KR20060101965A - Method of manufacturing a thin layer and methods of manufacturing a gate structure and a capacitor using the same - Google Patents

Abstract

In the method of manufacturing the thin film and the method of manufacturing the gate structure and the capacitor using the same, an oxidant including 85 to 100 vol% of ozone gas for oxidizing the metal precursor and the metal precursor is provided on the substrate. Subsequently, a metal oxide film made of a metal oxide is formed on the substrate by the reaction of the metal precursor provided on the substrate with the oxidant. The metal oxide film may be easily applied to a gate insulating film of a gate structure, a dielectric film of a capacitor, or the like.

Description

METHODS OF MANUFACTURING A THIN LAYER AND METHODS OF MANUFACTURING A GATE STRUCTURE AND A CAPACITOR USING THE SAME}

1 to 5 are cross-sectional views illustrating a method of manufacturing a metal oxide film according to an embodiment of the present invention.

6 to 9 are cross-sectional views illustrating a method of manufacturing a gate structure in accordance with an embodiment of the present invention.

10 to 13 are cross-sectional views illustrating a method of manufacturing a capacitor according to an embodiment of the present invention.

 14 is a graph showing the thickness change of the silicon oxide film according to the type of oxidant and the oxidation time of the silicon substrate.

15 is a graph showing the thickness change of the silicon oxide film according to the type of oxidizing agent and the oxidation temperature.

FIG. 16 is a graph showing capacitor leakage current characteristics of a dielectric film formed according to a change in the amount of ozone included in an oxidant.

Explanation of symbols on the main parts of the drawings

100: process chamber 10: semiconductor substrate

102 tunnel dielectric film 104 first conductive film

106: nitride film 110: first dielectric film

120: second dielectric film 130: composite dielectric film

140: second conductive film 150: control gate electrode

152: composite dielectric film pattern 154: nitride film pattern

156: floating gate electrode 158: tunnel dielectric layer pattern

160: gate structure

The present invention relates to a method for manufacturing a thin film, a gate structure using the same, and a method for manufacturing a capacitor, and more particularly, to a method for manufacturing a thin film including a metal oxide, and a method for manufacturing a gate structure and a capacitor using the same.

Recently, metal oxide films such as a gate insulating film of a MOS transistor, a dielectric film of a capacitor, or a dielectric film of a flash memory device have been formed using a material having a high-k dielectric. This sufficiently reduces the leakage current generated between the gate electrode and the channel or between the lower electrode and the upper electrode even though the metal oxide film made of the material having the high dielectric constant maintains a thin equivalent oxide thickness (EOT). In addition, the coupling ratio of the flash memory device can be improved. Examples of the material having the high dielectric constant may be a metal oxide such as _{Ta 2 O 5, Y 2 O} 3, HfO 2, ZrO 2, Nb 2 O5, BaTiO 3, SrTiO 3.

The metal oxide layers including the metal oxide may be formed using deposition methods such as chemical vapor deposition (CVD), low pressure chemical vapor deposition (LPCVD), plasma-enhanced chemical vapor deposition (PECVD), and sputtering. Among these, the atomic layer deposition method (ALD) can be carried out at a lower temperature than the conventional CVD method and exhibits excellent step coating properties, and thus is widely used as a conventional metal oxide film forming technique together with the CVD method.

 The metal oxide film made of the metal oxide may be formed using a metal precursor and an oxidizing agent. Processes for Forming the Metal Oxide Film Having the High Dielectric Constant The oxidizing agent used should be selected to satisfy various conditions as follows.

First, the ligands that bind to the metal must be quickly and cleanly separated to oxidize the metal. Second, when forming the metal oxide film to be finally formed should have a characteristic that the organic matter (carbon) does not remain. Third, the oxidation power should be excellent at a relatively low temperature. Fifth, the metal oxide should be deposited at a high deposition rate when forming the metal oxide film.

However, oxidizers O ₃ , H ₂ O, H ₂ O ₂ , CH ₃ OH, C ₂ H ₅ OH, and the like, which are generally widely used to date, do not fully satisfy the properties of the oxidants. In particular, the ozone (O ₃ ) gas is widely used as an oxidizing agent for forming metal oxides. A method of forming a metal oxide film having a high dielectric constant using the ozone gas as an oxidizing agent is disclosed in Korean Patent Laid-Open No. 2002-0061985 and Japanese Patent Laid-Open No. Hei 16-047660. The ozone (O ₃ ) gas used as an oxidant to form the metal oxide is generally composed of 20 to 30% ozone and excess oxygen.

That is, ozone gas used as the oxidant is ozone gas of low purity. The low purity ozone gas, that is, the oxidizing agent whose oxygen content is relatively higher than that of pure ozone (O ₃ ), has a relatively low oxidizing power as compared to pure ozone, and requires a higher temperature than pure ozone in the oxidation process.

