Batch type substrate processing apparatus

Abstract

The present invention relates to a batch-type substrate processing apparatus that stably forms plasma by means of a plurality of electrodes to perform a processing process on a substrate. A batch-type substrate processing apparatus according to an embodiment of the present invention comprises: a reaction tube providing a processing space for accommodating a plurality of substrates; and a first electrode unit to a second electrode unit each having a plurality of rod-shaped electrodes arranged in the circumferential direction of the reaction tube and extending along the longitudinal direction of the reaction tube; wherein the first electrode unit includes a first power electrode and a second power electrode provided spaced apart from each other, and the second electrode unit includes a third power electrode and a fourth power electrode provided spaced apart from each other, and the length of the third power electrode and the length of the fourth power electrode may each be shorter than the first power electrode.

Description

Technology Field

[0001] The present invention relates to a batch-type substrate processing apparatus, and more specifically, to a batch-type substrate processing apparatus that stably forms plasma by means of a plurality of electrodes to perform a processing process on a substrate. Background Technology

[0002] Generally, substrate processing devices are classified into single-wafer type, which can perform a substrate processing process on a single substrate, and batch type, which can perform a substrate processing process on multiple substrates simultaneously.

[0003] Recently, a batch-type substrate processing device can perform a processing process by supplying active species (or radicals) obtained by exciting a process gas injected around a plurality of electrodes to a substrate by generating plasma by supplying high-frequency power to a plurality of electrodes.

[0004] When a high-frequency power source is applied to a plurality of rod-shaped electrodes extending along the length of a reaction tube in a batch-type substrate processing apparatus using plasma, different voltage distributions (or profiles) can be formed along the length (or height) of the rod-shaped electrodes due to the antenna effect generated as the electric field waves propagate 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 devices process multiple substrates simultaneously, various attempts are being made to ensure uniformity in the substrate processing process between multiple substrates or within a single substrate to improve the efficiency of the substrate processing process. In particular, there is still a need for a method to suppress non-uniformity in the substrate processing process caused by the vertical position of substrates stacked in multiple layers in a batch-type substrate processing device. Prior art literature

[0006] Korean Registered Patent No. 10-1145538 The problem to be solved

[0007] The present invention provides a batch-type substrate processing apparatus capable of improving the uniformity of the substrate processing process between substrates stacked in multiple stages by forming uniform radicals in the vertical direction. means of solving the problem

[0008] A batch-type substrate processing apparatus according to an embodiment of the present invention comprises: a reaction tube providing a processing space for accommodating a plurality of substrates; and a first electrode unit to a second electrode unit each having a plurality of rod-shaped electrodes arranged in the circumferential direction of the reaction tube and extending along the longitudinal direction of the reaction tube; wherein the first electrode unit includes a first power electrode and a second power electrode provided spaced apart from each other, and the second electrode unit includes a third power electrode and a fourth power electrode provided spaced apart from each other, and the length of the third power electrode and the length of the fourth power electrode may each be shorter than the first power electrode.

[0009] The apparatus further includes first and second partitions connected to the reaction tube and spaced apart from each other, wherein the first electrode unit is provided in a first discharge space surrounded by the reaction tube and the first partition, and the second electrode unit may be provided in a second discharge space surrounded by the reaction tube and the second partition.

[0010] The length of the second power electrode may be the same as or shorter than the first power electrode.

[0011] The first electrode unit further includes a first ground electrode and a second ground electrode provided between the first power electrode and the second power electrode, the length of the first ground electrode is the same as the length of the first power electrode, and the length of the second ground electrode may be the same as the length of the second power electrode.

[0012] In the case where the length of the second power electrode is shorter than the length of the first power electrode, the first electrode unit may further include a first insulating member to a second insulating member provided respectively on the second ground electrode and the second power electrode; and a first floating electrode and a second floating electrode provided on the first insulating member to the second insulating member.

[0013] The total length of the second grounding electrode, the first insulating member, and the first floating electrode is the same as the length of the first grounding 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.

[0014] The length of the third power electrode and the length of the fourth power electrode may be different from each other.

[0015] The second electrode unit further includes a third ground electrode and a fourth ground electrode provided between the third power electrode and the fourth power electrode, the length of the third ground electrode is the same as the length of the third power electrode, and the length of the fourth ground electrode may be the same as the length of the fourth power electrode.

[0016] The second electrode unit may further include: a third to fourth insulating member provided respectively on the third power electrode and the third ground electrode; a third floating electrode and a fourth floating electrode provided on the third to fourth insulating members; a fifth to sixth insulating member provided respectively on the fourth ground electrode and the fourth power electrode; and a sixth floating electrode and a sixth floating electrode provided on the fifth to sixth insulating members.

[0017] The total length of the third power electrode, the third insulating member, and the third floating electrode; the total length of the third ground electrode, the fourth insulating member, and the fourth floating electrode; the total length of the fourth ground electrode, the fifth insulating member, and the fifth floating electrode; the total length of the fourth power electrode, the sixth insulating member, and the sixth floating electrode; each may be equal to the length of the first power electrode.

[0018] The frequency of the high-frequency power applied to the first power electrode, the second power electrode, the third power electrode, and the fourth power electrode may be greater than 25 MHz. Effects of the invention

[0019] According to the batch-type substrate processing apparatus of 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 homogenizing the dispersion of the substrate processing process in each vertical region of the substrate processing space. As a result, the yield of the substrate processing process for a plurality of substrates stacked in multiple stages can be effectively improved.

[0020] According to the electrode unit of the present invention, a high electric field induced by a high-frequency power supply applied to each of the plurality of power electrodes can be prevented by superimposing it on the ground electrode, and accordingly, plasma damage caused by a plasma potential that increases in proportion to the electric field can be suppressed or prevented.

[0021] In addition, by matching the lengths of the power electrode and the ground electrode, the formation of self-bias at the power electrode can be suppressed, thereby effectively preventing plasma damage and particle generation caused by self-bias.

[0022] Furthermore, by providing an insulating member and a floating electrode on a power electrode and a ground electrode having a shorter length than the first power electrode and the first ground electrode having a relatively longer length, interference caused by plasma generated between the first power electrode and the first ground electrode can be blocked, thereby effectively controlling the plasma or radical distribution in the electrode length direction (vertical direction).

