KR102475843B1 - Method of forming thin film - Google Patents

Abstract

A method of forming a thin film according to one aspect of the present invention includes forming a first thin film having a first thickness and having a first crystallinity on a substrate through an atomic layer deposition process, and an atomic layer etching process for the first thin film. and forming a second thin film having a second thickness lower than the first thickness by etching the first thin film through a predetermined thickness.

Description

Method of forming thin film {Method of forming thin film}

The present invention relates to a semiconductor process, and more particularly, to a method of forming a thin film using an atomic layer deposition (ALD) process and an atomic layer etching (ALE) process.

Due to the recent high integration of semiconductor devices, the thickness of thin films used in semiconductor devices is becoming thinner. In particular, when an atomic layer deposition (ALD) process is applied, it becomes possible to control the thickness of a thin film in units of atoms or molecular layers. However, when the thin film becomes thinner, it becomes difficult to match the required physical properties. For example, if the thin film is thinner than a certain thickness, crystallinity deteriorates and leakage current characteristics deteriorate. However, if the thickness of the thin film is increased in order to improve leakage current characteristics, it becomes difficult to secure a required permittivity or capacitance.

The present invention is to solve various problems including the above problems, and an object of the present invention is to provide a thin film forming method for securing thin film properties required as a thin film. However, these tasks are illustrative, and the scope of the present invention is not limited thereby.

A method of forming a thin film according to one aspect of the present invention includes forming a first thin film having a first thickness and having a first crystallinity on a substrate through an atomic layer deposition process, and an atomic layer etching process for the first thin film. and forming a second thin film having a second thickness lower than the first thickness by etching the first thin film through a predetermined thickness. Crystallinity of the second thin film may have a higher crystallinity than crystallinity of a third thin film formed to the second thickness on the substrate under the same conditions as the atomic layer deposition process.

In the thin film forming method, in the forming of the second thin film, the atomic layer etching process is performed in-situ following the atomic layer deposition process in the same chamber as the atomic layer deposition process in the forming of the first thin film. can be done with

In the thin film forming method, the atomic layer deposition process in the forming of the first thin film and the atomic layer etching process in the forming of the second thin film are separated in the gas supply unit while rotating the substrate in one chamber. The deposition gas and the etching gas may be alternately supplied through the formed gas supply holes.

In the thin film forming method, in the forming of the first thin film, the atomic layer deposition process comprises: supplying a source gas to the substrate; supplying a first purge gas to the substrate; A unit cycle including supplying a reaction gas to the substrate and supplying a second purge gas to the substrate may be repeatedly performed.

In the thin film forming method, the first thin film and the second thin film include zirconium oxide, the source gas includes a zirconium source gas, and the reaction gas reacts with the zirconium source gas to form zirconium oxide. An oxygen-based reactive gas may be included.

In the thin film forming method, the first thin film and the second thin film include aluminum oxide, the source gas includes an aluminum source gas, and the reaction gas reacts with the aluminum source gas to form aluminum oxide. An oxygen-based reactive gas may be included.

In the thin film forming method, in the step of forming the second thin film, the atomic layer etching process includes: supplying a surface treatment gas to the substrate; supplying a first purge gas to the substrate; A unit cycle including supplying an etching gas to the substrate and supplying a second purge gas to the substrate may be repeatedly performed.

In the thin film forming method, the first thin film and the second thin film include zirconium oxide, the surface treatment gas includes a fluorine-based surface treatment gas for surface treatment of the zirconium oxide with zirconium fluoride, and the etching gas may include an organic reaction gas for reacting the zirconium fluoride into a volatile zirconium compound.

In the thin film forming method, the first thin film and the second thin film include aluminum oxide, the surface treatment gas includes a fluorine-based surface treatment gas for surface treatment of the aluminum oxide with aluminum fluoride, and the etching gas may include an organic reaction gas for reacting the aluminum fluoride into a volatile aluminum compound.

In the thin film forming method, the fluorine-based surface treatment gas includes one or a combination selected from the group of HF, NF3 and F2 gases, and the organic reaction gas is trimethylamine (TMA), dimethylacetamide (DMAC), It may include one or a combination thereof selected from the group of silicon tetrachloride (SiCl4) and Sn(acac)2 gases.

