Mn, Cr) Cu] ₃ O ₄ .

In order to minimize the thermal conduction from the surrounding environment to the resistive film 340 when the bolometer is formed, the resistive film 340 is separated from the substrate 100 by the spacing space 360 without being in contact with the substrate 100, An organic material sacrificial layer 330 such as polyimide (PI) may be formed on the resistive thin film 340. Generally, in the case of the resistive thin film 340 deposited only by the metal organic decomposition method, a subsequent heat treatment temperature for crystallizing the resistive thin film 340 is A bubbling problem in which the organic material of the organic material sacrifice layer 330 boils up may occur because the temperature of the resistive thin film 340 is higher than 450 DEG C, and the damage of the readout integrated circuit and the thermal expansion coefficient Deformation due to mismatch may occur. Therefore, a lower heat treatment temperature of 400 占 폚 or less may be required to completely prevent the damage and bubbling problem of the readout integrated circuit caused by the high heat treatment temperature.

The post heat treatment according to the embodiment of the present invention can be performed at a temperature range of 300 ° C to 400 ° C. As the molar concentration of the precursor solution 110 increases, since many metal ions can readily contribute to crystallization, The resistive thin film 340 can be stably manufactured without a high temperature heat treatment by decreasing the resistivity through the heat treatment process and reducing the subsequent heat treatment temperature required for crystallization to 400 캜 or lower. That is, the resistance thin film 340 according to the embodiment of the present invention improves the crystal structure of the resistive thin film 340 by controlling the molar concentration so that the subsequent heat treatment temperature necessary for crystal growth can be reduced, Lt; RTI ID = 0.0 > C, < / RTI >

If the subsequent heat treatment required for crystallization is carried out at a temperature of less than 300 ° C., the temperature may not be sufficiently high and the precursor layer 120 may not change to the oxide layer 125, Can not be formed. In addition, if the subsequent heat treatment is performed at a temperature exceeding 400 캜, the heat treatment temperature may be too high as described above, and the burying problem of the organic sacrificing layer 330 may occur.

Therefore, the subsequent heat treatment at 300 ° C to 400 ° C is a temperature lower than the temperature at which the subsequent heat treatment is performed at a temperature higher than 450 ° C. Therefore, when the resistive thin film 340 according to the present invention is applied to the resistive thin film 340 for actual bolometer, The problem of damaging the readout integrated circuit formed in the lower substrate 100 caused by the process of forming the organic thin film 330 can be fundamentally blocked and the polyimide bubbling problem of the organic sacrificing layer 330 can be completely solved, Can be used easily.

The oxide layer 125 has a cubic spinel crystal structure and may have a composition of a compound represented by Chemical Formula 1 below. (Ni _y Mn _{1- y x} Cr _x ) Cu] ₃ O ₄ , and x is 0.04? X? 0.20. Also, the oxide resistive thin film 340 may have a resistivity at room temperature of less than 2? Cm.

Oxide layer 125, a subsequent heat treatment _{[(Ni y Mn 1 -y- x} Cr x) Cu] 3 O 4 (0.04? X? 0.20), and the composition of the oxide layer 125 is determined by the composition of the oxide layer 125 and the oxide seed layer 130 as a whole, the volume of the oxide seed layer 130 may be the oxide Layer 125, the entire composition range may not differ greatly.

Y may be 0.20? Y? 0.40 in the composition of the oxide layer 125. When the nickel has a composition of 0.20 or more and 0.40 or less, the resistance thin film 340 according to the embodiment of the present invention may have a spinel crystal structure And the crystal structure of the resistive thin film 340 can be improved by obtaining a uniform microstructure. As described above, since the resistivity of the resistive film 340 may be affected by the microstructure, the microstructure of the resistive film 340 must be uniform in order to have a low resistivity. Accordingly, when the nickel has a composition of 0.20 or more and 0.40 or less, the microstructure of the resistive film 340 can be uniformed and the crystal structure of the resistive film 340 can be improved, so that it can have a low resistivity. However, when nickel has a composition of less than 0.20 or more than 0.40, a phase change may occur to a phase other than the spinel crystal phase, which may result in a failure to have a desired low specific resistance.

