KR20180059609A - Apparatus For Depositing Thin Film, System Having The Same And Method of Depositing The Thin Film - Google Patents

Abstract

The present invention relates to a technique for a thin film deposition apparatus, a substrate processing system including the same, and a thin film deposition method. The thin film deposition method according to an embodiment of the present invention includes the steps of forming a first amorphous silicon thin film on a semiconductor substrate by using a process gas activated from first plasma; and forming a second amorphous silicon thin film on the upper side of the first amorphous silicon thin film by using a process gas activated from second plasma. The first plasma is a very high frequency (VHF) power source with a center frequency band of 20 to 70 MHz, and the second plasma is a high frequency (HF) power source with a center frequency band of 10 to 20 MHz. Accordingly, the present invention can improve etching and deposition characteristics.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film deposition apparatus, a substrate processing system including the same,

The present invention relates to a thin film deposition apparatus, a substrate processing system including the same, and a thin film deposition method, and more particularly, to a thin film deposition apparatus using a plasma deposition system, a substrate processing system including the same, and a thin film deposition method.

It is essential to miniaturize the pattern in manufacturing an integrated semiconductor device. As a mask for forming a fine pattern of a semiconductor element, a hard mask is formed from a material having corrosion resistance (etching selectivity) against the etching layer, and a patterning process is performed. In order to ensure the pattern uniformity and the pattern shape of the etching layer, the hard mask should have the surface roughness characteristics and adhesion characteristics with the etching layer in addition to the corrosion resistance.

The present hard mask uses a material having a large etching selectivity ratio and an etching selectivity ratio. In order to secure an optimum etch selectivity with the etching layer, for example, an RF (radio frequency) power source corresponding to HF And is formed by a plasma enhanced chemical vapor deposition (PECVD) method.

However, the hard mask deposited by the PECVD method using the RF power source has an increased generation of hydrogen groups and can have a compress stress on the lower etching layer. Due to the hydrogen generation and compressive stress characteristics, it is difficult to ensure adhesion characteristics between the etching layer and the hard mask, and also the surface roughness characteristics are poor and the deposition rate is also slowed down.

The present invention provides a method, an apparatus, and a substrate processing system for depositing a thin film for a hard mask having improved etching properties and deposition characteristics.

A thin film deposition method according to an embodiment of the present invention is a method of forming an amorphous silicon film on a semiconductor substrate, the method comprising: forming a first amorphous silicon thin film using a process gas activated from a first plasma on the semiconductor substrate; And forming a second amorphous silicon thin film on the first amorphous silicon thin film using a process gas activated from a second plasma. In this case, the first plasma is a VHF (very high frequency) power source having a center frequency band of 20 to 70 MHz, and the second plasma is a HF (high frequency) power source having a center frequency band of 10 to 20 MHz.

According to another embodiment of the present invention, a first amorphous silicon film is formed on a semiconductor substrate using a first plasma, and a second amorphous silicon film is formed on the first amorphous silicon film using a second plasma A gas supply device for injecting a process gas into the chamber; a substrate supporter installed so as to face the gas supply device and on which a substrate is mounted; And a VHF power supply connected to the gas supply device for supplying a VHF power supply having a center frequency band of 20 to 70 MHz to generate the first and second plasma in the chamber, 20 MHz, and an LF power supply portion having a center frequency band of 300 to 600 KHz, It includes. And a controller configured to apply the VHF power supply of the VHF power supply unit to generate the first plasma in the chamber when the first amorphous silicon film is formed.

According to another embodiment of the present invention, a first amorphous silicon film is formed on a semiconductor substrate using a first plasma, and a second amorphous silicon film is formed on the first amorphous silicon film using a second plasma A first thin film deposition apparatus for forming the first amorphous silicon film by using a first plasma formed by a VHF power supply generated from a VHF power supply unit on the semiconductor substrate; A second thin film deposition apparatus for forming the second amorphous silicon film by using a second plasma formed by an HF power source generated from an HF power supply unit and a second thin film deposition apparatus for interconnecting the first thin film deposition apparatus and the second thin film deposition apparatus And a transport chamber. The first plasma is generated by application of a VHF power source having a center frequency band of 20 to 70 MHz, and the second plasma is generated by application of an HF power source having a center frequency band of 10 to 20 MHz.

