Inductively coupled plasma device and coating apparatus

Abstract

The application discloses an inductively coupled plasma device and a coating equipment. The inductively coupled plasma device comprises a reaction chamber, a dielectric window sealing the reaction chamber, a coil set opposite to the reaction chamber through the dielectric window, the coil set has a plurality of planar rectangular spiral coils, and each of the rectangular spiral coils is connected in parallel. An RF power source is electrically connected with each of the rectangular spiral coils. The inductively coupled plasma device can provide a larger area of plasma source.

Description

Technical Field

[0001] This invention relates to the field of inductively coupled plasma technology, and more particularly to inductively coupled plasma devices and coating equipment. Background Technology

[0002] Inductively Coupled Plasma (ICP) is a low-temperature, high-density plasma source. It utilizes an inductively coupled coil for radio frequency discharge, which, driven by a radio frequency power supply, provides an excitation magnetic field to the reaction chamber, ionizing the reactant gas and thus forming plasma. Depending on the coil type, ICP is further divided into cylindrical inductively coupled coil plasma and planar inductively coupled coil plasma. Cylindrical inductively coupled coil plasma has advantages such as high density and high efficiency, but also disadvantages such as poor uniformity. Planar inductively coupled coil plasma has advantages such as high density and good uniformity, but also suffers from relatively lower efficiency.

[0003] Furthermore, in known planar inductively coupled coil plasmas, the coil shape is typically a circular spiral. However, with the advancement of coating processes, there are increasing demands for larger plasma areas, higher plasma densities, and lower ion damage. For example, when a larger plasma area is required, conventional planar circular spiral coils necessitate larger coil sizes to meet the plasma generation requirements. When the size of the coil acting as the transmission element exceeds one-eighth of the RF power supply wavelength, voltage and current variations along the coil length will cause significant changes in the electromagnetic field within the plasma generation region. This can potentially lead to non-uniform gas excitation, resulting in uneven sample processing. Additionally, larger coil sizes mean greater inductance, making it more difficult to achieve conjugate matching and increasing the risk of abnormal arcing, which significantly negatively impacts the process. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes an inductively coupled plasma device that can provide a larger plasma source area without adversely affecting the process. Furthermore, this invention also proposes a coating apparatus incorporating this inductively coupled plasma device.

[0005] According to one aspect of the present invention, an inductively coupled plasma device includes: a reaction chamber; a dielectric window sealing the reaction chamber; a coil group opposite to the reaction chamber via the dielectric window, the coil group having a plurality of planar rectangular helical coils connected in parallel; and a radio frequency power supply electrically connected to each of the rectangular helical coils.

[0006] According to one aspect of the present invention, the inductively coupled plasma device has the following advantages: it can provide a plasma source with a larger area without adversely affecting the process.

[0007] In some embodiments, the rectangular spiral coil has multiple turns of sub-coils; a radio frequency power feed terminal is provided at the middle of the rectangular spiral coil, and a first distance from the radio frequency power feed terminal to a sub-coil adjacent to the radio frequency power feed terminal is larger than a second distance between adjacent sub-coils at the edge of the rectangular spiral coil.

[0008] In some embodiments, a plurality of the rectangular helical coils are arranged in a row.

[0009] In some embodiments, the third spacing between the outermost turns of two adjacent rectangular spiral coils is smaller than the first spacing between the two adjacent rectangular spiral coils.

[0010] In some embodiments, the third spacing between two adjacent rectangular spiral coils can be adjusted.

[0011] In some implementations, the radio frequency current flows in the same direction on the adjacent sides of two adjacent rectangular spiral coils.

[0012] In some embodiments, magnetic elements are provided on both sides of the coil group along a direction orthogonal to the direction in which the plurality of rectangular spiral coils are arranged.

[0013] In some embodiments, the loadable frequency, radio frequency power, and / or the current flowing through each of the rectangular helical coils can be adjusted independently.

[0014] In some embodiments, each of the rectangular spiral coils is grounded via an adjustable reactance element.

