KR102268492B1 - Method of Manufacturing Composite Layer - Google Patents

Abstract

It is a technology related to a method for manufacturing a composite membrane. In the method for manufacturing a composite film according to the present embodiment, a first material layer using a first source gas including a first component configured in at least one layer and a reactive gas including oxygen reacting with the first source gas to deposit The second source gas is composed of at least one layer on the first material layer and includes a second component different from the first component and a second source gas including oxygen reacting with the second source gas. Deposit a material layer. The step of depositing the first material layer and the step of depositing the second material layer are set as one cycle, and the cycle is performed at least once.

Description

Composite film manufacturing method {Method of Manufacturing Composite Layer}

The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing a composite film applied to a semiconductor device.

In a highly integrated semiconductor device, the insulating film may perform various roles in addition to the basic role of insulating the conductive layers.

Such an insulating film may be composed of a single film or a composite film, and in addition to the basic role for insulating the conductive layer, it is applied to various fields, such as a spacer for forming a hard mask film or a fine pattern, or an etch stopper provided during an etching process. have.

In order to perform such various roles, the insulating film should be able to easily control insulating properties, hardness properties, roughness properties, etch selectivity properties, and thin film uniformity according to its functions.

An object of the present invention is to provide a method for manufacturing a composite membrane capable of performing various functions.

In the method for manufacturing a composite film according to the present embodiment, a first material layer using a first source gas including a first component configured as at least one layer and a reactive gas including an oxygen component reacting with the first source gas depositing a; and a second source gas comprising at least one layer on the first material layer and including a second component different from the first component and a reactive gas containing the oxygen reacting with the second source gas. and depositing a second material layer. The step of depositing the first material layer and the step of depositing the second material layer are set as one deposition cycle, and the deposition cycle is performed at least once to manufacture a hard mask layer, and the hard mask layer is formed even after the heat treatment process. The first component and the second component are included in a range in which crystallization does not occur.

According to the present invention, it is possible to manufacture a composite film capable of securing all of surface roughness, etch selectivity, and thin film uniformity.

1A to 1D are cross-sectional views showing the structures of various composite films according to an embodiment of the present invention.
2 is a cross-sectional view for explaining a method of manufacturing a first material layer according to an embodiment of the present invention.
3A to 3C are timing diagrams illustrating a process cycle for forming an atomic layer constituting a first material layer according to an embodiment of the present invention.
4 is a cross-sectional view of a semiconductor device for explaining a method of manufacturing a second material layer on the first material layer according to an embodiment of the present invention.
5A to 5C are timing diagrams illustrating a process cycle for forming an atomic layer constituting a second material layer according to an embodiment of the present invention.
6A to 6C are cross-sectional views illustrating an application example of a composite membrane according to an embodiment of the present invention.
7 is a graph showing a change in the component ratio of a first component and a second component according to the number of layers of the first and second atomic layers according to an embodiment of the present invention.
8 is a graph showing a change in crystallinity of a composite film according to an embodiment of the present invention.
9 is a graph showing a characteristic correlation between a wet etch rate (WER) and a dry etch rate (DER) according to a component ratio of a composite film according to an embodiment of the present invention.
10 is a graph showing deposition uniformity according to RF power when depositing a composite film according to an embodiment of the present invention.
11 is a graph showing the thickness uniformity of the composite film according to a change in frequency and a plasma application method (plasma application ratio within a pulse) when depositing a composite film according to an embodiment of the present invention.
12 is a graph showing etch selectivity of composite layers and individual layers according to an embodiment of the present invention.
13 and 14 are graphs showing the hardness characteristics of the composite membrane compared to the component ratio of the composite membrane according to an embodiment of the present invention.
15A to 15D are cross-sectional views for each process for explaining a method of forming a fine pattern according to an embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of description. Like reference numerals refer to like elements throughout.

1A to 1D are cross-sectional views showing the structures of various composite films according to an embodiment of the present invention.

Referring to FIG. 1A , the composite film 10 may include a first material layer 20 and a second material layer 30 .

The first material layer 20 may include a first component and an oxygen component. Here, the first component may include, for example, one selected from zirconium (Zr), silicon (Si), and titanium (Ti). Accordingly, the first material layer 20 may be a zirconium oxide layer (ZrO2), a silicon oxide layer (SiO2), or a titanium oxide layer (TiO2). The first material layer 20 may include at least one thin film layer (hereinafter, referred to as an atomic layer). At least one atomic layer constituting the first material layer 20 may be formed by, for example, any one of a thermal atomic layer deposition (ALD) method, a plasma enhanced deposition (PEALD) method, and a combination thereof. .

