KR20090066468A - Process of forming thin film with improved physical properties - Google Patents

Abstract

A method for forming a thin film having excellent physical property is provided to gain a uniform thin film by preventing adsorption of a source on the surface of an object to be processed and to improve physical property of the thin film. A method for forming a thin film having excellent physical property comprises the following steps of: adsorbing a first source on an object to be processed; forming a first source thin film by performing a first source removing process consecutively; adsorbing the first source on the object by supplying a second source reacting with the first source; and forming a first and second source thin film by removing the second source which is not adsorbed on the object.

Description

Process of Forming Thin Film with Improved Physical Properties

The present invention relates to a thin film deposition method, and more particularly, to a thin film deposition method having good physical properties such as step coverage and electrical properties of the device by performing a time-division of a specific gas deposition and purge process continuously.

As the information society progresses, the utilization of electronic devices such as semiconductor devices that make it possible is increasing. Conventionally, physical vapor deposition, such as sputtering, has been used to form a semiconductor device such as a fine metal interconnection. However, in the case of such physical vapor deposition, void coverage of a fine size is voided due to poor step coverage. It is very difficult to fill in without).

In particular, the chemical vapor deposition (CVD) method is a thin film deposition technology having uniform relatively excellent deposition characteristics and step coverage in the thin film deposition process according to the recent trend of super integration and ultra thin film of semiconductor devices. This was developed. However, according to the chemical vapor deposition method, it is difficult to form a film having a desired compositional ratio of physical properties by supplying all process materials necessary for forming a thin film at the same time, and in particular, a reaction of reacting with a metal organic compound using a chemical vapor deposition method. In the case of forming a metal thin film using gas as a raw material, if the reactivity between the raw materials is low, the thin film formation speed is slow, and the process is performed at a high temperature. Therefore, the formed film contains a large amount of impurities. In addition, in particular, in the case of the metal oxide film, oxidation occurs by an oxygen source between the metal oxide film formed in the metal oxide film and the metal surface pre-formed under the metal oxide film, resulting in deterioration of electrical characteristics or deterioration of capacitance. Since the composition ratio is determined according to the source-amount supplied, it becomes impossible to form a film having a composition ratio suitable for each use.

In order to solve such a problem, an atomic layer deposition (ALD) method of supplying process gases independently, that is, in a pulse form by time division, has been developed. A process of depositing a metal oxide film according to a reaction between a metal source and a reactant gas on an object surface by atomic layer deposition will be briefly described with reference to FIG. 1.

One cycle of a conventional atomic layer deposition process can be divided into four stages. In general, a metal source in the form of a metal organic compound is reacted to a reaction region inside a process chamber into which an object, such as a wafer, is introduced. Chemically adsorbing the metal source to the upper surface of the object and supplying an inert purge gas to the reaction zone for T2 hours to remove the metallic source that is not chemically adsorbed to the object and simply remains. Step, supplying and adsorbing a reaction gas that forms a metal thin film by chemical reaction with a metal source chemisorbed on the object to the reaction zone for T3 time, and again supplying a purge gas for T4 time to chemically react with the metal source Reaction gas that is not adsorbed and is physically bound or remains inside the substrate processing apparatus It consists of a huge step. Such a step forms a thin film deposition cycle, and the process is completed by repeating the thin film deposition cycle several times to several hundred times until a thin film having a desired thickness is realized.

That is, the atomic layer deposition method is a method of forming a thin film by supplying a source and a reaction gas independently through each other through time division, firstly chemically adsorbs a metal source precursor having a ligand on the upper part of the target object and chemically by supplying a purge gas After removing the metal source precursor that has not been adsorbed, a desired thin film is formed by supplying a reaction gas capable of performing a substitution reaction with a ligand of a precursor of a chemically adsorbed metal source. By using such an atomic layer deposition method, it is possible to prevent interaction between the sources and to form an atomic layer film, thereby obtaining a uniform thin film and controlling the thickness of the thin film. It is widely used to form various thin films, such as an oxide film, a metal nitride film, and a silicide film.