According to the present invention, the thin film layer that can be applied to the hard mask may be composed of a seed layer formed using a VHF plasma power source and a main thin film layer formed using the seed layer as a base and formed using an HF plasma power source .

Since the main thin film layer is formed based on the seed layer formed by using the VHF plasma power source, the problems due to the surface roughness characteristics and the stress can be improved, and the deposition rate and the etching rate can be satisfied at the same time.

FIG. 1 and FIG. 2 are sectional views of respective processes for explaining a thin film deposition method according to an embodiment of the present invention.
3 is a cross-sectional view of a thin film deposition apparatus according to an embodiment of the present invention.
4 to 7 are cross-sectional views for explaining a thin film deposition method according to another embodiment of the present invention.
8 is a cross-sectional view illustrating a thin film deposition apparatus for depositing the thin film according to FIG.
9 to 11 are block diagrams showing a substrate processing system for depositing the thin film according to Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. The dimensions and relative sizes of layers and regions in the figures may be exaggerated for clarity of illustration. Like reference numerals refer to like elements throughout the specification.

Referring to FIG. 1, a crystallization layer 110 is formed on a semiconductor substrate 100. A seed layer 120 for forming a hard mask is formed on the etching layer 110. The seed layer 120 may be a power supply (hereinafter referred to as a VHF power supply) that provides VHF (very high frequency) power having a center frequency band of 20 to 70 MHz, for example, in consideration of stress characteristics, surface roughness characteristics, May be used as a plasma power source having a center frequency of 27.12 MHz. In this embodiment, the seed layer 120 may be amorphous silicon. When an amorphous silicon film is formed as the seed layer 120 as in the present embodiment, SiH4 gas and Ar gas may be supplied as a source gas and a reactive gas.

Referring to FIG. 2, a main thin film layer 130 is formed on the seed layer 120 with the seed layer 120 as a base. For example, the main thin film layer 130 may be formed in situ in the same chamber as the seed layer 120. The main thin film layer 130 may have the same material and the same crystal state as the seed layer 120. That is, the main thin film layer 130 may be an amorphous silicon film like the seed layer 120. Hereinafter, the first amorphous silicon film can be interpreted as the seed layer 120, and the second amorphous silicon film formed on the first amorphous silicon film will be interpreted as the main thin film layer 130. The main thin film layer 130 may be formed as a thicker film than the seed layer 120. For example, the seed layer 120 may be formed to have a thickness range of 1 to 30% of the thickness of the main thin film layer 130. The main thin film layer 130 of the present invention may be formed using an RF (radio frequency) power source having a central frequency band of 10 to 20 MHz, preferably a HF having a central frequency band of 13.56 MHz, in consideration of the etch rate with the etching layer 110. [ (high frequency) power source. As is known, when the HF power source is provided as a plasma power source, the ion energy is relatively higher than when a plasma power source of another frequency band is used. As a result, decomposition of the raw material gas is relatively actively promoted, so that the probability of occurrence of a hydrogen group in the chamber can be increased. Accordingly, the main thin film layer 130 formed by supplying HF power can be formed in a form having a compressive stress due to a large amount of hydrogen.

The seed layer 120 and the main thin film layer 130 may be formed in situ in a thin film deposition apparatus having a VHF power supply unit and an HF power supply unit.

3, the thin film deposition apparatus 20 of the present embodiment includes a chamber 200, a controller 201, a gas supply apparatus 230, a substrate support apparatus 240, a driving unit 250, a plasma A power supply unit 260, a matching network 270, a filter 280, and a heater power supply unit 290.

The chamber 200 may include a main body 210 having an open upper part and a top lead 220 installed at an upper end periphery of the main body 210. The inner space of the top lead 220 can be closed by the gas supply device 230. An insulating ring r is provided between the gas supply device 230 and the top lead 220 so that the chamber 200 and the gas supply device 230 are electrically insulated.