The second material layer 30 may be formed on the first material layer 20 . The second material layer 30 may include a second component and an oxygen component. The second component may be a different material from the first component. For example, when the first component is zirconium (Zr), the second component may be titanium (Ti). Also, when the first component is silicon (Si), the second component may be titanium (Ti). In addition, when the first component is titanium (Ti), the second component may be zirconium (Zr) or silicon (Si). The second material layer 30 may also include at least one atomic layer.

For example, in the composite layer 10 , as shown in FIG. 1A , both the first and second material layers 20 and 30 may be composed of a plurality of atomic layers.

In addition, as shown in FIG. 1B , in the composite film 10 , the first material layer 20 may include one atomic layer, and the second material layer 30 may include a plurality of atomic layers.

In addition, as shown in FIG. 1C , in the composite film 10 , the first material layer 20 may include a plurality of atomic layers, and the second material layer 30 may include one atomic layer.

1A to 1C, the first and second material layers 20 and 30 including at least one atomic layer are alternately deposited at least once or more as shown in FIG. 1D, and the composite film 10 can form.

2 is a cross-sectional view for explaining a method of manufacturing a first material layer according to an embodiment of the present invention.

The first material layer 110 may be formed on the base layer 105 . Here, the base layer 105 may be a bare semiconductor substrate, a device layer, an insulating layer, a conductive layer, or an etched layer to be etched. As described above, the first material layer 110 may include at least one atomic layer 110a to 110n including a first component and an oxygen component. In addition, as described above as the first component, zirconium (Zr), silicon (Si), or titanium (Ti) may be used. The at least one atomic layer 110a to 110n may be formed by, for example, atomic layer deposition (ALD) or plasma enhanced atomic layer deposition (PEALD). . In this case, as the PEALD method, a continuous wave (CW) plasma application method or a pulsed PEALD method may be used.

3A to 3C are timing diagrams illustrating a process cycle for forming an atomic layer constituting a first material layer according to an embodiment of the present invention.

Referring to FIG. 3A , the first source including the first component is supplied for a predetermined time to adsorb atoms of the first component on the lower layer. Here, the lower layer may be, for example, the base layer 105 or a pre-formed first atomic layer.

When the first component is zirconium (Zr), as a first source, Cp-Zr (Cyclopentadienyl Tris(dimethylamino)Zirconium: CpZr[N(CH3)2]3 or Ethylcyclopentadienyl Tris(ethylmethylamino)Zirconium: ((C2H5)C5H4) Zr[N(CH3)C2H5]3 ), TEMA-Zr(Tetrakis(ethylmethylamino)Zirconium: Zr[N(CH3)(C2H5)]4), or ZrCl4 (Titanium Tetrachloride) source may be used.

When the first component is silicon (Si), as a first source, BDEAS (Bis(diethylamino)Silane: H2Si[N(C2H5)2]2), 3DMAS(Tris(dimethylamino)Silane:HSi[N(CH3) 2]3), 4DMAS (Tetrakis(DiMethylAmido)Silane: Si[N(CH3)2]4) or DIPAS Di(isoprophylamino)Silane / H3Si[N(C3H7)]) sources may be used.

In addition, when the first component is titanium (Ti), as a first source, CP-Ti (Tetrakis(dimethylamino)Titanium:Ti[N(CH3)2]4), TEMA-Ti(Tetrakis(ethylmethylamino)Titanium:Ti [N(CH3)(C2H5)]4, TTIP(Titanium Tetraisopropoxide: Ti[O(CH(CH3)2)]4), TiCl4(Titanium Tetrachloride) or TDMAT(Tetrakis(dimethylamino)Titanium :Ti[N(CH3) 2]4) source can be used.

Next, atoms of the first component that are not adsorbed on the lower layer are removed through a purge process.

After that, a reactive gas source for reacting with the atoms of the first component is supplied for a predetermined time. As the reactive gas source, an O2 source, an H2O source, or an O3 source may be used. More specifically, in the case of PEALD, an O2 source may be used as a reactive gas source, and in the case of thermal ALD, an H2O source or an O3 source may be provided as a reactive gas source. Atoms constituting the reactive gas source may react with atoms of the first component adsorbed to the lower layer as described above.

Thereafter, by performing a purge process to remove unreacted oxygen atoms, the first atomic layers 110a to 110n including the first component and the oxygen component are formed. That is, each of the first atomic layers 110a to 110n includes the steps of providing a first source, purging, providing a reactive gas source, and purging as a process cycle for forming one first atomic layer. can be set. In addition, by repeating the process cycle at least once, the first material layer 110 including a plurality of atomic layers may be formed.