Therefore, as the oxygen content in the ozone gas used as the oxidant increases, there is a problem in that the substitution and oxidizing power of the ligand of the metal precursor are lowered relatively. In addition, since the oxygen contained in the oxidant cannot be removed by completely removing organic substances from the metal precursor, the metal oxide film formed by being oxidized by oxygen has deteriorated electrical characteristics.

Therefore, there is a demand for a method of forming a metal oxide film using an oxidizing agent having excellent oxidizing power at a low temperature and a rapid oxidation reaction, and having a property of completely removing a ligand bound to a metal ion.

An object of the present invention is to provide a method for manufacturing a thin film that can increase the throughput of a semiconductor manufacturing process while having excellent electrical properties using an oxidizing agent consisting of high purity ozone gas.

Another object of the present invention is to provide a method for manufacturing a gate structure including a gate insulating film formed using an oxidizing agent made of the high purity ozone gas.

Still another object of the present invention is to provide a method of manufacturing a capacitor including a dielectric film formed using an oxidizing agent composed of high purity ozone gas.

According to a preferred embodiment of the present invention to achieve the above object, a method of manufacturing a thin film provides a metal precursor and an oxidant including 85 to 100 vol% of ozone gas for oxidizing the metal precursor. Subsequently, a solid material including a metal oxide is formed on the substrate using the metal precursor provided on the substrate and the oxidant. As a result, a metal oxide film containing a metal oxide is formed on the substrate.

According to another aspect of the present invention, there is provided a method of manufacturing a gate structure of a semiconductor device, wherein an oxidant including a metal precursor and 85 to 100 vol% of ozone gas for oxidizing the metal precursor is provided on the substrate. do. Subsequently, a gate insulating film including a metal oxide is formed on the substrate by reaction of the metal precursor provided on the substrate and the oxidant. Subsequently, a gate conductive film is formed on the gate insulating film. Subsequently, the gate conductive film and the gate insulating film are patterned sequentially. As a result, a gate pattern made of the gate oxide film pattern and the gate insulating film pattern made of the metal oxide is formed on the substrate.

According to a preferred embodiment of the present invention, there is provided a method of manufacturing a capacitor of a semiconductor device, which forms a lower electrode on a substrate. Subsequently, an oxidant including 85 to 100 vol% of an ozone gas for oxidizing the metal precursor and the metal precursor onto the lower electrode of the substrate is provided. Subsequently, a dielectric film including a metal oxide is formed on the lower electrode by a reaction between the metal precursor provided on the lower electrode and the oxidant. Subsequently, an upper electrode is formed on the dielectric layer. As a result, a capacitor comprising the lower electrode, the dielectric film made of the metal oxide and the upper electrode is formed on the substrate.

According to the present invention, the oxidant applied when forming the metal oxide film contains 85 to 100 vol% of ozone gas for oxidizing the metal precursor. For this reason, the oxidant composed of the high purity ozone gas has a higher oxidizing power than the oxidant having a high oxygen content. In addition, since it has high reactivity with the metal precursor at a low temperature, it is possible to form a metal oxide film faster. Therefore, it is possible to improve the throughput and the step cover characteristics of the process during the metal oxide film production process.

In addition, the present invention makes it possible to easily manufacture a metal oxide film having a high dielectric constant and good leakage current. As a result, the metal oxide film may be easily applied to a gate insulating film of a gate structure, a dielectric film of a capacitor, a dielectric film of a flash memory device, and the like.

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

Thin Film Manufacturing Method

1 to 5 are cross-sectional views illustrating a method of manufacturing a metal oxide film according to an embodiment of the present invention.

Referring to FIG. 1, a substrate 10 for forming a metal oxide film using an oxidant composed of a metal precursor and high purity ozone gas (85 to 100 vol% of ozone gas) is positioned in a process chamber 50. In this case, when the internal temperature of the process chamber 50 is less than about 200 ° C., the reactivity between the gaseous metal precursor and the substrate in the subsequent process is not preferable. On the other hand, when the temperature exceeds about 500 ° C., crystallization of the metal oxide film formed on the substrate 10 is not preferable.

Therefore, it is preferable to adjust the inside of the process chamber 50 to a temperature of about 200 to 500 ℃. In particular, it is preferable to adjust so that the temperature inside the said process chamber 50 may be about 200-400 degreeC, and it is more preferable to adjust so that it may become about 250-350 degreeC temperature. In this embodiment, the process chamber 50 is adjusted to have a temperature of about 250 ° C.