The space inside the chamber 200 may be a space for processing the substrate W such as a deposition process. At a designated position on the side of the main body 210, a gate G may be provided in which the substrate W is carried in and out. A through hole (not shown) through which the support shaft 244 of the substrate supporting apparatus 240 is inserted may be formed on the bottom surface of the main body 210. The inside of the chamber 200 is generally provided with a vacuum atmosphere so that the exhaust gas for discharging the gas existing in the internal space of the chamber 200 is supplied to the specified position of the main body 210, (Not shown). The exhaust port 212 may be connected to an external pump 213.

The gas supply device 230 is located inside the top lead 220 and may be installed to face the substrate supporting device 240. The gas supply unit 230 may supply various process gases supplied from the outside through the gas line 232 and inject the gas into the chamber 200. The gas supply device 230 may be selected from various types of gas supply devices such as a shower head type, an injector type, and a nozzle type. In one embodiment, gas supply 230 may act as a first electrode.

The substrate support apparatus 240 may include a substrate seating portion (susceptor) 242 and a support shaft 244. The substrate seating portion 242 has a generally flat shape so that at least one substrate W is seated on the upper surface thereof and may be substantially parallel to the top lead 220 in the chamber 200. The support shaft 244 is vertically coupled to the rear surface of the substrate seating part 242 and connected to the external driving part 250 through the through hole at the bottom of the chamber 200 to lift and / As shown in FIG. In one embodiment, the substrate seating 242 may act as a second electrode.

In addition, a heater 246 is provided inside the substrate seating part 242 to control the temperature of the substrate W placed on the upper part.

The controller 201 is configured to control the overall operation of the thin film deposition apparatus 20. In one embodiment, the controller 201 controls the operation of each of the components 200 to 290, and can set control parameters and the like for a thin film deposition process. Although not shown, the controller 201 may include a central processing unit, a memory, an input / output interface, and the like.

The plasma power supply 260 may include a VHF power supply unit 261 having a center frequency band of 20 to 70 MHz and an HF power supply unit 263 having a central frequency band of 10 to 20 MHz. The controller 201 can selectively turn on and off the VHF power supply unit 261 and the HF power supply unit 263 and other plasma power supply units in accordance with a predetermined deposition control parameter.

For example, the substrate W is mounted on the substrate mounting part 242 as a second electrode, and the chamber 200 is vacuumed. Then, the process gas is injected into the chamber 200, The VHF power supply or the HF power supply can be applied to the gas supply device 230 corresponding to one electrode. Accordingly, plasma having different functions can be formed between the gas supply device 230 and the substrate seating portion 242. [

The matching network 270 may include a first matching unit 271 connected to the VHF power supply unit 261 and a second matching unit 273 connected to the HF power supply unit 263. [ The first and second matching units 271 and 273 of the matching network 270 match the output impedance of the power supply units 261 and 263 with the load impedance of the chamber 200, As shown in FIG.

The filter 280 filters the high frequency power transmitted through the substrate seating part 242 when the high frequency power is applied to the gas supply device 230 through the plasma power supply part 260 so that the high frequency power is not radiated to the outside . The heater power supply unit 290 may be configured to supply power to the heater 246 so that the heater 246 generates heat.

3 illustrates the case where the exhaust port 212 is formed on the bottom of the chamber 200. However, the exhaust port 212 may be formed on the side surface of the chamber 200. [

When the first amorphous silicon film corresponding to the seed layer 120 is formed using the VHF power source as in the present embodiment, the seed layer 120 has a tensile stress due to the VHF plasma power supply characteristic . Accordingly, the seed layer 120 of the present embodiment can offset the stress of the main thin film layer 130 having compressive stress.

More specifically, when a VHF plasma power source in the 20 to 70 MHz band is used as the plasma power source, the plasma ion flux is increased while the ion energy and the ion bombardment are reduced . Thus, due to the decrease of the ion impurity ratio, the decomposition rate of the raw material gas (for example, SiH4) is reduced, and the amount of the hydrogen group H decomposed from the raw material gas is reduced. Accordingly, the seed layer 120 can be grown to have a tensile stress opposite to the compressive stress due to the decrease of the hydrogen group, and the deposition rate also increases.

