KR101125008B1 - Downward type deposition source and deposition apparatus having the same - Google Patents

Abstract

The present invention includes a main body, a crucible provided in the main body and containing a vapor deposition material in the upper part of the upper part of which has a cover for sealing and an opening made of a porous plate at the lower part thereof, and surrounding the crucible at a middle height of the crucible. A top-down evaporation source comprising a first coil disposed therein and a second coil under which the high frequency induction current is applied, and a second coil under which the high frequency induction current is applied. According to the present invention, by placing at least one evaporation source on the upper part of the chamber of the vapor deposition apparatus so that the molecular beams can be supplied downward, by using high frequency induction heating to ensure the uniformity of the thin film formed on the large area substrate Since the heating time of the source can be shortened, there is an effect of enabling a low-cost thin film production.

Description

Downward type deposition source and deposition apparatus having the same

The present invention relates to a top-down evaporation source using high frequency induction heating and a deposition apparatus having the same, and more particularly, by placing the evaporation source on the upper part of the chamber so that molecular beams can be supplied downward, and using high frequency induction heating, a large area The present invention relates to a top-down evaporation source and a deposition apparatus having the same, which enables securing a uniformity of a thin film formed on a substrate and shortening a heating time of a source, thereby enabling a low cost thin film production.

In general, an evaporation source refers to a source for vaporizing a material for physical vapor deposition, and can be broadly divided into a thermal evaporation source using heating, a sputtering evaporation source vaporizing by momentum transfer, and an arc evaporation source generating steam by an arc. Among these, the thermal evaporation source typically includes a resistance heating evaporation source and an electron beam evaporation source. A resistance heating evaporation source is a vaporization of evaporates contained therein by flowing a current through a heating source having a relatively high resistance, and using it, has a low melting point. Low-reaction metals can be evaporated relatively easily and can easily form thin films with high purity.

A vapor deposition apparatus using such an evaporation source is used for thin film deposition of various electronic components, and is particularly used for thin film formation of semiconductors, LCDs, organic light emitting display devices, and solar cells.

On the other hand, photovoltaic solar cells include crystalline silicon solar cells, amorphous silicon solar cells, CIGS solar cells, GaAs solar cells, and CdTe solar cells. Among them, CIGS, a compound semiconductor formed in CIGS solar cells, is directly above 1 eV. It has a transition type energy band gap, has the highest light absorption coefficient among semiconductors, and is very optically stable, making it an ideal material for the light absorption layer of solar cells. Have

Such a CIGS solar cell is generally deposited by mixing a compound of CIGS, that is, copper (Cu), indium (In), gallium (Ga), selenium (Se) on a glass substrate coated with molybdenum (Mo), and Cadmium sulfide (CdS), zinc oxide (ZnO), and magnesium fluoride (MgF 2) are sequentially formed thereon, and then aluminum (Al) electrodes are finally formed on top of magnesium fluoride. Here, the most important factor for determining the efficiency of the CIGS solar cell is the quality of the CIGS film, and deposition is generally used to form a CIGS film having high efficiency.

According to the conventional vapor deposition apparatus, when forming a CIGS film, copper, indium, gallium and selenium are simultaneously evaporated using an evaporation source, and the evaporated gas is sprayed from the bottom of the substrate toward the substrate to form the CIGS film on the substrate. It is.

1 is a cross-sectional view schematically illustrating a conventional bottom-up deposition apparatus. As shown therein, a substrate 40 is installed in an upper portion of a chamber 10 of a vacuum and an evaporation source 30 is installed in a lower portion thereof. By heating the deposition material contained in 30) to vaporize the deposition material, as the gas rises in a high vacuum to reach the substrate 40 to solidify, a thin film is formed on the substrate 40.

Recently, deposition on large-area substrates has been widely used. In this case, if a conventional bottom-up deposition apparatus is used, a phenomenon that sagging by the weight of the substrate may occur as the substrate is fixed on an evaporation source, thereby forming a uniform thin film. There was a fatal problem.

Accordingly, the present invention has been made to solve the above problems, by arranging the evaporation source in the upper portion of the chamber so that the molecular beam can be supplied down, by using high frequency induction heating, to ensure the uniformity of the thin film formed on the large-area substrate And it is an object of the present invention to provide a top-down evaporation source and a deposition apparatus having the same that can reduce the heating time of the source to enable a low-cost thin film production.