As a metal source for forming such a metal oxide film and a metal nitride film, conventionally, a halogenated metal compound such as HfCl ₄ or TiCl ₄ , AlCl ₃ , or an alkoxide metal compound (MOR) has been used, but the metal precursor is an oxygen source used as a reaction gas. In addition to generating by-products that corrode the inside of the process chamber, the carbon component present in the halogen or alkoxide functional group may remain in the thin film.

Due to these problems, to form a single metal or composite metal oxide film such as HfO ₂ , ZrO ₂ , HfSiO, HfAlO, ZrSiO, ZrAlO, which are high-k materials, which are required according to the recent trend of ultra-precision of semiconductor devices. As a precursor of the metal source, a substance having a ligand having an amino functional group such as TetrakisEthylMethylAmino (TEMA) is bound. In particular, the TEMA-based ligand has a low carbon content compared to other ligands to form a thin film of high purity and has been widely used because of good step coverage. That is, for example, a ligand having an amino functional group connected in the form of a coordination bond with a metal element in the center is not strongly bound to a metal atom as a thin film component, and thus may be substituted or removed from the metal atom so that the amino ligand remains in the formed thin film. Decreases significantly. However, since the metal precursor having the TEMA ligand is easily decomposed by heat as shown in the following scheme, the thermally decomposed non-reactive material has a limitation in obtaining a uniform thin film and good step coverage in a deep trench wafer.

Scheme

In order to solve this problem, in step of forming a thin film by a time division method using a metal precursor combined with an amino functional group such as TEMA, the feeding time or flow rate of the metal source is increased to increase the step coverage. Although a method of increasing sex is proposed, such a method has a problem of causing a decrease in productivity and an increase in cost.

The present invention has been proposed to solve the above problems, and an object of the present invention is to divide the source adsorption and purge inflow into multiple stages to prevent thermal decomposition of the source provided into the substrate processing apparatus through time division. It is to provide a method for forming.

Another object of the present invention is to provide a thin film formation method which can obtain a uniform thin film by preventing the adsorption of the same source to the surface of the workpiece, and can significantly improve the physical properties such as step coverage of the finally obtained device. .

It is still another object of the present invention to improve the distribution of the second source on top of the workpiece to which the first source is adsorbed, thereby uniformly and smoothly joining the first source to improve the electrical characteristics of the device, as well as to reduce the amount of The purpose of the present invention is to provide a method of forming a thin film that can increase productivity by reducing process cost and processing time by using a source of.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention and the accompanying drawings.

According to an embodiment of the present invention having the above object, a thin film forming method for providing a first source and a second source capable of reacting with the first source through time division, wherein the first source is adsorbed onto the workpiece. Forming a first source thin film by supplying a purge gas to continuously remove the first source that is not adsorbed on the target object two or more times; After supplying a second source capable of reacting with the first source and adsorbed to the first source adsorbed on the object to be treated, a purge gas is supplied to remove the second source that is not adsorbed on the object to be treated. A thin film forming method comprising forming a second source thin film.

In addition, according to another embodiment of the present invention, a thin film forming method for providing a first source and a second source capable of reacting with the first source through time division, wherein the first source is adsorbed onto the workpiece and then purged Supplying a gas to remove the first source that is not adsorbed to the workpiece to form a first source thin film; Supplying a second source capable of reacting with the first source and adsorbing the first source adsorbed to the object, and then supplying a purge gas to remove the second source not adsorbed to the object. It provides a thin film forming method comprising the step of performing a plurality of times in succession to form a first source-second source thin film.

In addition, according to another embodiment of the present invention, a thin film forming method for providing a first source and a second source capable of reacting with the first source through time division, wherein the first source is adsorbed onto the object to be treated, and then a purge gas Supplying a second step of continuously removing the first source that is not adsorbed to the object to be processed two or more times to form a first source thin film; Supplying a second source capable of reacting with the first source and adsorbing the first source adsorbed to the object, and then supplying a purge gas to remove the second source not adsorbed to the object. It provides a thin film forming method comprising the step of performing a plurality of times in succession to form a first source-second source thin film.