According to embodiments of the present invention made as described above, by using an atomic layer deposition process and an atomic layer etching process, it is possible to secure conflicting physical properties even for a thin film thickness on a substrate. Of course, the scope of the present invention is not limited by these effects.

1 is a schematic cross-sectional view showing the formation of a first thin film using an atomic layer deposition process according to an embodiment of the present invention.
2 is a schematic cross-sectional view showing the formation of a second thin film using an atomic layer etching process according to an embodiment of the present invention.
3 is a schematic cross-sectional view showing a substrate processing apparatus for implementing a thin film forming method according to an embodiment of the present invention.
FIG. 4 is a schematic plan view showing an example of a gas supply unit of the substrate processing apparatus of FIG. 3 .
5 is a schematic diagram showing gas supply to a schematic substrate of an atomic layer deposition process according to embodiments of the present invention.
6 is a schematic diagram showing gas supply to a schematic substrate of an atomic layer etching process according to embodiments of the present invention.
FIG. 7 is a schematic plan view showing another example of a gas supply unit of the substrate processing apparatus of FIG. 3 .
8 is an X-ray diffraction (XRD) analysis graph showing crystallinity of thin films formed according to Experimental Examples and Comparative Examples of the present invention.

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

The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified in many different forms, and the scope of the present invention is as follows It is not limited to the examples. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the spirit of the invention to those skilled in the art. In addition, the thickness or size of each layer in the drawings is exaggerated for convenience and clarity of explanation.

1 is a schematic cross-sectional view showing formation of a first thin film using an atomic layer deposition process according to an embodiment of the present invention, and FIG. 2 illustrates formation of a second thin film using an atomic layer etching process according to an embodiment of the present invention. This is a schematic cross section.

Referring to FIG. 1 , a first thin film 60 having a first crystallinity and a first thickness H1 may be formed on a substrate 50 through an atomic layer deposition process.

The atomic layer deposition (ALD) process is to adsorb the source gas on the substrate 50, purging the remaining source gas, and then supplying the reaction gas to the substrate 50 to supply the adsorbed source gas and the reaction gas. It may refer to a method of forming a thin film by repeating a cycle reaction of forming a unit thin film on a substrate by purging residual reactant gas after reacting.

Such an atomic layer deposition process is a time-division method in which the supply of a source gas, a reaction gas, and a purge gas is controlled on a time basis, or a space in which the supply of a source gas, a reaction gas, and a purge gas to a substrate is controlled through a relative movement between a gas supply unit and the substrate. All division methods may be included.

Referring to FIG. 2, the first thin film 60 is etched to a predetermined thickness through an atomic layer etching process for the first thin film (60 in FIG. 1) to form a second thickness H2 lower than the first thickness H1. 2 thin films 60a can be formed.

The atomic layer etching process refers to treating the surface of the thin film on the substrate 50 by supplying surface treatment gas onto the substrate 50 and purging the remaining surface treatment gas, It may refer to a method of etching a thin film by repeating a cycle reaction of supplying an etching gas to react with the etching gas to remove the surface-treated portion of the thin film and purging the remaining etching gas to remove the unit thin film.

Such an atomic layer etching process controls the supply of surface treatment gas, etching gas, and purge gas to the substrate through a time-division method in which the supply of surface treatment gas, etching gas, and purge gas is controlled on a time-by-time basis, or through relative movement of the gas supply unit and the substrate. It can include all spatial division methods that do.

In embodiments of the present invention, the atomic layer deposition process and the atomic layer etching process may be performed in the same chamber in the same substrate processing apparatus or in different chambers in the same substrate processing apparatus. For example, in the step of forming the second thin film 60a, the atomic layer etching process is followed by the atomic layer deposition process in the same chamber as the atomic layer deposition process in the step of forming the first thin film 60, followed by in-situ (in-situ). -situ).

Hereinafter, a method of forming a thin film according to the present invention using one substrate processing apparatus as an example will be described in more detail.

3 is a schematic cross-sectional view showing a substrate processing apparatus 100 for implementing a thin film forming method according to an embodiment of the present invention. The substrate processing apparatus 100 of FIG. 3 illustratively illustrates an apparatus for realizing an atomic layer deposition process and an atomic layer etching process of a spatial division method in-situ in one chamber.

