Heating element for a substrate processing system

Abstract

The invention relates to a heating element, a substrate processing system comprising such a heating element, and a method for processing a substrate in such a substrate processing system. The heating element includes a conductive electrode, where the conductive electrode extends along a path between the input contact and the output contact. The conductive electrode includes a section along the path in which the conductive electrode is split into at least two separate conductive electrode branches electrically connected in parallel. The conductive electrode and the at least two separate conductive branches comprise a heating member configured to generate heat and / or emit thermal radiation when an electrical current flows through the heating member.

Description

Background Art

[0001] The present invention relates to a heating element, a substrate processing system including such a heating element, and a method for processing a substrate using such a substrate processing system. In particular, the present invention relates to a heating element including a conductive electrode extending between an input contact and an output contact, wherein the conductive electrode extends along a path for providing a circuit pattern, wherein the conductive electrode includes a heating component, and wherein the path is configured to provide optimized heating performance.

[0002] The pattern design of the conductive electrodes and / or the arrangement of the heating components of a heating element directly impacts the performance of the heating element and, most importantly, the temperature uniformity across the area of the heating element. Poor uniformity of the heat generated by a heating element in a substrate processing system results in significant non-uniform heating of the substrate and, therefore, an inability to uniformly heat the substrate.

[0003] For example, US 2008 / 0029195 A1 discloses a wafer processing apparatus having an optimized electrode pattern for a resistive heating element. The optimized electrode pattern is designed to compensate for heat loss around contact areas, electrical connections, and vias by generating more heat near or around these areas, thereby providing maximum temperature uniformity. Furthermore, US 2008 / 0029195 A1 teaches the use of a multi-zone heater pattern with different geometries and specifications for each zone to achieve uniform heater temperature distribution.

[0004] Alternatively, US 2021 / 0398829 A1 discloses a substrate support for a substrate processing system that is configured to perform a deposition process on a substrate. The substrate support includes a base having an upper surface configured to support a substrate and a plurality of heating layers stacked vertically within the base below the upper surface. Each of the plurality of heating layers includes a corresponding resistive heating element in the form of a resistance coil. In at least one of the heating layers, the spacing of the resistance coils in a radial zone of the substrate support is different from the spacing of the resistance coils in another radial zone of the substrate support. Accordingly, the watt density of the resistive heating elements of at least one heating layer varies in the radial zone relative to other radial zones of the substrate support. By arranging different coils with different geometries in each heating layer and / or by individually controlling the power supplied to each heating layer, the unevenness of the temperature distribution on the upper surface of the base can be reduced.

[0005] Both prior art references recognize the problem of heat loss at the peripheral edge of the heater. According to US 2008 / 0029195 A1, this heat loss can be compensated by using a narrower outermost electrode path to generate more localized heat. According to US 2021 / 0398829 A1, this heat loss can be compensated by using a more tightly wound coil of the heating element in the outer zone to increase heat generation in the outer zone. Summary of the Invention

[0006] It is an object of the present invention to provide a heating element having an alternative way of varying the heat output in different areas of the heating element.

[0007] According to a first aspect, the present invention relates to a heating element for a substrate processing system, wherein the heating element comprises a conductive electrode, wherein the conductive electrode extends along a path between an input contact and an output contact, wherein the conductive electrode comprises a section along the path in which the conductive electrode is split into at least two independent conductive electrode branches electrically connected in parallel, and wherein the conductive electrode and the at least two independent conductive branches each comprise a heating component configured to generate heat and / or emit thermal radiation when current flows through the heating component.

[0008] In the heating element of the present invention, the conductive electrode comprises a section in which the electrode is split into at least two independent conductive electrode branches electrically connected in parallel. Thus, at the splitting point, the total current passing through the conductive electrode is divided into the at least two independent conductive electrode branches depending on the resistance of the independent conductive electrode branches relative to each other. For example, if the electrode is split into two independent electrode branches, and if the resistance of the two electrode branches is substantially equal, the total current passing through the conductive electrode is divided such that the current passing through each of the two electrode branches is substantially half of the total current. 1 Since the power generated by the heating element is a function of the current passing through the heating element, the power generated by the heating element arranged in the conductive electrode before splitting is higher than the power generated by the heating element arranged in each of the independent conductive electrode branches after splitting.