When each of the precursor precursor solutions is mixed at a preset ratio to produce the above-mentioned mixed solution, the mixing ratio is such that the oxide layer 125 is [(Ni _y Mn _{1- y x} Cr _x ) Cu] ₃ O ₄ (0.04 ≤ x ? 0.20), and the composition of the oxide layer 125 can be set to have a composition of [(Ni _y Mn _{1- y x} Cr _x ) Cu] ₃ O ₄ (0.04? X? 0.20) The oxide-resistive thin film 340 may have a very low resistivity (see FIG. 4) of 2? · Cm or less through the control of the molar concentration of the precursor solution 110.

The oxide resistive thin film 340 whose resistance value changes according to the temperature change due to infrared absorption is required to have a low resistivity because the noise of the bolometer increases as the resistance increases. When the resistive thin film 340 has a high resistivity, There is a problem that it is difficult to implement characteristics at the time of production. However, the oxide-resistive thin film 340 according to the present invention is characterized in that the oxide layer 125 has a composition of [(Ni _y Mn _{1- y x} Cr _x ) Cu] ₃ O ₄ (0.04 ≦ x ≦ 0.20) ) Can have a very low resistivity of less than 2? · Cm when having a molar concentration of 0.1M to 0.4M.

Accordingly, the oxide-resistive thin film 340 formed at a low heat treatment temperature of 400 ° C or less can have a very low resistivity of 2? · Cm or less, so that the uncooled infrared ray detector It is possible to manufacture a bolometer and an infrared ray detecting element having excellent infrared ray detecting characteristics and electrical characteristics when applied to the resistive thin film 340 for an actual bolometer.

6 is a cross-sectional view showing a manufacturing process of a bolometer according to another embodiment of the present invention.

Referring to FIG. 6, a method of manufacturing a bolometer according to another embodiment of the present invention includes: providing a substrate 310 on which a signal processing circuit is formed; Forming a plurality of metal pads (320) spaced apart from the upper surface of the substrate (310) to transmit an electric signal of the signal processing circuit; Forming an organic sacrificial layer (330) on the substrate (310); Forming an oxide resistive thin film (340) on the organic sacrificial layer (330) by the method of any one of the preceding claims; And patterning the organic sacrificial layer 330 and the oxide-resistive thin film 340.

First, a substrate 310 on which a signal processing circuit (not shown) is formed can be provided (FIG. 6A). The substrate 310 may include a signal processing circuit for detecting infrared rays, and may be a SiNx wafer or a semiconductor material such as silicon, but the material and structure thereof are not particularly limited.

A metal pad 320 electrically connected to the signal processing circuit may be deposited on the substrate 310 on which the signal processing circuit is formed by a physical vapor deposition method such as a sputtering deposition method. The metal pads 320 may be deposited by physical vapor deposition, but not limited thereto, by various deposition methods.

After the metal pads 320 are deposited, a photosensitive liquid is coated on the metal pads 320, exposed, developed, and etched so as to leave the metal pads 320 only at desired portions by a photolithography process, And a metal pad 320 pattern that is electrically connected to the signal processing circuit can be formed. The metal pad 320 may be connected to the resistance thin film 340 in contact with the conductive material of the support member 350, which will be described later.

The organic sacrificial layer 330 may then be applied to the substrate 310 on which the metal pad 320 is formed by spin coating or the like to form a spacing space 360 to be described later ). The organic sacrificial layer 330 may utilize a polyimide that is generally stable at high temperatures.

After forming the organic sacrificial layer 330, the oxide resistive thin film 340 may be formed on the organic sacrificial layer 330 by any one of the methods described above.

The oxide thin film (340) may be prepared by dissolving a plurality of metal oxide organic compounds in a first organic solvent to prepare a plurality of pre-precursor solutions; Mixing each of the precursor precursor solutions at a preset ratio to prepare a mixed solution; Preparing a precursor solution 110 by diluting the mixed solution with a second organic solvent different from the first organic solvent; Forming a precursor layer (120) on a substrate (100) by a liquid phase process using the precursor solution (110); And subsequent heat treatment of the precursor layer 120 in an oxidizing atmosphere to change into the oxide layer 125.