In order to achieve the above object, the top-down evaporation source according to the present invention includes a main body, a crucible having an injection hole formed in the main body and receiving the deposition material, and having a cover for sealing at the upper part of the opening and a porous plate at the lower part thereof. And a first coil disposed to surround the crucible at a middle height of the crucible and to which a high frequency induction current is applied, and a second coil disposed below the first coil to surround the injection port of the crucible and to which a high frequency induction current is applied. It characterized in that it comprises a coil.

In addition, the deposition apparatus according to the present invention includes a vacuum chamber, a substrate support provided at a lower portion of the chamber to support a substrate, and at least one evaporation source for inserting a deposition gas into the chamber by inserting at least a portion thereof into an upper portion of the chamber. In the evaporation apparatus comprising a, the evaporation source, the crucible is provided in the main body, the crucible is formed in the main body and the injection opening is formed in the upper part is coupled to the cover for sealing and the lower part of the porous plate, A first coil disposed to surround the crucible at an intermediate height of the first coil to which a high frequency induction current is applied, and a second coil disposed below the first coil to surround the injection port of the crucible and to which a high frequency induction current is applied. It is characterized by.

As described above, according to the present invention, at least one evaporation source is disposed on the upper part of the chamber of the deposition apparatus so that molecular beams can be supplied downward, and by using high frequency induction heating, the uniformity of the thin film formed on the large-area substrate is ensured. Since the heating time of the source can be shortened, there is an effect of enabling a low-cost thin film production.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention unclear.

Figure 2 is a schematic cross-sectional view showing a top down evaporation source according to the present invention. As shown therein, the evaporation source 30 includes a main body 31 and a spray hole provided in the main body 31 and containing a deposition material in the upper part of the upper part of which is opened, and a cover 32 for sealing is coupled to the lower part. A crucible 33 having a 34 formed therein, a first coil 35 disposed to surround the crucible 33 at a middle height of the crucible 33, to which a high frequency induction current is applied, and the first coil 35. The second coil 37 is disposed to surround the injection hole 34 of the crucible 33 and to which a high frequency induction current is applied.

The main body 31 is formed in a cylindrical or polygonal box shape, and a discharge port is formed in the lower part of the main body 31. The main body 31 supports and protects the crucible 33 and coils 35 and 37 which will be described later, and shields the heat generated from the coils 35 and 37 from dissipating in an undesired direction. Play a role.

In addition, the inside of the main body 31 is provided with a crucible 33 for receiving and storing the deposition material. The upper part of the crucible 33 is opened, and the deposition material accommodating space of a predetermined size is provided therein. Therefore, the deposition material to be deposited on the substrate 40 is in the deposition material receiving space. The deposition material may be either inorganic material or metal, and is contained in the crucible 33 in the form of pellets.

The crucible 33 may be formed of graphite, an electrically insulating ceramic such as PBN (Pyrolytic Boron Nitride) or alumina. Here, since the PBN is inert to corrosive gas, has excellent workability, is stable even at high temperature after sintering, has high electrical resistance and has very good thermal conductivity, it is preferable to form the crucible 33 with PBN. Accordingly, when the crucible 33 is heated using the coils described below, the crucible 33 is heated very quickly.

A cover 32 for sealing the crucible 33 is coupled to an upper portion of the opened crucible 33, and a spray hole 34 made of a porous plate is formed at the lower portion of the crucible 33, so that the crucible 33 The vapor deposition material inside the evaporation is discharged to the outside through the injection hole 34.

Between the main body 31 and the crucible 33 is provided with a first coil 35 and a second coil 37 along the outside of the crucible 33, the first coil 35 is a crucible 33 It is arranged to surround the crucible 33 at the middle height of the high frequency induction current is applied, the second coil 37 is the injection hole 34 of the crucible 33 below the first coil 35 and It is arranged to surround the lower end and a high frequency induction current is applied. When a high frequency current of approximately 10 kHz or more is applied to these coils 35 and 37 connected to an external power source, a conductor such as a metal located in the coil through which the high frequency current flows causes resistance of eddy current loss and hysteresis loss. Heats rapidly. This heating can be achieved by controlling the amount of current supplied to reach the vaporization temperature in the shortest possible time.