[0009] Accordingly, in the heating element of the present invention, the power generated in different parts of the conductive electrode is varied by dividing the current passing through the conductive electrode into at least two independent conductive electrode branches electrically connected in parallel. In particular, the different parts relate, on the one hand, to a portion of the conductive electrode outside the segment in which the conductive electrode is split into the at least two independent conductive electrode branches electrically connected in parallel, and a portion inside the segment. Because the power generated is a function of the current passing through the conductive electrode, the variation in the power generated can be much greater than, for example, using only a variation in the resistance of the heating element as described in US 2008 / 0029195 A1 or a more tightly wound heating coil as described in US 2021 / 0398829 A1.

[0010] Heating uniformity becomes more difficult to achieve for processing substrates at extremely high temperatures. At higher temperatures, heat leakage is generally higher, and therefore temperature non-uniformity is greater. Due to the possibility of large variations in the power generated in different parts of the conductive electrode, the heating element of the present invention is particularly suitable for use in substrate processing systems for processing substrates at higher temperatures, such as for growing 2D graphene layers on substrates at temperatures ranging between 600°C and 1300°C, particularly at or near 1000°C.

[0011] In an embodiment, the heating element extends along the conductive electrode. In an embodiment, the heating element extends along substantially the entire length of the conductive electrode. Accordingly, the heating element is distributed along at least a portion of the path of the conductive electrode, preferably substantially along the entire length of the path, which provides a more uniform distribution of the heat generated along the path.

[0012] In an embodiment, the heating element comprises a resistive heating element. Since the power generated by the resistive heating element is quadratically related to the current passing through the resistive heating element, the power generated in the resistive heating element in the conductive electrode before splitting can be four times the power generated in the resistive heating element in each of the independent conductive electrode branches after splitting (assuming that the conductive electrode is split into two independent electrode branches and the resistance of each of the independent conductive electrode branches is substantially equal).

[0013] In an embodiment, the path is arranged in a plane, preferably a substantially flat plane.The heating element according to this embodiment is particularly suitable for use in substrate processing systems for processing substantially flat substrates, such as thin silicon wafers or thin sapphire plates.

[0014] In an embodiment, the resistive heating element includes a cross-sectional area in a direction substantially transverse to a direction along the path from the input contact to the output contact, wherein the cross-sectional area varies along the path. Since the power generated is inversely proportional to the cross-sectional area of the resistive heating element, the variation in cross-sectional area along the path provides a means of varying the generated thermal power along the path of the conductive electrode, which can be particularly useful for fine-tuning large variations in generated power that occur due to the splitting of the conductive electrode into at least two separate conductive electrode branches electrically connected in parallel, so as to optimize the resistive heating element to provide optimally uniform heating of the substrate in a specific application.

[0015] In an embodiment, the thickness of the resistive heating element in a direction perpendicular to the plane is substantially constant, and wherein the width of the resistive heating element in a direction parallel to the plane varies along the path. This embodiment offers the same fine-tuning possibilities as the previous embodiment, and further allows the cross-sectional area to be varied in a less complex manner by varying only the width of the resistive heating element along its path and keeping the thickness of the resistive heating element substantially constant.

[0016] In an embodiment, the heating element comprises an edge, preferably a circumferential edge, wherein the conductive electrode comprises a first section adjacent to the edge, and a second section, wherein the first section and the second section are electrically connected in series, wherein the first section is arranged between the edge and the second section, wherein the second section of the conductive electrode comprises a section along the path in which the conductive electrode is split into at least two independent conductive electrode branches electrically connected in parallel. The first section does not comprise a section in which the conductive electrode is split into at least two independent conductive electrode branches electrically connected in parallel, and accordingly, in use, the total current flows through the conductive electrode of the first section, which thus provides relatively high power heat generation in the first section in order to compensate for heat losses at the edge of the plane.