[0023] In addition, by distributing the high-frequency power supplied from the high-frequency power supply to power electrodes of different lengths at a predetermined ratio through the power distribution unit, it is possible to form a uniform plasma or radical in the horizontal direction where multiple electrodes are arranged. Brief explanation of the drawing

[0025] FIG. 1 is a vertical cross-sectional view of a batch-type substrate processing apparatus according to an embodiment of the present invention. FIG. 2 is a horizontal cross-sectional view of a batch-type substrate processing apparatus according to an embodiment of the present invention. FIG. 3 is a configuration diagram illustrating an electrode unit according to an embodiment of the present invention. FIG. 4 is a configuration diagram illustrating an electrode unit according to another embodiment of the present invention. FIG. 5 is a horizontal cross-sectional view of a batch-type substrate processing apparatus according to another embodiment of the present invention. FIGS. 6 to 8 are configuration diagrams illustrating various first and second electrode units according to other embodiments of the present invention. Specific details for implementing the invention

[0026] Embodiments of the present invention will be described in more detail below 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 merely 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, the same 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 the same reference numerals in the drawings refer to the same elements.

[0028] 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 configuration diagram explaining an electrode unit according to an embodiment of the present invention, and FIG. 4 is a configuration diagram explaining an electrode unit according to another embodiment of the present invention.

[0029] Referring to FIGS. 1 to 4, a batch-type substrate processing apparatus according to an embodiment of the present invention may include: a reaction tube (110) providing a processing space (111) in which a plurality of substrates (10) are accommodated; and an electrode unit (120) having a plurality of rod-shaped electrodes (121, 122) arranged in the circumferential direction of the reaction tube (110) and extended along the longitudinal direction of the reaction tube (110).

[0030] The reaction tube (110) may be formed of a heat-resistant material such as quartz or ceramic in a cylindrical shape with the top closed and the bottom open, and may provide a processing space (111) in which a plurality of substrates (10) are accommodated and processed. 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 layers along the length of the reaction tube (110), and is a space where an actual processing process (e.g., a deposition process) takes place.

[0031] Here, the substrate boat (50) is configured to support the substrate (10), and may 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 may also form a plurality of unit processing spaces in which each of the plurality of substrates (10) is processed individually.

[0032] A plurality of rod-shaped electrodes (121, 122) may be extended 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, a plurality of rod-shaped electrodes (121, 122) may be extended along the longitudinal direction of the reaction tube (110) and have a slender, long rod shape or bar shape, and may be arranged side by side (or parallel to each other) and positioned along the circumferential direction of the reaction tube (110).

[0033] The discharge space (125) of the plasma forming unit, which is separated from the processing space (111) by a partition (115), is a space where plasma is formed by an electrode unit (120). The plasma forming unit decomposes the process gas supplied from the gas supply pipe (170) using plasma in the discharge space (125), and can provide radicals, etc., among the decomposed process gas to the processing space (111).

[0034] The process gas may include one or more types of 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 supplied directly to the processing space (111) through a separate source gas supply pipe (175). Unlike the source gas supply pipe (175) which supplies the source gas directly 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 (120), and the reaction gas may be activated by the plasma and 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 silicon-containing gas (e.g., dichlorosilane (SiH2Cl2, DCS), etc.) and the reaction gas may include a nitrogen-containing gas (e.g., NH3, N2O, NO, etc.).

[0035] Here, the partition wall (115) may extend along the longitudinal direction of the reaction tube (110), may be placed inside the reaction tube (110), or may be placed outside the reaction tube (110). For example, as shown in FIG. 1, the partition wall (115) may be placed inside the reaction tube (110) to form an inner wall of the reaction tube (110) and a discharge space (125), and may include a plurality of side wall portions (115a, 115b) connected to the inner wall (or inner surface) of the reaction tube (110) and a main wall portion (115c) between the plurality of side wall portions (115a, 115b). A plurality of auxiliary side wall sections (115a, 115b) protrude (or extend) from the inner wall of the reaction tube (110) into the interior of the reaction tube (110), and may be 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 section (115c). The main side wall section (115c) may be spaced apart from the inner wall of the reaction tube (110) and extend in the circumferential direction of the reaction tube (110), and may be positioned between the plurality of auxiliary side wall sections (115a, 115b) to connect the plurality of auxiliary side wall sections (115a, 115b). At this time, both the plurality of auxiliary side wall sections (115a, 115b) and the main side wall section (115c) may extend along the inner wall of the reaction tube (110) in the longitudinal direction of the reaction tube (110).

[0036] Meanwhile, the main side wall (115c) may be configured in the shape of a tube having a diameter smaller or larger than that of the reaction tube (110) to form a discharge space (125) between the side wall of the reaction tube (110) and the main side wall (115c) (i.e., between the inner wall of the reaction tube and the main side wall or between the outer wall of the reaction tube and the main side wall).

[0037] By forming plasma in a discharge space (125) separated from a processing space (111) by a partition wall (115), 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).

[0038] The plasma forming section may include a plurality of nozzles (123) that are provided offset from the discharge direction of the discharge port (171) formed in the gas supply pipe (170) and arranged along 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 nozzles (123) may be arranged along 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 offset from the discharge direction of the discharge port (171). Here, the plurality of nozzles (123) may be provided in a plurality of rows arranged along 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).

[0039] Here, a plurality of rod-shaped electrodes (121, 122) may include a first power electrode (121a) to a second power electrode (121b) spaced apart from each other; and a first ground electrode (122a) to a second ground electrode (122b) provided spaced apart from each other between the first power electrode (121a) to the second power electrode (121b). In addition, at least one of the first power electrode (121a) to the second power electrode (121b) and the first ground electrode (122a) to the second ground electrode (122b) may have a different length.

[0040] 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. 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 to each other or grounded in common.

[0041] The first power electrode (121a) and the first ground electrode (122a) provided adjacent to the first power electrode (121a) are paired with each other, and the second power electrode (121b) and the second ground electrode (122b) provided adjacent to the second power electrode (121b) are paired with each other, so that plasma can be formed in the space between each.

[0042] That is, the first power electrode (121a) and the first ground electrode (122a), and the second power electrode (121b) and the second ground electrode (122b) may have a four-electrode structure, and by dividing and supplying high-frequency power to the first power electrode (121a) and the second power electrode (121b) respectively, the high-frequency power required to generate plasma or the high-frequency power required to obtain a desired amount of radicals can be reduced, thereby preventing the generation of particles caused by high-frequency power.

[0043] In other words, if a four-electrode structure is provided as in the present invention, the high-frequency power required to generate plasma that decomposes process gas or to obtain a desired amount of radicals can be reduced by half or significantly, thereby preventing damage to the electrode protection part (130), partition (115), reaction tube (110), etc. caused by high high-frequency power, and also preventing the problem of particles being generated due to damage to the electrode protection part (130), partition (115), reaction tube (110), etc.

[0044] On the other hand, in a conventional three-electrode structure having a single common ground electrode and power electrodes provided on both sides thereof, when a high-frequency power supply is applied to the power electrodes on both sides, the voltages induced by the voltages applied to the power electrodes on both sides are superimposed on the common ground electrode, which can induce twice the voltage. That is, in a 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 in the common ground electrode, and due to this high electric field, the plasma potential proportional to the electric field increases, and plasma damage occurs.

