Batch-type substrate processing device

Abstract

A batch-type substrate processing device of the present invention may comprise: a reaction tube for providing a processing space in which multiple substrates are accommodated; and an electrode unit arranged in the circumferential direction of the reaction tube and having multiple rod-shaped electrodes extending in the longitudinal direction of the reaction tube. The multiple rod-shaped electrodes may comprise: first and second power electrodes spaced apart from each other; and first and second ground electrodes provided between the first and second power electrodes and spaced apart from each other. At least one of the first and second power electrodes and the first and second ground electrodes may have a different length.

Description

Batch substrate processing device

[0001] The present invention relates to a batch-type substrate processing device, and more specifically, to a batch-type substrate processing device that performs a processing process on a substrate by stably forming plasma by a plurality of electrodes.

[0002] In general, substrate processing devices are of the single wafer type, which can perform a substrate processing process on one substrate, and the batch type, which can perform a substrate processing process on multiple substrates simultaneously.

[0003] Recently, batch-type substrate processing devices can perform a processing process by supplying active species (or radicals) obtained by exciting process gases injected around the plurality of electrodes to generate plasma by supplying high-frequency power to multiple electrodes, thereby supplying the obtained active species (or radicals) to the substrate.

[0004] In a batch substrate processing device using plasma, when high-frequency power is applied to a plurality of rod-shaped electrodes extending along the length of a reaction tube, different potential distributions (or profiles) can be formed in the length (or height) direction of the rod-shaped electrodes due to the antenna effect generated as the electric field wave propagates along the rod-shaped electrodes. As a result, the plasma density and radical density generated vary depending on the vertical position, thereby affecting the speed and uniformity of the substrate processing process for a plurality of substrates depending on the vertical position of the processing space within the reaction tube.

[0005] Since batch-type substrate processing equipment processes multiple substrates simultaneously, various attempts are being made to ensure uniformity in the substrate processing process, both among multiple substrates and within a single substrate, to enhance the efficiency of the process. In particular, there is a continuing need for methods to suppress non-uniformity in the substrate processing process caused by the vertical position of substrates stacked in multiple stages in batch-type substrate processing equipment.

[0006] (Patent Document 1) Korean Patent No. 10-1145538

[0007] The present invention provides a batch substrate processing device capable of improving the uniformity of a substrate processing process between substrates loaded in multiple stages by forming uniform radicals in a vertical direction.

[0008] A batch substrate processing device according to an embodiment of the present invention comprises: a reaction tube providing a processing space in which a plurality of substrates are accommodated; and an electrode unit having a plurality of rod-shaped electrodes arranged in a circumferential direction of the reaction tube and extending along a longitudinal direction of the reaction tube; wherein the plurality of rod-shaped electrodes include first power electrodes and second power electrodes spaced apart from each other; and first ground electrodes and second ground electrodes provided spaced apart from each other between the first power electrodes and the second power electrodes, wherein at least one of the first power electrodes and the second power electrodes and the first ground electrodes and the second ground electrodes may have different lengths.

[0009] The length of the first power electrode and the first ground electrode provided adjacent to the first power electrode may be longer than the length of the second power electrode and the second ground electrode provided adjacent to the second power electrode.

[0010] The lengths of the first power electrode and the first ground electrode may be the same, and the lengths of the second power electrode and the second ground electrode may be the same.

[0011] The electrode unit may further include a first insulating member and a second insulating member provided on the second ground electrode and the second power electrode, respectively; and a first floating electrode and a second floating electrode provided on the first insulating member and the second insulating member.

[0012] The total length of the second ground electrode, the first insulating member, and the first floating electrode may be the same as the length of the second ground electrode, and the total length of the second power electrode, the second insulating member, and the second floating electrode may be the same as the length of the first power electrode.

[0013] The lengths of the first insulating member and the second insulating member may be the same, and the lengths of the first floating electrode and the second floating electrode may be the same.

[0014] The first to fourth electrode protection tubes are further included to receive and protect the first power electrode, the first ground electrode, the second ground electrode, and the second power electrode, respectively, and the first floating electrode, the first insulating member, and the second ground electrode can be inserted and received in the order of the third electrode protection tube, and the second floating electrode, the second insulating member, and the second power electrode can be inserted in the order of the fourth electrode protection tube.

[0015] The above electrode units may be provided in multiple numbers arranged in the circumferential direction of the reaction tube.

[0016] The apparatus may further include a high-frequency power supply unit that supplies high-frequency power to the first power electrode and the second power electrode; and a power distribution unit that is provided between the first power electrode and the second power electrode and the high-frequency power supply unit and distributes the high-frequency power supplied from the high-frequency power supply unit and provides the high-frequency power to the first power electrode and the second power electrode, respectively.

[0017] According to a batch substrate processing device according to an embodiment of the present invention, a uniform plasma density or radical density can be formed in the length (or height) direction of the electrodes by using a plurality of electrodes of different lengths, thereby minimizing and uniformizing dispersion of the substrate processing process in each vertical region of the substrate processing space. As a result, the substrate processing process yield for a plurality of substrates loaded in multiple stages can be effectively improved.

