PLASMA TREATMENT SYSTEM AND PLASMA TREATMENT PROCEDURE

Description

TECHNICAL AREA

[0001] The invention relates to treatment systems and plasma treatment processes in which an inductively coupled plasma (ICP) is excited by an ICP source. The invention particularly relates to such systems and processes that enable the coating, etching, cleaning, or other treatment of a substrate in a continuous or batch system. BACKGROUND

[0002] Treatment systems for treating a substrate using inductively coupled plasmas (ICPs) are known. Treatment using ICP sources for plasma excitation offers several advantages. For example, an ICP source provides a high-electron-density hydrogen mode, which is advantageous for efficient treatment.

[0003] Exemplary systems and plasma sources for generating ICP are disclosed in WO 2015 / 036494 A1 EP 1 146 569 A2, US 6 181 069 B1 and in DE 10 2016 107 400 A1. EP 3 104 418 A1 and WO 2011 / 080661 A1 disclose systems for generating microwave plasma.

[0004] Conventional treatment systems and processes for substrate treatment using an ICP still exhibit several disadvantages. For example, achieving high deposition rates, stable operating points even at comparatively high pressures, and / or high homogeneity during treatment processes can be challenging. For instance, parasitic coating processes in conventional ICP-based treatment systems can cause significant deposition on the internal surfaces of a treatment chamber, particularly around process gas outlet openings, leading to high maintenance costs and / or negatively impacting the deposition rate on the substrate. Conventional ICP-based treatment systems and processes can also have limitations regarding their scalability.This is especially true if the inductor or inductors of the ICP source are curved parallel to a substrate plane, as in a planar antenna arrangement with a spiral inductor. BRIEF DESCRIPTION OF THE INVENTION

[0005] The invention is based on the objective of providing an improved treatment system and an improved method for treating a substrate using inductively coupled plasma (ICP). In particular, the invention aims to provide a treatment system and a method that reduce parasitic deposition, enable a high deposition rate, and allow the treatment system to operate even at higher pressures in the process chamber and with larger substrate widths and throughputs.

[0006] According to the invention, a treatment system and a plasma treatment process are provided, comprising the features specified in the independent claims. The dependent claims define exemplary embodiments.

[0007] A treatment system according to the invention comprises a process chamber for the dynamic or static treatment of at least one substrate. The treatment system includes an inductively coupled plasma source (ICP source) with a longitudinal direction. The ICP source comprises at least one inductor extending along the longitudinal direction of the ICP source, a gas supply device for one or more process gases with at least one outlet opening configured to supply the process gas(es) at several positions along the longitudinal direction of the ICP source, and a gas deflection arrangement located in the process chamber. The gas deflection arrangement extends along the longitudinal direction of the ICP source and partially surrounds the at least one inductor.

[0008] In the treatment system according to the invention, a linear ICP source is provided with a gas deflection arrangement that partially surrounds the at least one inductor. This allows a directed flow of process gas at a higher velocity towards a substrate to be generated. The risk of parasitic deposition processes, for example in the vicinity of the process gas inlets, can be reduced by the directed flow at high velocity. When used in a deposition system, a high deposition rate can be achieved. The ICP source is scalable along its longitudinal direction such that high treatment homogeneity can be achieved even over larger substrate widths.

[0009] Each inductor can have one tubular conductor.

[0010] Each inductor can be surrounded by a cylindrical insulator, for example a quartz glass cylinder.

[0011] Each inductor can be designed to allow a cooling fluid to flow through or around it.

[0012] Any inductor can be a linear inductor.

[0013] The throttle control assembly can have one or more throttle deflectors.

[0014] The gas control arrangement has a gas hood covering at least one inductor and at least one outlet opening.

[0015] The gas hood may have an outlet whose width B 1 perpendicular to the longitudinal direction of the ICP source is a maximum of 300 mm, in particular a maximum of 200 mm, in particular a maximum of 150 mm, in particular a maximum of 130 mm.

[0016] The gas hood may have on its upper surface furthest from the outlet a further width B 2 perpendicular to the longitudinal direction of the ICP source, which is smaller than the width B 1 of the outlet.

[0017] The gas hood can have a clear width that decreases in the vertical direction, i.e., on the side of the gas hood facing away from the substrate.

[0018] The gas hood can have a height H in a median plane of the gas control arrangement and an outlet with a width B1 perpendicular to the longitudinal direction of the ICP source. The ratio of the width B1 of the outlet to the height of the gas control arrangement, B1 / H, is less than 1.0, in particular less than 0.7, in particular less than 0.6, in particular less than 0.5.

[0019] By designing the gas hood to be narrow in the direction perpendicular to the longitudinal direction of the ICP source, the risk of parasitic deposition processes can be efficiently reduced and / or a high deposition rate can be achieved.

[0020] The gas supply device can have at least one gas supply tube extending parallel to the at least one inductor in the gas hood along the longitudinal direction of the ICP source.

[0021] The outlet opening of the gas supply device and the at least one inductor can be spaced apart from each other along a central plane of the gas supply device.

[0022] The outlet opening of a gas supply pipe can be positioned above the at least one inductor, i.e., further away from the outlet of the gas hood.

[0023] At least one inductor can have a first inductor and a second inductor.

[0024] The first inductor can be electrically connected in series with the second inductor. In this way, an inductor loop can be formed.

[0025] The first inductor can be electrically connected in parallel with the second inductor.

[0026] The first inductor and the second inductor can be arranged in a central plane of the gas steering arrangement.

[0027] By arranging multiple inductors in this way, the ICP source can be designed with a narrow width, measured perpendicular to its longitudinal direction. This efficiently reduces the risk of parasitic deposition processes and / or achieves a high deposition rate.

[0028] The ICP source can include a generator coupled to at least one inductor.

[0029] The generator can be connected electrically or electromagnetically to the at least one inductor.

[0030] The ICP source may include a matching circuit, which may contain, but is not limited to, inductors and / or capacitors. The matching circuit may be connected between the generator and the at least one inductor.

