WO2022114583A1

WO2022114583A1 - Showerhead and thin film deposition device including same

Info

Publication number: WO2022114583A1
Application number: PCT/KR2021/015892
Authority: WO
Inventors: 김형근
Original assignee: 한국전자기술연구원
Priority date: 2020-11-24
Filing date: 2021-11-04
Publication date: 2022-06-02
Also published as: KR20240035984A

Abstract

The present invention relates to a showerhead, which uniformly sprays gas on a substrate to deposit a thin film, and a thin film deposition device including same. The showerhead according to the present invention includes a first showerhead and a second showerhead. A plurality of first spray nozzles for dispersing gas supplied from a gas supply pipe and spraying the gas downward are formed in a radial pattern on the first showerhead. Also, the second showerhead is installed below the first showerhead and has a larger spray surface than the first showerhead, and a plurality of second spray nozzles for dispersing the gas supplied from the first showerhead and spraying the gas on the substrate positioned below are formed in a radial pattern on the second showerhead.

Description

Shower head and thin film deposition apparatus including same

The present invention relates to a thin film deposition apparatus, and more particularly, to a shower head for depositing a thin film by uniformly spraying a gas on a substrate, and a thin film deposition apparatus including the same.

For reference, this invention is being carried out with support from the national R&D project described in the patent application and the Gyeonggi-do semiconductor/display material/parts equipment industry independence research support project.

Thin film deposition technology is a technology mainly used in semiconductor manufacturing processes. It uses plasma and heat to form a thin film on a substrate such as a semiconductor wafer by using gaseous chemical substances, or for isolation of metal lines or other purposes. It is a process aimed at

Thin film deposition technology is a method of depositing insulating materials, semiconductors, metals, etc., mainly using chemical reactions of gases, and is used to deposit specific materials on the surface of a substrate.

Examples of such thin film deposition techniques include chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD).

Although the detailed mechanism used in thin film deposition technology varies depending on the type of thin film deposition technology, gas flows into the chamber and has a common mechanism of depositing a thin film on a substrate through a reaction.

In such a thin film deposition apparatus, a shower head is used as a mechanism for introducing a gas into the chamber. The shower head has a two gas line structure. The reason why the two gas line structure is designed is to differentiate the reaction (precursor) and purge steps, and to generate a more uniform flow due to the characteristics of the ALD process, which has a relatively short precursor injection time compared to other gas injection times. Here, the first gas line may supply a precursor. The second gas line may supply a reactant gas or a purge gas.

At this time, the first gas line through which the precursor having a relatively low vapor pressure passes has a multi-layered structure in order to make the flow of the precursor as uniform as possible in a wide space. That is, the second gas line may include a two-stage shower head. The two-stage shower head includes a first shower head and a second shower head below the first shower head. The second shower head is larger than the first shower head.

The first and second shower heads each have a plurality of first and second spray nozzles. The number of second spray nozzles provided in the second shower head is greater than the number of first spray nozzles provided in the first shower head. The precursor supplied through the first gas line is injected to the substrate through the second shower head via the first shower head. In addition, the reactive gas and the purge gas supplied through the second gas line are sprayed onto the substrate through the second shower head.

In a conventional shower head, spray nozzles are formed in a rectangular pattern to uniformly spray gas on a substrate. That is, the spray nozzles are formed in the shower head in an m×n matrix.

In the shower head having such a rectangular pattern spray nozzle, when the diameter of the shower head increases as the size of the substrate on which the thin film is to be deposited increases, the distribution of the gas injected through the shower head is different from the center portion and the edge portion. Occurs. That is, there is a problem in that the gas is not uniformly distributed throughout the substrate. The non-uniform injection of the gas causes a problem in that the thin film cannot be deposited to a uniform thickness on the substrate.

[Prior art literature]

[Patent Literature]

Registered Patent Publication No. 10-2126091 (2020.06.24. Announcement)

Accordingly, an object of the present invention is to provide a shower head for depositing a thin film by uniformly spraying a gas on a substrate, and a thin film deposition apparatus including the same.