Table 1 below shows the rate of hydrogen evolution when the seed layer 120 of silicon material is formed by providing the same remaining conditions while providing the plasma power source differently.

Plasma power source The hydrogen concentration (atoms / cm2) VHF power source 1.09E + 17 HF power source 7.54E + 16

According to Table 1, it can be seen that the hydrogen concentration of the seed layer formed using the VHF plasma power source is significantly lower than the hydrogen concentration of the seed layer formed using the HF plasma power source.

Furthermore, when a VHF power source is used for plasma generation, the reactance component X of the impedance Z is reduced as shown in the following equation, thereby reducing the plasma loss. Thus, the deposition rate of the film quality can be improved.

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Table 2 below provides a comparison of the film quality surface roughness characteristics when the seed layer 120 made of a silicon material is formed by providing the same conditions as the other conditions while providing the plasma power source differently. More specifically, Table 2 shows the result of measuring the surface roughness when a 300 Å thick amorphous silicon seed layer is formed using the HF power source and the VHF power source.

HF plasma power VHF plasma power Surface roughness (Ra) 5.5 Å 1.7 Å

When an amorphous silicon seed layer was formed using an HF plasma power source, the average of the difference between the minimum thickness and the maximum thickness on the surface of the amorphous silicon seed layer was measured to be about 5.5 Å.

On the other hand, when forming the amorphous silicon seed layer using a VHF plasma power source, the average of the difference between the minimum thickness and the maximum thickness of the amorphous silicon seed layer surface was measured to be 1.7 Å.

From the above detection results, it can be seen that when the film quality is formed by using the VHF plasma power source, the surface roughness characteristic is superior to the case of using the HF plasma power source.

The surface roughness of the main thin film layer 130 is also improved by forming the main thin film layer 130 based on the seed layer 120 after forming the amorphous silicon seed layer 120 having improved surface roughness, The deposition uniformity is improved.

4, after the main thin film layer 130 is formed using the HF plasma power source, a surface protective layer 130 is formed on the main thin film layer 130 to compensate for surface morphology characteristics, (140) can be further formed. The surface protective layer 140 may be an amorphous silicon film formed by using the main thin film layer 130 as a seed. And may be deposited using a VHF plasma power source, such as seed layer 120. The surface protective layer 140 may be formed in situ in the same chamber as both the seed layer 120 and the main thin film layer 130. As described above, since the surface protective layer 140 is formed using the VHF plasma power source, the surface roughness characteristics can be further improved.

Further, as shown in FIG. 5, the whole thin film layer to be used as a hard mask can be formed by using a VHF plasma power source. In more detail, both the seed layer 120 and the main thin film layer 130 can be deposited using a VHF plasma power source.

As described above, in the case of using a VHF plasma power source, the hydrogen generation rate is reduced during the plasma deposition process, and the deposition rate of the silicon layer can be improved and the problem caused by the compressive stress can be prevented.

6, the first layer 120a formed using the VHF plasma power source and the second layer 130b formed using the HF plasma power source are alternately stacked a plurality of times, Lt; / RTI &gt; The compressive stress of the second layer 130a formed by the alternate deposition of the first layer 120a and the second layer 130a by using the HF plasma power source causes the compressive stress of the first layer 120a Can be mutually compensated for by the tensile stress of the test piece. For example, the first layer 120a may be thinner than the second layer 130a.

As shown in Fig. 7, before forming the seed layer 120 in Fig. 1, the surface of the etching layer can be pretreated. The pre-processing may be performed using an LF (low frequency) plasma power source having a center frequency of 300 KHz to 600 KHz. The pretreatment process using the LF plasma power source may be performed in order to remove hydrogen groups that may remain on the surface of the etching layer 110. A thin oxide layer (not shown) may be formed on the surface of the etching layer 110 by the pre- May be formed.