Referring to FIG. 3 , the substrate processing apparatus 100 may include a chamber 110 , a substrate support unit 105 , a gas supply unit 120 and a control unit 150 .

The chamber 110 may provide a substrate processing space 112 therein. For example, the substrate processing space 112 of the chamber 110 may be connected to a pumping unit (not shown) to provide a vacuum environment.

The substrate support 105 is rotatably installed in the chamber 110, and a plurality of substrates 50 may be radially seated thereon along the rotational direction. For example, the substrate support part 105 may include a shaft part sealably coupled from the outside to the inside of the chamber 110 and rotated by receiving rotational power, and an upper upper plate part coupled to the shaft part. Seating grooves in which the substrates 50 can be seated may be radially disposed in the upper plate portion. When the substrates 50 are wafers, the seating grooves may be circular.

The gas supplier 120 may be installed in the chamber 110 to face the substrate support 105 to supply a plurality of gases onto the substrate support 105 . For example, the gas supply unit 120 may include a body 122 in the form of a shower head, and the body 122 may be coupled to an upper portion of the chamber 110 .

The controller 150 may be in charge of overall control of the substrate processing apparatus 100 . For example, the control unit 150 may control the operation of the substrate support unit 105 and the gas supply of the gas supply unit 120 .

Using the substrate processing apparatus 100 described above, in the step of forming the first thin film 60, the atomic layer deposition process and the etching of the first thin film 60 to a predetermined thickness to form the second thin film 60a. The atomic layer etching process may be performed by alternately supplying deposition gas and etching gas through separated gas supply holes in the gas supply unit 120 while rotating the substrate 50 in one chamber.

FIG. 4 is a schematic plan view showing an example of a gas supply unit of the substrate processing apparatus of FIG. 3 .

Referring to FIGS. 3 and 4 , the gas supply unit 120 includes a radially separated first deposition gas supply unit 132 , a first etching gas supply unit 134 , a first purge unit 137 , and a second deposition gas supply unit 132 . A supply unit 133 , a second etching gas supply unit 135 , and a second purge unit 136 may be included. Optionally, the gas supply unit 120 may further include a curtain gas supply unit 131 at the center.

A plurality of first deposition gas supply holes 132a are formed in the first deposition gas supply unit 132, and a plurality of second deposition gas supply holes 133a are formed in the second deposition gas supply unit 133, A plurality of first etching gas supply holes 134a are formed in the first etching gas supply unit 134, and a plurality of second etching gas supply holes 135a are formed in the second etching gas supply unit 135, A plurality of first purge holes 137a may be formed in the first purge part 137 , and a plurality of second purge holes 136a may be formed in the second purge part 136 .

For example, the gas supply unit 120 is substantially circular, and includes a first deposition gas supply unit 132, a first etching gas supply unit 134, a first purge unit 137, a second deposition gas supply unit 133, The second etching gas supply unit 135 and the second purge unit 136 may have a shape obtained by dividing the circular gas supply unit 120 in an arc shape. That is, the gas supply unit 120 can be spatially divided and corresponded to the substrates 50 on the rotating substrate support unit 105 . In this sense, the substrate processing apparatus 100 may be referred to as a space division type facility.

The substrate processing apparatus 100 may be provided to selectively perform an atomic layer deposition process and an atomic layer etching process.

Accordingly, during the atomic layer deposition process, the first deposition gas supply unit 132 and the second deposition gas supply unit 133 selectively operate, and during the atomic layer etching process, the first etching gas supply unit 134 and the second etching gas supply unit 134 operate selectively. The gas supply unit 135 may selectively operate. Therefore, during the atomic layer deposition process, the gas supply is blocked so that the first etching gas supply unit 134 and the second etching gas supply unit 135 do not operate, and during the atomic layer etching process, the first deposition gas supply unit 132 and Gas supply to the second deposition gas supply unit 133 may be cut off so as not to operate.