Optionally, the reactive gas source may be continuously provided throughout the deposition cycle, as shown in FIG. 3B .

Also, as in FIGS. 3A and 3B , plasma may be applied during the process cycle. The atoms constituting the first source and the reactive gas source may be continuously supplied during a period in which they substantially react.

Meanwhile, as shown in FIG. 3C , the plasma may be provided in the form of a plurality of pulses during a period in which atoms constituting the first source and a reactive gas source substantially react. Such a method is called a pulsed PEALD method.

The first material layer 110 may be formed to have a laminate structure by repeating the process of forming the first atomic layers 110a to 110n at least once as described above.

4 is a cross-sectional view of a semiconductor device for explaining a method of manufacturing a second material layer on the first material layer according to an embodiment of the present invention.

As shown in FIG. 4 , the composite film 100 is formed by forming the second material layer 120 on the first material layer 110 . The second material layer 120 may include a second component different from the first component constituting the first material layer 110 and an oxygen component. For example, the second material layer 120 may include titanium (Ti) as a second component when the first component is zirconium (Zr), and may include titanium (Ti) as a second component when the first component is silicon (Si). It may include titanium (Ti), and when the first component is titanium (Ti), it may include zirconium (Zr) or silicon (Si) as the second component.

Like the first material layer 110 , the second material layer 120 may also include at least one atomic layer (hereinafter, second atomic layer: 120a to 120n). The second atomic layers 120a to 120n may also be formed by an ALD method, a thermal ALD method, a PEALD method, or a pulsed PEALD method.

5A to 5C are timing diagrams illustrating a process cycle for forming an atomic layer constituting a second material layer according to an embodiment of the present invention.

Referring to FIG. 5A , first, by supplying a second source for a predetermined time, the atoms of the second component are adsorbed to the lower layer. The lower layer may be the first material layer 110 or may be the second atomic layers 120a to 120n previously deposited.

Here, when the second component is titanium (Ti), as the second source, CP-Ti(Tetrakis(dimethylamino)Titanium:Ti[N(CH3)2]4), TEMA-Ti(Tetrakis(ethylmethylamino)Titanium:Ti [N(CH3)(C2H5)]4, TTIP(Titanium Tetraisopropoxide: Ti[O(CH(CH3)2)]4), TiCl4(Titanium Tetrachloride) or TDMAT(Tetrakis(dimethylamino)Titanium :Ti[N(CH3) 2]4) source can be used.

When the second component is zirconium, as a second source, Cp-Zr (Cyclopentadienyl Tris(dimethylamino)Zirconium: CpZr[N(CH3)2]3 or Ethylcyclopentadienyl Tris(ethylmethylamino)Zirconium: ((C2H5)C5H4)Zr[N (CH3)C2H5]3 ), TEMA-Zr (Tetrakis(ethylmethylamino)Zirconium: Zr[N(CH3)(C2H5)]4), or ZrCl4 (Titanium Tetrachloride) source may be used.

When the second component is silicon, as a second source, BDEAS (Bis(diethylamino)Silane: H2Si[N(C2H5)2]2), 3DMAS(Tris(dimethylamino)Silane:HSi[N(CH3)2]3) , 4DMAS (Tetrakis(DiMethylAmido)Silane: Si[N(CH3)2]4) or DIPAS Di(isoprophylamino)Silane/H3Si[N(C3H7)]) sources may be used.

Next, unreacted atoms of the second component are removed through a purge step.

Next, the reaction gas source is supplied for a predetermined time. As the reactive gas source, an O2 source, an H2O source, or an O3 source may be used. Similar to the deposition method of the first material layer 110 , an O2 source may be used as a reactive gas source, and in the case of thermal ALD, an H2O source or an O3 source may be provided as a reactive gas source.

Atoms constituting the reactive gas source react with atoms of the second component adsorbed on the lower layer.

Thereafter, unreacted oxygen atoms are removed through a purge process, thereby forming second atomic layers 120a to 120n having a second component and an oxygen component. That is, each of the second atomic layers 120a to 120n includes the steps of providing a second source, purging, providing a reactive gas source, and purging as a process cycle for forming one second atomic layer. can be set. In addition, by repeating the process cycle at least once, the first material layer 110 including a plurality of atomic layers may be formed.

In some cases, the reactive gas source may be continuously provided throughout the deposition cycle, as shown in FIG. 5B .

Also, as in FIGS. 5A and 5B , plasma may be applied during the process cycle. The atoms constituting the first source and the reactive gas source may be continuously supplied during a period in which they substantially react.