[0017] In an embodiment, the first section provides an outer ring that substantially surrounds the second section of the heating element. Accordingly, compensation for heat losses at the edge of the heating element is provided substantially along the entire circumference of the heating element. The second section is arranged in an inner zone of the heating element. In the inner zone, heat losses to the surroundings are much smaller than heat losses at the circumferential edges. Accordingly, regulating the uniformity of heat generation in the inner zone does not require such high-power heat generation, and the conductive electrode in the inner zone can be split into at least two independent conductive electrode branches electrically connected in parallel. In an embodiment, the temperature profile at the inner zone is fine-tuned using the above-mentioned change in the width of the resistive heating component, in particular the width of the resistive heating component in each of the at least two independent conductive electrode branches.

[0018] In an embodiment, the conductive electrode comprises a second segment and two first segments electrically connected in series, wherein the second segment is arranged between the two first segments, wherein each of the two first segments is arranged adjacent to an opposing edge, wherein the opposing edges are arranged on a side of the first segment facing away from the second segment. In an embodiment in which the heating element has a circular shape, the two first segments each provide a portion of an outer ring substantially surrounding the second segment of the heating element. Preferably, the heating element comprises the following items connected in series one after the other: an input contact, a first segment providing a portion of the outer ring, a second segment arranged in an area inside the outer ring and comprising at least two independent conductive electrode branches, a first segment providing the remainder of the outer ring, and an output contact. This embodiment provides the same advantages as the previous embodiment and, in addition, allows the input and output contacts to be arranged at or near the circumferential edge to facilitate connection of the heating element to a power source.

[0019] In an embodiment, the second section is substantially completely split into at least two independent conductive electrode branches electrically connected in parallel. Accordingly, the current in the conductive electrode is split after the outer ring, which allows a larger portion of the electrical power supplied to the heating element to be converted to generate heat and / or emit thermal radiation at the outer ring of the heating element (where greater heat loss occurs), thereby providing more uniform heating.

[0020] It should be noted that the at least two independent conductive electrode branches are recombined again inside the second section. Preferably, the at least two independent conductive electrode branches are confined within the second section.

[0021] In an embodiment, the conductive electrode comprises a carbon-based material, preferably a carbon-carbon composite (CCC) material. Such a CCC material allows the heating element in the substrate processing system to be used to process the substrate at higher temperatures, for example, for growing a 2D graphene layer on the substrate at a temperature in the range of 600° C. to 1300° C., more preferably at or near 1000° C.

[0022] In an embodiment, the heating element is a single-zone heating element having only one input contact and only one output contact. Such a single-zone heating element is relatively easy to produce and does not require a complex controller to individually control the power of multiple zones as in US 2008 / 0029195 A1 or multiple vertically stacked coils as in US 2021 / 0398829 A1.

[0023] According to a second aspect, the present invention relates to a substrate processing system comprising a first heating element and a second heating element according to the above-described heating element or an embodiment thereof, wherein the first heating element and the second heating element are arranged in a processing chamber and wherein the first heating element and the second heating element are spaced apart so as to arrange a processing compartment between the first heating element and the second heating element. The arrangement of the processing compartment between the two heating elements allows a relatively uniform temperature distribution to be obtained in the surface between the first heating element and the second heating element, while potentially having a temperature gradient in a direction perpendicular to the surface.

[0024] In an embodiment, the processing chamber comprises a top wall and a bottom wall, wherein the first heating element and the second heating element are arranged to abut against surfaces of the top wall and the bottom wall, respectively, outside the processing chamber. Accordingly, the first heating element and the second heating element are arranged outside the processing chamber and are not affected, or to a lesser extent, by materials used for processing the substrate (such as gaseous materials and / or plasma for chemical vapor deposition) inside the processing chamber. It should be noted that the first heating element and the second heating element and the processing chamber are arranged inside the processing chamber.