[0045] When a high-frequency power source or RF power source is applied to one end (or the bottom) of a rod-shaped electrode that extends in the longitudinal direction, there may be a difference in the potential formed on the rod-shaped electrode depending on the wavelength (λ) of the high-frequency power source and the length of the rod-shaped electrode.

[0046] If the λ / 4 of the high-frequency power source is about 2 to 3 times longer than the length of the rod electrode, stable movement of charge is possible along the length of the rod electrode, so that an equipotential can be formed in reality, and the potential difference between one end (or bottom) and the other end (top) of the rod electrode can be very small. Therefore, a plasma of uniform density can be formed along the length of the rod electrode.

[0047] On the other hand, if the length of the rod electrode is similar to or shorter than λ / 4 of the high-frequency power source, there is insufficient time for the charge to move stably according to the polarity change of the high-frequency power source having a high frequency, so a potential difference may occur between one end and the other end of the rod electrode to which the high-frequency power source is applied. In particular, a magnetic field may be induced at the other end (top) of the rod electrode due to the potential difference concentrated in the section near the other end (top) of the rod electrode, thereby forming a high-density plasma. As a result, non-uniformity of plasma density may occur between the top and bottom of the rod electrode.

[0048] For example, in a typical batch-type substrate processing device, the length of the rod electrode is about 2m to 3m, so when the frequency of the applied high-frequency power supply is 13.56MHz, λ / 4 is 5.53m, which is much longer than the length of the rod electrode, so uniformity of plasma density in the vertical direction can be ensured.

[0049] However, in order to increase the plasma density, the frequency of the high-frequency power source is increased so that when the frequency of the high-frequency power source is 27.12 MHz, λ / 4 becomes 2.77 m, which is similar to the length of the rod-shaped electrode, and thus a different potential difference may be generated in the length (or height) direction of the rod-shaped electrode. That is, due to the different potential difference formed in the length direction of the rod-shaped electrode, the plasma density and radical density may vary depending on the vertical position within the discharge space. Since radicals having different densities depending on the vertical position within the discharge space are introduced into the processing space through a plurality of nozzles arranged in the length direction (vertical direction) of the reaction tube (110), the amount of radicals reaching a plurality of substrates stacked in multiple stages within the processing space may vary, and as a result, non-uniformity in the substrate processing process depending on the vertical position may occur.

[0050] Non-uniformity in plasma density and substrate processing depending on the vertical position can be more severe in a 4-electrode structure that forms two pairs by having two power electrodes and two ground electrodes each, as the electrode pairs influence each other.

[0051] In the present invention, by making the lengths of at least one electrode different among the first power electrode (121a) and the first ground electrode (122a), and the second power electrode (121b) and the second ground electrode (122b) forming a four-electrode structure, the imbalance of potential difference according to electrode length is resolved, thereby allowing radical generation to be reduced in the upper part of the discharge space (125) and radical generation to be increased 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 larger amount of radicals can be generated in the lower part of the discharge space (125) than in the upper part between the long length first power electrode (121a) and the first ground electrode (122a). On the other hand, between the short-length second power electrode (121b) and the second ground electrode (122b), radicals are not generated in the upper part of the discharge space (125), and radicals are generated in the lower part of the discharge space (125) relatively more than in the first power electrode (121a), so 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 magnitude of the non-uniformity of the plasma distribution, electrodes having different lengths or their lengths can be selected.

[0052] In a 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 processing space (111), the length of the first power electrode (121a) and the first ground electrode (122a) can be made longer than the length of the second power electrode (121b) and the second ground electrode (122b). By making the length of the first power electrode (121a) and the first ground electrode (122a) longer, a large amount of radicals is generated in the upper part of the discharge space (125), and by making the length of the second power electrode (121b) and the second ground electrode (122b) shorter, radicals are not generated in the upper part of the discharge space (125), and a relatively large amount of radicals is generated in the lower part of the discharge space (125), thereby effectively resolving the non-uniformity of radical density.

[0053] 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 longer than or equal to the length of the first ground electrode (122a), and the length of the second power electrode (121b) may be longer than or equal to the length of the second ground electrode (122b).

[0054] Meanwhile, if the length (or size) of the power electrode and the ground electrode are different, distortion of the plasma formed near both ends of the power electrode or the ground electrode may occur. Therefore, the power electrode and the ground electrode may be arranged to face each other so that a parallel electromagnetic field can 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. Furthermore, the lengths of the second power electrode (121b) and the second ground electrode (122b), which have short lengths, may be selected according to the non-uniform plasma distribution in the vertical direction within the discharge space (125) or the magnitude of the non-uniformity of the plasma distribution.

[0055] In the third electrode structure of a conventional batch-type substrate processing device, a high electric field is induced in the middle common ground electrode, and when a high electric field is induced, the voltage imbalance occurring in the longitudinal direction of the rod-shaped electrode can become more severe. Likewise, even if the length of some of the three electrodes is changed, the electric fields induced in the common ground electrode are superimposed to form a high electric field, causing a greater voltage imbalance, making it difficult to improve the uneven plasma distribution in the vertical direction within the discharge space (125) by reducing the length of the electrode.

[0056] In a three-electrode structure, if the electrode with the shorter length is used as the common ground electrode, the non-uniformity of the overall plasma distribution within the discharge space may be exacerbated due to the difference in length between the common ground electrode and the long power electrodes on both sides. On the other hand, if one of the power electrodes in the three-electrode structure is shortened, the length (or size) of the common ground electrode becomes longer than that of the short power electrode, so self-bias formation in the short power electrode cannot be suppressed, and there may be problems such as plasma damage and particle generation caused by self-bias formation being exacerbated.

[0057] On the other hand, in the present invention, 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, so the voltage imbalance occurring in the longitudinal direction of the rod-shaped electrode is relatively small, and as a result, the non-uniformity of plasma density or radical density in the vertical direction of the discharge space (125) can be easily controlled by shortening the electrode length. Additionally, by making the lengths of the first power electrode (121a) and the first ground electrode (122b) correspond to each other and the lengths of the second power electrode (121b) and the second ground electrode (122b) correspond to each other and adjusting them equally, self-biasing in the first power electrode (121a) or the second power electrode (121b) can be effectively suppressed.