[0031] The generator can be configured to operate the ICP source in H-mode.

[0032] The generator can be an HF or RF generator.

[0033] The generator can be configured to produce electrical waves with a wavelength of at least 5 m, preferably at least 10 m, in the at least one inductor.

[0034] By designing the ICP source in this way, a high degree of treatment homogeneity can be achieved even if the ICP source extends over more than 1,000 mm in its longitudinal direction.

[0035] The ICP source can be configured to generate a plasma with an electron density of at least 10 16< / m 3< , advantageously of at least 10 17< / m 3< .

[0036] The ICP source can be configured for operation at a pressure in the process chamber in the range of 0.1 to 1000 Pa, in particular from 0.1 to 500 Pa, in particular from 0.1 Pa to 250 Pa, in particular from 0.1 Pa to 200 Pa, in particular from 1 Pa to 100 Pa, in particular from 10 Pa to 100 Pa.

[0037] The treatment plant can include a gas distributor for process gas, wherein the gas steering arrangement includes a shield for the gas distributor.

[0038] The shielding may include an outlet slot extending along the longitudinal direction of the ICP source and the gas deflection arrangement, or a series of passages arranged along the longitudinal direction of the ICP source.

[0039] The outlet slot or the passages may have a maximum width of 40 mm, in particular a maximum of 25 mm, in particular a maximum of 10 mm.

[0040] The gas distributor can have several outlet openings with an outlet opening diameter, wherein the ratio of the outlet opening diameter to the diameter of the gas distributor can be at most 0.5, in particular at most 0.1.

[0041] The gas deflection arrangement suppresses parasitic coatings in the immediate vicinity of the outlet openings. The velocity of a film-forming gas generated by the gas deflection arrangement, for example, counteracts back-diffusion of the excited film-forming agent towards the outlet openings, thereby reducing parasitic coating processes in the immediate vicinity of the gas distributor's outlet openings.

[0042] The at least one inductor can have a length of at least 1,000 mm, in particular at least 1,200 mm, in particular at least 1,400 mm along the longitudinal direction of the ICP source.

[0043] The treatment system can be a continuous flow system for the dynamic coating of substrates, in which the substrates are moved past the ICP source.

[0044] The longitudinal direction of the ICP source can extend perpendicular to a transport direction of the substrate in the continuous flow system.

[0045] The treatment plant can be designed for the static treatment of the substrates with the ICP source, e.g., it can be a batch plant.

[0046] The treatment system can be a coating system. The coating system can be configured for the deposition of aluminum oxide (AlOx) or silicon nitride (SiNx), but is not limited to these. For example, dielectric layers (oxides, nitrides, and / or oxynitrides), intrinsic and doped semiconducting layers, e.g., a-Si, n- / p-doped Si, and / or electrically conductive oxides (TCO) can be deposited.

[0047] The treatment system can be configured to etch the substrate. This can be achieved through chemical etching or physical etching with prestressing applied to the substrate or the ICP source.

[0048] The treatment system can be configured to clean the substrate.

[0049] The treatment system can be configured to oxidize a surface of at least one substrate.

[0050] The treatment system can be configured to generate oxides, nitrides, and / or oxynitrides. The treatment system can be configured to functionalize surfaces. For example, the treatment system can be configured to functionalize a surface with hydroxyl groups. The treatment system can be configured to generate OH groups on the surface by generating a plasma with oxygen and / or water.

[0051] The treatment plant can be configured to perform a cleaning process.

[0052] A plasma treatment method according to the invention for the static or dynamic treatment of substrates with a treatment system comprises the following steps: positioning at least one substrate in a process chamber of the treatment system, exciting an inductively coupled plasma (ICP) using an ICP source comprising at least one inductor extending along a longitudinal direction of the ICP source, a gas supply device, and a gas guidance arrangement arranged in the process chamber extending along a longitudinal direction of the ICP source and partially surrounding the at least one inductor, and supplying one or more process gases with the gas supply device at several positions along the longitudinal direction of the ICP source.

[0053] The effects achieved with the plasma treatment method according to the invention correspond to the effects described with reference to the treatment system.

[0054] The treatment system used in the plasma treatment process can be a treatment system according to one of the embodiments disclosed herein.

[0055] Plasma treatment can be a coating process. AlOx or SiNx can be deposited, but the process is not limited to these materials.

[0056] The plasma treatment process allows for dynamic layer deposition at a rate of at least 70 nm · m / min for the deposition of SiNx or at least 8 nm · m / min for the deposition of AlOx.

[0057] The plasma treatment process can achieve layer deposition with a deviation of less than ± 3%, in particular less than ± 2% along the longitudinal direction of the ICP source.

[0058] The plasma treatment process can involve etching the substrate. This can be achieved through chemical etching or physical etching with prestressing applied to the substrate.

[0059] The plasma treatment process may include cleaning or surface treatment (e.g., oxidation and / or functionalization) of the substrate.

[0060] The plasma treatment process can generate oxides, nitrides, and / or oxynitrides. Intrinsic and doped semiconducting layers, e.g., α-Si, n- / p-doped Si, and / or electrically conductive oxides (TCO), can be deposited.

[0061] Various effects and advantages can be achieved through the treatment system and treatment method according to the invention.

[0062] For example, using an ICP source enables operation in H-mode, i.e., with high plasma density and high plasma conductivity, without necessarily requiring magnets (permanent magnets and / or electromagnets) to generate plasma confinement. This facilitates the deposition of layers with high rates and homogeneity. Furthermore, the use of a gas-guided arrangement allows for the formation and operation of H-mode even at high pressures and with high stability, thereby also increasing the deposition rate.