For example, during atomic layer deposition to form a thin film on substrates 50, the control unit 150 rotates the substrate support unit 105 to supply the first deposition gas 132 and the first purge unit 137. ), the second deposition gas supply unit 133 and the second purge unit 136 may be selectively operated to control the gas supply unit 120 so that deposition gases are alternately exposed on the substrates 50 . Furthermore, during the atomic layer etching process, the control unit 150 rotates the substrate support unit 105 to operate the first etching gas supply unit 134, the first purge unit 137, the second etching gas supply unit 135, and the second etching gas supply unit 134. The gas supply unit 120 may be controlled so that etching gases are alternately exposed on the substrates 50 by selectively operating the branch 136 .

More specifically, for the atomic layer deposition process, the first deposition gas supply unit 132 supplies the source gas S1 through the first deposition gas supply holes 132a, and the second deposition gas supply unit 133 may supply a reaction gas S2 capable of forming a thin film by reacting with the source gas S1 through the second deposition gas supply holes 133a. When a thin film formed by an atomic layer deposition process is to avoid plasma damage, the source gas S1 and the reaction gas S2 may be supplied in a non-plasma state.

The first purge unit 137 and the second purge unit 136 may be disposed between them to remove the source gas S1 or the reaction gas S2 by purging or pumping. For example, one of the first purge part 137 and the second purge part 136 is disposed between the first deposition gas supply part 132 and the second deposition gas supply part 133 in a radial order, and the other one may be disposed between the second deposition gas supply unit 133 and the first deposition gas supply unit 132 .

4, for example, the first purge unit 137 is disposed between the first deposition gas supply unit 132 and the second deposition gas supply unit 133, and the second purge unit 136 is the second deposition gas supply unit. 133 and the first deposition gas supplier 132, but the opposite case is also possible.

For example, for an atomic layer etching process, the second etching gas supply unit 135 supplies a surface treatment gas E2 for surface treatment of the thin film through the second etching gas supply holes 135a, and The etching gas supply unit 134 may supply etching gas E1 for generating volatile compounds by reacting with the surface-treated portion of the thin film through the first etching gas supply holes 134a. When a thin film etched by an atomic layer etching process is to avoid plasma damage, the surface treatment gas E2 and the etching gas E1 may be supplied in a non-plasma state. In some embodiments, the second etching gas supply unit 135 may further include an E-Beam supply unit for radicalizing the surface treatment gas E2 to improve surface treatment efficiency.

The first purge unit 137 and the second purge unit 136 may be disposed between them to purge and remove the surface treatment gas E2 or the etching gas E1. For example, one of the first purge part 137 and the second purge part 136 is disposed between the first etching gas supply part 134 and the second etching gas supply part 135 in a radial order, and the other one may be disposed between the second etching gas supply unit 135 and the first etching gas supply unit 134 .

3, the first purge unit 137 is illustratively disposed between the first etching gas supply unit 134 and the second etching gas supply unit 135, and the second purge unit 136 is the second etching gas supply unit. 135 and the first etching gas supplier 134, but the opposite case is also possible. 3, the first deposition gas supply unit 132 and the first etching gas supply unit 134 are adjacent to each other, and the second deposition gas supply unit 133 and the second etching gas supply unit 135 are disposed adjacent to each other. However, the position may be changed in accordance with the foregoing provisions.

Optionally, a plurality of curtain gas supply holes 131 may be formed in the cut gas supply unit 131 to supply curtain gas C1 in order to prevent adjacent gases from being mixed in the center. This curtain gas may contain an inert gas.

Meanwhile, in the aforementioned gas supply unit 120 , spacers (not shown) may be further added between the first and second deposition gas supply units 132 and 134 . For example, the first spacer is added between the first deposition gas supply 132 and the first etching gas supply 134 to space the two apart, and the second spacer is between the second deposition gas supply 133 and the first etching gas supply 134. It may be added between the two etching gas supply units 135 to space them apart.

5 is a schematic diagram showing gas supply to a schematic substrate of an atomic layer deposition process according to embodiments of the present invention.

Referring to FIG. 5 , the atomic layer deposition process includes supplying a source gas (S1) to the substrate 50, then supplying a first purge gas (P1) to the substrate 50, and then supplying the substrate 50. ), the step of supplying the reaction gas (S2), and then the step of supplying the second purge gas (P2) to the substrate 50 may be repeated. That is, during the unit cycle, the source gas (S1) is supplied and adsorbed on the substrate 50, the source gas (S1) that is not adsorbed by the first purge gas (P1) is purged and removed, and the reaction gas (S2) is removed. The supplied and adsorbed source gas (S1) reacts and the remaining reactive gas (S2) is purged with the second purge gas (P2) to form a unit thin film. As these unit cycles are repeated, a thin film having a predetermined thickness may be formed.