[0058] As in the embodiment of the present invention, if the length of one pair of electrodes (the first power electrode (121a) and the first ground electrode (122a)) among two pairs of electrodes is made longer and the length of the other pair of electrodes (the second power electrode (121b) and the second ground electrode (122b)) is made shorter, there may be an empty space corresponding to the difference in length with respect to the long electrode on the upper side of the short electrode (see FIG. 3). In this case, high-frequency radiation (RF Radiation) may spread 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), and parasitic plasma may be generated in the empty space on the upper side of the second power electrode (121b) and the second ground electrode (122b). Parasitic plasma is in a very unstable state, making it difficult to stably generate radicals, and this may increase non-uniformity in the substrate processing process. As described below, even when the second power electrode (121b) and the second ground electrode (122b) are surrounded and protected by an electrode protection tube, parasitic plasma can be generated in the empty space inside the electrode protection tube formed above the second power electrode (121b) and the second ground electrode (122b).

[0059] To minimize these problems, the electrode unit (120) of the present invention may further include a first insulating member (126) to a second insulating member (127) provided respectively on a second ground electrode (122b) and a second power electrode (121b); and a first floating electrode (128) and a second floating electrode (129) provided on the first insulating member (126) to the second insulating member (127).

[0060] 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), were configured to act as a barrier to block the influence of the 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 be floated, a first insulating member (126) was inserted between the second ground electrode (122b) and the first floating electrode (128), and a second insulating member (127) was inserted between the second power electrode (121b) and the second floating electrode (129).

[0061] In the present invention, parasitic plasma can be effectively suppressed by providing the first floating electrode (128) and the second floating electrode (129) in the empty space above the second ground electrode (122b) and the second power electrode (121b), and thereby it is possible to stably and precisely control the radical distribution in the vertical direction of the discharge space (125) using two pairs of electrodes having different lengths.

[0062] Since the first power electrode (121a) and the first ground electrode (122a) are provided to face each other and 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 diffuse laterally to form parasitic plasma on the second power electrode (121b) and the second ground electrode (122b). That is, in order to effectively block the high-frequency radiation diffusing 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).

[0063] 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 as each other, and the lengths of the first floating electrode (128) and the second floating electrode (129) can be the same as each other.

[0064] The batch-type substrate processing device of the present invention may further include first electrode protection tubes to fourth electrode protection tubes (131a, 132a, 132b, 131b) that respectively accommodate and protect a first power electrode (121a), a first ground electrode (122a), a second ground electrode (122b), and a second power electrode (121b).

[0065] The first electrode protective tube to the fourth electrode protective tube (131a, 132a, 132b, 131b) may have a closed top and an open bottom, and may have an internal space that can accommodate the first power electrode (121a), the first ground electrode (122a), the second ground electrode (122b), and the second power electrode (121b), respectively, so that each electrode can be inserted upward through the opening at the bottom.

[0066] The electrode protection unit (130) including the first electrode protection tube to the fourth electrode protection tube (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).

[0067] The first to fourth electrode protective tubes (131a, 132a, 132b, 131b) surround the outside 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 protective tubes (131a, 132a, 132b, 131b) may be made of a heat-resistant material such as quartz or ceramic, and may be manufactured as a single unit with the reaction tube (110).

[0068] 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) that face each other, thereby maintaining the spacing between each electrode protection tube and preventing shaking or tilting, which enables the formation of a uniform plasma.

[0069] Additionally, the bridge tubes (133a, 133b) are provided with a passage through which gas can flow, thereby enabling communication between the internal spaces of the connected electrode protection tubes. During 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 their temperatures may rise. In this case, the first power electrode (121a), the first ground electrode (122a), the second ground electrode (122b), and the second power electrode (121b) can be cooled by flowing cooling gas through the first to fourth electrode protection tubes (131a, 132a, 132b, 131b) which are connected to each other by the bridge tubes (133a, 133b). Here, the cooling gas may include an inert gas such as nitrogen (N2) or argon (Ar).

[0070] It is important for stable plasma formation to stably install and maintain an insulating member and a floating electrode on a ground approach and a power electrode, which is a thin, long rod-shaped electrode that extends in one direction. To this end, in the present invention, the first floating electrode (128), the first insulating member (126), and the second ground electrode (122b) are inserted and accommodated in the third electrode protective tube (132b) in that order, and the second floating electrode (129), the second insulating member (127), and the second power electrode (121b) are inserted and accommodated in the fourth electrode protective 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 pre-assembled, and they can be structurally stable by being inserted and maintained in the internal space of the third electrode protective 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 can be structurally stable by being inserted and maintained in the internal space of the fourth electrode protection tube (131b).

[0071] The first insulating member (126) and the second insulating member (127) may be made of an insulating material such as alumina or quartz, and since they must be inserted into the internal space of the third electrode protective tube (132b) or the fourth electrode protective tube (131b), they may be bead-shaped with a diameter smaller than the internal space for assembly workability.

[0072] 4. A plurality of electrode units (120) including electrode structures may be provided, arranged in the circumferential direction of the reaction tube (110).

[0073] Due to the multiple electrode units, the plasma generation area can be expanded to the left and right or in the horizontal direction, 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).

[0074] A plurality of electrode units (120) may be provided within a single discharge space (125) partitioned by a partition wall (115), or a plurality of discharge spaces (125) partitioned by a partition wall (115) may be formed and then electrode units (120) may be provided within each discharge space (125). Additionally, long electrode pairs and short electrode pairs may be arranged alternately, or long electrode pairs and short electrode pairs may be arranged symmetrically on the left and right sides.

[0075] 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) provided between the first power electrode (121a) and the second power electrode (121b) and the high-frequency power supply unit (150), which distributes the high-frequency power supplied from the high-frequency power supply unit (150) and provides it to the first power electrode (121a) and the second power electrode (121b), respectively.

[0076] 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).

[0077] High-frequency power may be applied to the first power electrode (121a) and the second power electrode (121b) respectively through a plurality of high-frequency power supply units (150), but due to performance differences between the plurality of high-frequency power supply units (150), high-frequency power of different characteristics or quality may be applied to the first power electrode (121a) and the second power electrode (121b), so non-uniform plasma with 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 supply unit (150) is distributed through a power distribution unit (155) to provide to the first power electrode (121a) and the second power electrode (121b) respectively, high-frequency power of 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.

[0078] In the present invention, if the length of the first power electrode (121a) and the length of the second power electrode (121b) are different, a difference in impedance due to the difference in length occurs, so even if the same high-frequency power is supplied, currents of different magnitudes may flow in 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 sides of the discharge space (125).

[0079] In this case, by adjusting the magnitude 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 form a uniform plasma and generate uniform radicals in the horizontal direction as well as in the vertical direction of the discharge space (125).

[0080] In other words, in the present invention, the vertical direction 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 direction uniformity of the plasma can be secured by adjusting the magnitude 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 and vertical distributions of the plasma within the discharge space (125) mutually influence each other. After adjusting the vertical distribution of the plasma by adjusting the length of some of the rod-shaped electrodes, the magnitude or ratio of the high-frequency power input through the power distribution unit (155) can be controlled to form a plasma that is uniform not only in the vertical direction but also in the horizontal direction of the discharge space (125).