[0063] The inventive design of the ICP source allows the plasma volume to be reduced by means of the gas deflection arrangement located inside the process chamber. This increases the electron density for a given energy input and enables the stable maintenance of the H-mode even at higher pressures. As a result, high and homogeneous deposition rates can be achieved. A narrow gas deflection arrangement perpendicular to the longitudinal direction of the ICP source increases the gas velocity towards the substrate for a given gas flow rate. This gas flow counteracts the diffusion of a film-forming agent into the upper region of the ICP source. Consequently, a larger proportion of the film-forming agent is directed onto the substrate, resulting in a high deposition rate. Parasitic deposition in the region of the ICP source is reduced. This increases the deposition rate on the substrate and reduces the maintenance requirements of the treatment system. BRIEF DESCRIPTION OF THE FIGURES

[0064] Exemplary embodiments of the invention are described in detail below with reference to the figures, in which identical reference numerals denote identical or similar elements. Figure 1 is a schematic representation of a treatment plant according to an exemplary embodiment in a sectional view. Figure 2 is a schematic representation of an ICP source in a sectional view, wherein a drawing plane is perpendicular to a longitudinal direction of the ICP source. Figure 3 is a schematic representation of an ICP source in a sectional view, wherein a drawing plane is perpendicular to a longitudinal direction of the ICP source. Figure 4 is a schematic representation of an ICP source in a sectional view, wherein a drawing plane is perpendicular to a longitudinal direction of the ICP source. Figure 5is a schematic representation of an arrangement of inductors of an ICP source in a process chamber in a sectional view, wherein a drawing plane is parallel to a longitudinal direction of the ICP source. Figure 6 is a schematic representation of an ICP source in a sectional view, wherein a drawing plane is perpendicular to a longitudinal direction of the ICP source. Figures 7 to 10 show the density of a layer former for ICP sources with different geometries of a gas deflection arrangement. Figures 11 to 14 show a gas flow velocity for ICP sources with different geometries of a gas deflection arrangement. DETAILED DESCRIPTION OF EXAMPLES OF EXECUTION

[0065] While preferred or advantageous embodiments are described with reference to the figures, additional or alternative configurations can be implemented in other embodiments. For example, while the figures illustrate a continuous flow system, embodiments can also be used in static treatment systems, particularly batch systems.

[0066] While, for example, exemplary embodiments are described with reference to the figures in the context of a coating system for depositing a layer on a substrate, the treatment systems and treatment methods according to exemplary embodiments of the invention can also be used for etching, cleaning, functionalizing or for other treatment processes of substrates.

[0067] Figure 1Figure 1 shows a schematic representation of a treatment plant 100 for treating substrates, in particular for coating, etching, cleaning and / or functionalizing substrates.

[0068] The treatment system 100 has a process chamber 101, which defines a process space 102. One or more transport rollers 103 or other transport units may be provided for moving a substrate. One or more heating devices 104 and / or apertures 104 may be arranged in the process space 102 on one side or on opposite sides of a substrate plane. One or more heating devices 104 and / or one or more apertures 104 may, for example, be arranged opposite the ICP sources 120, 120' described below and / or between the ICP sources 120, 120'.

[0069] The treatment plant 100 has vacuum pumps 108 to evacuate the process chamber 101.

[0070] In process chamber 102, at least one ICP source 120, 120' is arranged. While two ICP sources 120, 120' are shown as examples, in other embodiments only one ICP source or more than two ICP sources may be arranged in process chamber 102.

[0071] In a treatment plant 100 designed as a continuous flow system, each ICP source 120, 120' can be oriented such that a longitudinal direction of the ICP source 120, 120' is perpendicular, in particular perpendicular, to a transport direction of the substrate.

[0072] One embodiment of the ICP source, which can be used in the systems and devices according to the invention, is described in detail below. Figures 2 to 6 The figures show possible configurations in detail. If the treatment facility 100 has several ICP sources in process room 102, one, several or all of the ICP sources 120, 120' can have the configuration described in detail here.

[0073] ICP source 120 has a longitudinal direction. This longitudinal direction extends perpendicular to the plane of the drawing. Figures 1-5 and 7-14 and parallel to the drawing plane of the Figure 6 When used in a continuous flow system, the longitudinal direction of the ICP source 120 can be directed along the lateral direction of the substrate, i.e. perpendicular to the transport direction in the continuous flow system.

[0074] The ICP source 120 has at least one linear inductor 130a, 130b. As in Figures 1 and 2 As shown, the ICP source can have two linear inductors 130a, 130b. The linear inductors 130a, 130b can each extend parallel to each other and parallel to a gas supply tube 141 of a gas supply device.

[0075] The inductors 130a, 130b can have a conductor 131, which may be tubular. The inductors 130a, 130b can be surrounded by a hollow cylindrical insulator 132, for example, a quartz tube. A cooling fluid can be arranged in a gap 133 between the hollow cylindrical insulator 132 and the conductor 131 and / or within the tubular conductor 131. During operation of the continuous flow system, the cooling fluid flows through or around the conductor 131. The cooling fluid can be circulated.

[0076] The ICP source has a gas supply device for one or more process gases with at least one outlet opening. The gas supply device can include a gas supply pipe 141, which is arranged within a gas hood 151 (described in more detail below) and extends linearly parallel to the inductors 130a, 130b. A reaction gas or another process gas can be supplied via the gas supply pipe 141. The gas supply device can include a gas distributor with one or more additional pipes 142, through which, for example, a precursor can be supplied.

[0077] The gas supply device can be configured to supply the process gas(es) at several positions along the longitudinal direction of the ICP source 120. For this purpose, an outlet slot and / or a series of outlet openings can be provided in the gas supply pipe 141 and in the further pipes 142.

[0078] According to the invention, the ICP source 120 has a gas steering arrangement 150 located in the process chamber 101. The gas steering arrangement 150 extends along the longitudinal direction of the ICP source 120. The gas steering arrangement 150 partially surrounds the at least one inductor 130a, 130b and the gas supply tube 141 in order to restrict an area in which plasma is excited in a direction transverse to the longitudinal direction of the ICP source 120.