8, in addition to the VHF power supply unit 261 and the HF power supply unit 263, the plasma power supply unit 260 of the thin film deposition apparatus 200 may include an LF power supply unit 265 ). &Lt; / RTI &gt; The matching network 270 of the thin film deposition apparatus 200 may further include a third matching unit 275 connected to the LF power supply unit 265. The third matching unit 275 may match the output impedance of the LF power supply unit 265 with the load impedance in the chamber 200. The controller 201 also drives the VHF power supply 261 during the step of forming the seed layer 120 and forming the protective layer 140 by driving the LF power supply 265 during the preprocessing step , The HF power supply unit 263 can be driven in the step of forming the main thin film layer 130. [

In addition, the controller 201 may selectively perform the pre-treatment process by selectively driving the LF power supply unit 265 and the HF power supply unit 263 before the seed layer 120 is deposited.

The substrate processing system according to the present embodiments may be composed of thin film processing apparatuses including a plurality of plasma chambers provided with different plasma power sources.

Referring to FIG. 9, the substrate processing system 300 may include a first thin film deposition apparatus 310, a second thin film deposition apparatus 320, a pre-treatment apparatus 330, and a transfer chamber 340.

The first thin film deposition apparatus 310 may include a plasma chamber provided with a VHF power source generated from a VHF power supply unit. The first amorphous silicon film corresponding to the seed layer 120 may be formed on the semiconductor substrate by the plasma formed by the VHF power source.

The second thin film deposition apparatus 320 may include a plasma chamber provided with the HF power generated from the HF power supply unit. The second amorphous silicon film corresponding to the main thin film layer 130 may be formed on the first amorphous silicon film by the plasma formed by the HF power source.

The preprocessing apparatus 330 may be operated using a plasma formed by application of the HF power supply of the HF power supply unit and the LF power supply of the LF power supply unit having a center frequency band of 300 to 600 KHz.

The transfer chamber 340 may be configured to interconnect the first thin film deposition apparatus 310, the second thin film deposition apparatus 320, and the pre-processing apparatus 330. For example, the first thin film deposition apparatus 310, the second thin film deposition apparatus 320, and the pretreatment apparatus 330 may be disposed radially with respect to the transfer chamber 340.

In addition, as shown in FIG. 10, the first thin film deposition apparatus 310a may further include an LF power supply unit in addition to the VHF power supply unit. Accordingly, the seed layer 120 may be formed by a plasma formed by the VHF power source and the LF power source.

11, the first thin film deposition apparatus 310b may include both a VHF power supply unit, an HF power supply unit, and an LF power supply unit, and the second thin film deposition apparatus 320 may include an HF power supply unit . A plurality of the second thin film deposition apparatuses 320 may be provided in consideration of the thickness of the main thin film layer 130.

The seed layer 120 corresponding to the pretreatment process and the first amorphous silicon film may be performed in the first thin film deposition apparatus 310b. More specifically, the preprocessing process may be performed by a plasma formed by the LF power source in the first thin film deposition apparatus 310b, and the seed layer 120 may be formed by a plasma formed by the VHF power source and the LF power source . The second thin film deposition apparatus 320 can be disposed on both sides of the transfer chamber 340 and the first thin film deposition apparatus 310b on both sides of the first thin film deposition apparatus 310. By the simultaneous driving of the plurality of second thin film deposition apparatuses 320, Can be shortened.

As described in detail above, according to the present invention, a thin film layer which can be applied to a hard mask is formed by using a seed layer formed using a VHF plasma power source and a seed layer formed using the seed layer as a base and formed using an HF plasma power source And a main thin film layer.

Since the main thin film layer is formed based on the seed layer formed by using the VHF plasma power source, the problems due to the surface roughness characteristics and the stress can be improved, and the deposition rate and the etching rate can be satisfied at the same time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but variations and modifications may be made without departing from the scope of the present invention. Do.

100: semiconductor substrate 110:
120: seed layer 130: main thin film layer

Claims (19)