[0081] 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 can adjust the size or ratio of the high-frequency power supplied from the high-frequency power (150) by changing the capacitance (or storage capacity).

[0082] The batch-type substrate processing device of the present invention may further include a control unit (160) that selectively controls the high-frequency power applied to each of the first power electrode (121a) and the second power electrode (121b).

[0083] The control unit (160) can selectively adjust the high-frequency power applied to each of the first and second power electrodes (121a, 121b), and can selectively adjust 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 adjust the magnitude or ratio of the high-frequency power applied to each of the first and second power electrodes (121a, 121b) by adjusting the variable capacitor of the power distribution unit (155).

[0084] The control unit (160) can control the power distribution unit (155) to adjust the high-frequency power applied to each of the first power electrode (121a) and the second power electrode (121b) by using a plasma measurement unit to measure the plasma density value 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), or by using a sensor unit connected to the first power electrode (121a) and the second power electrode (121b) to measure the RF parameters (voltage, current, phase, etc.).

[0085] The batch-type substrate processing device (100) of the present invention may further include an exhaust unit (180) that is connected to a reaction tube (110) and exhausts process residues within a processing space (111) to the outside.

[0086] The exhaust unit (180) is connected to the processing space (111) and can serve to exhaust process residues within the processing space (111) to the outside. Here, the exhaust unit (180) can be positioned to face the electrode unit (120).

[0087] The exhaust section (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 be provided with a plurality of exhaust ports (183) arranged in the longitudinal direction (i.e., vertical direction) of the reaction tube (110), each corresponding to a unit processing space(s) of the substrate boat (50) and facing a plurality of nozzles (123). Accordingly, a process gas activated by the electrode unit (120) may be supplied through the plurality of nozzles (123), pass over the surface of the substrate (10), and be sucked into the plurality of exhaust ports (183), thereby forming a laminar flow.

[0088] As described above, according to the batch-type substrate processing apparatus of 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 homogenizing the dispersion of the substrate processing process in each vertical region of the substrate processing space. As a result, the yield of the substrate processing process for a plurality of substrates stacked in multiple stages can be effectively improved.

[0089] According to the electrode unit of the present invention, a high electric field induced by a high-frequency power supply applied to each of the plurality of power electrodes can be prevented by superimposing it on the ground electrode, and accordingly, plasma damage caused by a plasma potential that increases in proportion to the electric field can be suppressed or prevented.

[0090] In addition, by matching the lengths of the first power electrode and the first ground electrode, and the second power electrode and the second ground electrode, the formation of self-bias in the first power electrode and the second power electrode can be suppressed, thereby effectively preventing plasma damage and particle generation caused by self-bias.

[0091] Furthermore, by providing an insulating member and a floating electrode on a second power electrode and a second ground electrode having relatively short lengths, interference caused by plasma generated between a first power electrode and a 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).

[0092] In addition, by distributing the high-frequency power supplied from the high-frequency power supply unit to the first and second power electrodes having different lengths at a predetermined ratio through the power distribution unit, a uniform plasma or radical can be formed in the horizontal direction in which a plurality of electrodes are arranged.

[0094] FIG. 5 is a horizontal cross-sectional view of a batch-type substrate processing apparatus according to another embodiment of the present invention, and FIGS. 6 to 8 are configuration diagrams illustrating various first electrode units to second electrode units according to another embodiment of the present invention.

[0095] Referring to FIGS. 5 to 8, a batch-type substrate processing apparatus according to another embodiment of the present invention may include: a reaction tube (110) providing a processing space for accommodating a plurality of substrates; and a first electrode unit (120) to a second electrode unit (220) each having a plurality of rod-shaped electrodes (121, 122, 221, 222) arranged in the circumferential direction of the reaction tube (110) and extended along the longitudinal direction of the reaction tube (110). And, the first electrode unit (120) includes a first power electrode (121a) and a second power electrode (121b) provided to be spaced apart from each other, and the second electrode unit (220) includes a third power electrode (221a) and a fourth power electrode (221b) provided to be spaced apart from each other, and the length of the third power electrode (221a) and the length of the fourth power electrode (221b) may each be shorter than the first power electrode (121a).

[0096] In describing a batch-type substrate device according to another embodiment of the present invention, matters that overlap with the previously described parts regarding the batch-type substrate device according to an embodiment of the present invention are omitted. Since the first electrode unit (120), which is one of a plurality of electrode units included in the batch-type substrate device according to another embodiment of the present invention, corresponds to the electrode unit (120) of the batch-type substrate device according to an embodiment of the present invention, the reference number associated with the first electrode unit (120) is used identically to the reference number associated with the electrode unit (120).

[0097] The first electrode unit (120) and the second electrode unit (220) are spaced apart from each other and arranged in the circumferential direction of the reaction tube (110), and may individually provide a plurality of rod-shaped electrodes (120, 220). The plurality of rod-shaped electrodes (120, 220) may extend along the longitudinal direction of the reaction tube (110) and may be arranged (or placed) along the circumferential direction of the reaction tube (110). For example, the plurality of rod-shaped electrodes (120, 220) may extend along the longitudinal direction of the reaction tube (110), have a slender and long rod shape or a bar shape, and may be arranged parallel to each other.

[0098] The first power electrode (121a) to the second power electrode (121b) included in the first electrode unit (120) may be spaced apart from each other, and high-frequency power (or RF power) may be supplied to each. The third power electrode (221a) to the fourth power electrode (221b) included in the second electrode unit (220) may be spaced apart from each other, and high-frequency power (or RF power) may be supplied to each. At this time, high-frequency power may be supplied to the first electrode unit (121a) to the fourth power electrode (221b) through the bottom.

[0099] As previously discussed, when a high-frequency power source is applied to one end (or the bottom) of a rod-shaped electrode that extends in the longitudinal direction, there may be a difference in the potential formed on the rod-shaped electrode depending on the wavelength (λ) of the high-frequency power source and the length of the rod-shaped electrode. In particular, among the power electrodes to which a high-frequency power source having a predetermined frequency is applied, non-uniformity of potential difference and plasma density in the longitudinal direction may occur in the first power electrode (121a) which has the longest length.

[0100] In the case where plasma is formed with a single electrode unit (120), such as in the batch-type substrate processing device according to the embodiment of the present invention, it may be difficult to fully secure uniformity in the vertical direction because the first power electrode (121a) and the second power electrode (121b), having different lengths, are insufficient to precisely control the plasma density in multiple stages in the vertical direction. In particular, since the length of the second power electrode (121b) is relatively short, the plasma density generated by the second power electrode (121b) is inevitably smaller than the plasma density generated by the first power electrode (121a), and thus may not be sufficient to improve the uniformity of the plasma density in the vertical direction within the discharge space (125).