In this case, preferably, the first source may be a metal material having an amino ligand, and the finally formed thin film may be selected from the group consisting of a metal oxide film, a metal nitride film, a silicide thin film, or a combination thereof.

In particular, the first source as a metal material is aluminum (Al), silicon (Si), titanium (Ti), cobalt (Co), gallium (Ga), germanium (Ge), strontium (Sr), yttrium (Y), Zirconium (Zr), Niobium (Nb), Ruthenium (Ru), Indium (Id), Barium (Ba), Lanthanum (La), Hafnium (Hf), Tantalum (Ta), Tungsten (W), Iridium (Ir), It may be selected from the group consisting of lead (Pb), bismuth (Bi), or a combination thereof.

On the other hand, the oxygen precursor as a second source that can be substituted with the ligand of the first source precursor when forming a metal oxide film is composed of H ₂ O, oxygen, N ₂ O, ozone (O ₃ ), or a combination thereof In the case of forming the metal nitride film, the nitrogen precursor of the second source is nitrogen or ammonia, and when the metal silicide thin film is formed, the silicon precursor of the second source is SiH ₄ , SiH ₂ , SiCl ₂ , SiCl ₄ , Si _2. H _x Cl _6-x (x is an integer between 0-6), or a combination thereof.

In this case, the first source and / or the second source is hydrogen (H ₂ ), helium (He), nitrogen (N ₂ ), neon (Ne), argon for the smooth supply of the first source and / or second source (Ar), krypton (Kr), xenon (Xe), or a mixture of these carrier gases.

In the present invention, through a thin film formation method for dividing the source adsorption and purge gas inlet by a multi-step continuously repeated by the conventional time division, in particular, the source adsorbed to the upper portion of the workpiece can be prevented from thermal decomposition.

Accordingly, by preventing the adsorption of the same source onto the surface of the workpiece, a uniform thin film can be obtained, and the physical properties such as the step coverage of the finally obtained device can be improved. By improving the distribution of the two sources, the electrical characteristics of the device can be improved by uniformly and smoothly coupling the first source.

In particular, compared to the conventional time-division thin film formation process, the use of a small amount of source can reduce the production cost and process time, thereby increasing productivity.

In the present invention, the source material supplied to the inside of the substrate processing apparatus through time division is heat-decomposed without being adsorbed to the upper part of the pre-adsorbed thin film or the source material to be processed such as a wafer or the upper part of the processed material. Alternatively, in order to solve the problem of lowering the uniformity, the physical properties of the formed thin film are controlled by dividing the first source adsorption-purge gas inlet and / or the second source adsorption-purge gas inlet into two or more multi-steps. It was configured to be.

FIG. 2A schematically illustrates the steps of a thin film formation process in which a first source adsorption-purge gas injection and a second source adsorption-purge gas injection are each performed two or more successive multi-step processes through time division according to an embodiment of the present invention. 3 is a thin film forming process in which a first source adsorption-purge gas injection and a second source adsorption-purge gas injection are each performed two or more successive multi-step processes according to an embodiment of the present invention. Is a graph schematically.

As shown, according to an embodiment of the present invention, unlike the conventional time-division thin film formation process in which one source adsorption-purge inflow-2 source adsorption-purge inflow is one cycle, the process of forming the thin film of the first source is performed. The process of first source adsorption-purge inlet-first source adsorption-purge inlet is divided into multiple stages, and reacting with the first source to form the first source-second source thin film. The process of the second source adsorption-purge inlet was divided into multiple stages. That is, in this embodiment, the first source adsorption-purge gas inflow process is continuously performed two or more times before the second source is supplied to form the first source thin film, while the second source adsorption-purge gas inflow process is performed two times. It is performed successively more than once to form the first source-second source thin film. In FIG. 3, the processes of 'first source adsorption-purge gas inflow' and 'second source adsorption-purge gas inflow' are respectively repeated twice in succession. The 'inflow' and / or the second source adsorption-purge gas inflow 'process may be comprised of a multi-step process, each repeated several times in succession as needed, which will be described in detail.