A method of forming an amorphous silicon film on a semiconductor substrate,
Forming a first amorphous silicon thin film on the semiconductor substrate using a process gas activated from a first plasma; And
Forming a second amorphous silicon thin film on the first amorphous silicon thin film using a process gas activated from a second plasma,
The first plasma is a VHF (very high frequency) power source having a center frequency band of 20 to 70 MHz,
Wherein the second plasma is a HF (high frequency) power source having a center frequency band of 10 to 20 MHz. The method according to claim 1,
Forming the first amorphous silicon thin film layer and forming the second amorphous silicon thin film layer in situ in the same chamber. 3. The method of claim 2,
Wherein the forming of the first amorphous silicon thin film layer and the forming of the second amorphous silicon thin film layer each proceed in different chambers. The method according to claim 1,
The first amorphous silicon thin film and the second amorphous silicon thin film are deposited using the same process gas,
Wherein the process gas comprises SiH4, He, and Ar. The method according to claim 1,
Wherein the first and second amorphous silicon films are used as a hard mask. The method according to claim 1,
After the step of forming the second amorphous silicon film,
And forming a third amorphous silicon film on the second amorphous silicon film using the first plasma. The method according to claim 6,
Wherein the first to third amorphous silicon films are formed in situ in the same chamber. The method according to claim 6,
Wherein the first to third amorphous silicon films are used as a hard mask. The method according to claim 1,
Before the step of forming the first amorphous silicon film,
Further comprising pretreating the substrate product using a low frequency (LF) power source having a center frequency between 300 KHz and 600 KHz. The method according to claim 1,
Wherein the step of forming the first amorphous silicon film and the step of forming the second amorphous silicon are repeated at least once or more. The method according to claim 1,
Wherein the thickness of the first amorphous silicon film is smaller than the thickness of the second amorphous silicon film. The method according to claim 1,
Wherein the thickness of the third amorphous silicon film is smaller than the thickness of the second amorphous silicon film. A thin film processing apparatus for forming a first amorphous silicon film on a semiconductor substrate using a first plasma and forming a second amorphous silicon film on the first amorphous silicon film using a second plasma,
A chamber for processing a semiconductor substrate by generating a plasma therein;
A gas supply device for injecting a process gas into the chamber;
A substrate supporting device installed to face the gas supply device and having a substrate placed thereon; And
A VHF power supply connected to the gas supply device for supplying the VHF power with a center frequency of 20 to 70 MHz to generate the first and second plasma in the chamber; And a plasma power supply unit including an LF power supply unit having a center frequency band of 300 to 600 KHz,
And a controller configured to apply the VHF power supply of the VHF power supply unit to generate the first plasma in the chamber when the first amorphous silicon film is formed. 14. The method of claim 13,
Wherein the controller is configured to apply HF power of the HF power supply when generating the second plasma in the chamber. 15. The method of claim 14,
Wherein the controller generates a plasma in the chamber configured to apply the HF power of the HF power supply and the LF power of the LF power supply to pre-process the semiconductor substrate prior to forming the first amorphous silicon film. 1. A substrate processing system for forming a first amorphous silicon film on a semiconductor substrate using a first plasma and then forming a second amorphous silicon film on the first amorphous silicon film using a second plasma,
A first thin film deposition apparatus for forming the first amorphous silicon film using a first plasma formed by a VHF power source generated from a VHF power supply unit on the semiconductor substrate;
A second thin film deposition apparatus for forming the second amorphous silicon film on the first amorphous silicon film by using a second plasma formed by an HF power source generated from an HF power supply unit; And
And a transfer chamber for interconnecting the first thin film deposition apparatus and the second thin film deposition apparatus,
The first plasma is generated by application of a VHF power source having a center frequency band of 20 to 70 MHz,
Wherein the second plasma is generated by application of an HF power source having a center frequency band of 10 to 20 MHz. 17. The method of claim 16,
Further comprising a pretreatment device connected to one side of the transfer chamber for pretreating the semiconductor substrate before forming the first amorphous silicon film,
Wherein the preprocessing apparatus uses plasma generated by applying an HF power supply of an HF power supply unit and an LF power supply of an LF power supply unit having a center frequency band of 300 to 600 KHz. 17. The method of claim 16,
The first thin film deposition apparatus may further include an LF power supply unit having a center frequency of 300 to 600 KHz,
Wherein the first plasma is generated by applying the VHF power supply and the LF. 19. The method of claim 18,
The first thin film deposition apparatus further includes an HF power supply unit having a central frequency band of 10 to 20 MHz,
Wherein prior to forming the first amorphous silicon film, pre-processing of the substrate proceeds using plasma generated by the HF power supply of the HF power supply and the LF power supply of the LF power supply.

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