[0101] Accordingly, in a batch-type substrate processing apparatus according to another embodiment of the present invention, plasma or radicals are effectively supplied to the lower part of the processing space (111) using a plurality of electrode units (120, 220) to precisely control the plasma density in multiple stages in the vertical direction. To this end, the lengths of the third power electrode (221a) and the fourth power electrode (221b) included in the second electrode unit (220) can be made shorter than the first power electrode (121a) included in the first electrode unit (120). Plasma generated by the third power electrode (221a) and the fourth power electrode (221b), which are shorter than the first power electrode (121a), can be effectively supplied to the lower part of the processing space (111). The plasma density can be controlled more precisely in multiple stages in the vertical direction by the first electrode unit (120) and the second electrode unit (220) having different lengths.

[0102] The batch-type substrate processing apparatus of the present invention may further include a first partition (115) and a second partition (215) that are connected to the reaction tube (110) and provided to be spaced apart from each other. In addition, a first electrode unit (120) may be provided in a first discharge space (125) surrounded by the reaction tube (110) and the first partition (115), and a second electrode unit (220) may be provided in a second discharge space (225) surrounded by the reaction tube (110) and the second partition (215). In order to uniformly supply radicals to a substrate (10) located within the processing space (111) in both vertical and horizontal directions, the first discharge space (125) and the second discharge space (225) that supply radicals to the processing space (111) may be provided symmetrically with respect to an imaginary line connecting the exhaust section (180) and the center of the substrate (10). Likewise, the first electrode unit (120) and the second electrode unit (220) may also be provided symmetrically around the virtual line.

[0103] A plurality of first nozzles (123) and a plurality of second nozzles (223) formed in the first partition (115) and the second partition (215) may be provided with the same shape, height, number, etc., so as to maintain the same flow of fluid, such as radicals, supplied to the processing space (111).

[0104] Radicals formed individually in the first discharge space (125) and the second discharge space (225) are supplied to the processing space (111) through the first nozzle (123) and the second nozzle (223) formed in the first partition (115) and the second partition (215), so that the density of the radicals can be uniform regardless of the vertical position of the processing space (111).

[0105] A first electrode unit (120) provided inside a first discharge space (125) defined by a first partition (115) forms a first plasma forming part (A), and a second electrode unit (220) provided inside a second discharge space (225) defined by a second partition (215) can form a second plasma forming part (B). That is, a batch-type substrate processing device according to another embodiment of the present invention may include an 8-electrode structure by providing a pair of 4-electrode structures.

[0106] The length of the second power electrode (121b) may be the same as or shorter than the first power electrode (121a). In a batch-type substrate processing apparatus comprising a plurality of electrode units, the second power electrode (121a) included in the first electrode unit may be optionally made the same as or shorter than the first power electrode (121a) to control the plasma density in the vertical direction. For example, the second power electrode (121b) may be provided with the same length as the first power electrode (121a) to supply more radicals to the upper part of the processing space (111), or it may be shorter than the length of the first power electrode (121a) to control the plasma density by further subdividing it into multiple stages along the vertical direction. More specifically, the length of the second power electrode (121b) may be shorter than the first power electrode (121a) and longer than the third power electrode (221a) and / or the fourth power electrode (221b).

[0107] The first electrode unit (120) may further include a first ground electrode (122a) and a second ground electrode (122b) provided between the first power electrode (121a) and the second power electrode (121b). 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 grounded in common.

[0108] If the lengths of the power electrode and the ground electrode are different, distortion of the plasma formed near both ends of the power electrode or the ground electrode may occur. Therefore, the power electrode and the ground electrode may be arranged to face each other so that a parallel electromagnetic field can 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 invention, the length of the first ground electrode (122a) may be the same as the length of the first power electrode (121a), and the length of the second ground electrode (122b) may be the same as the length of the second power electrode (121b).

[0109] When the length of the second ground electrode (122b) is shorter than that of the first power electrode (121a), radiofrequency radiation (RF Radiation) may spread 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), thereby generating parasitic plasma in the empty space above the second power electrode (121b) and the second ground electrode (122b). Parasitic plasma is in a very unstable state, making it difficult to stably generate radicals, which may increase non-uniformity in the substrate processing process.

[0110] To suppress parasitic plasma, the first electrode unit (120) may further include a first insulating member (126) to a second insulating member (127) provided respectively on a relatively short second ground electrode (122b) and a second power electrode (121b); and a first floating electrode (128) and a second floating electrode (129) provided on the first insulating member (126) to the second insulating member (127). 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), can suppress parasitic plasma by acting as a barrier that blocks the influence of plasma formed between the first power electrode (121a) and the first ground electrode (122a).

[0111] 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 first 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). By having such an electrode structure with corresponding lengths, high-frequency radiation spreading laterally can be blocked, thereby effectively suppressing parasitic plasma that may be formed on the second power electrode (121b) and the second ground electrode (122b).

[0112] In addition, when 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 as each other, and the lengths of the first floating electrode (128) and the second floating electrode (129) can be the same as each other.

[0113] In the present invention, the lengths of the third power electrode (221a) and the fourth power electrode (221b) can be made different from each other to further improve the uniformity of plasma density according to the vertical position. That is, in order to more precisely control the plasma density in the vertical direction in the second plasma forming unit (B) that supplies radicals to the lower part of the processing space (111), the length of the third power electrode (221a) can be made longer than the length of the fourth power electrode (221b).

[0114] The second electrode unit (220) may further include a third ground electrode (222a) and a fourth ground electrode (222b) provided between the third power electrode (221a) and the fourth power electrode (221b).

[0115] In order to suppress distortion of plasma that may occur near both ends of the power electrode or ground electrode and to generate an electromagnetic field parallel to the power electrode and the ground electrode, the length of the third ground electrode (222a) is the same as the length of the third power electrode (221a), and the length of the fourth ground electrode (222b) may be the same as the length of the fourth power electrode (221b).

[0116] Since the first electrode unit (120) and the second electrode unit (220) are arranged facing the exhaust section (180) with the substrate (10) as the center, the first electrode unit (120) and the second electrode unit (220) can be adjacent to each other. Parasitic plasma may be generated on the upper portions of the third power electrode (221a) and the third ground electrode (222a) and on the upper portions of the fourth ground electrode (222b) and the fourth power electrode (221b) by the plasma formed between the first power electrode (121a) and the first ground electrode (122a). Additionally, if the lengths of the third power electrode (221a) and the fourth power electrode (221b) are different, parasitic plasma may be generated on the upper portions of the fourth ground electrode (222b) and the fourth power electrode (221b) by the plasma formed between the third power electrode (221a) and the third ground electrode (222a).