[0025] In an embodiment, the top and bottom walls of the process chamber comprise Shapal (AlN) plates. Shapal or aluminum nitride is an electrical insulator material with high thermal conductivity, which can advantageously transfer the heat generated by the heating element to the interior of the process chamber.

[0026] In an embodiment, the bottom wall of the processing chamber is configured to support the substrate to be processed. In other words, the wall on top of the lower of the first and second heating elements is configured to support the substrate to be processed. Accordingly, gravity can assist in maintaining the substrate at a desired position within the processing chamber.

[0027] In one embodiment, the substrate processing system further includes a first thermal barrier and / or a second thermal barrier, wherein the first thermal barrier is spaced apart from the first heating element and disposed on a side of the first heating element facing away from the processing compartment, and wherein the second thermal barrier is spaced apart from the second heating element and disposed on a side of the second heating element facing away from the processing compartment. In one embodiment, the first thermal barrier and / or the second thermal barrier comprise a sheet of one or more of carbon-carbon composite (CCC), tungsten, molybdenum, or stainless steel. The first thermal barrier and / or the second thermal barrier substantially reduce heat loss from the side of the heating element facing away from the processing compartment and thereby contribute to more uniform heat generation from the heating element. In one embodiment, the substrate processing system includes a plurality of first thermal barriers and / or a plurality of second thermal barriers, the plurality of thermal barriers being spaced apart one behind the other in a direction away from the heating element. Preferably, the plurality of thermal barriers comprises four or five thermal barriers.

[0028] In an embodiment, the substrate processing system further includes a third thermal barrier and / or a fourth thermal barrier, wherein the third thermal barrier is configured to form a ring around the first heating element, wherein the third thermal barrier is arranged to be spaced apart from the first heating element, and wherein the fourth thermal barrier is configured to form a ring around the second heating element, wherein the fourth thermal barrier is arranged to be spaced apart from the second heating element. In an embodiment, the third thermal barrier and / or the fourth thermal barrier comprises a sheet of one or more of carbon-carbon composite (CCC), tungsten, molybdenum, or stainless steel. The third thermal barrier and / or the fourth thermal barrier substantially reduces heat loss at the circumferential edge of the heating element and thereby further contributes to more uniform heat generation of the heating element.

[0029] According to a third aspect, the present invention relates to a method for processing a substrate in a substrate processing system as described above or in an embodiment thereof, wherein the method comprises at least the following steps:

[0030] - providing the substrate and arranging the substrate inside a processing compartment;

[0031] - heating the substrate inside the processing compartment using the first heating element and the second heating element.

[0032] In an embodiment, the first and second heating elements are provided with electric power for generating heat and / or emitting thermal radiation to heat the substrate and / or the processing chamber to a temperature in the range between 600°C and 1300°C, in particular at or around 1000°C.

[0033] The various aspects and features described and illustrated in the specification can be applied independently where possible. These individual aspects, in particular the aspects and features described in the accompanying dependent claims, can become the subject of divisional patent applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The invention will be explained on the basis of exemplary embodiments shown in the accompanying drawings, in which:

[0035] Figure 1A is a schematic diagram of a first example of a heating element according to the present invention;

[0036] Figure 1B is a schematic top view of an alternative to the first example of a heating element according to the invention;

[0037] Figure 2 is a top view of a second example of a heating element according to the present invention;

[0038] Figure 3 is a partial cross-sectional view of a first example of a substrate processing system according to the present invention;

[0039] Figure 4 Schematically shows Figure 3 a temperature profile in a substrate processing system; and

[0040] Figure 5 is a top view of a third example of a resistive heating element according to the present invention. DETAILED DESCRIPTION

[0041] Figure 1A A first example of a heating element 100 according to the present invention is schematically shown. The heating element 100 of this example has a substantially planar geometry. It should be noted that the plane 130 in which the heating element 100 is arranged does not need to be a flat plane, but can also be curved, for example so that the plane extends substantially parallel to the curved surface of the substrate.