[0015] According to a second aspect of the present invention, a coating apparatus includes a coating chamber connected to an inductively coupled plasma device provided with any of the above-mentioned items.

[0016] The coating apparatus according to the second aspect of the present invention has the following advantages: it can provide a plasma source with a larger area without adversely affecting the process. Attached Figure Description

[0017] Figure 1 This is a simplified schematic diagram of one embodiment of the inductively coupled plasma device of the present invention.

[0018] Figure 2 This is a top view of one embodiment of the coil assembly of the inductively coupled plasma device of the present invention.

[0019] Figure 3 yes Figure 2 Side view of the coil assembly.

[0020] Figure 4 This is a simplified schematic diagram of one embodiment of a coating apparatus having the inductively coupled plasma device of the present invention. Detailed Implementation

[0021] The embodiments of this implementation are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this implementation, and should not be construed as limiting this implementation.

[0022] In the description of this embodiment, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this embodiment.

[0023] In the description of this embodiment, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0024] In the description of this embodiment, unless otherwise explicitly limited, terms such as setting, installing, and connecting should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this embodiment in conjunction with the specific content of the technical solution.

[0025] Figure 1 This is a simplified schematic diagram of the inductively coupled plasma device 100. Figure 2 This is a top view of coil group 103. Figure 3 This is a side view of coil group 100. Figure 4 This is a simplified schematic diagram of the coating equipment 200.

[0026] Reference Figures 1 to 4 and mainly refer to Figure 1The inductively coupled plasma apparatus 100 of the first embodiment includes a reaction chamber 101, a dielectric window 102, a coil assembly 103, and a radio frequency power supply 104. An inlet 106 is provided on the side of the reaction chamber 101, for example, to introduce reaction gas into the reaction chamber 101. The dielectric window 102 seals the reaction chamber 101. The dielectric window 102 includes, for example, a dielectric coupling plate 105, which vacuum-seals the reaction chamber 101. The coil assembly 103 is positioned opposite the reaction chamber 101 across the dielectric window 102. For example, the coil assembly 103 may be positioned above the dielectric coupling plate 105. The coil assembly 103 has a plurality of planar rectangular spiral coils 107 (hereinafter sometimes simply referred to as "coils 107"), which are connected in parallel. The radio frequency power supply 104 is electrically connected to each rectangular spiral coil 107. Specifically, the radio frequency power supply 104 feeds radio frequency current into the rectangular spiral coils 107 via a matching unit 108, causing each rectangular spiral coil 107 to generate a changing magnetic field. This magnetic field can induce an electric field, thereby ionizing the reaction gas introduced into the reaction chamber 101 to generate plasma.

[0027] The inductively coupled plasma device 100 of this embodiment can provide a larger plasma source area without adversely affecting the process. Specifically, in a coating apparatus 200 such as a PECVD (plasma-enhanced chemical vapor deposition) or PEALD (plasma-enhanced atomic layer deposition) apparatus, a substrate 205 is coated. As the size of the substrate 205 continues to increase, especially when coating rectangular (it should be noted that rectangle includes both rectangles and squares; in other words, a square is considered a special type of rectangle) substrate 205, a rectangular plasma source is desired. In the prior art, to accommodate such electrode sizes, capacitively coupled plasma sources are typically used, and process requirements are met by continuously increasing the electrode length and / or power. However, capacitively coupled plasma devices, compared to inductively coupled plasma devices, have limitations such as lower density and higher energy, which may not meet the process requirements for coating the substrate 205. Therefore, it is considered to select an inductively coupled plasma device to meet specific process requirements. In the inductively coupled plasma device 100 of this embodiment, by providing a coil group 103 having a plurality of parallel, planar rectangular spiral coils 107, the coverage area of ​​the plasma source can be expanded by laying the coils 107 without excessively increasing the size of a single coil 107. For example, the plasma source can be made into a rectangular shape. Furthermore, since there are no areas that the planar rectangular spiral coils 107 cannot radiate when they are laid, the uniformity of the plasma source can be controlled even when multiple coils 107 are laid.