In order to achieve the above object, the present invention provides a first shower head in which a plurality of first spray nozzles for dispersing and spraying down the gas supplied to the gas supply pipe are radially formed; and a plurality of second spray nozzles installed under the first shower head and having a larger spray surface than the first shower head, and for dispersing the gas supplied from the first shower head and spraying the gas onto the substrate positioned below. It provides a shower head for a thin film deposition apparatus comprising a; a second shower head formed in a radial shape.

The first and second shower heads have a disk shape, and the first and second spray nozzles are formed radially with respect to the center of the disk.

A first radiation angle between adjacent first spray nozzles with respect to the center of the first shower head is greater than a second radiation angle between adjacent second spray nozzles of the second shower head.

The first radiation angle may be twice the second radiation angle.

The number of spray nozzles formed on the radiation is greater in the second shower head than in the first shower head.

The first shower head may include a first body having a plurality of first through holes radially formed with respect to a center thereof; and a plurality of first injection nozzles respectively installed in the plurality of first through holes and protruding from the lower surface of the first body.

The second shower head may include a second body having a plurality of second through holes radially formed with respect to a center thereof; and a plurality of second injection nozzles respectively installed in the plurality of second through holes and protruding from the lower surface of the second body.

The first shower head may not have a first through hole formed in its center, and the second shower head may have the second through hole formed in its center.

The first and second spray nozzles may be formed on a plurality of circumferences having different radii with respect to the center.

A distance between adjacent first spray nozzles positioned on the same radiation may be the same, and a distance between adjacent second spray nozzles positioned on the same radiation may be the same.

A distance between adjacent first spray nozzles positioned on the same radiation may be the same as a distance between adjacent second spray nozzles positioned on the same radiation.

The present invention also includes a stage on which a substrate is mounted and fixed on the upper surface; the shower head installed on the stage and supplying gas to the substrate; and a gas supply pipe for supplying gas to the shower head.

In addition, when the distance between the second injection nozzle and the substrate is 25 mm, the gas flow uniformity at a position 1 mm to 7 mm away from the substrate is higher than other heights.

According to the present invention, by forming the spray nozzle radially in the shower head, the gas is uniformly sprayed on the substrate, and through this, a thin film can be deposited on the substrate with a uniform thickness. That is, since the semiconductor wafer used as the substrate is circular, the gas can be uniformly sprayed onto the semiconductor wafer through the spray nozzle by forming the spray nozzle in a radial shape to correspond to the shape of the semiconductor wafer.

The shower head according to the present invention has the same distance between neighboring spray nozzles on the same radiation, but by forming the radiation angle of the spray nozzle of the second shower head narrower than that of the first shower head, finally spraying through the second shower head It is possible to increase the uniformity of the gas used. That is, since the first and second spray nozzles are formed in the first and second shower heads in a radial and circular pattern, the uniformity of the gas finally sprayed through the second shower head may be increased.

In the shower head according to the present invention, when the second shower head is viewed from above the first shower head, the first and second spray nozzles are uniformly disposed on the spray surface while reducing the number of overlapping first and second spray nozzles By doing so, it is possible to increase the uniformity of the gas injected through the second shower head.

Since the radial spray nozzle according to the present invention can reduce the number of spray nozzles formed in the shower head compared to the conventional square pattern spray nozzle, it is possible to simplify the manufacturing process of the shower head and lower the manufacturing cost. have.

1 is a view showing a thin film deposition apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating the first shower head of FIG. 1 .

3 is a plan view of the first shower head of FIG. 2 .

4 is a perspective view illustrating a second shower head of FIG. 1 .

FIG. 5 is a plan view illustrating the second shower head of FIG. 4 .

6 is a plan view illustrating a first shower head according to a comparative example.

7 is a plan view illustrating a second shower head according to a comparative example.