Meanwhile, as shown in FIG. 5C , the plasma may be provided in the form of a plurality of pulses during a period in which atoms constituting the second source and a reactive gas source substantially react.

The second material layer 120 may also be formed in a laminate form by repeating the process of forming the second atomic layers 120a to 120n at least once.

In addition, the composite film 100 of this embodiment is formed by the steps of forming the first material layer 110 composed of at least one first atomic layer 110a to 110n and at least one two atomic layers 120a to 120n. The composite layer 100 may be formed by setting the step of forming the second material layer 120 composed of , as one deposition cycle, and repeating the deposition cycle at least once.

In addition, since the first material layer 110 and the second material layer 120 according to the embodiment of the present invention are formed by an ALD-based deposition method, at a low temperature, for example, at a temperature of 50 to 300°C. can be deposited. In some cases, when TDMAT (Tetrakis(dimethylamino)Titanium:Ti[N(CH3)2]4) having high thermal decomposition characteristics is used as a titanium source, it is preferable to deposit at a temperature of 250° C. or less.

6A to 6C are cross-sectional views illustrating an application example of a composite membrane according to an embodiment of the present invention.

As shown in FIG. 6A , the composite film 100 is formed by alternately stacking the first material layer 110 and the second material layer 120 including at least one atomic layer on the etched layer 108 . can do. After the composite layer 100 is formed on the layer 108 to be etched, it may be patterned in an appropriate shape. Thereafter, the etched layer 108 may be etched in a predetermined shape using the composite layer 100 as a hard mask.

As shown in FIG. 6B , the layer to be etched 130 may be formed on the composite film 100 in which the first material layer 110 and the second material layer 120 are alternately stacked. Subsequently, in the process of batch etching or patterning the etched layer 130 in a predetermined shape, the composite layer 100 may be used as an etch stopper due to a difference in the etch selectivity of the etched layer 130 .

In addition, as shown in FIG. 6C , the composite film 100 in which the first material layer 110 and the second material layer 120 are alternately stacked is formed on the sidewall of the pattern 140 and used as a spacer. could be

By changing the number of stacked first atomic layers 110a to 110n constituting the first material layer 110 and the number of stacked second atomic layers 120a to 120n constituting the second material layer 120 , A component ratio between the first component and the second component of the film 100 may be adjusted.

7 is a graph showing a change in the component ratio of a first component and a second component according to the number of layers of the first and second atomic layers according to an embodiment of the present invention.

For example, FIG. 7 is a graph showing the result of setting the first material layer as a zirconium oxide film (ZrO2) and setting the second material layer as a titanium oxide film (TiO2).

As shown in FIG. 7 , a zirconium oxide film (ZrO2) corresponding to the first material layer 110 is composed of seven atomic layers, and a titanium oxide film (TiO2) corresponding to the second material layer 120 is 1 When composed of atomic layers of layers, the component ratio of the first component (Zr) to the second component (Ti) of the composite film 100 is 90%:10% (a). Here, the component ratio of the first component (Zr) to the second component (Ti) is a ratio when the ratio of the oxygen component is removed from the composite film and the sum of the first component and the second component is 100%. . Hereinafter, the component ratio of the first and second components will be interpreted as excluding the oxygen component and based on 100% of the total of the first and second components.

On the other hand, the zirconium oxide film (ZrO2) corresponding to the first material layer 110 is composed of one atomic layer, and the titanium oxide film (TiO2) corresponding to the second material layer 120 is composed of five atomic layers. In this case, it was observed that the component ratio of the first component (zirconium) to the second component (titanium) of the composite film 100 was 22%:78% (b).

That is, from the experimental results of FIG. 7 , it can be seen that as the number of stacking of the atomic layer increases, the component ratio of the corresponding material layer increases.

Tables 1 and 2 below are tables showing roughness characteristics of composite films according to embodiments of the present invention. Here, Table 1 shows an example in which a zirconium oxide film (ZrO2) is used as the first material layer and a titanium oxide film (TiO2) is used as the second material layer. Table 2 shows an example in which a silicon oxide film (SiO2) is used as the first material layer and a titanium oxide film (TiO2) is used as the second material layer.