In addition, when the pressure inside the process chamber 50 is less than about 0.01 torr, it is not preferable because the reactivity of the metal precursor in the subsequent process is not easy. On the other hand, if the pressure exceeds about 10.0torr, it is not preferable because the process control is not easy. Therefore, it is preferable to adjust the inside of the process chamber 50 to have a pressure of about 0.01 to 10.0 torr. In particular, it is preferable to adjust the inside of the process chamber 50 to have a pressure of about 0.05 to 5.0 torr, more preferably to a pressure of about 0.1 to 3.0 torr. In this embodiment, the process chamber 50 is adjusted to have a pressure of about 1.0 torr.

As such, after placing the substrate 10 in the process chamber 50 having the temperature condition and the pressure condition, a metal precursor having a gas state is provided to the process chamber 50. The provision of the metal precursor uses a canister or LDS (liquid delivery system). The metal precursor is then provided over the substrate for about 0.5 to 5 seconds. In particular, in this embodiment, the metal precursor is provided on the substrate in the process chamber for about 1 second.

As a result, the first portion 12 of the metal precursor is chemisorbed onto the substrate 10, and the second portion 14 except for the first portion 12 of the metal precursor is the first portion 12. It is physically adsorbed on) and has a loose coupling force or floats inside the process chamber 50.

In addition, a portion of the metal precursor chemisorbed on the substrate may be thermally decomposed by heat in the chamber. Therefore, the metal ion of the metal precursor is chemisorbed on the substrate and a portion of the ligand bound to the metal ion may be separated from the metal ion.

Here, the metal precursor used is in a liquid state at room temperature, vaporized at a temperature of 60 ℃ or more has a gaseous state. As the metal precursor applied to the present invention, a metal precursor, an aluminum precursor, a titanium precursor, a zirconium precursor, a silicon precursor, or the like can be used. The gaseous metal precursor may be formed by, for example, accommodating a liquid metal precursor inside a canister and generating an inert gas bubble while heating the liquid metal precursor to a temperature of 60 to 95 ° C. As a result, a gaseous metal precursor is produced in the canister. In this case, the metal precursor is produced until the gaseous metal precursor formed in the canister is saturated.

Referring to FIG. 2, a purge gas that is an inert gas is provided into the process chamber 50. Examples of the purge gas include argon gas and nitrogen gas. At this time, the purge gas is provided for about 1 to 30 seconds. In this embodiment, the purge gas is provided for about 30 seconds.

As such, by providing the purge gas into the process chamber 50, the metal precursors are allowed to drift in the process chamber 50 or the second part 14 physically adsorbed to the first part 12 is removed. As a result, metal precursor molecules 12a remain on the substrate 10 as the chemisorbed first portion 12.

Alternatively, instead of providing the purge gas, the inside of the process chamber 50 may remain in the process chamber 50 or drift in the process chamber 50 even if the vacuum is maintained for about 1 to 30 seconds. It is possible to remove the physically adsorbed second portion 14. As another embodiment, the purge gas and the vacuum purge may be performed together to remove the second part 14 that is drift in the process chamber 50 or physically adsorbed to the first part 12. .

Referring to FIG. 3, an oxidant 16 made of high purity ozone gas is provided into the process chamber 50. The oxidant is provided onto the substrate inside the process chamber for about 0.5 to 5 seconds.

The oxidant applied to oxidize the metal precursor is provided in a gaseous state, and contains 85 to 100 vol% of ozone gas (O ₃ ; 16) based on the total volume. In particular, the oxidant comprises 89 to 99 vol% ozone gas, preferably 90 to 97 vol% ozone gas.

That is, the oxidant has a composition including 85 to 100 vol% ozone gas and 0 to 15 vol% oxygen gas. In particular, it has a composition containing 89 to 99 vol% of ozone gas and 1 to 11 vol% of oxygen gas. For example, the composition of the oxidizing agent composed of ozone gas having high purity may be expressed as a volume ratio or molar ratio of ozone gas and oxygen gas at the same pressure and temperature.

When the content of ozone gas contained in the oxidant is less than 85 vol%, the content of oxygen gas having a smaller oxidizing power than that of ozone gas increases, so that the oxidizing agent reduces the oxidizing power of the metal oxide.

When the oxidizing power of the oxidant is reduced, the metal oxide formed by reacting the metal precursor with the oxidant may include carbon. When carbon is included in the metal oxide, the metal oxide film made of the metal oxide is degraded in electrical characteristics such as permittivity. Here, carbon is retained in the metal oxide when the oxygen atoms do not completely remove the ligand from the metal atoms when the metal atoms and oxygen gas contained in the metal precursor reacts.