[0028] Therefore, the inductively coupled plasma device 100 of this embodiment can provide a larger area plasma source without adversely affecting the process, while ensuring the uniformity of the plasma source is controllable.

[0029] Continue to refer to Figure 4 Therefore, the plasma generator 100 of this embodiment can be installed in the coating equipment 200 and connected to the coating chamber 201 of the coating equipment 200 to deliver plasma into the coating chamber 201. Examples of coating equipment 200 include PECVD equipment and PEALD equipment. Taking a PEALD equipment as an example, examples include horizontal PEALD equipment with a linearly reciprocating base and vertical PEALD equipment with a rotating base. Taking a horizontal PEALD equipment as an example, the PEALD equipment includes a coating chamber 201, a precursor air inlet device 202, a purge and isolation device 203, the plasma generator 100 of this embodiment, and a base 204. A substrate 205 to be coated is mounted on the base 204. The substrate 205 is driven sequentially through the base 204 to the precursor air intake device 202, the purge isolation device 203, the plasma generator 100, and back to the purge isolation device 203, thereby completing one process cycle. By increasing the number of cycles, the specified coating thickness can be achieved.

[0030] Continue to refer to Figure 2 And supplementary reference Figure 1The radio frequency power supply 104 is fed in, for example, from the middle of the coil 107. The loadable frequency, radio frequency power, and / or current value of each coil 107 can be independently adjusted. Specifically, the coil 107 is, for example, a hollow copper tube into which a coolant can be injected. The coolant is not particularly limited as long as it can cool the coil 107; for example, deionized water can be selected. A radio frequency power feed end 109 (hereinafter sometimes referred to as "feed end 109" for ease of explanation) is provided in the middle of the coil 107. The portion of the coil 107 that serves as the radio frequency power feed end 109 extends in a direction that is approximately perpendicular to the rectangular plane of the coil 107. The copper tube serving as the coil 107 extends from the radio frequency power feed end 109 outwards in a generally rectangular shape with multiple turns. In other words, coil 107 has multiple turns of sub-coils 110, each turn of which is approximately rectangular (it should be noted that due to the manufacturing process, the coil 107 will form rounded corners when bent), and the area of ​​the rectangular shape of the sub-coils 110 gradually increases from the center to the edge. Preferably, the shape of each turn of the sub-coils 110 is approximately square, that is, in a top view, the outer periphery of the planar coil 107 is square and each sub-coil 110 is also square. This improves the uniformity of the coil 107 in all directions. In addition, an RF power output terminal 111 (for ease of explanation, it will sometimes be referred to as "output terminal 111" hereafter) is formed on the outermost turn of coil 107. The RF power output terminal 111 also extends in the same direction as the RF power feed terminal 109 along a plane that is approximately perpendicular to the rectangle of coil 107. Thus, each coil 107 can be connected to an RF power supply and grounded, for example, on the same side (the upper side in the figure).

[0031] Continue to refer to Figure 1 Each coil 107 can, for example, be connected to the same RF power supply 104. For instance, the RF power supply 104 is connected to a matching converter 108, which has multiple output ports, each connected to the feed input 109 of the coil 107. Furthermore, the matching converter 108 can be equipped with a known current adjustment device, allowing each coil 107 to determine whether current adjustment is needed based on actual conditions. Alternatively, each coil 107 can be partially or fully connected to an independent RF power supply 104. For example, each coil 107 can be connected to a separate RF power supply 104, with each independent RF power supply 104 connected to the coil 107 via a separate matching converter 108. Thus, based on the actual conditions of each coil 107, different frequencies, different current ratios of RF power sources can be applied. The frequency range of the coil 107 is, for example, 2MHz to 160MHz, and the current ratio range of the coil 107 is, for example, 1% to 99%.

[0032] Continue to refer to Figure 1Furthermore, each coil 107 can be grounded, for example, via an adjustable reactive element 112. An example of the reactive element 112 is an adjustable vacuum capacitor, with an adjustment range of, for example, 10 pF to 500 pF. This allows for independent adjustment of the impedance characteristics of each coil 107, and by adjusting the voltage distribution, power distribution, etc., of each coil 107, the intensity of the electromagnetic field generated by each coil 107 can be adjusted independently.