First, the first source precursor is supplied through a supply line to a substrate processing apparatus such as a process chamber into which a workpiece is introduced into the substrate for a short time t1 compared to the adsorption time T1 of the conventional time division method. The first source precursor is adsorbed to the upper surface of the water (101). At this time, inert hydrogen (H ₂ ), helium (He), nitrogen (N ₂ ), neon (Ne), argon (Ar) so that the first source precursor can be smoothly supplied and introduced into the substrate processing apparatus. Carrier gases such as krypton (Kr), xenon (Xe), or mixtures thereof may be injected with the first source precursor. Subsequently, the inert purge gas is injected in the conventional time division method so as to stop the supply of the first source and to remove the first source which is not chemically adsorbed to the object to be physically adsorbed or remains inside the substrate processing apparatus. Supply 102 for a short time t2 compared to time T2. Purge gases that can be used in connection with the present invention are inert argon (Ar), helium (He) or nitrogen (N ₂ ).

Subsequently, instead of proceeding with the adsorption and purge step of the second source, the inside of the substrate processing apparatus for a short time t'1 compared to the first source adsorption time T1 in the conventional time division method again. Is injected into the upper surface of the first source precursor adsorbed on the workpiece or the upper portion thereof (103), the supply of the first source is stopped and the purge gas is shorter than the purge gas injection time T2 in the conventional time division method. Supplying for a time t'2 removes the first source precursor that has not been chemically adsorbed to the workpiece (104).

In this manner, the first source adsorption-purge gas process divided into multiple stages is repeatedly performed two or more times in succession. In particular, since the first source precursor is supplied and adsorbed for a short time (t1, t'1) as compared to the supply time T1 for adsorption of the first source, unreacted residues due to pyrolysis of the first source precursor. It is possible to prevent the decrease in the uniformity of the thin film due to the first source precursor, the first source precursor adsorbed to the target object because purge gas is introduced before the same source is adsorbed on the surface of the first source due to the short source of the first source, adsorption time Can improve the uniformity.

To this end, the adsorption times t1 and t'1 and the purge gas injection times t2 and t'2 of the first source are shorter than those of the conventional first source adsorption time T1 and the purge gas injection time T2, respectively. As the time, for example, when the first source adsorption-purge gas injection is performed twice in succession, each of the first source adsorption times t1 and t'1 is 1/2 of the conventional adsorption time T1, and the purge gas injection The times t2 and t'2 can be set to 1/2 of the conventional injection time T2.

At this time, the total time of the first source adsorption time (t1, t'1) is set to be the same as the conventional first source adsorption time (T1), each time of the adsorption time (t1, t'1) as necessary Alternatively, or the total time of the purge gas injection times t2 and t'2 is the same as the conventional purge gas injection time T2, but the time of each purge gas injection time t2 and t'2 is necessary. Different settings are also possible.

As described above, the first source adsorption-purging gas injection is performed in a multi-step form repeated two or more times, so that the first source is uniformly adsorbed on the workpiece to form a thin film of the first source. The purge gas inlet may be performed in two or more multi-steps to form a thin film of the first source-second source.

That is, a shorter time than the second source adsorption time T3 in the conventional time division method of the second source precursor through a separate supply line into the substrate processing apparatus in which the target material to which the first source is adsorbed is embedded ( supplied during t3), the first source precursor and the second source precursor react to allow the second source to be adsorbed with the first source in place of the ligand of the first source precursor (201). The purge gas of the inert purge gas is then purged in a conventional time division method so as to stop the supply of the second source and to remove the second source that is not adsorbed to the first adsorbed first source and is physically adsorbed or remains inside the substrate processing apparatus. Supplying for a short time t4 compared to the gas injection time (T4) (202).