In addition, when the oxidizing power of the oxidant is reduced, it takes more time to reduce the oxidation reaction of the metal precursor and the oxidant to form a metal oxide film having a target thickness. As a result, the reduction in oxidizing power results in a decrease in throughput of the semiconductor manufacturing process.

Therefore, when the metal oxide film is formed using the oxidizing agent consisting of only the ozone gas, it is possible to form a metal oxide film having excellent electrical characteristics at a lower temperature faster. In addition, when the metal oxide film is formed using the oxidant consisting of only the ozone gas, a process advantage that can be formed at a temperature of about 50 ° C. lower than when the metal oxide film is formed by using an oxidant having a higher oxygen gas content than the ozone gas. Have

In the method for producing the oxidant containing the ozone gas, first, a mixed oxidizing gas containing ozone and oxygen is prepared. The mixed oxide gas has an oxygen content of at least five times higher than that of ozone. The mixed oxidizing gas is introduced into the ozone liquefaction apparatus to liquefy only ozone contained in the mixed gas. Subsequently, oxygen remaining in the gas state in the ozone liquefaction apparatus is discharged to the outside of the liquefaction apparatus. Subsequently, the liquefied ozone is vaporized into a gaseous state to form an oxidizing agent containing 85 to 100 vol% of ozone gas. The oxidant thus formed is provided on top of the substrate.

An oxidant containing 85 to 100 vol% of the ozone gas is provided in this embodiment for about 1 second with an oxidant having the above composition. The metal precursor molecule is the first portion 12 of the reactant chemically adsorbed on the substrate 10 because an oxidant comprising 85 to 100 vol% of the ozone gas 16 is provided on the substrate. The metal precursor molecules 12a are oxidized by chemically reacting with the metals 12a.

Referring to FIG. 4, a purge gas is provided into the process chamber 50. The type and provision time of the purge gas are the same as described with reference to FIG. 2. As such, by providing a purge gas into the process chamber 50, the oxidant 16 which is not chemically reacted is removed from the process chamber 50.

Accordingly, the metal oxide film 18 including the metal oxide is formed on the substrate 10. The metal oxidant depends on the type of metal precursor applied. The metal oxide is especially HfO ₂ , ZrO ₂ , Ta ₂ O ₅ , Y ₂ O ₃ , Nb ₂ O ₅ , Al ₂ O ₃ , TiO ₂ , CeO ₂ , In ₂ O ₃ , B ₂ O ₃ , SiO ₂ , GeO ₂ , SnO ₂ , PbO, PbO ₂ , Pb ₃ O ₄ , La ₂ O ₃ , As ₂ O ₅ , As ₂ O ₃ , Pr ₂ O ₃ , Sb ₂ O ₃ , Sb ₂ O _5, P ₂ O ₅ It consists of such substances.

Referring to FIG. 5, the processes described with reference to FIGS. 1 to 4 are repeated at least once. As a result, a metal oxide film 20 having a target thickness is formed on the substrate 10. At this time, the thickness of the metal oxide film 20 is adjusted according to the number of repetitions of the processes.

As another example of forming the metal oxide layer, unlike an atomic layer deposition process in which an oxidant including the metal precursor and ozone gas 85 to 100 vol% is separately provided, an oxidant including the metal precursor in the gas state and 85 to 100 vol% ozone gas is used. It can be formed by a chemical vapor deposition method of simultaneously implanting into the process chamber to form a metal oxide film.

Here, the formation of the metal oxide film simultaneously injects an oxidant consisting of the metal precursor and ozone in a gaseous state onto the substrate located in the process chamber. Subsequently, an oxidant consisting of the metal precursor and ozone simultaneously injected is chemically reacted on the substrate to form a metal oxide. Subsequently, the formed metal oxide is chemically deposited on the surface of the substrate. Thereafter, the metal oxide is continuously chemically deposited for a predetermined time, thereby forming a metal oxide film having a desired thickness. The thickness of the metal oxide film is adjusted according to the chemical deposition time of the metal oxide.

According to the present embodiment, when the oxidant and the metal precursor containing 85 to 100 vol% of the ozone gas are used as described above, a metal oxide film having a high dielectric constant and a good leakage current can be manufactured more quickly. As a result, the metal oxide film may increase throughput of a semiconductor device manufacturing process including a gate insulating film of a gate structure, a dielectric film of a capacitor, and the like.

Manufacturing method of gate structure

6 to 9 are cross-sectional views illustrating a method of manufacturing a gate structure in accordance with an embodiment of the present invention.

Referring to FIG. 6, a general device isolation process is performed to separate the substrate 100 into an active region and a field region 102. Here, examples of the substrate 100 include a silicon substrate, a silicon-on-insulator (SOI) substrate, and the like.