ZrO2 ZrO2: TiO2 ZrO2: TiO2 ZrO2: TiO2 ZrO2: TiO2 ZrO2: TiO2 ZrO2: TiO2 ZrO2: TiO2 ZrO2: TiO2 TiO Zr:Ti
(%) 100:0 90:10 88:12 80:20 60:40 32:68 22:78 13:87 7:93 0:100 surface roughness
(Rq,Å) 0.603 0.151 0.152 0.183 0.125 0.133 0.155 0.129 0.143 0.269

According to Table 1, in the case of the zirconium oxide film (ZrO2: 100%) composed only of zirconium (Zr)-oxygen (O2) components, the roughness characteristics (Rq, roughness) were measured to be 0.603 Å, and titanium (Ti)-oxygen In the case of the titanium oxide film (TiO2: 100%) composed only of (O2) components, the roughness characteristic (Rq) was measured to be 0.269.

On the other hand, in the case of a composite film in which a zirconium oxide film (ZrO2) and a titanium oxide film (TiO2) having a laminate structure are alternately stacked (Zr:Ti = 90% to 7%: 10% to 93%), the surface roughness characteristics of the composite films ( Rq: roughness) was measured to have a range of 0.151 to 0.143 Å.

From the above results, it can be seen that the surface roughness characteristics are excellent when the composite film 100 is formed by stacking the zirconium oxide film (ZrO2) or the titanium oxide film (TiO2), rather than when they are used separately.

SiO2 SiO2:TiO2 SiO2:TiO2 SiO2:TiO2 SiO2:TiO2 SiO2:TiO2 TiO2 ingredient ratio 100% 70%:30% 50%:50% 40%:60% 30%:70% 20%:80% 100% surface roughness
(Rq) 0.136 0.133 0.134 0.122 0.178 0.191 0.269

Similarly, as shown in Table 2, when a composite film of a silicon oxide film and a titanium oxide film is used, the surface roughness characteristics are good at 0.122 to 0.191 level, rather than when the titanium oxide film (TiO2:100) is used alone. characteristics were observed.

In particular, according to Table 2, when a composite film is formed by stacking a silicon oxide film (SiO2) and a titanium oxide film (TiO2), the component ratio of the silicon oxide film (SiO2) and the titanium oxide film (TiO2) is 70%: 30% to 20%: When it is in the range of 80%, it can be seen that it has stable surface roughness characteristics.

As such, the roughness characteristic of the composite film 100 is of course important even when a general insulating film is applied, but becomes a more important factor when applied as a spacer. As a current mask pattern, since a line width smaller than the exposure limit is required, when the surface of the mask layer is irregular, it is difficult to define a desired shape of the pattern, and even the roughness portion may contribute to the line width of the pattern. Therefore, when a composite film is used as a mask film for manufacturing a fine pattern, it is important to control the first and second components to have low roughness (0 to 2 Å).

8 is a graph showing a change in crystallinity of a composite film according to an embodiment of the present invention. 8 shows changes in intensity after heat treatment of composite films having various component ratios. In the experiment of FIG. 8 , a zirconium oxide film (ZrO2) was used as the first material layer, and a titanium oxide film (TiO2) was used as the second material layer. In addition, the heat treatment process was performed at a temperature of 400° C. for 30 minutes, for example, in a state in which 2 torr pressure and about 2000 sccm of Ar gas were supplied. In this experiment, the heat treatment process is an ancillary process for applying the same conditions as the subsequent process in order to check whether the properties of the composite film are changed due to the incidental heat treatment process that is performed during the subsequent process after the formation of the composite film. can

Referring to FIG. 8 , in the case of a composite film composed only of a titanium oxide film (TiO2), it is observed that the titanium oxide film (TiO2) rapidly changes to crystalline in the range of 20 to 30 theta. Similarly, in the case of a composite film composed only of the zirconium oxide film (ZrO2), it is also observed that the zirconium oxide film (ZrO2) rapidly changes to crystalline in the range of 30 to 40 theta.

On the other hand, when the composite film is composed of a laminated film of a zirconium oxide film and a titanium oxide film, and the components of zirconium (Zr) and titanium (Ti) constituting the composite film are in the range of 88 to 13%: 12% to 87%, crystallization occurs It was observed that it did not occur (the phenomenon of sudden increase in intensity did not occur).

From this, the case of configuring the composite film to include both the zirconium oxide film (ZrO2) and the titanium oxide film (TiO2) is superior in terms of crystallization properties than when configuring the composite film alone with the zirconium oxide film (ZrO2) or the titanium oxide film (TiO2). Able to know.

From the above experiment, it was observed that the crystallinity was changed according to the ratio of the first component and the second component ratio included in the composite film, and from this, the surface roughness can be controlled according to the component ratio of the composite film.