Subsequently, the second source precursor is again injected into the substrate processing apparatus for a short time t'3 compared to the second source adsorption time T3 in the conventional time division method, so that the second source precursor is not adsorbed. After adsorbing to the first source by a method of substituting with (203), the supply of the second source is stopped and the purge gas is supplied for a time t'4 shorter than the purge gas injection time (T4) in the conventional time division method. The first source precursor that has not been chemically adsorbed to the workpiece is removed (204).

In order to repeatedly perform the second source adsorption-purge gas injection which is divided into multiple stages, the second source adsorption time t3 and t'3 and the purge gas injection time t4 and t'4 are respectively As a time shorter than the conventional second source adsorption time T3 and purge gas injection time T4, respectively, the chemical adsorption of the second source to the first source is also uniform since the second source is uniformly distributed into the reaction zone. Because of this, it is possible to obtain a thin film having a uniform composition of each source material and to improve electrical characteristics. As described in the first source, the adsorption times t3 and t'3 of the second source purge gas injection times t4 and t'4 are lower than those of the conventional second source adsorption time T3 and the purge gas injection time T4. It is a short time, and each of the second source adsorption times t3 and t'3 and the purge gas injection times t4 and t'4 may be the same or differently set as necessary.

In FIGS. 2A and 3, the injection of the first source adsorption-purge gas as well as the injection of the second source adsorption-purge gas are all performed in two or more successive processes in which the multi-stage is divided into the first source or the second source. Only the process of adsorbing any one may be divided into multiple stages.

FIG. 2B is a flow chart schematically illustrating the steps of a thin film forming process in which a first source adsorption-purge gas injection is repeatedly performed two or more times through time division according to another embodiment of the present invention. The process of forming the first source thin film according to the step is repeatedly performed two or more times, and the second source adsorption-purge gas injection represents the thin film forming process made of the same process as the conventional time division method.

2C is a flow chart schematically illustrating the steps of a thin film formation process in which two source adsorption-fuge gas injection is repeatedly performed two or more times through time division according to another embodiment of the present invention. The purge gas injection is performed in the same steps as the conventional time-division method, but shows a thin film formation process in which the process of forming the first source-second source thin film according to the second source adsorption-purge gas injection step is repeated two or more times. .

As a result, according to the present invention, by adsorbing the first source and / or the second source independently supplied through time division, the process of removing the remaining source gas through the purge gas is divided into two or more continuous multi-stages. In addition to enhancing the electrical properties by improving the uniformity of the properties can be improved such as the step coverage of the final device. In addition, by remaining without being adsorbed with the workpiece or the first source, the amount of the source finally removed can be reduced, thereby achieving economics such as productivity improvement through cost reduction and process time reduction.

In connection with the present invention, the first source which can be adsorbed into the workpieces inside the substrate processing apparatus or the thin film formed thereon is preferably a metal material obtained from a metal precursor bound by an amino ligand. On the other hand, a second source that can be adsorbed to the first source by substituting a ligand bound to the first source can be obtained from a reactive second source precursor capable of chemically binding to the first source ligand. For example, the precursor of the second source may be formed of an oxygen precursor, a nitrogen precursor, a carbon precursor, a silicon precursor, or a combination thereof, and reacted with the metal precursor, which is the first source precursor, to form a metal oxide film, a metal nitride film, and a metal carbide film, respectively. , A metal silicide thin film can be formed.

In this regard, the metal source as the first source provided to the reaction region inside the substrate processing apparatus may be used, for example, in a dielectric of a semiconductor device or a conductor of a flat panel display device such as a liquid crystal display. That is the source material. The first source that can be used to form this type of thin metal film is aluminum (Al), silicon (Si), titanium (Ti), cobalt (Co), gallium (Ga), germanium (Ge), strontium (Sr ), Yttrium (Y), Zirconium (Zr), Niobium (Nb), Ruthenium (Ru), Indium (Id), Barium (Ba), Lanthanum (La), Hafnium (Hf), Tantalum (Ta), Tungsten (W) ), A metal material such as iridium (Ir), lead (Pb), bismuth (Bi), or a combination thereof. However, it should be noted that some of the above-described metal materials may not be used depending on the final thin film form.