Subsequently, a gate insulating film 104 is formed on the substrate 100. In this case, the gate insulating layer 104 should be able to sufficiently reduce the leakage current generated between the gate electrode and the channel while maintaining a thin equivalent oxide film thickness. Therefore, in the present embodiment, it is preferable that the gate insulating film 104 is a metal oxide film formed by using an oxidizing agent containing 85 to 100 vol% of ozone gas and a metal precursor.

The metal oxide film may be formed by applying the atomic layer deposition method except that the metal oxide film is formed to have a thickness of 30 to 100 kPa. In addition, the metal oxide layer may be formed by depositing a chemically reacted reactant by simultaneously injecting the metal precursor and an oxidant containing 85 to 100 vol% of ozone gas.

The oxidant applied in the atomic layer deposition method or the chemical vapor deposition method includes 85 to 100 vol% of ozone gas. That is, the oxidant has a composition including 85 to 100 vol% ozone gas and 0 to 15 vol% oxygen gas. In particular, it has a composition containing 89 to 99 vol% ozone gas and 1 to 11 vol% oxygen gas.

In the method for producing the oxidant containing the ozone gas, first, a mixed oxidizing gas containing ozone and oxygen is prepared. Next, the mixed oxidizing gas ozone liquefaction apparatus is introduced to liquefy only ozone contained in the mixed gas. Subsequently, oxygen remaining in the gas state in the ozone liquefaction apparatus is discharged to the outside of the liquefaction apparatus. Subsequently, the liquefied ozone is vaporized into a gaseous state to form an oxidizing agent containing 85 to 100 vol% of ozone gas. The oxidant thus formed is provided on top of the substrate.

In the present embodiment, the metal is formed on the substrate 100 by applying TEMAH (tetrakis ethyl methyl amino hafnium, Hf [NC ₂ H ₅ CH ₃ ] ₄ ), which is an oxidizing agent and a metal precursor consisting of 93 vol% ozone gas and 7 vol% oxygen gas. It is preferable to form the gate insulating film 104 made of oxide.

Referring to FIG. 7, a gate conductive layer 110 is formed on the gate insulating layer 104. The gate conductive layer 110 is formed by sequentially stacking a polysilicon layer 106 and a metal silicide layer 108 such as a tungsten silicide layer. In addition, a capping insulating layer 112 including a silicon oxide material may be formed on the gate conductive layer 110.

Referring to FIG. 8, the capping insulating layer 112, the gate conductive layer 110, and the gate insulating layer 104 formed on the substrate 100 are sequentially patterned. As a result, a gate structure 115 including a gate insulating film pattern 104a, a gate conductive film pattern 110a, and a capping insulating film pattern 112a is formed on the substrate 100. Patterning for forming the gate structure 115 is accomplished by a photolithography process.

9, a source / drain region 120 may be formed on a surface portion of the substrate 115 adjacent to the gate structure 115. The source / drain region 120 is formed before the gate insulating layer 104 is formed or after the spacer 114 is formed in the gate structure 115.

As such, the gate insulating film pattern formed using the metal precursor and the oxidant containing 85 to 100 vol% of the ozone gas may sufficiently reduce the leakage current generated between the gate conductive film pattern and the substrate while maintaining a thin equivalent insulating film thickness. . In addition, the gate insulating film formed by applying the oxidant containing 85 to 100 vol% of ozone gas can reduce the manufacturing time, thereby forming the gate structure faster.

Method of manufacturing a capacitor

10 to 13 are cross-sectional views illustrating a method of manufacturing a capacitor according to an embodiment of the present invention.

Referring to FIG. 10, after preparing a substrate on which an interlayer insulating film 124 including a contact hole 126 exposing a contact plug is provided, a lower electrode conductive film 132 electrically connected to the contact plug 122 is formed. Form. In particular, when the semiconductor device formed using the substrate 130 is a DRAM, a gate structure 115, a bit line (not shown), and a contact plug 122 having a spacer 114 formed on the substrate 130 may be provided. It is preferable that semiconductor structures such as the like be formed.

The conductive film 132 continuously forms the lower electrode conductive film 132 on the side and bottom of the contact hole 126. The conductive layer 132 may be formed using a material such as polysilicon, titanium nitride, tantalum nitride, tungsten nitride, rudenium, or the like. It is preferable to use the above materials alone, but in some cases, two or more of them may be used in combination.

Referring to FIG. 11, a lower electrode 140 electrically connected to the contact plug 122 is formed. Referring to the method of forming the lower electrode 140, after forming a sacrificial film (not shown) on the resultant having the conductive film 132, the sacrificial film is removed until the surface of the conductive film is exposed. . Subsequently, when the conductive layer 132 formed on the surface of the interlayer insulating layer 124 is removed, the lower electrode 140 existing on the side and bottom of the contact hole 126 is formed. Subsequently, the lower electrode 140 is completed by completely removing the sacrificial film (not shown) and the interlayer insulating film 124 remaining in the contact hole 126. In particular, the lower electrode 140 has a cylindrical shape in which the width of the inlet is wider than that of the bottom surface.