[0018] According to the electrode unit of the present invention, it is possible to prevent a high electric field that is superimposed on a ground electrode and induced by a high-frequency power applied to each of a plurality of power electrodes, and thus suppress or prevent plasma damage caused by a plasma potential that increases in proportion to the electric field.

[0019] In addition, by making the lengths of the first power electrode and the first ground electrode, and the second power electrode and the second ground electrode correspond, the formation of self-bias can be suppressed in the first power electrode and the second power electrode, thereby effectively preventing plasma damage and particle generation due to self-bias.

[0020] Furthermore, by providing an insulating material and a floating electrode on the second power electrode and the second ground electrode having relatively short lengths, interference caused by plasma generated between the first power electrode and the first ground electrode having relatively long lengths can be blocked, thereby effectively controlling the plasma or radical distribution in the electrode length direction (vertical direction).

[0021] In addition, by distributing the high-frequency power supplied from the high-frequency power source to the first power electrode and the second power electrode having different lengths through the power distribution unit to the first power electrode and the second power electrode at a predetermined ratio, a uniform plasma or radicals can be formed in the horizontal direction in which the plurality of electrodes are arranged.

[0022] Figure 1 is a vertical cross-sectional view of a batch substrate processing device according to an embodiment of the present invention.

[0023] Figure 2 is a horizontal cross-sectional view of a batch substrate processing device according to an embodiment of the present invention.

[0024] Figure 3 is a schematic diagram illustrating an electrode unit according to an embodiment of the present invention.

[0025] Figure 4 is a schematic diagram illustrating an electrode unit according to another embodiment of the present invention.

[0026] Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. In the description, identical reference numerals are assigned to identical components, and the drawings may be partially exaggerated in size to accurately describe the embodiments of the present invention, and identical numerals in the drawings indicate identical elements.

[0027] FIG. 1 is a vertical cross-sectional view of a batch-type substrate processing device according to an embodiment of the present invention, FIG. 2 is a horizontal cross-sectional view of a batch-type substrate processing device according to an embodiment of the present invention, FIG. 3 is a schematic diagram illustrating an electrode unit according to an embodiment of the present invention, and FIG. 4 is a schematic diagram illustrating an electrode unit according to another embodiment of the present invention.

[0028] Referring to FIGS. 1 to 4, a batch substrate processing device according to an embodiment of the present invention may include a reaction tube (110) that provides a processing space (111) in which a plurality of substrates (10) are accommodated; and an electrode unit (120) that is arranged in the circumferential direction of the reaction tube (110) and has a plurality of rod-shaped electrodes (121, 122) that extend along the longitudinal direction of the reaction tube (110).

[0029] The reaction tube (110) may be formed of a heat-resistant material such as quartz or ceramic in a cylindrical shape with a closed upper portion and an open lower portion, and may provide a processing space (111) in which a plurality of substrates (10) are accommodated and processed inside. The processing space (111) of the reaction tube (110) accommodates a substrate boat (50) in which a plurality of substrates (10) are stacked in multiple stages in the longitudinal direction of the reaction tube (110), and is a space in which an actual processing process (e.g., a deposition process) is performed.

[0030] Here, the substrate boat (50) is configured to support the substrate (10), and can be formed so that a plurality of substrates (10) are loaded in the longitudinal direction (i.e., vertical direction) of the reaction tube (110), and a plurality of unit processing spaces in which the plurality of substrates (10) are individually processed can be formed.

[0031] A plurality of rod-shaped electrodes (121, 122) may extend along the longitudinal direction of the reaction tube (110) and may be arranged (or positioned) along the circumferential direction of the reaction tube (110). For example, the plurality of rod-shaped electrodes (121, 122) may extend along the longitudinal direction of the reaction tube (110) and have a thin and long rod shape or bar shape, may be positioned side by side (or parallel) to each other, and may be positioned along the circumferential direction of the reaction tube (110).

[0032] The discharge space (125) of the plasma formation section, which is separated from the processing space (111) by a partition wall (115), is a space where plasma is formed by the electrode unit (120). The plasma formation section can decompose process gas supplied from a gas supply pipe (170) using plasma in the discharge space (125), and provide radicals, etc. among the decomposed process gas to the processing space (111).

[0033] The process gas may include one or more gases, and may include a source gas and / or a reaction gas that reacts with the source gas, and the source gas and the reaction gas may react to form a thin film. Here, the process gas activated by the plasma may be a reaction gas, and the source gas may be directly supplied to the processing space (111) through a separate source gas supply pipe (175). Unlike the source gas supply pipe (175) that directly supplies the source gas to the processing space (111), the gas supply pipe (170) may first supply the reaction gas to the discharge space (125) within the plasma forming unit, and the reaction gas may be activated by the plasma and then provided to the processing space (111). For example, when the thin film material to be deposited on the substrate (10) is silicon nitride, the source gas may include a gas containing silicon (e.g., dichlorosilane (SiH2Cl2, DCS), etc.), and the reaction gas may include a gas containing nitrogen (e.g., NH3, N2O, NO, etc.).