[0079] The gas guidance arrangement 150 can comprise one or more plates. The gas guidance arrangement 150 directs gas from the area surrounding the at least one inductor 130a, 130b, by which plasma can be excited in H-mode, through an outlet 152 of the gas guidance arrangement 150 towards a substrate. The gas guidance arrangement 150 can define the flow direction of the gas and / or spatially confine the plasma in a direction transverse to the longitudinal direction of the ICP source, acting as guide plates or baffles.

[0080] The gas guidance arrangement 150 comprises a gas hood. The gas hood extends along the longitudinal direction of the ICP source over and partially around the gas supply tube 141 and the at least one inductor 130a, 130b. The gas hood 151 can have a clear width that decreases in the vertical direction 119 of the gas hood 151, i.e., from its outlet 152 towards its closed upper end located adjacent to the gas supply tube 141. The width B1 of the outlet can be small, according to the invention, smaller than the height of the gas guidance arrangement 150. Such a narrow design of the gas guidance arrangement 150 allows for efficient definition of a flow towards the substrate and / or facilitates excitation in H-mode.

[0081] The gas deflection assembly 150 can have one or more shields 158. The shields 158 can extend along the longitudinal direction of the ICP source. The shields 158 can be provided on the outside of the gas hood 151 to surround the additional tubes 142 of the gas supply device and to suppress the flow of precursor gas exiting the additional tubes 142 into the interior of the gas hood 151. An outlet slot or openings 159 in the shields 158 can direct the process gas exiting the additional tubes 142 to the vicinity of the outlet 152, where a relatively high flow velocity within the gas deflection assembly 150 reduces the diffusion of this process gas to the inductors 130a, 130b and the gas supply tube 141. The outlet slot 159 can be a continuous slot parallel to the longitudinal direction of the ICP source 120 or can have a series of openings or penetrations along the longitudinal direction of the ICP source 120.

[0082] Figure 3 Figure 1 shows an embodiment of the ICP source 120 in which only a linear inductor 130 is arranged in the gas hood 151 of the gas control assembly 150. The inductor 130 can have a conductor 131, which may be tubular. The inductor 130 can be surrounded by a hollow cylindrical insulator 132, for example, a quartz tube. A cooling fluid can be arranged in a gap 133 between the hollow cylindrical insulator 132 and the conductor 131 and / or within the tubular conductor 131. During operation of the continuous flow system, the cooling fluid flows through or around the conductor 131. The cooling fluid can be circulated. Gases or air can be used as the cooling fluid in the gap 133. The tubular conductor 131 can be cooled with liquid media, for example, water.

[0083] Figure 4Figure 1 shows an embodiment of the ICP source 120 in which three linear inductors 130a, 130b, 130c are arranged in the gas hood 151 of the gas control assembly 150. The inductors 130a, 130b, 130c can have a conductor 131, which may be tubular. The inductors 130a, 130b, 130c can be surrounded by a hollow cylindrical insulator 132, for example, a quartz tube. A cooling fluid can be arranged in a gap 133 between the hollow cylindrical insulator 132 and the conductor 131 and / or within the tubular conductor 131. During operation of the continuous flow system, the cooling fluid flows through or around the conductor 131. The cooling fluid can be circulated.

[0084] If two inductors 130a, 130b or more than two inductors 130a, 130b, 130c are arranged in the gas hood 151 of the gas steering arrangement 150, the inductors 130a, 130b, 130c are advantageously arranged in a central plane of the ICP source 120.

[0085] The middle plane can be a plane of symmetry of the ICP source 120, extending parallel to the longitudinal direction of the ICP source 120.

[0086] Alternatively or additionally, the median plane 160 of the ICP source 120 can be defined such that it passes through a center line of the outlet 152 of the gas steering arrangement 150 of the ICP source 120 and through a center line of the upper end of the gas steering arrangement 150 of the ICP source 120, which is spaced from the outlet 152 and adjacent to the gas supply pipe 141.

[0087] Alternatively or additionally, the mean plane 160 of the ICP source 120 can be defined by a mean velocity vector of the gas exiting the ICP source 120 at the outlet 152, whereby the averaging can be carried out over the area of ​​the outlet 152.

[0088] Alternatively or additionally, the middle plane 160 of the ICP source 120 can be perpendicular to a substrate plane.

[0089] Alternatively or additionally, the central plane 160 of the ICP source 120 can contain a center line of the gas supply tube 141 and at least one, preferably all, inductors 130, 130a-c.

[0090] If two inductors 130a, 130b or more than two inductors 130a, 130b, 130c are arranged in the gas hood 151 of the gas steering assembly 150, the two inductors 130a, 130b or more than two inductors 130a, 130b, 130c can be electrically connected in series or in parallel.

[0091] Figure 5 Figure 1 shows a sectional view of inductors 130a and 130b of an ICP source. The gas deflection assembly 150 is not shown.

[0092] The inductors 130a and 130b can be electrically and / or fluidically connected to each other via a coupling unit 115. The coupling unit 115 can establish an electrical connection between the inductors 130a and 130b to connect them in series and / or to ground. The coupling unit 115 can establish a fluidic connection between the inductors 130a and 130b, allowing cooling fluid to be passed sequentially through or over the first inductor 130a and then through or over the second inductor 130b. Cooling fluid and / or electrical energy can be coupled in via terminals 116.

[0093] Shields 113 can be provided at opposite ends of the inductors 130a, 130b to terminate the gas deflection assembly 150 in the longitudinal direction. The inductors 130a, 130b can be attached to the shields 113 via seals 114, for example, compression seals. The seals 114 allow the inductors 130a, 130b to be connected vacuum-tight to the walls 111 of the process chamber 102 via flanges 112, 112'.

[0094] The walls 111 of the process chamber 102 can be designed to allow the ICP source 120 to be installed on either side. For example, the walls 111 can have a symmetrical opening on opposite sides to allow the inductors 130a, 130b to be installed from either side of the process chamber 102 using the flanges 112, 112'.