At this time, the first coil 35 heats the deposition material at the intermediate height of the crucible 33, and the second coil 37 around the injection hole 34 is the first coil 35 located thereon. In order to prevent the heated deposit from flowing down and condensation again, the deposit is continuously heated. Although the temperature of the first coil 35 and the second coil 37 may be the same, the temperature of the second coil 37 may be higher than that of the first coil 35. In this crucible 33, the straight line moves smoothly without condensation to the discharge port of the main body 31, and then the molecular beam is directed toward the substrate. At this time, while the deposition material such as, for example, the metal contained in the lower portion of the crucible 33 is melted, the deposition material on the upper portion may continue to be supplied due to its weight. The surface tension causes evaporation without falling off the injection hole 34.

The evaporation source 30 may be further provided with a temperature sensor (not shown) for measuring the temperature at which the deposition material contained in the crucible 33 is vaporized, thereby maintaining a temperature rising rate or a set temperature in a predetermined range. Control can be performed. In addition, a cooling means (not shown) may be further provided in the main body 31 to prevent heat generated from the crucible 33 from being transferred to the main body 31.

3 is a cross-sectional view schematically showing a first embodiment of a deposition apparatus having a top-down evaporation source according to the present invention. As shown therein, the deposition apparatus according to the first embodiment of the present invention includes a vacuum chamber 10, a substrate support 20 provided below the chamber 10 to support the substrate 40, At least a part of the chamber 10 is inserted into the upper portion and includes at least one evaporation source 30 to provide a deposition gas in the chamber 10.

In addition, the evaporation source is shown in Figure 2 and as described above, the main body 31, the cover 32 for sealing is coupled to the upper portion is provided in the main body 31 and accommodates the evaporation material, the opening and the lower portion A crucible (33) having an injection hole (34) formed of a porous plate, a first coil (35) disposed to surround the crucible (33) at a middle height of the crucible (33), to which a high frequency induction current is applied, and A second coil 37 is disposed below the first coil 35 to surround the injection hole 34 of the crucible 33 and to which a high frequency induction current is applied.

The chamber 10 is formed in a cylindrical or polygonal box shape, and a space for processing the substrate 40 is provided therein. The shape of the chamber 10 is not limited, and is preferably formed to correspond to the shape of the substrate 40. For example, when forming a CIGS film for a CIGS solar cell as described above, a rectangular glass substrate is used. Accordingly, the shape of the chamber 10 is formed in a rectangular box shape corresponding to the glass substrate. That's it. A substrate entrance 11 may be formed at one side wall of the chamber 10 to allow the substrate 40 to enter and exit. In the bottom surface of the chamber 10, a turbo may be formed to form a vacuum in the chamber 10 during the deposition process. Molecular pumps (not shown) may be connected. Although the chamber 10 is shown integrally in the figure, the chamber 10 can also be configured as a vertical separation type.

The substrate support 20 is positioned below the chamber 10 and serves to seat the substrate 40 introduced into the chamber 10. In general, the shape of the substrate support 20 may be formed to correspond to the shape of the substrate 40. For example, when forming a CIGS film for a CIGS solar cell, the rectangular glass substrate may be formed to correspond to the shape of the rectangular glass substrate. As such, since the substrate 40 is positioned below the chamber 10 and is supported by the substrate support 20, the substrate 40 may be sag due to the weight of the substrate 40.

The lower portion of the substrate support 20 may be provided with a driving means 21 having a motor to rotate the substrate support 20. In addition, the substrate support 20 may be provided with a heating means (not shown) for heating the substrate 40 to a predetermined temperature, a mask having a predetermined pattern formed on the upper surface of the substrate 40 45 may be located.

At least one evaporation source 30 may be installed at least partially inserted into the chamber 10 to face the substrate 40. The detailed structure of this evaporation source 30 is as above-mentioned. Here, the number of the evaporation source 30 is installed and the direction in which the deposition material is injected may be changed, a single evaporation source 30 may be used, a plurality of concentric circles so that a plurality of evaporation sources 30 uniformly spray the deposition material Of course, the phases may be arranged collectively or at intervals. The evaporation source 30 is preferably positioned approximately vertically, but may also have an inclination of approximately 70 degrees to 110 degrees with respect to the horizontally placed substrate 40. In conclusion, one evaporation source 30 or a plurality of evaporation sources 30 may be disposed at appropriate inclinations and intervals in various forms that may increase the uniformity of the thin film throughout the substrate 40.