9 is a graph showing a correlation between a wet etch rate (WER) and a dry etch rate (DER) according to a component ratio of a composite film according to an embodiment of the present invention. In this experiment, a zirconium oxide film (ZrO2) was applied as a first material layer, and a titanium oxide film (TiO2) was applied as a second material layer.

Referring to FIG. 9 , it was observed that the dry etching ratio of the composite film tends to increase as the ratio of the zirconium oxide film (ZrO2), which is the first material layer, increases. On the other hand, it was observed that the wet etching rate tends to increase as the ratio of the titanium oxide layer (TiO2), which is the second material layer, increases.

Here, the high wet etching rate means that it can be easily removed after performing the role of the mask.

Therefore, according to this graph, by adjusting the first component and the second component, not only the dry etch rate characteristic of the composite layer can be adjusted, but also the wet etch rate can be easily adjusted.

10 is a graph showing deposition uniformity according to RF power when depositing a composite film according to an embodiment of the present invention.

This experiment measured the change in the deposition thickness of the composite film while changing the RF power for generating plasma to 200W, 150W, 100W, and 50W, respectively, when depositing the composite film of this embodiment in the PEALD method.

As a result of the experiment, it was observed that the lower the RF power, the smaller the thickness change of the composite film. Accordingly, in order to secure the thickness uniformity of the composite film, it is preferable to apply RF power in the range of 50W to 300W when depositing the composite film.

11 is a graph showing the thickness uniformity of the composite film according to a change in frequency and a plasma application method (plasma application ratio within a pulse) when depositing a composite film according to an embodiment of the present invention.

This experiment is to measure the thickness change of the composite film according to the change of the pulse frequency and duty time (eg, plasma application rate) for plasma generation during the deposition of the composite film.

Referring to FIG. 11 , it was observed that when the pulse frequency was changed to 100 Hz, 1 KHz, and 10 KHz bands under the same plasma duty time standard, the difference in thickness of the composite film for each frequency band was not very large.

On the other hand, when the plasma duty time was changed to 10%, 50%, and 90%, respectively, in the same frequency band, it was observed that the thickness uniformity of the composite film was significantly changed according to the plasma duty time.

From these experimental results, it can be predicted that excellent deposition uniformity can be secured when the plasma duty time is adjusted in the range of 10 to 50% in a state where a pulse frequency of 100 Hz to 10 KHz is applied.

12 is a graph showing the dry etching selectivity of composite layers and individual layers according to an embodiment of the present invention.

In FIG. 12, L1 denotes a first composite film composed of a zirconium oxide film and a titanium oxide film (ZrO2-TiO2) having a component ratio of zirconium (Zr) and titanium (Ti) of 88%:12%, and L2 is zirconium (Zr) and titanium It indicates a second composite film composed of a zirconium oxide film and a titanium oxide film (ZrO2-TiO2) having a component ratio of (Ti) of 13%:87%. In addition, this experiment measured the etching selectivity under the plasma etching process.

12 , it was measured that the first composite layer L1 and the silicon oxide layer SiO2 had an etching selectivity of 1:226 with respect to the etching gas for the silicon oxide layer SiO2. In addition, it was measured that the first composite layer L1 and the silicon oxynitride layer (SiON) had an etching selectivity of 1:22 with respect to the etching gas for the silicon nitroxide layer (SiON). The first composite layer L1 and the silicon nitride layer (SiN) were measured to have an etching selectivity of 1:8 with respect to the etching gas for the silicon nitride layer (SiN).

Meanwhile, it was measured that the second composite layer L2 and the silicon oxide layer SiO2 had an etching selectivity of 1:8 with respect to the etching gas for the silicon oxide layer SiO2. It was measured that the second composite layer L2 and the silicon oxynitride layer SiON also had an etch selectivity of 1:8 with respect to the etching gas for the silicon nitroxide layer (SiON). It was measured that the second composite layer L2 and the silicon nitride layer (SiN) had an etching selectivity of 1:4 with respect to the etching gas for the silicon nitride layer (SiN).

From the experimental results, the first and second composite films L1 and L2 have an etch selectivity of at least 4 times or more with respect to a silicon oxide film (SiO2), a silicon nitride film (SiON), and a silicon nitride film (SiN), which are representative insulating film components. You can check that you can get it.

In addition, securing the excellent etching selectivity as described above under the plasma etching process in which strong energy is irradiated means that the first and second composite films L1 and L2 have superior hardness characteristics compared to general insulating films. suggest Accordingly, it is possible to use it as a spacer, a hard mask film, and an etch stopper.

13 and 14 are graphs showing the hardness characteristics of the composite membrane compared to the component ratio of the composite membrane according to an embodiment of the present invention.