[0034] Here, the partition wall (115) may extend along the length of the reaction tube (110), may be arranged inside the reaction tube (110), or may be arranged outside the reaction tube (110). For example, the partition wall (115) may be arranged inside the reaction tube (110) as shown in FIG. 1 to form an inner wall of the reaction tube (110) and a discharge space (125), and may include a plurality of sub-side wall portions (115a, 115b) connected to the inner wall (or inner surface) of the reaction tube (110) and a main side wall portion (115c) between the plurality of sub-side wall portions (115a, 115b). A plurality of sub-side wall portions (115a, 115b) may protrude (or extend) from the inner wall of the reaction tube (110) into the inner side of the reaction tube (110), may be arranged spaced apart from each other in the circumferential direction of the reaction tube (110), and may be symmetrical with respect to the main side wall portion (115c). In addition, the main side wall portion (115c) may be spaced apart from the inner wall of the reaction tube (110) and may extend in the circumferential direction of the reaction tube (110), and may be arranged between the plurality of sub-side wall portions (115a, 115b) to connect the plurality of sub-side wall portions (115a, 115b). At this time, both the plurality of sub-side wall portions (115a, 115b) and the main side wall portion (115c) may extend in the longitudinal direction of the reaction tube (110) along the inner wall of the reaction tube (110).

[0035] Meanwhile, the main side wall portion (115c) may be configured in a tube shape having a diameter smaller or larger than that of the reaction tube (110), thereby forming a discharge space (125) between the side wall of the reaction tube (110) and the main side wall portion (115c) (i.e., between the inner wall of the reaction tube and the main side wall portion or between the outer wall of the reaction tube and the main side wall portion).

[0036] The plasma forming unit forms plasma in a discharge space (125) separated from the processing space (111) by a partition wall (115), so that the process gas supplied from the gas supply pipe (170) can be supplied to the processing space (111) after being activated in the discharge space (125), which is a space separated from the processing space (111), rather than being activated in the processing space (111).

[0037] The plasma forming unit may include a plurality of injection ports (123) that are provided in a direction different from the discharge direction of the discharge port (171) formed in the gas supply pipe (170) and arranged in the longitudinal direction of the reaction tube (111) to supply radicals among the process gas decomposed by the plasma to the processing space (111). The plurality of injection ports (123) may be arranged in the longitudinal direction of the reaction tube (111) and may supply radicals among the process gas decomposed by the plasma to the processing space (111) and may be provided in a direction different from the discharge direction of the discharge port (171). Here, the plurality of injection ports (123) may be provided in a plurality of rows arranged in the longitudinal direction of the reaction tube (111), and each row may be provided spaced apart from each other in the circumferential direction of the reaction tube (110).

[0038] Here, the plurality of rod-shaped electrodes (121, 122) may include first power electrodes (121a) to second power electrodes (121b) that are spaced apart from each other; and first ground electrodes (122a) to second ground electrodes (122b) that are provided spaced apart from each other between the first power electrodes (121a) to the second power electrodes (121b). In addition, at least one of the first power electrodes (121a) to the second power electrodes (121b) and the first ground electrodes (122a) to the second ground electrodes (122b) may have different lengths.

[0039] The first power electrode (121a) to the second power electrode (121b) may be spaced apart from each other, and high frequency power (or RF power) may be supplied (or applied) to each other. The first ground electrode (122a) to the second ground electrode (122b) are provided spaced apart from each other between the first power electrode (121a) to the second power electrode (121b), and may be grounded individually or may be grounded in common.

[0040] The first power electrode (121a) and the first ground electrode (122a) provided adjacent to the first power electrode (121a) correspond to each other and form a pair, and the second power electrode (121b) and the second ground electrode (122b) provided adjacent to the second power electrode (121b) correspond to each other and form a pair, so that plasma can be formed in the space between each of them.

[0041] That is, the first power electrode (121a) and the first ground electrode (122a), the second power electrode (121b) and the second ground electrode (122b) can have a four-electrode structure, and by allowing high-frequency power to be supplied separately to the first power electrode (121a) and the second power electrode (121b), the high-frequency power required to generate plasma or the high-frequency power to obtain a desired amount of radicals can be reduced, thereby preventing the generation of particles due to high-frequency power.

[0042] In other words, in the case of having a four-electrode structure as in the present invention, the high-frequency power required to generate plasma for decomposing process gas or to obtain a desired amount of radicals can be reduced by half or significantly, thereby preventing damage to the electrode protection unit (130), partition wall (115), reaction tube (110), etc. caused by high-frequency power, and also preventing the problem of particles being generated due to damage to the electrode protection unit (130), partition wall (115), reaction tube (110), etc.

[0043] On the other hand, in the conventional three-electrode structure having a common ground electrode and power electrodes provided on both sides, when high-frequency power is applied to the power electrodes on both sides, the voltages induced by the voltages applied to the power electrodes on both sides may overlap at the common ground electrode, thereby inducing twice the voltage. That is, in the three-electrode structure using a common ground electrode, the voltages applied to the power electrodes on both sides have the same phase difference, so an electric field higher than that of the two power electrodes is induced at the common ground electrode, and due to this high electric field, the plasma potential proportional to the electric field increases, resulting in plasma damage.