[0095] The ICP source 120 includes a schematically depicted generator 106, which can be a high-frequency (HF) or radio-frequency (RF) generator. The HF or RF generator 106 can be electrically or electromagnetically connected to the inductors 130a, 130b, for example via a matching network 105. The HF or RF generator 106 can be configured to generate electrical waves with a wavelength of at least 5 m, preferably at least 10 m, in the at least one inductor 130a, 130b. Such a configuration allows for high treatment homogeneity even when the ICP source extends over more than 1,000 mm in its longitudinal direction.

[0096] The HF or RF generator 106 can be configured to generate a plasma with an electron density of at least 10 16< / m 3< , advantageously of at least 10 17< / m 3< .

[0097] Figure 6Figure 1 shows a geometry of the gas steering arrangement 150 that can be used in exemplary embodiments. While two inductors 130a, 130b are shown as examples, the geometry can also be used with an ICP source with only one inductor or with more than two inductors in the gas steering arrangement.

[0098] The gas control arrangement 150 has a gas hood 151 with an outlet 152. The gas supply pipe 141 and the at least one inductor 130a, 130b are arranged in the gas hood 151. The gas supply pipe 141 and the at least one inductor 130a, 130b can be positioned on a central plane 160 of the ICP source 120.

[0099] The gas control arrangement 150 has a height H in the central plane 160 of the gas control arrangement. The outlet 152 has a width B1 perpendicular to the longitudinal direction of the ICP source 120. The ratio of the width B1 of the outlet 152 to the height H, B1 / H, is less than 1.0. Furthermore, the ratio of the width B1 of the outlet 152 to the height H, B1 / H, is less than 0.7, particularly less than 0.6, and especially less than 0.5.

[0100] In an exemplary embodiment, the width B 1 of the outlet 152 perpendicular to the longitudinal direction of the ICP source is a maximum of 300 mm, in particular a maximum of 200 mm, in particular a maximum of 150 mm, in particular a maximum of 130 mm.

[0101] The gas control arrangement 150 has a top surface far from the outlet 152, which has a width B2 transverse to the longitudinal direction of the ICP source 120. The width B2 is smaller than the width B1 of the outlet 152. Advantageously, B2 / B1 is less than 1, particularly less than 0.9, and especially less than 0.8.

[0102] The clear width of the gas hood 151 can decrease from the outlet 152 to the top surface far from the outlet 152, in particular decreasing monotonously (but not necessarily strictly monotonously).

[0103] The slot 159 or each of the openings 159 of the shielding 158 can have a width W which, in exemplary embodiments, can be a maximum of 40 mm, in particular a maximum of 25 mm, in particular a maximum of 10 mm.

[0104] The inductor 130 or all inductors 130a, 130b, 130c, the gas steering arrangement 150 and the tubes 141, 142 of the gas supply device can extend linearly over a length of at least 1,000 mm, in particular at least 1,200 mm, in particular at least 1,400 mm along the longitudinal direction of the ICP source 120.

[0105] The inductor 130, or all inductors 130a, 130b, 130c, can, for example, be configured as a coaxial arrangement of a copper tube as the inner conductor 131, which is located inside a quartz glass tube 132. A coolant (e.g., water) can flow through the copper tube for cooling. The copper tube can be sheathed with an insulating ceramic. This has the advantage that the insulation can be very thin, for example, 0.1 to 2 mm thick, and / or that no air gap is required. This results in a small ratio of the radii of the insulator 132 and the inner conductor 131.

[0106] When the plasma becomes the coaxial outer conductor in this arrangement, which occurs particularly in ICP-H mode, the reduction in the radius ratio of outer tube 132 to inner conductor 131 causes the reactance or impedance of the source to decrease, thereby increasing the currents and decreasing the voltages for the same coupled power. This increases the coupling efficiency in a current-driven ICP.

[0107] Furthermore, the source impedance can be varied along the longitudinal direction of the ICP source 120 by varying the copper tube radius, e.g., by turning it, and / or by varying the insulation thickness. This allows the inhomogeneity of the plasma density along the longitudinal direction of the ICP source 120, such as that occurring at the two ends of the ICP source, to be partially or completely compensated. The inductor 130 or the multiple inductors 130a, 130b, 130c can be designed for this purpose such that the impedance decreases from the ends of the inductors towards their center.

[0108] The coupling of power into several inductors 130a, 130b of an ICP source 130 can be carried out in various ways: a) The inductors 130a and 130b can be electrically connected in series. The conductors of the inductors 130a and 130b are connected to form a loop in the coupling unit 115. This coupling unit can be designed as a closed cavity, preferably at atmospheric pressure. Power is supplied by the HF or RF generator 106 to only one of the inductors on the side opposite the coupling unit 115. The power can be coupled into either inductor 130a or 130b. The other inductor can be connected to ground directly or via passive electronic components. Alternatively, it can be open-ended. b) The inductors 130a and 130b can be operated in parallel. The conductors of the inductors 130a and 130b are connected on the coupling side. The power is supplied by the HF or RF generator 106 to both inductors 130a, 130b on the side opposite the coupling unit 115.In the coupling unit 115, the conductors can be grounded. Alternatively, the conductors can be grounded via passive electronic components or each via its own passive electronic component, whereby the passive components can have the same or different impedances. The conductors in the coupling unit 115 can be neither connected nor grounded (open end). c) The coupling into the inductors 130a, 130b can be reversed. For this, an additional conductor, insulated from the rest of the assembly and from the plasma, must be routed to the coupling unit 115. The inductors can then be independently connected to ground, connected to ground via passive electronic components, or be open. d) Only one of the inductors 130a, 130b is operated. The power is supplied by the RF generator 106 on the side opposite the coupling unit 115 to only one of the inductors.In coupling unit 115, the conductor is either connected to ground, or connected to ground via passive electronic components, or open.

[0109] The ICP source 120 can be configured so that two different process gases or process gas mixtures can be supplied via the gas supply device. The flow rate of the different process gases or process gas mixtures can be adjusted independently of each other.