When a plurality of evaporation sources 30 are used, the same or different evaporation temperatures may be supplied. For example, in the case of forming a CIGS film for a CIGS solar cell as described above, copper (Cu), indium (In), gallium (Ga), and selenium (Se) are supplied to four evaporation sources 30, respectively, to a substrate. It can deposit on (10). As described above, by being able to deposit various kinds of deposition materials having different vaporization temperatures on the substrate 10 at the same time, it is possible to produce a new functional thin film.

Figure 4 is a cross-sectional view schematically showing a second embodiment of the deposition apparatus with a top-down evaporation source according to the present invention, the second embodiment is the arrangement and substrate support of the evaporation source 30 for the first embodiment described above ( Only the configuration of 20) is different, and other components are the same as in the first embodiment, and thus descriptions of the same components will be omitted.

As shown in FIG. 4, the deposition apparatus according to the second embodiment of the present invention includes a vacuum chamber 10 and a substrate support 20 provided below the chamber 10 to support the substrate 40. And at least one evaporation source 30 installed above the chamber 10 to provide deposition gas in the chamber 10.

The substrate support 20 is located below the chamber 10 and has a conveying means 22 for horizontally moving the substrate 40 drawn into the chamber 10, which conveying means 22 is provided. It may be configured by a roller or a belt or a combination thereof. At this time, the substrate entrance 11 for entering and withdrawing the substrate 40 is formed on both side walls of the chamber 10.

In addition, at least one evaporation source 30 may be installed to face the substrate 40 in the upper portion of the chamber 10. Accordingly, the deposition material sprayed from the evaporation source 30 is deposited on the upper surface of the substrate 40 while the substrate 40 seated on the substrate support 20 moves. According to a process, a plurality of evaporation sources 30 may be arranged in a line, and a plurality of evaporation sources 30 may be supplied with deposition materials having the same or different vaporization temperatures from each other. For example, in the case of forming a CIGS film for a CIGS solar cell as described above, copper (Cu), indium (In), gallium (Ga), and selenium (Se) are supplied to four evaporation sources 30, respectively, to a substrate. It can deposit sequentially on (10).

Due to such a configuration, the processing speed of the large-area substrate 40 is increased, and at the same time, the deposition efficiency of the thin film is increased.

5 is a cross-sectional view schematically showing a third embodiment of a deposition apparatus having a top-down evaporation source according to the present invention, the third embodiment of the above-described first embodiment of the evaporation source 30 and the substrate support ( Only the configuration of 20) is different, and other components are the same as in the first embodiment, and thus descriptions of the same components will be omitted.

As shown in FIG. 5, in the deposition apparatus according to the third embodiment of the present invention, an evaporation source transfer device 50 capable of horizontally moving the evaporation source 30 according to the present invention in an upper portion of the chamber 10 is provided. It is installed. At this time, the evaporation source transfer device 50 is a device suitable for use in the chamber 10 maintained in vacuum, it is possible to adjust the moving speed of the evaporation source 50 according to the process conditions. For example, the evaporation source transfer device 50 may include a ball screw 51, a motor 52 for rotating the ball screw 51, and a guide 53 for guiding the evaporation source 30.

The at least one evaporation source 30 is preferably arranged approximately vertically, but may also have an inclination of approximately 70 degrees to 110 degrees with respect to the horizontally placed substrate 40. The detailed structure of this evaporation source 30 is as above-mentioned.

In addition, a mask 45 having a predetermined pattern may be positioned on an upper surface of the substrate 40.

The substrate support 20 is positioned below the chamber 10 and serves to seat the substrate 40 introduced into the chamber 10. In this case, the driving means for rotating the substrate support 20 or the conveying means for horizontally moving the substrate 40 may be omitted.

Hereinafter, the operation of the deposition apparatus with a top-down evaporation source according to the present invention will be described.

First, the substrate 40 is introduced through the substrate entrance 11 formed on the sidewall of the chamber 10 and positioned on the upper surface of the substrate support 20, and then the mask 45 having a predetermined pattern formed on the upper surface of the substrate 10. ) And the substrate support 20 is heated to maintain a constant temperature.