[0044] When high-frequency power or RF power is applied to one end (or the lower end) of a rod-shaped electrode that extends in the longitudinal direction, there may be a difference in the potential formed at the rod-shaped electrode depending on the wavelength (λ) of the high-frequency power and the length of the rod-shaped electrode.

[0045] If the λ / 4 of the high-frequency power source is about 2 to 3 times longer than the length of the rod-shaped electrode, stable charge movement along the length of the rod-shaped electrode is possible, so that an equipotential can be formed in practice, and the potential difference between one end (or bottom) and the other end (top) of the rod-shaped electrode can be very small. Therefore, a plasma with a uniform density can be formed in the length direction of the rod-shaped electrode.

[0046] On the other hand, when the length of the rod-shaped electrode is similar to or shorter than λ / 4 of the high-frequency power source, there is not enough time for charges to move stably due to the change in polarity of the high-frequency high-frequency power source, so a potential difference may be generated between one end and the other end of the rod-shaped electrode to which the high-frequency power source is applied. In particular, a magnetic field may be induced at the other end (upper) of the rod-shaped electrode by the potential difference concentrated in the section near the other end (upper) of the rod-shaped electrode, which may form a high-density plasma. This may cause an uneven plasma density between the upper and lower ends of the rod-shaped electrode.

[0047] For example, in a typical batch substrate processing device, the length of the rod-shaped electrode is about 2 to 3 m, so when the frequency of the applied high-frequency power is 13.56 MHz, λ / 4 is 5.53 m, which is much longer than the length of the rod-shaped electrode, so that uniformity of plasma density in the vertical direction can be secured.

[0048] However, in order to increase the plasma density, the frequency of the high-frequency power source is increased, and when the frequency of the high-frequency power source is 27.12 MHz, λ / 4 is 2.77 m, which is similar to the length of the rod-shaped electrode, so that different potential differences may be generated in the length (or height) direction of the rod-shaped electrode. That is, the plasma density and radical density may vary depending on the vertical position in the discharge space due to the different potential differences formed in the length direction of the rod-shaped electrode. Since radicals having different densities depending on the vertical position in the discharge space are injected into the treatment space through a plurality of injection holes arranged in the longitudinal direction (vertical direction) of the reaction tube (110), the amount of radicals reaching a plurality of substrates stacked in multiple stages in the treatment space may be different, which may cause non-uniformity in the substrate treatment process depending on the vertical position.

[0049] The non-uniformity of plasma density and substrate processing depending on the vertical position can be more serious in a four-electrode structure with two pairs of power and ground electrodes each, as each pair of electrodes influences the other.

[0050] In the present invention, by making the lengths of at least one electrode among the first power electrode (121a) and the first ground electrode (122a), the second power electrode (121b) and the second ground electrode (122b) forming a four-electrode structure different, the imbalance in potential difference according to the electrode length can be resolved, thereby reducing the generation of radicals in the upper part of the discharge space (125) and increasing the generation of radicals in the lower part of the discharge space (125). For example, if the length of the second power electrode (121b) is made shorter than that of the first power electrode (121a), a greater amount of radicals can be generated in the lower part of the discharge space (125) than in the upper part between the long first power electrode (121a) and the first ground electrode (122a). On the other hand, since radicals are not generated in the upper part of the discharge space (125) between the short second power electrode (121b) and the second ground electrode (122b) and are generated relatively lower in the discharge space (125) than the first power electrode (121a), the non-uniformity of radical density in the vertical direction within the entire discharge space (125) can be effectively resolved. Depending on the non-uniform plasma distribution or the size of the non-uniformity of the plasma distribution, electrodes having different lengths or their lengths can be selected.

[0051] In the four-electrode structure, since two pairs of electrodes form plasma, in order to control the vertical plasma or radical distribution within the discharge space (125) or the processing space (111), the lengths of the first power electrode (121a) and the first ground electrode (122a) can be longer than the lengths of the second power electrode (121b) and the second ground electrode (122b). By lengthening the lengths of the first power electrode (121a) and the first ground electrode (122a), a large number of radicals are generated at the upper part of the discharge space (125), and by shortening the lengths of the second power electrode (121b) and the second ground electrode (122b), no radicals are generated at the upper part of the discharge space (125) and a relatively large amount of radicals are generated at the lower part of the discharge space (125), thereby effectively resolving the unevenness of the radical density.

[0052] Since the size (or length) of the power electrode must be greater than or equal to the size (or length) of the ground electrode to suppress the formation of self-bias in the power electrode to which high-frequency power is applied, the length of the first power electrode (121a) may be greater than or equal to the length of the first ground electrode (122a), and the length of the second power electrode (121b) may be greater than or equal to the length of the second ground electrode (122b).

[0053] Meanwhile, when the lengths (or sizes) of the power electrode and the ground electrode are different, distortion of the plasma formed near the ends of the power electrode or the ground electrode may occur, so the power electrode and the ground electrode may be arranged to face each other so that a parallel electromagnetic field may be generated between the power electrode and the ground electrode, and the lengths of the power electrode and the ground electrode may be the same. That is, in the present invention, the lengths of the first power electrode (121a) and the first ground electrode (122b) may be the same, and the lengths of the second power electrode (121b) and the second ground electrode (122b) may be the same. In addition, the lengths of the second power electrode (121b) and the second ground electrode (122b) having shorter lengths may be selected according to the non-uniform plasma distribution in the vertical direction within the discharge space (125) or the size of the non-uniformity of the plasma distribution.