[0110] A first process gas or a first process gas mixture can be supplied via the gas supply pipe 141.

[0111] A second process gas, different from the first process gas, or a second process gas mixture, different from the first process gas mixture, can be supplied via the additional pipes 142.

[0112] Pipes 141 and 142 are provided with gas outlet bores for supplying process gases or process gas mixtures. The gas outlet bores can be arranged at any desired intervals and diameters. To improve gas mixing and protect against clogging by parasitic coatings, these gas outlet bores can be located on the side of pipes 141 and 142 facing away from the substrate plane and / or on the side facing away from outlet 152.

[0113] The pipes 141, 142 can be gas-tightly interrupted, i.e., segmented, along the longitudinal direction of the ICP source 120. The treatment system can be configured to supply each segment with an independent gas flow. Advantageously, the sum of the cross-sectional areas of all gas outlet bores per segment is at least three times smaller than the cross-sectional area 141, 142 of the corresponding pipe 141, 142. This ensures that the gas flow of a gas outlet bore is proportional to its cross-sectional area and that defined flows are generated in the process chamber 102. The gas outlet bores and the gas flow are selected such that the gas velocity does not approach the speed of sound, in order to prevent nonlinear behavior.

[0114] The ICP source 120 can be configured such that the maximum electron density in the generated plasma is 1014 to 1021 / m3, in particular 1014 to 1020 / m3, and in particular 1014 to 1019 / m3. The maximum electron density in the generated plasma can be at least 1016 / m3, and advantageously at least 1017 / m3.

[0115] The ICP source 120 can be configured such that the gas velocity in the center of the outlet 152 is from 0.01 to 100 m / s, in particular from 0.01 to 50 m / s, and in particular from 0.01 to 10 m / s.

[0116] The ICP source 120 can be configured such that the plasma power per length of the ICP source is 0.1 to 100 kW / m, in particular 0.1 to 50 kW / m, and in particular 0.1 to 10 kW / m.

[0117] The ICP source 120 is designed for operation in a process chamber with a process chamber pressure of 0.1 to 1000 Pa, in particular 0.1 to 500 Pa, in particular 0.1 to 250 Pa, in particular 0.1 to 200 Pa, in particular 1 to 100 Pa, in particular 10 to 100 Pa. The process chamber pressure can be determined at any of the process gas outlet openings inside the process chamber.

[0118] If the treatment plant 100 is configured as a coating plant, it can be designed for deposition with a dynamic deposition rate of 0 to 1000 nm·m / min, in particular 0 to 500 nm·m / min, and especially 0 to 200 nm·m / min. These deposition rates are the deposition rates achieved in the treatment plant 100, which may have multiple ICP sources.

[0119] When used in a process chamber with a pressure of 0.1 to 1000 Pa, particularly from 0.1 to 500 Pa, 0.1 to 250 Pa, 0.1 to 200 Pa, 1 Pa to 100 Pa, and 10 Pa to 100 Pa, the gas flow becomes relevant for process control. Unlike the lower pressure in PVD systems, transport phenomena become more significant than diffusion at increasing pressures. The high reactive gas flow in the substrate direction minimizes the diffusion of the precursor gas in the opposite direction of this flow. This promotes deposition on the substrate and simultaneously reduces the unwanted coating of the remaining components of the ICP source 120, such as the inductors 130, 130a-c and / or the tubes 141, 142.By using a narrow design of the gas deflection arrangement 150, a good separation rate of the source can be achieved with reduced parasitic coating of the ICP source 120 on the gas supply pipe 141 and the at least one inductor 130, 130a-c.

[0120] The ICP source 120, 120' can be used to deposit dielectric layers (oxides, nitrides, and / or oxynitrides), intrinsic and doped semiconducting layers, e.g., a-Si, n- / p-doped Si, and / or electrically conductive oxides (TCO).

[0121] The treatment plant 100 can be designed as an alternative or additional method for etching, cleaning, functionalizing or for other treatment of substrates.

[0122] For example, using electronegative gases (e.g., F₂, NF₃, Cl₂, O₂) and / or hydrogen as process gases, the ICP source 120, 120' can be used for the chemical etching of substrates such as silicon, glass, plastic, metal, and layers of carbon or dielectric materials (e.g., silicon dioxide). Alternatively, in combination with a bias voltage applied to the substrate or the ICP source 120, 120', the ICP source 120, 120' can be used for the physical etching of substrates and surfaces.

[0123] In further embodiments, the oxidation and generation of nitrides or oxynitrides on metallic or semiconducting substrates or coatings is possible with the ICP source 120, 120'. Process gases containing oxygen, nitrogen, or compounds containing oxygen and / or nitrogen can be used for this purpose. Using the ICP source 120, 120', for example, tunnel oxide layers (e.g., silicon oxide) can be deposited on substrates.

[0124] The treatment unit 100 can be configured to generate OH groups on a surface by producing a plasma with oxygen and / or water, in order to functionalize the surface. In this way, the surface can be functionalized with hydroxyl groups.

[0125] Figures 7 to 10The figures exemplify the influence of the width of the gas control arrangement 150 on the concentration of SiH3 when SiH4 is supplied. Lines of equal SiH3 concentration are shown with contour lines indicating the concentration (in arbitrary units), where in Figures 7 to 10 (where mutually consistent units are used) is shown. With a narrower design of the gas deflection arrangement, for example with a smaller ratio of the width B 1 of the outlet 152 to the height H, B 1 / H, not only can the concentration of SiH 3 be increased, but the concentration maximum can also be shifted downwards along the vertical direction 119 of the ICP source 120 towards the outlet 152. This reduces parasitic coatings in the ICP source 120 and increases the deposition rate on the substrate.