The first organic solvent used in the preparation of the plurality of precursor precursors may be toluene (C ₆ H ₅ CH ₃ ), xylene (C ₆ H ₄ (CH ₃ ) ₂ ), naphthalene (C ₁₀ H ₈ ) C ₁₄ H ₁₀ ), and the second organic solvent for diluting the mixed solution is an organic solvent such as ethyl acetate (C ₄ H ₈ O ₂ ), butyl acetate (C ₆ H ₁₂ O ₂ ), methyl acetate (C ₃ H ₆ O ₂ ), cellosolve acetate (C ₆ H ₁₂ O ₃ ), and carbitol acetate (C ₁₀ H ₂₀ O ₄ ).

More specifically, since the metal oxide organic compound having a small polarity and having a small polarity has a long chain length, it can not be dissolved in a polar solvent and can be dissolved in a non-polar solvent such as benzene, toluene, xylene and the like owing to its hydrophobic property A plurality of preliminary precursor solutions can be prepared by first dissolving a plurality of metal oxide organic compounds in a first organic solvent which is a nonpolar solvent.

A plurality of preliminary precursor solutions are mixed so that the oxide layer 125 has a composition of [(Ni _y Mn _{1- y x} Cr _x ) Cu] ₃ O ₄ (x = 0.08) to prepare a mixed solution, The precursor solution 110 may be prepared by diluting the precursor solution 110 with a second organic solvent different from the organic solvent. Since the second organic solvent includes oxygen atoms in the respective organic solvents differently from the first organic solvent, And the resistance between the resistance thin film 340 can be improved.

Therefore, instead of using the single organic solvent to prepare the precursor solution 110, the precursor solution 110 is prepared twice using the first organic solvent and the second organic solvent different from the first organic solvent, The metal organic compound can be effectively dissolved and adhesion with the substrate 100 can be improved.

The molar concentration of the precursor solution 110 varies depending on the concentration, and affects the microstructure of the resistive film 340 such as grain size, thickness, uniformity, roughness, etc. Therefore, in order to control the electrical characteristics, Concentration control may be required. Accordingly, the crystal structure of the resistive thin film 340 can be improved by adjusting the molar concentration of the precursor solution 110 according to the present invention in the range of 0.1M to 0.4M, and the electrical characteristics can be improved.

The oxide resistive thin film 340 manufactured by this method can have an improved electrical characteristic and a specific resistance at room temperature of 2? Cm or less, thereby improving the infrared detection sensitivity and temperature stability of the bolometer.

The method of manufacturing the oxide-resistive thin film 340 formed on the organic sacrificial layer 330 is the same as that of the first embodiment described with reference to FIGS. 1 to 5, and therefore detailed description thereof will be omitted with reference to FIGS. 1 to 5 and the first embodiment .

When the organic sacrificial layer 330 and the oxide resistive thin film 340 are formed on the substrate 310, the photosensitive liquid is coated on the resistive thin film 340 and the organic sacrificial layer 330 and the resistive layer 330 are formed only by the photolithography process, The organic sacrificial layer 330 and the resistive thin film 340 may be patterned to expose a part of the metal pad 320 by exposing, developing and etching the remaining thin film 340 (FIG. 6C).

Next, the method may further include forming a support member 350 having one side connected to the metal pad 320 and the other side connected to the resistance thin film 340 (FIG. 6D).

The support member 350 supports the resistance thin film 340 by connecting the metal pad 320 and the resistance thin film 340. The support member 350 may include at least a pair of May be formed in the shape of a support member 350.

The resistance thin film 340 can be brought into contact with the lower surface of the protruding portion of the support member 350 and can have sufficient mechanical strength to support the resistance thin film 340 while minimizing the thermal conductivity And may be made of a material having thermal conductivity and formed to have a small cross-sectional area. That is, a single or composite metal such as aluminum, titanium, or tungsten may be used for conductivity and mechanical stability.

The supporting member 350 may further include a conductive layer (not shown) electrically connecting the substrate 310 and the resistive thin film 340. The conductive layer of the supporting member 350 may include a resistance thin film 340, And a conductive material for electrically connecting the signal processing circuit with the signal processing circuit.