[0117] To suppress such parasitic plasma, the second electrode unit (220) may further include: a third insulating member (226a) to a fourth insulating member (227a) provided respectively on the third power electrode (221a) and the third ground electrode (222a); a third floating electrode (228a) and a fourth floating electrode (229a) provided on the third insulating member (226a) to the fourth insulating member (227a); a fifth insulating member (226b) to a sixth insulating member (227b) provided respectively on the fourth ground electrode (222b) and the fourth power electrode (221b); and a sixth floating electrode (228b) and a sixth floating electrode (229b) provided on the fifth insulating member (226b) to the sixth insulating member (227b).

[0118] The total length of the third power electrode (221a), the third insulating member (226a), and the third floating electrode (228a) so that the third floating electrode (228a) to the sixth floating electrode (229b) can effectively act as a barrier to block high-frequency radiation spreading laterally; the total length of the third ground electrode (222a), the fourth insulating member (227a), and the fourth floating electrode (229a); the total length of the fourth ground electrode (222b), the fifth insulating member (226b), and the fifth floating electrode (228b); and the total length of the fourth power electrode (221b), the sixth insulating member (227b), and the sixth floating electrode (229b); each of which may be equal to the length of the first power electrode (121a).

[0119] Meanwhile, the frequency of the high-frequency power applied to one end (or the bottom) of the first power electrode (121a), the second power electrode (121b), the third power electrode (221a), and the fourth power electrode (221b) may be greater than 25 MHz.

[0120] In the case of a high-frequency power supply frequency of 13.56 MHz used in general substrate processing devices, λ / 4 is 5.53 m, which is much longer than the length of a typical rod-shaped electrode. This allows for equipotentiality to be achieved, thereby ensuring uniformity of plasma density in the vertical direction. However, recently, there has been an increasing need to increase the plasma density to increase the amount of radicals generated in order to activate process gases using plasma energy and lower the substrate processing temperature. To achieve this, it is necessary to increase the frequency of the high-frequency power supply to 25 MHz or higher. With a λ / 4 of 3 m for a 25 MHz high-frequency power supply, it can not only be utilized as a power electrode for batch-type substrate processing devices but can also effectively increase radical density. When using a high-frequency power source having a frequency of 25 MHz or higher, a large amount of radicals can be supplied to the upper part of the processing space (111) from the first power electrode (121a), and a third power electrode (221a) and / or a fourth power electrode (221b), etc., having a length shorter than λ / 4, can be used to stably form an equipotential surface despite the high frequency, thereby allowing radicals to be supplied to the lower part of the processing space (111) at a constant rate.

[0121] More effectively, the frequency of the high-frequency power applied to one end (or the bottom) of the first power electrode (121a) to the fourth power electrode (221b) may be 25 MHz to 35 MHz. In the case of a rod-shaped electrode long in the longitudinal direction, if the frequency of the applied high-frequency power increases to 35 MHz or more, the impedance increases due to the occurrence of inductive coupling, so that current does not flow well, which may actually reduce the plasma density.

[0122] And, the batch-type substrate processing device of the present invention may further include: a first 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 first power distribution unit (155) provided between the first power electrode (121a) and the second power electrode (121b) and the first high-frequency power supply unit (150) to distribute high-frequency power and provide it to the first power electrode (121a) and the second power electrode (121b), respectively. Likewise, the batch-type substrate processing device of the present invention may further include a second high-frequency power supply unit (250) that supplies high-frequency power to a third power electrode (221a) and a fourth power electrode (221b); and may further include a second power distribution unit (255) provided between the third power electrode (221a) to the fourth power electrode (221b) and the second high-frequency power unit (250) to distribute high-frequency power and provide it to the third power electrode (221a) and the fourth power electrode (221b) respectively.

[0123] High-frequency power may be applied to the first power electrode (121a) and the second power electrode (121b), the third power electrode (221a), and the fourth power electrode (221b) respectively through independent multiple high-frequency power supplies. However, due to performance differences between the multiple high-frequency power supplies, high-frequency power of different characteristics or quality may be supplied, so non-uniform plasma with different plasma densities may be formed in the first power electrode (121a) to the fourth power electrode (221b). On the other hand, if high-frequency power supplied from a single high-frequency power supply (150, 250) provided to the first plasma forming unit (A) and the second plasma forming unit (B) is distributed through a power distribution unit (155, 255) and provided to the power electrodes respectively, high-frequency power of the same characteristics and quality may be applied to each plasma forming unit, and a uniform plasma may be formed.

[0124] In the present invention, a difference in impedance occurs due to the difference in length between the first power electrode (121a) and the fourth power electrode (221b), so even if the same high-frequency power is supplied, currents of different magnitudes may flow in the first power electrode (121a) and the fourth power electrode (221b), so that the plasma density may be non-uniform on the left and right sides of the discharge space (125).

[0125] In this case, by using a power distribution unit (155, 255) to adjust the magnitude or ratio of high-frequency power provided to each of the first electrode unit (120) and the second electrode unit (220) and providing it to the power electrodes, it is possible to form a uniform plasma and generate uniform radicals in the horizontal direction as well as in the vertical direction of the first discharge space (125) and the second discharge space (225).

[0126] Here, the first power distribution unit (155) and the second power distribution unit (255) may include a variable capacitor. The variable capacitor can adjust the size or ratio of the high-frequency power supplied from the first high-frequency power source (150) and the second high-frequency power source (250) by changing the capacitance (or storage capacity).

[0127] The batch-type substrate processing apparatus of the present invention may further include a first control unit (160) and a second control unit (260) that control a first power distribution unit (155) and a second power distribution unit (255) to selectively adjust the high-frequency power supplied to each of the power electrodes. The first control unit (160) and the second control unit (260) can selectively adjust the high-frequency power applied to each of the first power electrode (121a) to the fourth power electrode (221b), and can selectively adjust the high-frequency power applied according to the plasma state, such as discharge current, discharge voltage, and phase. At this time, the first control unit (160) and the second control unit (260) can adjust the magnitude or ratio of the high-frequency power applied to each of the first power electrode (121a) to the fourth power electrode (221b) by adjusting the variable capacitors of the first power distribution unit (155) and the second power distribution unit (255).

[0128] The first control unit (160) and the second control unit (260) can control the distribution unit (255) to adjust the high-frequency power applied to each power electrode by using a plasma density value measured between the power electrode and the ground electrode using a plasma measuring unit, or a measured value of RF parameters (voltage, current, phase, etc.) measured using a sensor unit connected to each power electrode.