[0033] Continue to refer to Figure 2 For a single coil 107, the electromagnetic field strength in the central region is higher than that at the surrounding edges. Therefore, in some embodiments, the first spacing a1 from the RF power feed 109 to a sub-coil 110 adjacent to the RF power feed 109 is larger than the second spacing a2 between adjacent sub-coils 110 at the edges of the rectangular spiral coil 107. For example, a coil 107 has multiple turns, in one specific example, five turns of sub-coils 110, with the first turn located in the middle and the fifth turn located at the outermost edge. The first spacing a1 from the feed 109 to the center of the first turn of the sub-coil 110 (the copper tube adjacent to the feed 109) is larger than the second spacing a2 between the individual turns of the sub-coil 110 (e.g., the spacing between the centers of adjacent copper tubes between the first and second turns of the sub-coil 110). For example, the first spacing a1 is more than twice and less than four times the second spacing a2. Furthermore, the second spacing a2 between the first and second turns of the sub-coil 110 can, for example, be larger than the second spacing a2 between the fourth and fifth turns of the coil 107. Further, the second spacing a2 can also gradually decrease from the center of the coil 107 towards its edges. Thus, as the size between the first spacing a1 and the second spacing a2 increases, the difference in electromagnetic field intensity between the center and the surrounding edges of the coil 107 decreases. This allows for adjustment of the uniformity of the plasma source based on these electromagnetic field intensities. Furthermore, as the second spacing a2 decreases from the center relative to the edges, the difference in electromagnetic field intensity between the center and the surrounding edges of the coil 107 can also be altered to some extent.

[0034] Continue to refer to Figure 1 And supplementary reference Figure 2In some embodiments, multiple rectangular helical coils 107 are arranged in a row. Specifically, for example, four coils 107 are arranged in a straight line in one direction, thereby forming a coil group 103 with a length more than four times the length of a single coil 107 and a width approximately the same as the width of the coil 107. By forming such a coil group 103, a larger area plasma source can be provided. Furthermore, by arranging multiple coils 107 in a row, it is easier to control and adjust the electromagnetic field of the coil group 103. For example, when multiple coils 107 are arranged in a row, only the coupling of the arrangement direction needs to be considered for the coils 107.

[0035] The third spacing a3 between two adjacent rectangular helical coils 107 is smaller than the first spacing a1 of each of the two adjacent rectangular helical coils 107. Specifically, for example, the first spacing a1 can also be a distance that is more than twice but less than four times the third spacing a3. More specifically, for example, the distance between the centers of the copper tubes of the fifth turn of the sub-coil 110 of each coil 107 that are adjacent to each other, i.e., the third spacing a3, can be equal to the spacing a2 of the second spacing between the two adjacent coils 107. As a result, the electromagnetic field strength at the adjacent positions of the two coils 107 can be made approximately the same as the electromagnetic field strength of the coils 107 themselves, thereby improving the uniformity of the plasma source based on these electromagnetic field strengths.

[0036] Furthermore, the third distance a3 between two adjacent rectangular helical coils 107 can be adjusted. For example, differences in the material, manufacturing process, and power loss of the coils 107 may cause differences in the electromagnetic field strength at adjacent positions of the two coils 107. By adjusting the third distance a3 between the coils 107, the electromagnetic field strength at adjacent positions of the two coils 107 can be adjusted to a certain extent, thereby improving the uniformity of the plasma source based on these electromagnetic field strengths.