8 is an image showing a simulation result of gas flow using a shower head according to a comparative example.

9 is an image showing a result of simulating the flow of gas using the shower head according to the embodiment.

10 is a graph showing the flow uniformity of gas in shower heads according to Examples and Comparative Examples.

11 is an image showing gas distribution at a height of 5 mm from a substrate in shower heads according to Examples and Comparative Examples.

It should be noted that, in the following description, only parts necessary for understanding the embodiments of the present invention will be described, and descriptions of other parts will be omitted without departing from the gist of the present invention.

The terms or words used in the present specification and claims described below should not be construed as being limited to their ordinary or dictionary meanings, and the inventors have appropriate concepts of terms to describe their invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined in Accordingly, the embodiments described in this specification and the configurations shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention, so various equivalents that can be substituted for them at the time of the present application It should be understood that there may be variations and variations.

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

Referring to FIG. 1 , the thin film deposition apparatus 100 according to the embodiment includes a stage 20 , a shower head 30 , and a gas supply pipe 60 . The stage 20 is fixed by mounting a substrate 70 on its upper surface. The shower head 30 is installed on the stage 20 , and supplies gas onto the substrate 70 . In addition, the gas supply pipe 60 supplies a gas required for thin film deposition to the shower head 30 .

In addition, the thin film deposition apparatus 100 according to the embodiment may further include a chamber 10 . A portion of the stage 20 on which the substrate 70 is mounted, and a portion of the shower head 30 and the gas supply pipe 60 may be installed in the chamber 10 .

The shower head 30 according to the embodiment may be used to supply a precursor to the substrate 70 . The shower head 30 according to this embodiment includes a first shower head 40 and a second shower head 50 . The first shower head 40 has a plurality of first spray nozzles 45 that disperse and spray the gas supplied to the gas supply pipe 60 in a radial shape. In addition, the second shower head 50 is installed under the first shower head 40 and has a larger spray surface than the first shower head 40 by dispersing the gas supplied from the first shower head 40 to the bottom. A plurality of second spray nozzles 55 for spraying onto the substrate 70 positioned in the radial direction are formed.

The shower head 30 according to this embodiment will be described with reference to FIGS. 1 to 5 as follows. Here, FIG. 2 is a perspective view showing the first shower head 40 of FIG. 1 . 3 is a plan view of the first shower head 40 of FIG. 2 . 4 is a perspective view illustrating the second shower head 50 of FIG. 1 . And FIG. 5 is a plan view showing the second shower head 50 of FIG. 4 .

The gas supply pipe 60 supplies gas to the first shower head 40 . Here, the gas supplied to the first gas supply pipe 60 may be a precursor. That is, the gas supply pipe 60 forms a first gas line together with the first and second shower heads 40 and 50 .

Although not shown, a gas supply pipe (hereinafter, referred to as a second gas supply pipe) for directly supplying gas to the second shower head 50 may be further included. The gas supplied to the second gas supply pipe may include a reaction gas and a purge gas. That is, the second gas supply pipe forms a second gas line together with the second shower head 50 .

The first and second shower heads 40 and 50 have a disk shape, and first and

second spray nozzles

45 and 55 are formed radially with respect to the center of the disk. The second shower head 50 is disposed under the first shower head 40 , and the first and second shower heads 40 and 50 are vertically disposed so that their centers coincide.

The second shower head 50 is larger than the first shower head 40 . That is, the radius R2 of the second shower head 50 is greater than the radius R1 of the first shower head 40 , and the lower surface of the second shower head 50 on which the second spray nozzle 55 is formed is formed of a thin film. It may include or have an area corresponding to the upper surface of the substrate 70 to be deposited.

As described above, by forming the first and

second spray nozzles

45 and 55 in a radial shape on the shower head 30 , the gas is uniformly sprayed on the substrate 70 , and through this, a thin film is formed on the substrate 70 to a uniform thickness. can be deposited with That is, since the semiconductor wafer used as the substrate 70 is circular, the first and second injection nozzles 45, 55), the gas can be uniformly sprayed onto the semiconductor wafer.