In particular, such a first source material is adsorbed to the top of the workpiece, preferably in the form of a precursor bound by a ligand with amino functional groups, wherein the first source precursor with amino ligands retains impurities in the resulting thin film. This can be greatly reduced. When using a first source precursor bound to a ligand having an amino functional group, a metal source containing aluminum, titanium, or hafnium, which is easily chemically bonded to the ligand containing such amino group, may be used as the first source precursor. . In particular, in the ligand containing an amino group that can be used in the present invention, the same ligand does not necessarily need to be bonded to the central metal element, and at least one ligand of the ligand which is bonded to the metal element may contain an amino group.

According to the present invention, as a first source precursor in which all ligands coordinated with the central metal atom contain amino functional groups, functional groups bonded to amino groups such as TEMA have 1-10 carbon atoms, preferably alkyl 1-4 carbon atoms. It may have an amino functional group substituted with an aliphatic chain such as kenyl. The first to the first source precursor and as containing the amino group substituted with an alkyl group is tetrakis-ethyl-methyl-amino-hafnium _{(Hf [N (C 2 H} 5) CH 3] 4), tetrakis-dimethylamino-hafnium (Hf [ N (CH ₃ ) ₂ ] ₄ ), tetrakis-diethylamino hafnium (Hf [N (C ₂ H ₅ ) ₂ ] ₄ ), tetrakis-dimethylamino titanium (Ti [N (CH ₃ ) ₂ ] ₄ ) , Tetrakis-diethylamino titanium (Ti [N (C ₂ H ₅ ) ₂ ] ₄ ), or pentakis-dimethylamino titanium (Ta [N (CH ₃ ) ₂ ] ₅ ).

On the other hand, only one of the ligands bonded to the central metal element may have an amino ligand. In this case, the ligand containing an amino group is a cyclic functional group, not a chain-type alkyl group, as described above. It may have a form of binding, the cyclic substituent is preferably in the form of a heterocyclic amine containing 5 to 8 carbon atoms and at least one nitrogen or oxygen. This is because a metal source having such a heterocyclic amino group can be deposited at a wide temperature range and has excellent deposition rate, dielectric constant, and the like.

As a ligand to which such a cyclic substituent is bonded to an amino group, an alkyl pyrolidine having a pentagonal ring in which an alkyl group (1-10 carbon atoms, preferably 1-5) is substituted with a hetero atom nitrogen. , Hexagonal ring-shaped alkyl piperidine in which an alkyl group (1-10 carbon atoms, preferably 1-5) is substituted on at least one carbon of a hetero nitrogen atom and / or a cyclic carbon atom ), An alkyl group (1-10 carbon atoms, preferably 1-5) is substituted with a hetero atom nitrogen, and a hexagonal cyclic alkyl mprpholine containing an oxygen atom in the ring, 2 forming a ring Hexagonal alkyl piperazine or dialkyl piperazine in which at least one nitrogen atom of the four nitrogen atoms is substituted with an alkyl group (1-10 carbon atoms, preferably 1-5) ) To be selected There.

More specifically, alkyl pyrrolidines having amino functional groups in heterocyclic form include 1,2-dimethylpyrrolidine, 1-methylpyrrolidine, 1, 1-butylpyrrolidine, and alkyl piperi Deans include 1-methylpiperidine, 1-ethylpiperidine, alkyl morpholines include 4-ethylmorpholine, and dialkyl piperazine include 1,4-dimethyl piperizine .

More specifically, the first source precursor including at least one ligand having such an amino functional group may be methylpyrrolidine trimethyl aluminum (Al (CH ₃ ) ₃ N (CH ₂ ) ₄ CH ₃ ), butylpyrrolidine trimethyl Aluminum (Al (CH ₃ ) ₃ N (CH ₂ ) ₄ C ₄ H ₉ ), ethylpiperidine trimethylaluminum (Al (CH ₃ ) ₃ N (CH ₂ ) ₅ C ₂ H ₅ ), methylpyrrolidine tri Ethylaluminum (Al (C ₂ H ₅ ) ₃ N (CH ₂ ) ₄ CH ₃ ), butylpyrrolidine triethylaluminum (Al (C ₂ H ₅ ) ₃ N (CH ₂ ) ₄ C ₄ H ₉ ), ethyl Piperidine triethylaluminum (Al (C ₂ H ₅ ) ₃ N (CH ₂ ) ₅ C ₂ H ₅ ), dimethylaluminum hydride: ethylpiperidine (HAl (CH ₃ ) ₂ N (CH ₂ ) ₅ C ₂ H ₅₎ and the like, but the present invention is not limited thereto.