[0054] In the third electrode structure of the conventional batch-type substrate processing device, a high electric field is induced in the common ground electrode in the middle. If a high electric field is induced, the voltage imbalance occurring in the longitudinal direction of the rod-shaped electrode may become more serious. Similarly, even if the lengths of some of the three electrodes are changed, the electric fields induced in the common ground electrode overlap to form a high electric field, causing a greater voltage imbalance. Therefore, it is difficult to improve the non-uniform plasma distribution in the vertical direction within the discharge space (125) by reducing the length of the electrodes.

[0055] In a three-electrode structure, if the short electrode is used as a common ground electrode, the non-uniformity of the overall plasma distribution within the discharge space may be aggravated due to the difference in length between the long power electrodes on both sides of the common ground electrode. On the other hand, if the length of one of the power electrodes in the three-electrode structure is shortened, the length of the common ground electrode (or its size) may become longer than the short power electrode, making it impossible to suppress self-bias formation at the short power electrode, and there may be a problem in that plasma damage and particle generation due to self-bias formation may be aggravated.

[0056] On the other hand, in the present invention, since a high electric field is not induced in the first ground electrode (122a) and the second ground electrode (122b) due to the four-electrode structure, the voltage imbalance occurring in the longitudinal direction of the rod-shaped electrode is relatively small, and thus, by shortening the electrode length, it is easy to control the non-uniformity of plasma density or radical density in the vertical direction of the discharge space (125). Additionally, by making the lengths of the first power electrode (121a) and the first ground electrode (122b) correspond to each other, and by making the lengths of the second power electrode (121b) and the second ground electrode (122b) correspond to each other and adjusting them to be the same, it is possible to effectively suppress self-bias from occurring in the first power electrode (121a) or the second power electrode (121b).

[0057] In an embodiment of the present invention, when the length of one pair of electrodes (the first power electrode (121a) and the first ground electrode (122a)) among the two pairs of electrodes is lengthened and the length of one pair of electrodes (the second power electrode (121b) and the second ground electrode (122b)) is shortened, an empty space corresponding to the length difference with respect to the long electrode may exist on the upper portion of the shorter electrode (see FIG. 3). In this case, the diffusion of high-frequency radiation (RF Radiation) from the plasma formed between the first power electrode (121a) and the first ground electrode (122a) to the adjacent second power electrode (121b) and the second ground electrode (122b) may occur, thereby generating parasitic plasma in the empty space on the upper portions of the second power electrode (121b) and the second ground electrode (122b). The parasitic plasma is in a very unstable state, making it difficult to stably generate radicals, which may increase the non-uniformity of the substrate processing process. Even when the second power electrode (121b) and the second ground electrode (122b) are surrounded and protected by an electrode protection tube as described below, parasitic plasma may be generated in the empty space inside the electrode protection tube formed on the upper portion of the second power electrode (121b) and the second ground electrode (122b).

[0058] In order to minimize these problems, the electrode unit (120) of the present invention may further include a first insulating member (126) and a second insulating member (127) provided on the second ground electrode (122b) and the second power electrode (121b), respectively; and a first floating electrode (128) and a second floating electrode (129) provided on the first insulating member (126) and the second insulating member (127).

[0059] That is, the first floating electrode (128) and the second floating electrode (129) provided in the empty space above the second ground electrode (122b) and the second power electrode (121b) are configured to function as a barrier to block the influence of plasma formed between the first power electrode (121a) and the first ground electrode (122a). In order for the first floating electrode (128) and the second floating electrode (129) to be electrically separated from the second ground electrode (122b) and the second power electrode (121b) and to float, a first insulating member (126) is inserted between the second ground electrode (122b) and the first floating electrode (128), and a second insulating member (127) is inserted between the second power electrode (121b) and the second floating electrode (129).

[0060] In the present invention, parasitic plasma can be effectively suppressed by providing a first floating electrode (128) and a second floating electrode (129) in the empty space above the second ground electrode (122b) and the second power electrode (121b), and through this, it is possible to stably and precisely control the radical distribution in the vertical direction of the discharge space (125) by using two electrode pairs having different lengths.

[0061] The first power electrode (121a) and the first ground electrode (122a) are provided to face each other, and since plasma is formed by an electromagnetic field formed laterally, the high-frequency radiation of the plasma generated between the first power electrode (121a) and the first ground electrode (122a) can spread laterally and form parasitic plasma above the second power electrode (121b) and the second ground electrode (122b). That is, in order to effectively block the high-frequency radiation spreading laterally, the total length of the second ground electrode (122b), the first insulating member (126), and the first floating electrode (128) may be the same as the length of the second ground electrode (122a), and the total length of the second power electrode (121b), the second insulating member (127), and the second floating electrode (129) may be the same as the length of the first power electrode (121a) (see FIG. 4).