The first shower head 40 includes a first body 41 and a plurality of first spray nozzles 45 . The first body 41 has a plurality of first through holes 43 radially formed with respect to the center. In addition, the plurality of first spray nozzles 45 are respectively installed in the plurality of first through holes 43 to protrude from the lower surface of the first body 41 .

The second shower head 50 includes a second body 51 and a plurality of second spray nozzles 55 . The second body 51 has a plurality of second through holes 53 radially formed with respect to the center thereof. In addition, the plurality of second injection nozzles 55 are respectively installed in the plurality of second through holes 53 to protrude from the lower surface of the second body 51 .

In this case, the first and second shower heads 40 and 50 may be formed as follows so that the gas can be uniformly sprayed onto the substrate 70 through the shower head 30 according to the embodiment.

The first shower head 40 does not have the first through hole 43 formed in the center, and the second shower head 50 has the second through hole 53 formed in the center. The plurality of first and

second injection nozzles

45 and 55 are formed on a plurality of circumferences having different radii with respect to the center. That is, the plurality of first and

second spray nozzles

45 and 55 are formed in a radial shape, and are formed in a circular pattern with different radii.

The distance between the adjacent first spray nozzles 45 positioned on the same radiation may be the same. The distance between the adjacent second injection nozzles 55 positioned on the same radiation may be the same. That is, in circular patterns having different radii, the difference in radii between neighboring perimeters may be the same. Here, the radiation refers to a straight line drawn out from the centers of the first and second shower heads 40 and 50 .

The distance between the adjacent first spray nozzles 45 positioned on the same radiation and the distance between the adjacent second spray nozzles 55 positioned on the same radiation may be the same.

As such, the shower head 30 according to the embodiment reduces the number of overlapping first and

second spray nozzles

45 and 55 when the second shower head 50 is viewed from above the first shower head 40 . While the first and

second spray nozzles

45 and 55 are uniformly disposed on the spray surface as a whole, the uniformity of the gas sprayed through the second shower head 50 may be increased. By increasing the uniformity of the gas, the deviation of the gas flow between the center and the edge of the substrate 70 is reduced, so that a thin film having a uniform thickness can be deposited on the entire surface of the substrate 70 .

The first shower head 40 has a first radiation angle θ1 between the adjacent first spray nozzles 45 with respect to the center of the second shower head 50 and the second radiation between the adjacent second spray nozzles 55 of the second shower head 50 . greater than the angle θ2. For example, the first radiation angle θ1 may be twice the second radiation angle θ2. The number of the first and

second spray nozzles

45 and 55 formed on the radiation is greater in the second shower head 50 than the first shower head 40 .

As described above, in the shower head 30 according to the embodiment, the spacing between neighboring spray nozzles on the same radiation is the same, but the second spray nozzle 55 of the second shower head 50 is less than the first shower head 40 . By forming the radiation angle θ2 to be narrow, the uniformity of the gas finally injected through the second shower head 50 may be increased. That is, since the first and

second spray nozzles

45 and 55 are formed in the first and second shower heads 40 and 50 in a radial and circular pattern, the gas finally injected through the second shower head 50 . can increase the uniformity of

In addition, the distance between the second spray nozzle 55 of the shower head 30 and the substrate 70 according to the embodiment is also a factor affecting the uniformity of the gas. In order to ensure uniform gas uniformity over the entire surface of the substrate 70 , it is necessary to maintain a distance between the second spray nozzle 55 of the shower head 30 and the wafer at about 25 mm. When the distance between the second injection nozzle and the wafer is maintained at about 25 mm, the gas flow uniformity at a position 1 mm to 7 mm away from the substrate is high. Preferably, the gas flow uniformity is maximized at a location about 5 mm away from the substrate.