On the other hand, the second source that can be substituted with the ligand of the first source precursor described above and adsorbed to the first source is provided in the form of a highly reactive precursor. In this case, the thin film finally formed according to the second source precursor may have a form of a metal oxide film, a metal nitride film, a metal carbide film, and a metal silicide thin film.

For example, when the thin film to be finally formed is a metal oxide film, the second source as an oxygen source is selected from the group consisting of H ₂ O, oxygen, N ₂ O, ozone (O ₃ ), or a combination thereof. Provided in the form of a second source precursor into the substrate processing apparatus. In particular, in the case of continuously forming different metal oxide films according to the present invention, an aluminum oxide film-hafnium oxide film ([(Al ₂ O ₃ ) _x (HfO ₂ ) _y ] _z , an aluminum oxide film-titanium oxide film ([(Al ₂ O ₃ ) _x (TiO ₂ ) _y ] _z , titanium oxide-hafnium oxide ([(TiO ₂ ) _x (HfO ₂ ) _y ] _z , aluminum oxide-zirconium oxide ([(Al ₂ O ₃ ) _x (ZrO ₂ ) _y ] _z , aluminum oxide film-tantalum oxide film ([(Al ₂ O ₃ ) _x (Ta ₂ O ₅ ) _y ] _z ), tantalum oxide film-hafnium oxide film ([(Ta ₂ O ₅ ) _x (HfO ₂ ) _y ] _z ), An aluminum oxide film-silicon oxide film ([(Al ₂ O ₃ ) _x (SiO ₂ ) _y ] _z ) and the like.

Meanwhile, when the thin film to be finally formed is a metal nitride film, the second source as the nitrogen source may be provided into the substrate processing apparatus in the form of a second source precursor which is nitrogen or ammonia.

In addition, when the thin film to be finally formed is a metal carbide film, the second source as a carbon source is a second source precursor which is a hydrocarbon having 1 to 5 carbon atoms, such as methane, ethane, and propane. Is provided.

If the thin film to be finally formed is a metal silicide thin film, the second source as a silicon source is SiH ₄ , SiH ₂ , SiCl ₂ , SiCl ₄ , Si ₂ H _x Cl _6-x (x is 0-6 In the form of a second source precursor selected from the group consisting of, or a combination thereof.

In accordance with the present invention, by dividing the first source adsorption-purge gas injection and / or the second source adsorption-purge gas injection into multiple stages and repeating the process two or more times, the physical properties are improved through preventing the thermal decomposition of the source as described above. This can be done, Figure 4 is a zirconium oxide obtained by performing the first source adsorption-purge gas injection and the second source adsorption-purge gas injection in each of two successive processes according to the conventional method and one embodiment of the present invention SEM image of the (ZrO ₂ ) thin film. In the figure, the left side is a thin film photograph formed by a conventional general time division process, and the right side is a thin film photograph formed by a characteristic process of the present invention. As shown, the thickness of the zirconium oxide thin film formed according to the conventional method can be seen that there is a problem in the step coverage or uniformity of the thin film formed by showing a difference of up to 20 times or more depending on the position. In contrast, in the case of the zirconium oxide thin film formed according to the multi-step method of the present invention, it can be confirmed that a thin film having a uniform thickness is formed regardless of its position.

In the above, the technical idea of the present invention has been described in detail based on the preferred embodiment of the present invention, but the present invention is not limited thereto. Rather, those skilled in the art will be able to easily make various modifications and changes with reference to the above-described embodiments and the accompanying drawings. It should be noted, however, that such modifications and variations are within the scope of the present invention, which will become more apparent through the appended claims.