For example, when the atomic layer deposition process is performed in a time-division manner, the aforementioned source gas S1, first purge gas P1, reaction gas S2, and second purge gas P2 are time-divisionally pulsed. It can be provided on the substrate 50 according to.

As another example, when the atomic layer deposition process is performed in a space division manner, referring to FIGS. 3 to 5 , during the atomic layer deposition process, the first deposition gas supply unit 132 in the gas supply unit 120 supplies the source gas S1 , the second deposition gas supplier 133 continuously injects the reaction gas S2, the first purge part 137 continuously injects the first purge gas P1, and The branch 136 may continuously supply the second purge gas P2. However, due to the characteristics of the space division method, since the substrate support 105 rotates, one substrate 50 receives these gases sequentially rather than continuously.

For example, in the case of forming a zirconium oxide film used as a high dielectric constant dielectric film in a semiconductor memory device or a blocking insulating film in a NAND flash memory as the first thin film 60 and the second thin film 60a, the first deposition The gas supply unit 132 may supply a source gas including a zirconium source gas, and the second deposition gas supply unit 133 may supply a reaction gas including an oxygen-based reactive gas that reacts with the zirconium source gas to form zirconium oxide. . For example, the zirconium source gas may include Cp Zr, and the oxygen-based reaction gas may include ozone gas.

As another example, in the case of forming an aluminum oxide film used as a high dielectric constant dielectric film in a semiconductor memory device or a blocking insulating film in a NAND flash memory with the first thin film 60 and the second thin film 60a, the first deposition gas The supply unit 132 may supply an aluminum source gas as a source gas, and the second deposition gas supply unit 133 may supply an oxygen-based reactive gas that reacts with the aluminum source gas to form aluminum oxide as a reactive gas. For example, the aluminum source gas may include trimethylamine (TMA) gas, and the oxygen-based reaction gas may include ozone gas.

6 is a schematic diagram showing gas supply to a schematic substrate of an atomic layer etching process according to embodiments of the present invention.

Referring to FIG. 6 , the atomic layer etching process includes supplying a surface treatment gas (E2) to the substrate 50, then supplying a first purge gas (P1) to the substrate 50, and then supplying the substrate ( A unit cycle including supplying the etching gas E1 to the substrate 50 and then supplying the second purge gas P2 to the substrate 50 may be repeatedly performed. That is, during the unit cycle, the surface treatment gas E2 is supplied onto the substrate 50 and adsorbed on the thin film to treat the surface of the thin film, and the surface treatment gas E2 not adsorbed by the first purge gas P1 ) is purged and removed, an etching gas (E1) is supplied to react with the surface-treated portion of the thin film, and the remaining etching gas (E1) is removed by the second purge gas (P2) to etch the unit thin film. . As these unit cycles are repeated, a thin film having a predetermined thickness may be etched.

For example, when the atomic layer etching process is performed in a time division manner, the surface treatment gas E2, the first purge gas P1, the etching gas E1, and the second purge gas P2 are pulsed. Depending on time, it may be provided on the substrate 50 .

As another example, when the atomic layer etching process is performed in a spatial division manner, referring to FIGS. 3, 4, and 6 , during the atomic layer etching process, the second etching gas supply unit 135 in the gas supply unit 120 supplies the surface The processing gas E2 may be continuously sprayed, and the first etching gas supplier 134 may continuously spray the etching gas E1. However, due to the characteristics of the space division method, since the substrate support 105 rotates, one substrate 50 receives these gases sequentially rather than continuously.

For example, when the first thin film 60 and the second thin film 60a include zirconium oxide, the second etching gas supply unit 135 supplies fluorine for surface treatment of zirconium oxide to zirconium fluoride as a surface treatment gas. The first etching gas supply unit 134 may include and supply an organic reaction gas for reacting zirconium fluoride with a volatile zirconium compound as the etching gas. For example, the fluorine-based surface treatment gas may include one or a combination thereof selected from the group of HF, NF3 and F2 gases. Organic reactive gases include methyl, chloride, or acac ligands, and are volatilized in a stable state, and gases capable of exchange reactions between ligands, such as trimethylamine (TMA) and dimethylacetamide. (Dimetylacetamide, DMAC), silicon tetrachloride (SiCl4), and Sn(acac)2 gas, or a combination thereof.