[0129] The batch-type substrate processing device of the present invention may further include a first electrode protection unit (130) and a second electrode protection unit (230) that respectively accommodate and protect a first electrode unit (120) and a second electrode unit (220). The first electrode protection unit (130) and the second electrode protection unit (230) can electrically insulate the rod-shaped electrodes (121, 122, 221, 222) of the first electrode unit (120) and the second electrode unit (220) from each other and protect them from plasma, and can safely protect them from contamination or particles that may be generated by plasma.

[0130] The first electrode protection unit (130) may include first to fourth electrode protection tubes (131a, 132a, 132b, 131b) and first to second bridge tubes (133a) connecting them. Additionally, the second electrode protection unit (230) may include fifth to eighth electrode protection tubes (231a, 232a, 232b, 231b) and third to fourth bridge tubes (233a) connecting them.

[0132] As described above, according to the batch-type substrate processing apparatus of 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 homogenizing the dispersion of the substrate processing process in each vertical region of the substrate processing space. As a result, the yield of the substrate processing process for a plurality of substrates stacked in multiple stages can be effectively improved.

[0133] According to the electrode unit of the present invention, a high electric field induced by a high-frequency power supply applied to each of the plurality of power electrodes can be prevented by superimposing it on the ground electrode, and accordingly, plasma damage caused by a plasma potential that increases in proportion to the electric field can be suppressed or prevented.

[0134] In addition, by matching the lengths of the first to fourth power electrodes and the first to fourth ground electrodes, the formation of self-bias in the first to fourth power electrodes can be suppressed, thereby effectively preventing plasma damage and particle generation caused by self-bias.

[0135] Furthermore, by providing an insulating member and a floating electrode on the second to fourth power electrodes and the second to fourth ground electrodes 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).

[0136] In addition, by distributing the high-frequency power supplied from the high-frequency power supply unit to the first to second power electrodes and the third to fourth power electrodes, which have different lengths, at a predetermined ratio through the power distribution unit, a uniform plasma or radical can be formed in the horizontal direction in which a plurality of electrodes are arranged.

[0138] The term 'on' as used in the above description includes cases of direct contact as well as cases where it is positioned facing the upper or lower surface without direct contact. It is possible to be positioned facing the entire upper or lower surface, or to be positioned facing it partially; it is used to mean facing it from a distance or in direct contact with the upper or lower surface. Furthermore, terms such as 'up,' 'down,' 'front end,' 'rear end,' 'upper,' 'lower,' 'top end,' and 'bottom end' used in the above description are defined based on the drawings for convenience, and the shape and position of each component are not restricted by these terms.

[0139] Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the embodiments described above, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible without departing from the gist of the present invention as claimed in the claims. Accordingly, the technical scope of protection of the present invention should be determined by the claims below. Explanation of the symbols

[0141] 10: Substrate 50: Substrate boat 110: Reaction tube 111: Processing space 115: Bulkhead (1st bulkhead) 120: Electrode unit (1st electrode unit) 130: Electrode protection unit (1st electrode protection unit) 150: High-frequency power supply unit (1st high-frequency power supply unit) 160: Control unit (1st control unit) 170: Gas supply pipe 220: Second electrode unit 230: Second electrode protection part 250: Second high-frequency power supply 260: Second control unit

Claims

Claim 1 A reaction tube providing a processing space for accommodating multiple substrates; The apparatus comprises: a first electrode unit and a second electrode unit, each having a plurality of rod-shaped electrodes arranged in the circumferential direction of the reaction tube and extending along the longitudinal direction of the reaction tube; wherein the first electrode unit includes a first power electrode and a second power electrode provided spaced apart from each other, and the second electrode unit includes a third power electrode and a fourth power electrode provided spaced apart from each other, and the length of the third power electrode and the length of the fourth power electrode are each shorter than the first power electrode, and the length of the second power electrode is equal to or shorter than the first power electrode, and the first electrode unit further includes a first ground electrode and a second ground electrode provided between the first power electrode and the second power electrode, the length of the first ground electrode is equal to the length of the first power electrode, and the length of the second ground electrode is equal to the length of the second power electrode, and in the case where the length of the second power electrode is shorter than the length of the first power electrode, the first electrode unit is provided on the second ground electrode and the second power electrode, respectively. A batch-type substrate processing apparatus further comprising: a first insulating member to a second insulating member; and a first floating electrode and a second floating electrode provided on the first insulating member to the second insulating member. Claim 2 A batch-type substrate processing apparatus according to claim 1, further comprising first and second partitions connected to the reaction tube and provided to be spaced apart from each other, wherein the first electrode unit is provided in a first discharge space surrounded by the reaction tube and the first partition, and the second electrode unit is provided in a second discharge space surrounded by the reaction tube and the second partition. Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A batch-type substrate processing apparatus according to claim 1, wherein the total length of the second ground electrode, the first insulating member, and the first floating electrode is the same as the length of the first ground electrode, and 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. Claim 7 delete Claim 8 delete Claim 9 A reaction tube providing a processing space for accommodating multiple substrates; and a first electrode unit to a second electrode unit each having a plurality of rod-shaped electrodes arranged in the circumferential direction of the reaction tube and extending along the longitudinal direction of the reaction tube; wherein the first electrode unit includes a first power electrode and a second power electrode provided spaced apart from each other, and the second electrode unit includes a third power electrode and a fourth power electrode provided spaced apart from each other, and the length of the third power electrode and the length of the fourth power electrode are each shorter than the first power electrode, and the length of the third power electrode and the length of the fourth power electrode are different from each other, and the second electrode unit further includes a third ground electrode and a fourth ground electrode provided between the third power electrode and the fourth power electrode, the length of the third ground electrode is the same as the length of the third power electrode, and the length of the fourth ground electrode is the same as the length of the fourth power electrode, and the second electrode unit includes a third insulating member to a fourth insulating member provided on the third power electrode and the third ground electrode, respectively; A batch-type substrate processing apparatus further comprising: a third floating electrode and a fourth floating electrode provided on the third to fourth insulating members; a fifth to sixth insulating member, respectively provided on the fourth ground electrode and the fourth power electrode; and a sixth floating electrode and a sixth floating electrode provided on the fifth to sixth insulating members. Claim 10 A batch-type substrate processing apparatus according to claim 9, wherein the total length of the third power electrode, the third insulating member, and the third floating electrode; the total length of the third ground electrode, the fourth insulating member, and the fourth floating electrode; the total length of the fourth ground electrode, the fifth insulating member, and the fifth floating electrode; and the total length of the fourth power electrode, the sixth insulating member, and the sixth floating electrode, each having the same length as the first power electrode. Claim 11 A batch-type substrate processing apparatus according to claim 1, wherein the frequency of the high-frequency power applied to the first power electrode, the second power electrode, the third power electrode, and the fourth power electrode is greater than 25 MHz.

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