13 shows the hardness characteristics of a composite film of a zirconium oxide film (ZrO2) and a titanium oxide film (TiO2) according to a component ratio of zirconium (Zr) and titanium (Ti). According to FIG. 13 , it can be confirmed that the hardness of the composite film increases as the content of zirconium (Zr) increases.

14 shows the hardness characteristics of a composite film of a silicon oxide film (SiO2) and a titanium oxide film (TiO2) according to the component ratio of silicon (Si) and titanium (Ti). According to FIG. 14 , it can be confirmed that the hardness of the composite film increases as the content of titanium (Ti) increases.

15A to 15D are cross-sectional views for each process for explaining a method of forming a fine pattern according to an embodiment of the present invention.

Currently, a semiconductor integrated circuit device uses a fine mask pattern having a line width equal to or less than an exposure limit, and the fine mask pattern is limited by a double patterning mask technique or a spacer mask technique. Since the fine mask patterns must maintain a line width below the exposure limit, roughness characteristics and high etch selectivity characteristics must be secured at the same time. More specifically, since the line width of the current fine mask pattern requires a line width of 10 nm or less, it becomes difficult to achieve the function of the fine pattern when high surface roughness (eg, 2 Å or more) occurs. On the other hand, since the fine mask pattern has a narrow line width, the etch selectivity for the etched layer is very important. That is, if the etch selectivity characteristic is not secured, the layer to be etched and the etched layer are removed at the same time as the etching, so that the etch selectivity and the deposition uniformity must be secured simultaneously with the roughness characteristic.

In this embodiment, based on the experimental conditions described with reference to FIGS. 7 to 14 , a fine mask pattern using the composite film is manufactured with an optimal component ratio and optimal process conditions of the composite film.

Referring to FIG. 15A , a layer to be etched 205 is deposited on the semiconductor substrate 200 . The layer to be etched 205 may be a silicon oxide film, a silicon nitride film, a silicon nitride oxide film, or a combination thereof. A sacrificial pattern 210 may be formed on the layer to be etched 205 . The sacrificial pattern 210 may be formed of a material that can be easily removed compared to the etched layer 205 . Here, the line width of the sacrificial pattern 210 may be an interval between micropatterns to be formed later.

A composite layer 220 is formed on the etched layer 205 on which the sacrificial pattern 210 is formed. The composite film 220 may be formed through the structure and manufacturing method of FIGS. 1A to 5C . For example, in the composite film 220, when the first component constituting it is zirconium (Zr) and the second component is titanium (Ti), about 90%: 10% to 7%: 93% or 90%: It may have a ratio of 10% to 88%:12%. In addition, when the first component is silicon (Si) and the second component is titanium (Ti), the ratio may be about 70%:30% to 20%:80%. Such a component ratio may be adjusted according to the number of depositions of the first and second atomic layers. In addition, the composite layer 220 may be deposited in a PEALD method in a temperature range of 50°C to 300°C. In addition, when the plasma is applied, the pulse frequency may be set in the range of 100 Hz to 10 kHz, the plasma pulse duty time may be set to 10 to 50%, and the RF power may be set to 50 W to 300 W.

The thickness of the composite layer 220 may be determined in consideration of a line width of a fine pattern to be formed later. In addition, since the composite film 220 can be deposited in units of atomic layers by the above-described ALD method, deposition is possible as a thin film of 10 nm or less.

Referring to FIG. 15B , the composite layer 220 is anisotropically etched to expose the surface of the sacrificial pattern 210 to form spacers 220a on both sides of the sacrificial pattern 210 .

Referring to FIG. 15C , the sacrificial pattern 210 is selectively removed. Accordingly, only the spacer 220a remains.

Referring to FIG. 15D , the exposed to-be-etched layer 205 is etched using the spacer 220a to form a pattern 205a having a fine line width.

Thereafter, although not shown in the drawings, the spacers 220a are selectively removed by a known method.

As described in detail above, according to the present invention, it is possible to manufacture a composite film capable of securing all of the surface roughness characteristics, etch selectivity characteristics, and hardness characteristics of the composite film by controlling the component ratio of the composite film.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various modifications are possible by those skilled in the art within the scope of the technical spirit of the present invention. Do.