Referring to FIG. 12, the dielectric layer 150 is formed by applying an oxidant and a metal precursor including 85 to 100 vol% ozone gas on the surface of the lower electrode 140. The dielectric film is a metal oxide film made of a metal oxide having a very small content of impurities such as carbon. Accordingly, the dielectric film 150 has a thin equivalent oxide film thickness and high dielectric constant, but has a characteristic of sufficiently reducing the leakage current generated between the lower electrode 140 and the upper electrode.

The dielectric film 150 made of the metal oxide may be formed by applying the atomic layer deposition method except that the dielectric film 150 is formed to have a thickness of 30 to 100 Å. In addition, the metal precursor may be formed by depositing a chemically reacted reactant by simultaneously injecting an oxidant including 85 to 100 vol% of ozone gas.

In order to generate the oxidant containing the ozone gas, first, a mixed oxidizing gas including ozone and oxygen is prepared. Next, the mixed oxidizing gas ozone liquefaction apparatus is introduced to liquefy only ozone contained in the mixed gas. Subsequently, oxygen remaining in the gas state in the ozone liquefaction apparatus is discharged to the outside of the liquefaction apparatus. Subsequently, the liquefied ozone is vaporized into a gaseous state to form an oxidizing agent containing 85 to 100 vol% of ozone gas. The oxide thus formed is provided on top of the substrate.

In addition, the oxidizing agent applied in the atomic layer deposition method or chemical vapor deposition method has a composition containing 85 to 100 vol% ozone gas and 0 to 15 vol% oxygen gas. In particular, it has a composition containing 89 to 99 vol% ozone gas and 1 to 11 vol% oxygen gas.

In this embodiment, it is preferable to apply the metal precursor (NOH-31) to the atomic layer deposition process to form a dielectric film 150 made of a metal oxide on the lower electrode 140.

Referring to FIG. 13, after the dielectric film 150 is formed, the dielectric film 150 is heat treated to remove contaminants formed on the dielectric film 150 or included in the dielectric film 150 and to recover oxidation defects. . The heat treatment process mainly performs ultraviolet ozone (UV-O ₃ ) treatment, plasma treatment and the like.

In addition, the upper electrode 160 is formed on the surface of the dielectric layer 150. The upper electrode 160 is formed using a material such as polysilicon, titanium nitride, tantalum nitride, tungsten nitride, rudenium, or the like. It is preferable to use the above materials alone, but in some cases, two or more of them may be used in combination. Accordingly, the capacitor 170 including the lower electrode 140, the dielectric film 150 made of the metal oxide, and the upper electrode 160 is formed on the substrate 130.

As described above, in this embodiment, since the ozone gas contains 85 to 100 vol%, a dielectric film which is a metal oxide film having a high dielectric constant can be formed. Therefore, the dielectric film of this embodiment can maintain the thickness of the thin equivalent dielectric film.

Oxidation capacity assessment 1

When the silicon oxide film was formed on the surface of the silicon substrate, the thickness of the oxide film formed according to the type of oxidant applied and the change in oxidation time was measured. As the oxidant, a first oxidant containing 85 to 100% vol% of ozone gas and a second oxidant containing 10 to 20% of ozone gas were used. At this time, the oxidation process conditions for forming a silicon oxide film on the substrate is 830 ℃. That is, the silicon oxide film is formed on the surface of the silicon substrate by providing first and second oxidants, respectively, on top of the silicon substrates located in the process chamber where about 830 ° C. heat is provided. The thickness of the silicon oxide film thus formed was measured according to the oxidation time. The results are shown in the graph of FIG. 14 is a graph showing the thickness change of the silicon oxide film according to the type of oxidant and the oxidation time of the silicon substrate.

Referring to FIG. 14, a silicon oxide film having a thickness of about 6 nm was obtained by oxidizing a surface of a silicon substrate for 1 minute using a first oxidant containing 85 to 100 vol% of ozone gas at a temperature of 830 ° C. as shown in the graph. Was formed, and after oxidizing the surface of the silicon substrate for 3 minutes, a silicon oxide film having a thickness of about 11 nm was formed (solid line graph).

On the other hand, after oxidizing the surface of the silicon substrate for 1 minute using a second oxidant containing 10-20 vol% of ozone gas at 830 ° C., a silicon oxide film having a thickness of about 0.4 nm was formed, and the silicon substrate was formed for 3 minutes. As a result of oxidizing the surface of, a silicon oxide film having a thickness of about 0.6 nm was formed.