[0062] And, in the case where the first power electrode (121a) and the first ground electrode (122a) have the same length, and the second power electrode (121b) and the second ground electrode (122b) have the same length, in order to match the length of the four-electrode structure of the electrode unit (120), the lengths of the first insulating member (126) and the second insulating member (127) can be the same, and the lengths of the first floating electrode (128) and the second floating electrode (129) can be the same.

[0063] The batch-type substrate processing device of the present invention may further include first to fourth electrode protection tubes (131a, 132a, 132b, 131b) that accommodate and protect the first power electrode (121a), the first ground electrode (122a), the second ground electrode (122b), and the second power electrode (121b), respectively.

[0064] The first to fourth electrode protection tubes (131a, 132a, 132b, 131b) can have an upper end that is closed and a lower end that is open, and have an internal space in which a first power electrode (121a), a first ground electrode (122a), a second ground electrode (122b), and a second power electrode (121b) can be accommodated, respectively, so that each electrode can be inserted upward through the open portion at the lower end.

[0065] The electrode protection unit (130) including the first to fourth electrode protection tubes (131a, 132a, 132b, 131b) may include a first bridge tube (133a) connecting the first electrode protection tube (131a) and the second electrode protection tube (132a) and a second bridge tube (133b) connecting the third electrode protection tube (132b) and the fourth electrode protection tube (131b).

[0066] The first to fourth electrode protection tubes (131a, 132a, 132b, 131b) surround the exterior of the electrodes accommodated in their respective internal spaces, thereby electrically insulating the first power electrode (121a), the first ground electrode (122a), the second ground electrode (122b), and the second power electrode (121b) from each other while protecting them from plasma and safely protecting them from contamination or particles that may be generated by plasma. At this time, the first to fourth electrode protection tubes (131a, 132a, 132b, 131b) may be made of a heat-resistant material such as quartz or ceramic, and may be manufactured as an integral part with the reaction tube (110).

[0067] The bridge tubes (133a, 133b) connect the first electrode protection tube (131a) and the second electrode protection tube (132a) and the third electrode protection tube (132b) and the fourth electrode protection tube (131b) which are opposed to each other, thereby maintaining the gap between each electrode protection tube and preventing shaking or tilting, thereby enabling uniform plasma formation.

[0068] In addition, the bridge tubes (133a, 133b) may have a flow path through which gas can flow inside, so that the internal spaces of the connected electrode protection tubes can be connected to each other. In the process of generating plasma, the first power electrode (121a), the first ground electrode (122a), the second ground electrode (122b), and the second power electrode (121b) may generate heat and the temperature may rise. However, the first power electrode (121a), the first ground electrode (122a), the second ground electrode (122b), and the second power electrode (121b) may be cooled by flowing a cooling gas through the first to fourth electrode protection tubes (131a, 132a, 132b, 131b) that are connected to each other by the bridge tubes (133a, 133b). Here, the cooling gas may include an inert gas such as nitrogen (N2), argon (Ar), etc.

[0069] In order to form a stable plasma, it is important to stably install and maintain an insulating member and a floating electrode on a power electrode, which is a thin and long rod-shaped electrode that extends in one direction, and a grounding electrode. To this end, in the present invention, the first floating electrode (128), the first insulating member (126), and the second ground electrode (122b) may be inserted and accommodated in the third electrode protection tube (132b) in that order, and the second floating electrode (129), the second insulating member (127), and the second power electrode (121b) may be inserted and accommodated in the fourth electrode protection tube (131b) in that order. The first floating electrode (128), the first insulating member (126), and the second ground electrode (122b) do not necessarily need to be formed integrally or assembled in advance, and they can be structurally stable by being inserted and maintained in the internal space of the third electrode protection tube (132b). Likewise, the second floating electrode (129), the second insulating member (127), and the second power electrode (121b) do not necessarily need to be formed integrally or pre-assembled, and they can be structurally stable by being inserted and maintained in the internal space of the fourth electrode protection tube (131b).

[0070] The first insulating member (126) and the second insulating member (127) may be made of an insulating material such as alumina or quartz, and may be in the shape of a bead with a smaller diameter than the internal space for the purpose of assembly workability, as they must be inserted into the internal space of the third electrode protection tube (132b) or the fourth electrode protection tube (131b).

[0071] A plurality of electrode units (120) including a 4-electrode structure may be provided arranged in the circumferential direction of the reaction tube (110).

[0072] The plasma generation area can be expanded left and right or in the horizontal direction by using multiple electrode units, thereby increasing the amount of radicals generated. The circumference (length) of the reaction tube (110) is determined according to the size (or circumference) of the substrate (10), and the number of electrode units (120) can be determined according to the circumference of the reaction tube (110).

[0073] A plurality of electrode units (120) may be provided inside a single discharge space (125) partitioned by a partition wall (115), or a plurality of discharge spaces (125) partitioned by the partition wall (115) may be formed and then an electrode unit (120) may be provided inside each discharge space (125). In addition, long electrode pairs and short electrode pairs may be arranged alternately, or long electrode pairs and short electrode pairs may be arranged symmetrically left and right.