1 is a graph schematically showing a thin film forming process according to a conventional atomic layer deposition method.

2A is a flow diagram schematically illustrating the steps of a thin film formation process in which the first source adsorption-purge gas injection and the second source adsorption-purge gas injection are each repeated two or more times through time division according to an embodiment of the present invention. FIG. 2B is a flowchart schematically illustrating the steps of a thin film forming process in which the first source adsorption-purge gas injection is repeatedly performed two or more times through time division according to another embodiment of the present invention, and FIG. According to yet another embodiment of the present invention, a flow chart schematically illustrating the steps of a thin film formation process in which two-source adsorption-purge gas injection is repeatedly performed two or more times through time division.

FIG. 3 is a graph schematically illustrating a thin film formation process in which a first source adsorption-purge gas injection and a second source adsorption-purge gas injection are repeatedly performed two or more times, respectively, according to an embodiment of the present invention.

4 is a SEM photograph of a thin film formed by a conventional atomic layer deposition process and a characteristic multi-step separation process of the present invention.

Claims (10)

A thin film forming method for providing a first source and a second source capable of reacting with the first source through time division, Adsorbing the first source to the workpiece, and supplying a purge gas to remove the first source that has not been adsorbed to the workpiece to form the first source thin film at least two times in succession; After supplying a second source capable of reacting with the first source and adsorbed to the first source adsorbed on the object to be treated, a purge gas is supplied to remove the second source that is not adsorbed on the object to be treated. Forming a second source thin film. A thin film forming method for providing a first source and a second source capable of reacting with the first source through time division, Adsorbing the first source to the workpiece, supplying a purge gas to remove the first source that is not adsorbed to the workpiece to form a first source thin film; Supplying a second source capable of reacting with the first source and adsorbing the first source adsorbed to the object, and then supplying a purge gas to remove the second source not adsorbed to the object. A method of forming a thin film comprising the step of forming the first source-second source thin film by performing the process more than once in succession. A thin film forming method for providing a first source and a second source capable of reacting with the first source through time division, Adsorbing the first source to the workpiece, and supplying a purge gas to remove the first source that has not been adsorbed to the workpiece to form the first source thin film at least two times in succession; Supplying a second source capable of reacting with the first source and adsorbing the first source adsorbed to the object, and then supplying a purge gas to remove the second source not adsorbed to the object. Forming a first source-second source thin film by continuously performing the step more than once. The method according to any one of claims 1 to 3, And the first source is a metal material having an amino ligand. The method of claim 4, wherein And the thin film is selected from the group consisting of a metal oxide film, a metal nitride film, a silicide thin film, or a combination thereof. The method of claim 4, wherein The first source may be aluminum (Al), silicon (Si), titanium (Ti), cobalt (Co), gallium (Ga), germanium (Ge), strontium (Sr), yttrium (Y), zirconium (Zr), Niobium (Nb), Ruthenium (Ru), Indium (Id), Barium (Ba), Lanthanum (La), Hafnium (Hf), Tantalum (Ta), Tungsten (W), Iridium (Ir), Lead (Pb), A thin film forming method selected from the group consisting of bismuth (Bi), or a combination thereof. The method of claim 4, wherein And the second source is selected from the group consisting of H ₂ O, oxygen, N ₂ O, ozone (O ₃ ), or a combination thereof. The method of claim 4, wherein And the second source is nitrogen or ammonia. The method of claim 4, wherein Wherein the second source is selected from the group consisting of SiH ₄ , SiH ₂ , SiCl ₂ , SiCl ₄ , Si ₂ H _x Cl _6-x (x is an integer between 0-6), or a combination thereof. . The method according to any one of claims 1 to 3, The first source or the second source may be hydrogen (H ₂ ), helium (He), nitrogen (N ₂ ), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), or a mixture thereof. The thin film formation method provided with the carrier gas which consists of.

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