Therefore, it can be seen that the oxidant of the present invention forms an execon oxide film having a thickness of about 10 times or more than a conventional oxidant under the same temperature as shown in FIG. 14. For this reason, when the oxide film is formed by applying the oxidizing agent of the present invention, the process time for forming the oxide film can be reduced.

Oxidation Capacity Assessment 2

When the silicon oxide film was formed on the surface of the silicon substrate, the thickness of the oxide film formed according to the type of oxidant applied and the change in oxidation temperature was measured. As the oxidant, a first oxidant including 93 vol% of ozone gas and 7 vol% of oxygen gas and a second oxidant including 15% of ozone gas and 85 vol% of oxygen gas were used. At this time, the silicon oxide film is a silicon substrate by providing each oxidant on top of the silicon substrate located in the process chamber is provided with respective heat of 260 ℃, 330 ℃, 410 ℃, 500 ℃, 600 ℃, 710 ℃ and 830 ℃ Is formed on the surface. The thickness change of the silicon oxide film formed on the surface of the silicon substrate is shown in the graph of FIG. 15. 15 is a graph showing the thickness change of the silicon oxide film according to the type of oxidizing agent and the oxidation temperature.

Referring to FIG. 15, as a result of oxidizing a surface of a silicon substrate using an oxidant including 93 vol% of ozone gas and 7 vol% of oxygen gas, a silicon oxide film is formed at 260 ° C., and thickness of about 11 nm or more within 4 minutes at 830 ° C. FIG. A silicon oxide film having was formed. On the other hand, as a result of oxidizing the surface of the silicon substrate using a second oxidant containing 15 vol% ozone gas and 85 vol% oxygen gas, the rate at which the silicon oxide film is formed at 830 ° C. is obtained by using the first oxidant of the present invention. It can be seen that it is significantly lower than the rate of forming (dotted graph). That is, the oxidizing agent containing 93 vol% of the ozone gas and 7 vol% of the oxygen gas has a characteristic of about 20 times or more superior to the conventional oxidizing agent at the same temperature condition. (Solid line graph) Such a characteristic is a silicon oxide film to be formed. Since the thickness can be improved, the processing time of the semiconductor device to which the oxide film is applied can be shortened.

Leakage Current Characteristics

FIG. 16 is a graph showing capacitor leakage current characteristics of a dielectric film formed according to a change in the amount of ozone included in an oxidant.

The atomic layer deposition process was performed while varying the ozone gas content included in the oxidant to form a hafnium oxide film having a thickness of about 20 Pa. In this case, the low hafnium oxide film during the atomic layer deposition process was applied to the dielectric film of the 90nm cell capacitor. Referring to FIG. 16, a dielectric film formed by applying an oxidant having an ozone gas content of 15% (250 g / cm 3) is (B) a dielectric film formed by applying an oxidizing agent having an ozone content of 10% (180 g / cm 3). It has better leakage current characteristics. Therefore, it can be seen that the dielectric film formed as the content of the ozone gas included in the oxidant increases may further improve the electrical characteristics of the semiconductor device.

When the metal oxide film is formed by applying the oxidant containing ozone of the present invention, the oxidant made of the ozone gas applied to the present invention has not only higher oxidizing property than the oxidant, but also high reactivity with metal at low temperature. By using the oxidant of the present invention having such a high oxidative property and reactivity, a metal oxide film can be formed at a lower temperature at a high speed. This can increase the throughput of the semiconductor manufacturing process. In addition, the metal oxide film does not contain impurities and has good leakage current characteristics.

Therefore, the metal oxide film can be easily applied to the gate insulating film of the gate structure, the dielectric film of the capacitor, and the like, and as a result, the electrical reliability of the semiconductor device can be obtained.

As described above, although described with reference to the embodiments of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. It will be appreciated that it can be changed.

Claims (19)