[0126] Figures 11 to 14Figure 1 illustrates the influence of the width of the gas deflection arrangement 150 on the gas flow velocity. The flow direction is represented as a vector field, where the length of each vector represents the velocity. Lines with the same velocity magnitude are also shown as contour lines. With a narrower gas deflection arrangement, for example, with a lower ratio of the width B1 of the outlet 152 to the height H, B1 / H, higher velocities towards the substrate can be achieved at the outlet 152. This reduces parasitic coatings in the ICP source 120 by decreasing diffusion towards the tube 141 and the inductors 130a, 130b, and increases the deposition rate on the substrate.

[0127] Various advantages and effects can be achieved through a treatment system and treatment procedure using the ICP source 120.

[0128] When used in a coating system, the ICP source enables a high deposition rate. This can be at least 70 nm · m / min for the deposition of SiNx or at least 8 nm · m / min for the deposition of AlOx.

[0129] For the deposition of layers of a specific thickness, fewer sources can be used in a system for a given throughput, and / or the potential throughput of a coating system can be increased for a given number of coating sources. This can reduce the problem of high system costs.

[0130] Stable operating points are also possible at higher pressures in the process chamber. Typically, the achievable mass flow rate of a vacuum pump increases with increasing process gas pressure, and consequently, so does the achievable mass flow rate of a process, which limits the separation rate. For a given process mass flow rate, lower-powered pumps can be used at higher pressures, or higher mass flow rates and thus separation rates can be achieved by using pumps with a given power rating. This can reduce the problem of high system costs.

[0131] Homogeneous layer deposition can be achieved. This homogeneity can be achieved with regard to the deposition rate and / or the layer properties in the longitudinal direction of the ICP source. This allows for the treatment of wider substrates or the simultaneous treatment of a larger number of small substrates. Plant costs can thus be reduced and / or throughput increased.

[0132] Maintenance requirements can be reduced due to the suppression of parasitic coating at process gas outlet openings and high deposition on the substrate. Problems arising from intensive PECVD-typical maintenance are also reduced.

[0133] Process-specific reactive gas flow is facilitated. This is particularly advantageous for AlOx processes. The process-specific reactive gas flow allows the reactivity of the excited process gas to be reduced as needed. To achieve low reactivity of the excited reactive gas, the coupled plasma power should not be reduced below the limit required to maintain the H-mode. Electromagnetic induction remains the dominant energy coupling process. Due to the constant electric current in the inductor loop, homogeneous plasma conditions can be maintained in the longitudinal direction of the source.

[0134] The problem of excessive reactivity of the reactive gas, which increases parasitic deposits in the ICP source and thus reduces the deposition rate, can therefore also be reduced.

[0135] The ICP source is scalable in the longitudinal direction. Source lengths of more than 1,000 mm, and especially more than 1,400 mm, can be achieved while still maintaining good treatment homogeneity. This allows for larger coating widths while preserving homogeneity. The throughput of the coating system can be increased, and / or, for a given throughput, the number of sources can be reduced.

[0136] The process chamber boundary, extending from the reactive gas inlet on the gas supply pipe 141 to the precursor inlet at the opening 159, encloses the inductors 130, 130a-c transversely to the longitudinal direction of the ICP source and thus limits the plasma chamber. Due to the arrangement of the inductors 130a, 130b along the central plane 160 of the ICP source, the gas deflection arrangement 150 can be designed to be narrower compared to a parallel inductor loop arrangement. This reduces the plasma volume, thereby increasing the plasma density and consequently the plasma conductance for a given energy input. H-mode discharge can thus also occur at higher pressures.

[0137] Furthermore, a narrow design of the gas deflection arrangement 150, perpendicular to the longitudinal direction of the ICP source, leads to an increase in the average gas velocity towards the substrate for a given reactive gas flow rate. The diffusion-driven transport of the precursor gas from the corresponding gas inlets near the substrate plane towards the at least one inductor is reduced. The shield 158, which surrounds the gas outlet openings in the additional gas tubes 142 for the precursor gas, prevents excited reactive gas from diffusing into the interior of the shields 158. Parasitic coatings in this area are avoided, thus reducing the risk of clogging the gas outlet openings in the additional gas tubes 142.

[0138] The gas outlet gap 159 or the openings 159 of this shield 158 can be arranged close to the substrate without creating inhomogeneity of deposition in the longitudinal direction of the ICP source 120. Any concentration gradients along the further gas tube 142 are homogenized within the shield 158, so that a homogeneous current density of the exiting precursor gas can be generated at the gas outlet gap 159 or the openings 159 in the longitudinal direction of the ICP source 120.

[0139] The ICP source 120 can be used for both dynamic and static coating systems, as well as for other treatment systems.

Claims

1. Treatment system comprising: a process chamber (101) for treating at least one substrate, and an inductively coupled plasma source, ICP source (120, 120'), with a longitudinal direction, wherein the ICP source (120, 120') comprises: at least one inductor (130; 130a, 130b; 130a, 130b, 130c) extending along the longitudinal direction of the ICP source (120, 120'), a gas supply device (141, 142) for one or more process gases with at least one outlet opening configured to supply the process gas or process gases at multiple positions along the longitudinal direction of the ICP source (120, 120'), and a gas steering arrangement (150) arranged in the process chamber (101), which extends along the longitudinal direction of the ICP source (120, 120') and partially surrounds at least one inductor (130; 130a, 130b; 130a, 130b, 130c), wherein the gas steering arrangement (150) comprises a gas hood (151) covering the at least one inductor (130; 130a, 130b; 130a, 130b, 130c) and the at least one gas outlet opening of the gas supply device (141), wherein the gas steering arrangement (150) has a height H in a central plane of the gas steering arrangement (150) and an outlet (152) with a width B1 perpendicular to the longitudinal direction of the ICP source (120, 120') and wherein a ratio of the width B1 of the outlet (152) to the height H of the gas steering arrangement (150), B1 / H, is smaller than 1.0.