In order to check whether the shower head 30 according to this embodiment uniformly sprays gas, the flow uniformity of the gas was confirmed through simulation together with the shower head according to the comparative example. Here, ANSYS Fluent was used as the simulation software.

6 is a plan view illustrating the first shower head 140 according to a comparative example. And FIG. 7 is a plan view showing the second shower head 150 according to the comparative example.

6 and 7 , the shower head according to the comparative example includes first and second shower heads 140 and 150 . The plurality of first and second shower heads 140 and 150 include a plurality of first and second spray nozzles 145 and 155 each formed in a rectangular pattern. A plurality of first and second spray nozzles 145 and 155 are formed in the first and second shower heads 140 and 150 in an m×n matrix.

The first shower heads 40 and 140 and the second shower heads 50 and 150 according to the embodiment and the comparative example have the same size in the form of a disk.

Table 1 shows the number of the first spray nozzles 45 and 145 and the second spray nozzles 55 and 155 according to the embodiment and the comparative example.

	제1 분사 노즐first spray nozzle	제2 분사 노즐second spray nozzle
실시예Example	6868	5252
비교예comparative example	184184	185185

It can be seen that the number of the first and second spray nozzles 145 and 155 according to the comparative example is greater than the number of the first and

second spray nozzles

45 and 55 according to the embodiment.

As gases supplied to the shower head according to Examples and Comparative Examples, argon (Ar) gas and nitrogen (N ₂ ) gas were used.

The flow uniformity of the gas was analyzed by simulating the flow of nitrogen (N ₂ ) gas into argon gas in the shower head according to Examples and Comparative Examples, respectively. At this time, although the analysis result of the simulation may be partially different depending on the type of gas injected into the shower head, it is determined that there is no significant difference from the analysis result of the present simulation.

And the gas flow uniformity was analyzed in a state where the distance between the shower head and the substrate was maintained at about 25 mm. The gas flow uniformity was analyzed at positions with heights of 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, and 25 mm from the substrate.

Here, the reason for maintaining the distance between the shower head and the substrate at about 25 mm is as follows. This is because, as a result of the flow analysis according to the position of the substrate, the gas flow uniformity was analyzed the highest at a height of about 25 mm. That is, when the height of the second injection nozzle and the substrate was less than or greater than 25 mm, it was interpreted that the gas flow in the vicinity of the wafer became non-uniform.

8 is an image showing a simulation result of gas flow using a shower head according to a comparative example. And FIG. 9 is an image showing a result of simulating the flow of gas using the shower head according to the embodiment. Here, the distance between the shower head and the substrate was maintained at about 25 mm.

8 and 9, the shower head according to the embodiment, compared with the shower head according to the comparative example, the height from the substrate is 1mm, 5mm, 10mm, 15mm, 20mm, 25mm at positions of a uniform gas flow can be checked.

Referring to FIG. 10 , it can be seen that the gas flow uniformity is maximized at a height of about 5 mm from the substrate in both the shower heads according to the embodiment and the comparative example.

Furthermore, in the shower head according to the embodiment, when the distance between the second spray nozzle and the wafer is maintained at about 25 mm, it can be confirmed that the gas flow uniformity is high at a position 1 mm to 7 mm away from the substrate.

Referring to FIG. 11 , a red circular dotted line indicates the substrate 70 . As the substrate 70, an 8-inch semiconductor wafer was exemplified.

In the shower head according to the comparative example, it can be seen that the gas flow at the edge of the substrate 70 is smaller than the gas flow at the center of the substrate 70 and is non-uniformly distributed. That is, it can be seen that the gas injected from the shower head according to the comparative example is not uniformly distributed over the entire surface of the substrate 70 .

On the other hand, in the shower head according to the embodiment, it can be seen that the flow of gas is uniformly distributed at the edge and the center of the substrate 70 . That is, it can be seen that the gas injected from the shower head according to the embodiment is uniformly distributed over the entire surface of the substrate 70 .