[0074] The batch type substrate processing device of the present invention may further include a high frequency power supply unit (150) that supplies high frequency power to a first power electrode (121a) and a second power electrode (121b); and a power distribution unit (155) that is provided between the first power electrode (121a) to the second power electrode (121b) and the high frequency power supply unit (150) and distributes the high frequency power supplied from the high frequency power supply unit (150) and provides the high frequency power to the first power electrode (121a) and the second power electrode (121b), respectively.

[0075] The power distribution unit (155) may be a power splitter, and may be provided between the high-frequency power supply unit (150) and the first power electrode (121a) to the second power electrode (121b) to distribute the high-frequency power supplied (or output) from the high-frequency power supply unit (150), and the distributed high-frequency power may be provided to each of the first power electrode (121a) and the second power electrode (121b).

[0076] Although high-frequency power may be applied to the first power electrode (121a) and the second power electrode (121b) through a plurality of high-frequency power sources (150), high-frequency power having different characteristics or qualities may be applied to the first power electrode (121a) and the second power electrode (121b) due to a difference in performance between the plurality of high-frequency power sources (150), so that non-uniform plasma having different plasma densities may be formed on the first power electrode (121a) side and the second power electrode (121b) side. On the other hand, if high-frequency power supplied from one high-frequency power source (150) is distributed through a power distribution unit (155) and provided to each of the first power electrode (121a) and the second power electrode (121b), high-frequency power having the same characteristics and quality may be applied to the first power electrode (121a) and the second power electrode (121b), and a uniform plasma may be formed.

[0077] In the present invention, when the length of the first power electrode (121a) and the length of the second power electrode (121b) are different, a difference in impedance occurs due to the difference in length, so that even if the same high-frequency power is supplied, currents of different magnitudes may flow to the first power electrode (121a) and the second power electrode (121b), and thus the plasma density may become non-uniform on the left and right of the discharge space (125).

[0078] In this case, by controlling the size or ratio of the high-frequency power provided to each of the first power electrode (121a) and the second power electrode (121b) through the power distribution unit (155) and providing it to each of the first power electrode (121a) and the second power electrode (121b), it is possible to enable the formation of uniform plasma and uniform radical generation not only in the vertical direction of the discharge space (125) but also in the horizontal direction.

[0079] In other words, in the present invention, the vertical uniformity of the plasma can be secured by adjusting the length of some of the plurality of rod-shaped electrodes of the electrode unit (120), and the horizontal uniformity of the plasma can be secured by adjusting the size or ratio of the high-frequency power provided to each of the first power electrode (121a) and the second power electrode (121b) through the power distribution unit (155). Since the impedance as well as the potential difference changes depending on the length of the rod-shaped electrode, the horizontal distribution and the vertical distribution of the plasma within the discharge space (125) influence each other. After adjusting the length of some of the rod-shaped electrodes to adjust the vertical distribution of the plasma, by controlling the size or ratio of the high-frequency power input through the power distribution unit (155), it is possible to form a uniform plasma not only in the vertical direction but also in the horizontal direction of the discharge space (125).

[0080] Here, the power distribution unit (155) may include a distribution point where the high-frequency power (150) is distributed to the first power electrode (121a) and the second power electrode (121b) and a variable capacitor provided between at least one of the first and second power electrodes (121a, 121b). The variable capacitor may change the electrostatic capacitance (or storage capacitance) to adjust the size or ratio of the high-frequency power supplied from the high-frequency power source (150).

[0081] The batch-type substrate processing device of the present invention may further include a control unit (160) that selectively controls high-frequency power applied to each of the first power electrode (121a) and the second power electrode (121b).

[0082] The control unit (160) can selectively control the high-frequency power applied to each of the first and second power electrodes (121a, 121b), and can selectively control the high-frequency power applied to each of the first and second power electrodes (121a, 121b) according to the plasma state such as discharge current, discharge voltage, and phase. At this time, the control unit (160) can control the size or ratio of the high-frequency power applied to each of the first and second power electrodes (121a, 121b) by controlling the variable capacitor of the power distribution unit (155).

[0083] The control unit (160) can control the power distribution unit (155) using the plasma density value measured between the first power electrode (121a) and the first ground electrode (122a) and between the second power electrode (121b) and the second floating electrode (122b) using the plasma measurement unit, or the measured value of the RF parameter (voltage, current, phase, etc.) measured using the sensor unit connected to the first power electrode (121a) and the second power electrode (121b), thereby adjusting the high-frequency power applied to each of the first power electrode (121a) and the second power electrode (121b).

[0084] The batch-type substrate processing device (100) of the present invention may further include an exhaust unit (180) that is connected to the reaction tube (110) and exhausts process residues within the processing space (111) to the outside.

[0085] The exhaust unit (180) may be connected to the processing space (111) and serve to exhaust process residues within the processing space (111) to the outside. Here, the exhaust unit (180) may be arranged to face the electrode unit (120).

[0086] And the exhaust unit (180) may include an exhaust member (181) extending in the longitudinal direction of the reaction tube (110), an exhaust line (182) connected to the exhaust member (181), and an exhaust pump (not shown). The exhaust member (181) may have a plurality of exhaust ports (183) arranged in the longitudinal direction (i.e., up and down direction) of the reaction tube (110) so as to face the plurality of injection holes (123) and correspond to the unit processing space(s) of the substrate boat (50), respectively. Accordingly, a process gas activated by the electrode unit (120) may be supplied through the plurality of injection holes (123), pass over the surface of the substrate (10), and be sucked into the plurality of exhaust holes (183), thereby forming a laminar flow.