2. Treatment system according to claim 1, wherein the gas hood (151) has an outlet (152) whose width B1 perpendicular to the longitudinal direction of the ICP source (120, 120') is at most 300 mm, in particular at most 200 mm, in particular at most 150 mm, in particular at most 130 mm, wherein the gas hood (151) preferably has a further width B2, perpendicular to the longitudinal direction of the ICP source (120, 120'), on its top side remote from the outlet (152), which is smaller than the width B1 of the outlet (152), wherein the gas hood (151) preferably has a clear width that decreases in the height direction (119) of the gas hood (151).

3. Treatment system according to any one of claims 1 to 2, wherein the gas supply device (141, 142) has at least one gas supply tube (141, 142) which extends parallel to the at least one inductor (130; 130a, 130b; 130a, 130b, 130c) in the gas hood (151) along the longitudinal direction of the ICP source (120, 120').

4. Treatment system according to any one of the preceding claims, wherein the outlet opening of the gas supply device (141, 142) and the at least one inductor (130; 130a, 130b; 130a, 130b, 130c) are spaced apart from each other along a central plane (160) of the gas supply device (141, 142), wherein the outlet opening of a gas supply tube (141) is preferably positioned above the at least one inductor (130; 130a, 130b; 130a, 130b, 130c).

5. Treatment system according to any one of the preceding claims, wherein the at least one inductor (130; 130a, 130b; 130a, 130b, 130c) comprises a first inductor (130a) and a second inductor (130b, 130c), wherein the first inductor (130a) is electrically connected in series with the second inductor (130b), or wherein the first inductor (130a) is electrically connected in parallel with the second inductor (130b), wherein the first inductor (130a) and the second inductor (130b) are preferably arranged in a central plane (160) of the gas steering arrangement (150).

6. Treatment system according to any one of the preceding claims, wherein the ICP source (120, 120') comprises a generator (106) coupled to the at least one inductor (130; 130a, 130b; 130a, 130b, 130c), wherein the generator (106) is configured to generate electric waves with a wavelength of at least 5 m, preferably at least 10 m, in the at least one inductor (130; 130a, 130b; 130a, 130b, 130c).

7. Treatment system according to any one of the preceding claims, wherein the ICP source (120, 120') is configured for operation at a pressure in the process chamber (101) in the range from 0.1 to 1000 Pa, in particular from 0.1 to 500 Pa, in particular from 0.1 Pa to 250 Pa, in particular from 0.1 Pa to 200 Pa, in particular from 1 Pa to 100 Pa, in particular from 10 Pa to 100 Pa.

8. Treatment system according to any one of the preceding claims, further comprising a gas distributor (142) for at least one process gas, wherein the gas steering arrangement (150) comprises a shield (158) for the gas distributor (142).

9. Treatment system according to claim 8, wherein the shield (158) has an outlet slot (159) extending in the longitudinal direction of the ICP source (120, 120') along the gas steering arrangement (150) or a plurality of outlet openings (159) disposed along the longitudinal direction of the ICP source (120, 120'), wherein the outlet slot (159) or the outlet openings (159) preferably have a width of at most 40 mm, in particular at most 25 mm, in particular of at most 10 mm.

10. Treatment system according to any one of claims 8 to 9, wherein the gas distributor (142) has a plurality of outlet openings with an outlet opening diameter, wherein a ratio of the outlet opening diameter to a diameter of the gas distributor (142) is at most 0.5, in particular at most 0.1.

11. Treatment system according to any one of the preceding claims, wherein the at least one inductor (130; 130a, 130b; 130a, 130b, 130c) has a length of at least 1,000 mm, in particular at least 1,200 mm, in particular at least 1,400 mm along the longitudinal direction of the ICP source (120, 120').

12. Treatment system according to any one of the preceding claims, wherein the at least one inductor (130; 130a, 130b; 130a, 130b, 130c) has an impedance that varies along the longitudinal direction of the ICP source (120, 120'), wherein the at least one inductor (130; 130a, 130b; 130a, 130b, 130c) has a stepped inner conductor presenting a change in conductor tube radius along the longitudinal direction of the ICP source (120, 120') and / or a variable insulation thickness along the longitudinal direction of the ICP source (120, 120').

13. Treatment system according to any one of the preceding claims, wherein the treatment system is configured to perform a coating process, a chemical or physical etching process and / or to oxidize a surface of the at least one substrate and / or wherein the treatment system is configured to generate oxides, nitrides, and / or oxynitrides and / or wherein the treatment system is configured to functionalize surfaces and / or wherein the treatment system is configured to perform a cleaning process.

14. Plasma treatment method for treating substrates with a treatment system (100), comprising the steps of: positioning at least one substrate in a process chamber (101) of the treatment system (100), exciting an inductively coupled plasma, ICP, using an ICP source (120, 120') comprising at least one inductor (130; 130a, 130b; 130a, 130b, 130c) which extends along the longitudinal direction of the ICP source (120, 120'), a gas supply device (141, 142) and a gas steering arrangement (150) arranged in the process chamber (101), which extends along a longitudinal direction of the ICP source (120, 120') and partially surrounds the at least one inductor (130; 130a, 130b; 130a, 130b, 130c), wherein gas steering arrangement (150) comprises a gas hood (151) covering the at least one inductor (130; 130a, 130b; 130a, 130b, 130c) and the at least one outlet opening of the gas supply device (141), wherein the gas steering arrangement (150) has a height H in a central plane of the gas steering arrangement (150) and an outlet (152) with a width B1 perpendicular to the longitudinal direction of the ICP source (120, 120') and wherein a ratio of the width B1 of the outlet (152) to the height H of the gas directing arrangement (150), B1 / H, is smaller than 1.0 and suppling a process gas or several process gases with the gas supply device (141, 142) at multiple positions along the longitudinal direction of the ICP source (120, 120').

15. Plasma treatment method according to claim 14, wherein a dynamic layer deposition takes place at a rate that is at least 70 nm · m / min for SiNx deposition, or that is at least 8 nm · m / min for AlOx deposition, and / or wherein a layer deposition takes place with a deviation of less than ± 3%, in particular less than ± 2% along the longitudinal direction of the ICP source (120, 120').