[0037] Continue to refer to Figure 2In some embodiments, the direction of the radio frequency current (indicated by the arrows in the figures) on the adjacent sides of two adjacent rectangular helical coils 107 is the same. The method of making the radio frequency current flow the same is not particularly limited. For example, when each coil 107 has its middle as the feed end 109 and its edge as the output end 111, the helical directions of the coils 107 can be opposite, thus ensuring that the direction of the radio frequency current flow is the same on the adjacent sides of each coil 107. Furthermore, it is also possible to have the middle of one of the two adjacent coils 107 as the feed end 109 and the other edge as the output end 111, which also ensures that the direction of the radio frequency current flow is the same on the adjacent sides of each coil 107. Therefore, by making the current flow direction of the two sets of coils 107 the same, constructive interference of the electromagnetic waves of the coils 107 can be achieved, thereby strengthening the electromagnetic field intensity on the adjacent sides of the two coils 107 and improving the uniformity of the plasma source based on these electromagnetic field intensities.

[0038] Continue to refer to Figure 1 , Figure 2 In some embodiments, magnetic elements 113 are provided on both sides of the coil assembly 103 in a direction orthogonal to the direction in which the plurality of rectangular helical coils 107 are arranged. Examples of magnetic elements 113 include permanent magnets and electromagnets; examples of electromagnets include electromagnets with adjustable magnetic strength. The magnetic elements 113 are provided on both sides of the coil assembly 103 in the width direction. Furthermore, the number of magnetic elements 113 is not particularly limited; for example, one magnetic element 113 or multiple magnetic elements 113 can be provided on each side of the coil assembly 103 in the width direction. By providing magnetic elements 113 on both sides of the coil assembly 103 in the width direction, electrons in the plasma undergo Ramohr motion (spinning along strong magnetic lines of force) under an applied magnetic field. This increases the collision path and probability with the neutral gas, thereby increasing the plasma density. Adding magnetic elements on the sides where the plasma is weaker helps improve the plasma uniformity on both sides.

[0039] Continue to refer to Figure 4 As described above, the inductively coupled plasma device 100 of each embodiment can be installed in the coating apparatus 200 and connected to the coating chamber 201 of the coating apparatus 200 to deliver plasma into the coating chamber 201. Examples of coating apparatus 200 include PECVD apparatus and PEALD apparatus. By using the inductively coupled plasma device 100 of each embodiment, the coating apparatus 200 of the second embodiment can provide a plasma source with a larger area.

[0040] Although embodiments of this implementation have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this implementation, the scope of which is defined by the claims and their equivalents.

Claims

1. An inductively coupled plasma device, characterized in that, include: Reaction chamber; Medium window, sealing the reaction chamber; A coil assembly is positioned opposite the reaction chamber across the medium window. The coil assembly has multiple planar rectangular spiral coils connected in parallel. A radio frequency power supply, wherein the radio frequency power supply is electrically connected to each of the rectangular spiral coils; The rectangular spiral coil has multiple turns of sub-coil; The rectangular spiral coil has an RF power feed terminal in the middle. The first distance between the RF power feed terminal and a sub-coil adjacent to the RF power feed terminal is larger than the second distance between adjacent sub-coils at the edge of the rectangular spiral coil. Multiple rectangular spiral coils are arranged in a row; The third spacing between the outermost turns of two adjacent rectangular spiral coils is smaller than the first spacing between the two adjacent rectangular spiral coils.

2. The inductively coupled plasma device according to claim 1, characterized in that, The third spacing between two adjacent rectangular spiral coils can be adjusted.

3. The inductively coupled plasma device according to claim 1, characterized in that, The radio frequency current flows in the same direction on the adjacent sides of two adjacent rectangular spiral coils.

4. The inductively coupled plasma device according to claim 1, characterized in that, Magnetic elements are provided on both sides of the coil group along a direction orthogonal to the direction in which the plurality of rectangular spiral coils are arranged.

5. The inductively coupled plasma device according to claim 1, characterized in that, The loadable frequency, radio frequency power, and / or current value of each of the rectangular spiral coils can be adjusted independently.

6. The inductively coupled plasma device according to claim 5, characterized in that, Each of the rectangular spiral coils is grounded via an adjustable reactance element.

7. A coating equipment, comprising a coating chamber, characterized in that, The coating chamber is connected to the inductively coupled plasma device provided with any one of claims 1 to 6.

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