As another example, when the first thin film 60 and the second thin film 60a include aluminum oxide, the second etching gas supply unit 135 is a surface treatment gas for surface treatment of aluminum oxide to aluminum fluoride. The first etching gas supply unit 134 may include an organic reaction gas for reacting aluminum fluoride with a volatile aluminum compound as the etching gas. For example, the fluorine-based surface treatment gas may include one or a combination thereof selected from the group of HF, NF3 and F2 gases. Organic reactive gases include methyl, chloride, or acac ligands, and are volatilized in a stable state, and gases capable of exchange reactions between ligands, such as trimethylamine (TMA) and dimethylacetamide. (Dimetylacetamide, DMAC), silicon tetrachloride (SiCl4), and Sn(acac)2 gas, or a combination thereof.

In some embodiments, the fluorine-based surface treatment gas may include HF/NF3 gas, and the organic reactant gas may include trimethylamine (TMA) gas. In this case, since the aluminum source gas supplied from the first deposition gas supply unit 132 and the organic reaction gas supplied from the first etching gas supply unit 134 are the same as trimethylamine, the first deposition gas supply unit 132 and the first etching gas supply unit 132 It is also possible that one etching gas supply unit 134 is integrated into one gas supply unit 132 as shown in FIG. 7 .

According to the above-described embodiment, it is economical because the atomic layer deposition process and the atomic layer etching process can be performed in one chamber. Furthermore, when the process temperatures of the atomic layer deposition process and the atomic layer etching process are substantially the same or similar, the process can be immediately followed without a temperature change, enabling efficient process progress.

8 is an X-ray diffraction (XRD) analysis graph showing crystallinity of thin films formed according to Experimental Examples and Comparative Examples of the present invention. In FIG. 8 , graph G1 shows a case of forming a zirconium oxide film to a second thickness H2 by an atomic layer deposition process, and graph G2 shows a case of forming a zirconium oxide film to a first thickness H1 by an atomic layer deposition process. The graph G3 shows a case in which the first thickness H1 is formed through an atomic layer deposition process and then etched through an atomic layer etching process to form a second thickness H2.

Referring to FIG. 8 as well, when the thin film is formed with a first thickness H1 through an atomic layer deposition process (G2), the crystallinity is higher than that of the case (G1) when the thin film is formed with a lower second thickness H2. higher can be found. Furthermore, when the first thickness H1 is formed by an atomic layer deposition process and then etched by an atomic layer etching process to lower it to a second thickness H2 (G3), the original crystallinity is maintained and the second thickness H1 is formed from the beginning. It can be seen that the crystallinity is higher than in the case of formation.

These results are useful when it is desired to reduce leakage current by increasing crystallinity while maintaining capacitance by reducing the thickness of a high-k film. That is, if a high dielectric film is formed with a low thickness from the beginning, it is difficult to match the leakage current characteristics due to poor crystallinity of the film. can keep

For example, the first thin film 60 has a first crystallinity to secure leakage current characteristics, and the second thin film 60a has a second thickness to secure capacitance characteristics, so that the second thin film 60a It is possible to secure leakage current characteristics and capacitance characteristics at the same time. For example, the second thin film 60a made of zirconium oxide may be used as a high dielectric constant thin film of a memory device. Therefore, if the substrate processing apparatus 100 according to the above-described embodiment is used, it is possible to form a thin film that can satisfy conflicting characteristics even in a low-thickness thin film required for a high-integration device.

As another example, the second thin film 60a may be used as a blocking oxide layer of a memory device. In the case of a charge trap memory device, it is necessary to suppress reverse tunneling from the control gate electrode to the charge trap layer during an erase operation. To this end, a high dielectric constant film is used as a blocking insulating layer between the charge trap layer and the control gate electrode. In the case of such a high-permittivity film, a thin film quality capable of suppressing reverse tunneling is required, so a second thin film 60a such as aluminum oxide may be used as such a blocking insulating film.