The support member 350 not only functions to support the resistance thin film 340 but also forms the resistance thin film 340 and the metal pad 320 through the conductive material So that the signal processing circuit can be electrically connected.

Next, the organic sacrificial layer 330 may be removed (FIG. 6E).

The organic sacrificial layer 330 may be removed by plasma burning using a reactive gas containing oxygen to form a spacing space 360 as shown in FIG. 6E. The space between the substrate 310 on which the organic sacrificial layer 330 is formed and the resistive film 340 is left in the spacing space 360 and the optical resonance structure can be provided by the spacing interval of the spacing space 360 . Therefore, in order to minimize the thermal conduction from the surrounding environment to the resistive thin film 340 for the bolometer, the resistive thin film 340 may be spaced apart by the spacing space 360 without being in contact with the substrate 310.

Although the present invention has been described in detail with reference to the specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be defined by the appended claims, as well as the appended claims.

100, 310: substrate 110: precursor solution
120: precursor layer 125: oxide layer
130: oxide seed layer 210: support unit
220: nozzle 320: metal pad
330: organic sacrificial layer 340: oxide resistive thin film
350: support member 360: spacing space

Claims (15)

Preparing a plurality of preliminary precursor solutions in which a plurality of metal oxide organic compounds each containing a plurality of metal oxides are respectively dissolved in a first nonporous organic solvent;
Mixing each of the precursor precursor solutions at a preset ratio to prepare a mixed solution;
Diluting the mixed solution with a second organic solvent having a polarity different from that of the first organic solvent to prepare a precursor solution;
Forming a precursor layer on the substrate by a liquid phase process using the precursor solution; And
And subsequent heat treatment of the precursor layer in an oxidizing atmosphere to change into an oxide layer,
Wherein the second organic solvent comprises an oxygen atom,
The subsequent heat treatment is performed at a temperature ranging from 300 to 400 캜,
Wherein the oxide layer has a cubic spinel crystal structure and has a composition of a compound represented by the following formula (1).
≪ Formula 1 >
[(Ni _y Mn _{1- y x} Cr _x ) Cu] ₃ O ₄ wherein x is 0.04? X? 0.2 and y is 0.2? Y? 0.4.
The method according to claim 1,
Wherein the first organic solvent is an aromatic hydrocarbon organic solvent.
The method according to claim 1,
Wherein the second organic solvent is an acetate-based organic solvent.
The method according to claim 1,
Wherein the molar concentration of the plurality of metal oxides relative to the second organic solvent is 0.1M to 0.4M.
The method according to claim 1,
Wherein the precursor layer is formed by a metal organic decomposition method.
delete The method according to claim 1,
Wherein the metal oxide comprises nickel oxide, manganese oxide, copper oxide, and chromium oxide.
The method according to claim 1,
Before the process of forming the precursor layer,
And forming a metal layer including at least one metal of the metal oxide organic compound on the substrate.
The method of claim 8,
Wherein the metal layer is formed by physical vapor deposition.
The method of claim 8,
Before forming the metal layer and forming the precursor layer,
Further comprising the step of subjecting the metal layer to a preliminary heat treatment at a temperature lower than the temperature of the subsequent heat treatment to change into an oxide seed layer.
delete The method according to any one of claims 1 to 5, and claims 7 to 10,
Wherein the oxide resistive thin film has a specific resistance at room temperature of less than 2? Cm.
Providing a substrate on which a signal processing circuit is formed;
Forming a plurality of metal pads spaced apart from the upper surface of the substrate to transmit an electric signal of the signal processing circuit;
Forming an organic sacrificial layer on the substrate;
Forming an oxide resistive thin film on the organic sacrificial layer by the manufacturing method of any one of claims 1 to 5 and 7 to 10; And
And patterning the organic sacrificial layer and the oxide-resistant thin film.
14. The method of claim 13,
And forming a support member having one side connected to the metal pad and the other side connected to the oxide resistive thin film.
14. The method of claim 13,
And removing the organic sacrificial layer.

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