[0087] As described above, according to the batch substrate processing device according to the embodiment of the present invention, a uniform plasma density or radical density can be formed in the length (or height) direction of the electrodes by using a plurality of electrodes of different lengths, thereby minimizing and uniformizing dispersion of the substrate processing process in each vertical region of the substrate processing space. As a result, the substrate processing process yield for a plurality of substrates loaded in multiple stages can be effectively improved.

[0088] According to the electrode unit of the present invention, it is possible to prevent a high electric field that is superimposed on a ground electrode and induced by a high-frequency power applied to each of a plurality of power electrodes, and thus suppress or prevent plasma damage caused by a plasma potential that increases in proportion to the electric field.

[0089] In addition, by making the lengths of the first power electrode and the first ground electrode, and the second power electrode and the second ground electrode correspond, the formation of self-bias can be suppressed in the first power electrode and the second power electrode, thereby effectively preventing plasma damage and particle generation due to self-bias.

[0090] Furthermore, by providing an insulating material and a floating electrode on the second power electrode and the second ground electrode having relatively short lengths, interference caused by plasma generated between the first power electrode and the first ground electrode having relatively long lengths can be blocked, thereby effectively controlling the plasma or radical distribution in the electrode length direction (vertical direction).

[0091] In addition, by distributing the high-frequency power supplied from the high-frequency power source to the first power electrode and the second power electrode having different lengths through the power distribution unit to the first power electrode and the second power electrode at a predetermined ratio, a uniform plasma or radicals can be formed in the horizontal direction in which the plurality of electrodes are arranged.

[0092] The meaning of 'on' used in the above description includes cases where they are in direct contact and cases where they are not in direct contact but are positioned opposite the upper or lower surface, and it is possible to be positioned opposite the entire upper or lower surface as well as partially opposite, and it is used to mean that they are positionally opposite or directly in contact with the upper or lower surface. In addition, the terms 'above', 'below', 'leading end', 'rear end', 'upper part', 'lower part', 'top', 'bottom', etc. used in the above description are defined based on the drawings for convenience, and the shape and position of each component are not limited by these terms.

[0093] While preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-described embodiments, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible without departing from the gist of the present invention as claimed in the claims. Accordingly, the technical protection scope of the present invention should be defined by the claims below.

Claims

1. A reaction tube providing a processing space in which multiple substrates are accommodated; and An electrode unit having a plurality of rod-shaped electrodes arranged in the circumferential direction of the reaction tube and extending along the length of the reaction tube; The above plurality of rod-shaped electrodes are, First and second power electrodes spaced apart from each other; and Including a first ground electrode and a second ground electrode provided to be spaced apart from each other between the first power electrode and the second power electrode, A batch-type substrate processing device in which at least one of the first power electrode, the second power electrode, and the first ground electrode, the second ground electrode has a different length.

2. In claim 1, A batch-type substrate processing device wherein the length of the first power electrode and the first ground electrode provided adjacent to the first power electrode is longer than the length of the second power electrode and the second ground electrode provided adjacent to the second power electrode.

3. In claim 2, The lengths of the first power electrode and the first ground electrode are equal to each other, A batch-type substrate processing device in which the lengths of the second power electrode and the second ground electrode are the same.

4. In claim 2, The above electrode unit, First and second insulating members respectively provided on the second ground electrode and the second power electrode; and A batch type substrate processing device further comprising a first floating electrode and a second floating electrode provided on the first insulating member and the second insulating member.

5. In claim 4, The total length of the second ground electrode, the first insulating member, and the first floating electrode is equal to the length of the second ground electrode, A batch-type substrate processing device wherein the total length of the second power electrode, the second insulating member, and the second floating electrode is the same as the length of the first power electrode.

6. In claim 4, The lengths of the first insulating member and the second insulating member are equal to each other, A batch-type substrate processing device in which the lengths of the first floating electrode and the second floating electrode are the same.

7. In claim 4, Further comprising first to fourth electrode protection tubes that respectively accommodate and protect the first power electrode, the first ground electrode, the second ground electrode, and the second power electrode, The first floating electrode, the first insulating member, and the second ground electrode are inserted and accommodated in the third electrode protection tube in that order, A batch-type substrate processing device in which the second floating electrode, the second insulating member, and the second power electrode are inserted and accommodated in the fourth electrode protection tube in that order.

8. In claim 1, A batch-type substrate processing device in which a plurality of the above electrode units are provided arranged in the circumferential direction of the reaction tube.

9. In claim 1, A high-frequency power supply unit that supplies high-frequency power to the first power electrode and the second power electrode; and A batch-type substrate processing device further comprising a power distribution unit provided between the first power electrode or the second power electrode and the high-frequency power supply unit, and distributing the high-frequency power supplied from the high-frequency power supply unit and providing it to the first power electrode and the second power electrode, respectively.

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