Furthermore, the second thin film 60a may be applied to a thin film having grain boundaries growing at a critical thickness or more to increase crystallinity, for example, a thin film of zirconium oxide or aluminum oxide. Furthermore, the second thin film 60a may include a film whose grain boundary increases as the thickness increases, for example, a thin film of polysilicon, zirconium oxide, or aluminum oxide. Furthermore, the second thin film 60a may also be applied to a thin film whose resistivity is lowered at a critical thickness or more, for example, a thin film of polysilicon, tungsten, or titanium nitride (TiN).

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

50: substrate
60: first thin film
60a: second thin film
100: substrate processing device
105: substrate support
110: chamber
120: gas supply unit

Claims (11)

Forming a first thin film having a first thickness and having a first crystallinity on a substrate through an atomic layer deposition process; and
Forming a second thin film having a second thickness lower than the first thickness by etching the first thin film to a predetermined thickness through an atomic layer etching process on the first thin film,
The crystallinity of the second thin film has a higher degree of crystallization (crystallinity) than the crystallinity of the third thin film formed to the second thickness on the substrate under the same conditions as the atomic layer deposition process,
Thin film formation method. According to claim 1,
The atomic layer etching process in the forming of the second thin film is performed in-situ following the atomic layer deposition process in the same chamber as the atomic layer deposition process in the forming of the first thin film,
Thin film formation method. According to claim 2,
The atomic layer deposition process in the forming of the first thin film and the atomic layer etching process in the forming of the second thin film are performed through separate gas supply holes in the gas supply unit while rotating the substrate in one chamber. Performed by cross-supplying wear gas and etching gas,
Thin film formation method. According to any one of claims 1 to 3,
In the step of forming the first thin film, the atomic layer deposition process,
supplying a source gas onto the substrate;
supplying a first purge gas onto the substrate;
supplying a reactive gas onto the substrate; and
Repeatedly performing a unit cycle comprising supplying a second purge gas to the substrate,
Thin film formation method. According to claim 4,
The first thin film and the second thin film include zirconium oxide,
The source gas includes a zirconium source gas, and the reaction gas includes an oxygen-based reaction gas that reacts with the zirconium source gas to form zirconium oxide.
Thin film formation method. According to claim 5,
The first thin film and the second thin film include aluminum oxide,
The source gas includes an aluminum source gas, and the reaction gas includes an oxygen-based reaction gas that reacts with the aluminum source gas to form aluminum oxide.
Thin film formation method. According to any one of claims 1 to 3,
In the step of forming the second thin film, the atomic layer etching process,
supplying a surface treatment gas onto the substrate;
supplying a first purge gas onto the substrate;
supplying an etching gas onto the substrate; and
Repeatedly performing a unit cycle comprising supplying a second purge gas to the substrate,
Thin film formation method. According to claim 7,
The first thin film and the second thin film include zirconium oxide,
The surface treatment gas includes a fluorine-based surface treatment gas for surface treatment of the zirconium oxide with zirconium fluoride,
The etching gas includes an organic reaction gas for reacting the zirconium fluoride into a volatile zirconium compound.
Thin film formation method. According to claim 8,
The fluorine-based surface treatment gas includes one or a combination thereof selected from the group of HF, NF3 and F2 gases,
The organic reactant gas includes one or a combination thereof selected from the group of trimethylamine (TMA), dimethylacetamide (DMAC), silicon tetrachloride (SiCl4) and Sn (acac) 2 gas,
Thin film formation method. According to claim 7,
The first thin film and the second thin film include aluminum oxide,
The surface treatment gas includes a fluorine-based surface treatment gas for surface treatment of the aluminum oxide with aluminum fluoride,
The etching gas includes an organic reaction gas for reacting the aluminum fluoride with a volatile aluminum compound.
Thin film formation method. According to claim 10,
The fluorine-based surface treatment gas includes one or a combination thereof selected from the group of HF, NF3 and F2 gases,
The organic reactant gas includes one or a combination thereof selected from the group of trimethylamine (TMA), dimethylacetamide (DMAC), silicon tetrachloride (SiCl4) and Sn (acac) 2 gas,
Thin film formation method.

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