Subsequently, the inside of the chamber 10 is converted into a vacuum state to create a process atmosphere, and a deposition material to be deposited on the substrate 10 is supplied to the evaporation source 30. If a plurality of evaporation sources 30 are used, the same or different vaporization temperatures may be supplied.

The deposition material of the evaporation source 30 is stored in the crucible 33 provided inside the evaporation source 30, and the crucible 33 is formed by induction heating by the coils 35 and 37 surrounding the crucible 33. The deposition material in the vaporization is vaporized.

The vaporized deposition material is injected toward the upper portion of the substrate 40 in the chamber 10 through the injection hole 34 formed in the lower part of the crucible 33, and the sprayed deposition material moves toward the substrate 40. A uniform thin film is deposited on the substrate 40.

The evaporation source 30 may be fixed or moved toward the substrate 40, and the substrate support 20 may be rotated, moved or fixed. In addition, the injection direction of the evaporation source 30 can be adjusted.

In addition, it may be deposited on the upper surface of the substrate 40 exposed through the pattern of the mask 45 to form a predetermined thin film pattern.

As described above, the deposition apparatus equipped with the evaporation source 30 according to the present invention can form a uniform thin film on the entire substrate 40 using at least one evaporation source 30 even when the substrate 40 having a large area is processed. It has an effect. Moreover, the deposition apparatus may use various kinds of deposition materials, and in particular, it is possible to simultaneously deposit deposition materials having different vaporization temperatures, thereby producing a new functional thin film.

In addition, since the evaporation source 30 according to the present invention uses high frequency induction heating, it is possible to simply adjust the temperature and time through the control of the current supply amount, so that rapid and uniform deposition can be achieved and the heating time of the source can be shortened. As a result, the thin film can be manufactured at low cost.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the scope of the present invention but to limit the scope of the technical idea of the present invention by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a schematic cross-sectional view of a conventional bottom-up deposition apparatus.

Figure 2 is a schematic cross-sectional view showing a top down evaporation source according to the present invention.

3 is a cross-sectional view schematically showing a first embodiment of a deposition apparatus having a top-down evaporation source according to the present invention.

4 is a cross-sectional view schematically showing a second embodiment of a deposition apparatus having a top-down evaporation source according to the present invention.

5 is a schematic cross-sectional view of a third embodiment of a deposition apparatus having a top-down evaporation source according to the present invention.

Claims (7)

With the body, A crucible provided in the main body and accommodating a deposition material, the upper part of which is opened a cover for sealing and an injection hole formed of a porous plate in the lower part thereof; A first coil disposed to surround the crucible at a middle height of the crucible and to which a high frequency induction current is applied; And a second coil disposed below the first coil to surround the injection port of the crucible and to which a high frequency induction current is applied. The top-down evaporation source of claim 1, wherein the first coil and the second coil have the same temperature, or the temperature of the second coil is higher than that of the first coil. The top-down evaporation source according to claim 1, further comprising a temperature sensor for measuring a temperature at which the deposition material contained in the crucible is vaporized, wherein the temperature sensor is located in the crucible. A vapor deposition apparatus comprising a chamber of vacuum, a substrate support provided at a lower portion of the chamber to support a substrate, and at least one evaporation source inserted into at least a portion of the upper portion of the chamber to provide a deposition gas in the chamber. The evaporation source, With the body, A crucible provided in the main body and accommodating a deposition material, the upper part of which is opened a cover for sealing and an injection hole formed of a porous plate in the lower part thereof; A first coil disposed to surround the crucible at a middle height of the crucible and to which a high frequency induction current is applied; And a second coil disposed below the first coil to surround the injection hole of the crucible and to which a high frequency induction current is applied. 5. The deposition apparatus according to claim 4, wherein a driving means having a motor is installed below the substrate support to rotate the substrate support. 5. The substrate support according to claim 4, wherein the substrate support is provided with a transfer means for horizontally moving the substrate, which may be configured by a roller or a belt or a combination thereof, while the substrates are introduced into both side walls of the chamber. A vapor deposition apparatus characterized by having a substrate entrance for withdrawing. According to claim 4, wherein the evaporation source transfer device for moving the evaporation source horizontally installed in the upper portion of the chamber, the evaporation source transfer device is a ball screw, a motor for rotating the ball screw, and a guide for guiding the evaporation source Evaporation apparatus characterized in that it comprises.

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