10: composite film 20,110: first material layer
30,120: second material layer

Claims (17)

depositing a first material layer using a first source gas including a first component including at least one layer and a reactive gas including an oxygen component reacting with the first source gas; and
The second source gas is composed of at least one layer on the first material layer and includes a second component different from the first component and a second source gas including oxygen reacting with the second source gas. depositing a material layer;
The step of depositing the first material layer and the step of depositing the second material layer are set as one deposition cycle, and the deposition cycle is performed at least once to manufacture a hard mask film,
The hard mask film is a composite film manufacturing method including the first component and the second component to a range in which crystallization does not occur even after the heat treatment process. The method of claim 1,
The first source gas is a gas including one selected from zirconium (Zr) and titanium (Ti),
When the second source gas is a gas containing the other one of zirconium (Zr) and titanium (Ti), the method of manufacturing a composite film, characterized in that the hardness increases as the concentration of the zirconium (Zr) increases. 3. The method of claim 2,
The gas containing the zirconium (Zr),
Cp-Zr(Cyclopentadienyl Tris(dimethylamino)Zirconium: CpZr[N(CH3)2]3 or Ethylcyclopentadienyl Tris(ethylmethylamino)Zirconium: ((C2H5)C5H4)Zr[N(CH3)C2H5]3 ), TEMA-Zr(Tetrakis (ethylmethylamino)Zirconium: Zr[N(CH3)(C2H5)]4), or ZrCl4 (Titanium Tetrachloride) source. The method of claim 1,
The first source gas is a gas containing one selected from silicon (Si) and titanium (Ti),
When the second source gas is a gas containing the other one of the silicon (Si) and the titanium (Ti), the composite film manufacturing method, characterized in that the hardness increases as the concentration of the titanium increases. 5. The method of claim 4,
The gas containing the silicon (Si),
BDEAS(Bis(diethylamino)Silane: H2Si[N(C2H5)2]2), 3DMAS(Tris(dimethylamino)Silane: HSi[N(CH3)2]3), 4DMAS(Tetrakis(DiMethylAmido)Silane: Si[N( CH3)2]4) or DIPAS Di(isoprophylamino)Silane / H3Si[N(C3H7)]) source. 5. The method according to claim 2 or 4,
The gas containing titanium (Ti),
CP-Ti(Tetrakis(dimethylamino)Titanium: Ti[N(CH3)2]4), TEMA-Ti(Tetrakis(ethylmethylamino)Titanium: Ti[N(CH3)(C2H5)]4, TTIP(Titanium Tetraisopropoxide: Ti[ O(CH(CH3)2)]4), TiCl4 (Titanium Tetrachloride), or TDMAT (Tetrakis(dimethylamino)Titanium:Ti[N(CH3)2]4) source. 3. The method of claim 2,
A method for manufacturing a composite film, characterized in that the composition ratio of zirconium (Zr) and titanium (Ti) in the composite film is 90%: 10% to 7%: 93%. 3. The method of claim 2,
A method for manufacturing a composite film, characterized in that the composition ratio of zirconium (Zr) and titanium (Ti) in the composite film is 90%:10% to 88%:12%. The method of claim 1,
The reaction gas is a method for manufacturing a composite film, characterized in that oxygen (O2) or ozone (O3). The method of claim 1,
The method for manufacturing a composite film, characterized in that the first material layer and the second material layer are each formed in a temperature range of 50 °C to 300 °C. The method of claim 1,
The first material layer and the second material layer are thermal ALD (atomic layer deposition) method, PEALD (plasma enhanced ALD) method, characterized in that the composite film manufacturing method, characterized in that formed by any one of these combinations. 12. The method of claim 11,
When at least one of the first material layer and the second material layer is deposited by the thermal ALD method, O3 or H2O is provided as the reaction gas. 12. The method of claim 11,
When at least one of the first material layer and the second material layer is deposited by the PEALD method, O ₂ as the reaction gas is provided. 12. The method of claim 11,
When at least one of the first material layer and the second material layer is deposited by the PEALD method,
A method for manufacturing a composite film, characterized in that the plasma is continuously applied during the reaction period between the first component or the second component and the reaction gas. 12. The method of claim 11,
When at least one of the first material layer and the second material layer is deposited by the PEALD method,
A method for manufacturing a composite film, characterized in that the plasma is applied in the form of a pulse during the reaction period between the first component or the second component and the reaction gas. 12. The method of claim 11,
When at least one of the first material layer and the second material layer is deposited by the PEALD method,
For plasma generation, a method for manufacturing a composite film, characterized in that applying RF power of 50W to 300W. 12. The method of claim 11,
Depositing at least one of the first material layer and the second material layer by a pulsed PEALD method in which plasma is applied in the form of a pulse,
When the plasma is applied, in a state in which RF power of 50 to 300 W is applied, the pulse frequency is set in the range of 100 Hz to 10 kHz, and the plasma pulse duty time is set to 10 to 50%.

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