Providing an oxidant comprising a metal precursor and 85 to 100 vol% ozone gas for oxidizing the metal precursor over the substrate; And Forming a metal oxide film on the substrate by reaction of the metal precursor provided on the substrate with the oxidant. The method of claim 1, wherein the oxidizing agent comprises 89 to 99 vol% of the ozone gas and 1 to 11 vol% of the oxygen gas. According to claim 1, wherein the oxidizing agent containing 85 to 100 vol% of the ozone gas Liquefying the gaseous ozone from a mixed gas comprising gaseous ozone and gaseous oxygen; Removing the oxygen in the gas phase; And Thin film manufacturing method characterized in that it is prepared by performing the step of vaporizing the liquefied ozone. The method of claim 1, wherein the metal precursor comprises at least one selected from the group consisting of a hafnium precursor, an aluminum precursor, a titanium precursor, and a zirconium precursor. The metal oxide of claim 1, wherein the metal oxide is HfO ₂ , ZrO ₂ , Ta ₂ O ₅ , Y ₂ O ₃ , Nb ₂ O ₅ , Al ₂ O ₃ , TiO ₂ , CeO ₂ , In ₂ O ₃ , B ₂ O ₃ , SiO ₂ , GeO ₂ , SnO ₂ , PbO, PbO ₂ , Pb ₃ O ₄ , La ₂ O ₃ , As ₂ O ₅ , As ₂ O ₃ , Pr ₂ O ₃ , Sb ₂ O ₃ , Sb ₂ O _{5 ,} P ₂ O _{5 It} is any one selected from the group consisting of a thin film manufacturing method. The method of claim 1, wherein the forming of the metal oxide layer comprises: Introducing the metal precursor onto the substrate; Chemisorbing a first portion of the metal precursor onto the substrate and physically adsorbing a second portion of the metal precursor; Removing a second portion of the metal precursor physically adsorbed to the substrate using a purge gas; Introducing an oxidant comprising 85 to 100 vol% of the ozone gas onto the substrate; And Reacting the first portion of the metal precursor with the oxidant. The method of claim 6, wherein the forming of the metal oxide layer is repeated at least once. The method of claim 6, wherein providing the metal precursor is Preparing a metal precursor in a liquid state; Prepared by heating the liquid metal precursor to a temperature of 60 to 95 ° C. to form a gaseous metal precursor; And And providing the gaseous metal precursor to the top of the substrate. The method of claim 1, wherein the forming of the metal oxide layer comprises: Simultaneously injecting an oxidant including the metal precursor and the 85 to 100 vol% of the ozone gas into the upper portion of the substrate to chemically react the metal precursor and the oxidant on the substrate to form a metal oxide; And And chemically adsorbing the metal oxide on the surface of the substrate. The method of claim 1, wherein the metal oxide film including the metal oxide is a gate oxide film. The method of claim 1, wherein the metal oxide film including the metal oxide is a dielectric film. Providing an oxidant comprising a metal precursor and 85 to 100 vol% ozone gas for oxidizing the metal precursor to the top of the substrate; Forming a gate insulating film including a metal oxide on the substrate by reaction of the metal precursor provided on the substrate with the oxidant; Forming a gate conductive film on the gate insulating film; And And sequentially patterning the gate conductive layer and the gate insulating layer to form a gate pattern including a gate conductive layer pattern and a gate insulating layer pattern. The method of claim 12, wherein the oxidizing agent comprises 89 to 99 vol% of the ozone gas and 1 to 11 vol% of the oxygen gas. The oxidizing agent of claim 12, wherein the oxidizing agent comprises 85 to 100 vol% of the ozone gas. Liquefying the gaseous ozone from a mixed gas comprising gaseous ozone and gaseous oxygen; Removing the oxygen in the gas phase; And And evaporating the liquefied ozone. The method of claim 12, wherein the forming of the gate oxide layer comprises: Introducing the metal precursor onto the substrate; Chemisorbing a first portion of the metal precursor onto the substrate and physically adsorbing a second portion of the metal precursor; Removing a second portion of the metal precursor physically adsorbed to the substrate using a purge gas; Introducing an oxidant comprising 85 to 100 vol% ozone gas to the substrate; Oxidizing the first portion of the metal precursor and the oxidant; And Introducing the metal precursor to repeating the oxidation reaction at least once. The method of claim 12, wherein the forming of the gate oxide layer comprises: Simultaneously injecting an oxidant containing 85 to 100 vol% of the metal precursor and the ozone gas to an upper portion of the substrate to chemically react the metal precursor and the oxidant on the substrate to form a metal oxide; And And chemically adsorbing the metal oxide on the surface of the substrate. Forming a lower electrode on the substrate; Providing an oxidant comprising 85 to 100 vol% of an ozone gas for oxidizing the metal precursor and the metal precursor onto the lower electrode of the substrate; Forming a dielectric film including a metal oxide on the substrate by reaction of the metal precursor provided over the lower electrode and the oxidant; And Forming an upper electrode on the dielectric layer. The method of claim 17, wherein the oxidant comprises 89 to 99 vol% of the ozone gas and 1 to 11 vol% of the oxygen gas. The oxidizing agent of claim 17, wherein the oxidizing agent comprises 85 to 100 vol% of the ozone gas. Liquefying the gaseous ozone from a mixed gas comprising gaseous ozone and gaseous oxygen; Removing the oxygen in the gas phase; And Capacitor manufacturing method characterized in that it is prepared by performing the step of vaporizing the liquefied ozone.

Images