And, the

radial spray nozzles

45 and 55 according to the embodiment have the number of

spray nozzles

45 and 55 formed in the shower head 30 compared to the square pattern spray nozzles 145.155 according to the comparative example. Since it can be reduced, the manufacturing process of the shower head 30 according to the embodiment can be simplified and the manufacturing cost can be lowered.

On the other hand, the embodiments disclosed in the present specification and drawings are merely presented as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

[Explanation of code]

10: chamber

20: Stage

30 : shower head

40, 140: first shower head

41, 141: first body

43, 143: first through hole

45, 145: first injection nozzle

50, 150: second shower head

51, 151: second body

53, 153: second through hole

55, 155: second injection nozzle

60: gas supply pipe

70: substrate

100: thin film deposition device

Claims

a first shower head in which a plurality of first spray nozzles for dispersing and spraying the gas supplied to the gas supply pipe are radially formed; and

A plurality of second spray nozzles installed under the first shower head and having a larger spray surface than the first shower head and dispersing the gas supplied from the first shower head and spraying the gas onto the substrate positioned below are radial. A second shower head formed of;

A shower head for a thin film deposition apparatus comprising a.
According to claim 1,

The first and second shower heads have a disk shape, and the shower head for a thin film deposition apparatus, characterized in that the first and second spray nozzles are formed radially with respect to the center of the disk.
3. The method of claim 2,

The shower head for a thin film deposition apparatus, characterized in that a first radiation angle between adjacent first spray nozzles with respect to the center of the first shower head is greater than a second radiation angle between adjacent second spray nozzles of the second shower head. .
4. The method of claim 3,

The first radiation angle is a shower head for thin film deposition, characterized in that twice the second radiation angle.
4. The method of claim 3,

The shower head for a thin film deposition apparatus, characterized in that the number of spray nozzles formed on the radiation is greater in the second shower head than in the first shower head.
According to claim 2, wherein the first shower head,

a first body having a plurality of first through holes radially formed with respect to the center; and

and a plurality of first injection nozzles respectively installed in the plurality of first through-holes and protruding from the lower surface of the first body;

The second shower head,

a second body having a plurality of second through holes radially formed with respect to the center; and

the plurality of second injection nozzles respectively installed in the plurality of second through holes and protruding from the lower surface of the second body;

A shower head for a thin film deposition apparatus comprising a.
7. The method of claim 6,

The shower head for a thin film deposition apparatus, characterized in that the first shower head does not have a first through hole formed in the center, and the second shower head has the second through hole formed in the center.
7. The method of claim 6,

The shower head for a thin film deposition apparatus, characterized in that the first and second spray nozzles are formed on a plurality of circumferences having different radii with respect to the center.
9. The method of claim 8,

A showerhead for a thin film deposition apparatus, characterized in that the distance between the adjacent first spray nozzles positioned on the same radiation is the same, and the distance between the adjacent second spray nozzles positioned on the same radiation is the same.
10. The method of claim 9,

A shower head for a thin film deposition apparatus, characterized in that the distance between the adjacent first spray nozzles positioned on the same radiation and the distance between the adjacent second spray nozzles positioned on the same radiation are the same.
a stage on which the substrate is mounted and fixed on the upper surface; and

a shower head installed on the stage and supplying gas to the substrate;

Including; a gas supply pipe for supplying gas to the shower head;

The shower head is

a first shower head in which a plurality of first spray nozzles for dispersing the gas supplied to the gas supply pipe and spraying the gas downward are radially formed; and

A plurality of second spray nozzles installed under the first shower head and having a larger spray surface than the first shower head, and for dispersing the gas supplied from the first shower head and spraying the gas onto the substrate positioned below. a second shower head radially formed;

A thin film deposition apparatus comprising a.
12. The method of claim 11,

When the distance between the second injection nozzle and the substrate is 25 mm, the gas flow uniformity at a position 1 mm to 7 mm away from the substrate is higher than other heights.