[0042] The heating element 100 according to this example includes the following components electrically connected in series one after another:

[0043] Input contact 102;

[0044] A first section 121 comprising a conductive electrode 103 including a first heating element 111;

[0045] a second section 122 , wherein the conductive electrode is split into at least two independent conductive electrode branches 141 , 142 electrically connected in parallel, wherein each conductive electrode comprises a second heating element 112 and a third heating element 113 , respectively;

[0046] a third section 123 comprising the conductive electrode 105 including the fourth heating element 114; and

[0047] Output contact 106.

[0048] It should be noted that the two independent conductive electrode branches 141 , 142 are reconnected in the second section 122 .

[0049] The first heating element 111, the second heating element 112, the third heating element 113, and / or the fourth heating element 114 of this example include emitters for emitting infrared radiation or thermal radiation. Preferably, the amount of infrared radiation or thermal radiation emitted is a function of the current passing through the emitter. Examples of emitters for infrared radiation are heat lamps, infrared lamps, or infrared light emitting diodes (LEDs).

[0050] In use of the heating element 100, the current flowing from the input contact 102 to the output contact 106 flows through the conductive electrode 103 of the first section 121, where the current is divided into the second section 122 on at least two independent conductive electrode branches 141, 142 electrically connected in parallel, and recombined before reaching the third section 123, where the total current again flows through the conductive electrode 105. Accordingly, the first heating element 111 and the fourth heating element 114 are subjected to the total current through the heating element 100. The second heating element 112 and the third heating element 113 are subjected to a portion of the total current through the heating element 100 depending on the resistance of the independent conductive electrode branches 141, 142 relative to each other. In this example, there are two independent conductive electrode branches 141, 142, and if the resistance of the two electrode branches 141, 142 is substantially equal, then the total current through the heating element 100 is divided so that the current through each of the two electrode branches 141, 142 is substantially equal to the total current. 1 Because the power generated by the heating elements is a function of the current passing through the heating elements, the power generated by the first heating element 111 and the fourth heating element 114 is higher than the power generated by the second heating element 112 and the third heating element 113, respectively. The relatively high power heat generation in the first section 121 and the third section 123 serves to compensate for heat losses at the edges 131 and 132 of the plane 130.

[0051] Figure 1B A first alternative example of a heating element 100 according to the invention is schematically shown. The heating element 100 of this example has a Figure 1A The examples in are essentially the same plane geometry. Figure 1B In an alternative example, the number of heat generating elements along the edge of the heating element is equal to the number of heat generating elements at the center of the heating element.

[0052] The heating element 100 according to this alternative example comprises the following components electrically connected in series one after the other:

[0053] Input contact 102;

[0054] a first section 121 comprising a conductive electrode 103 including a set of first heating elements 111a, 111b electrically connected in series;

[0055] a second section 122 , wherein the conductive electrode is split into at least two independent conductive electrode branches 141 , 142 electrically connected in parallel, wherein each conductive electrode comprises a second heating element 112 and a third heating element 113 , respectively;

[0056] a third section 123 comprising the conductive electrode 105 including a set of fourth heating elements 114a, 114b electrically connected in series; and

[0057] Output contact 106.

[0058] It should be noted that the two independent conductive electrode branches 141 , 142 are reconnected in the second section 122 .

[0059] Similarly, the first heating element 111a, 111b, the second heating element 112, the third heating element 113, and / or the fourth heating element 114a, 114b of this alternative example include emitters for emitting infrared radiation or thermal radiation, wherein the amount of infrared radiation or thermal radiation emitted is a function of the current passing through the emitters. Accordingly, the heating elements 111a, 111b, 114a, and 114b have a high output power because they are subjected to the total current. The central heating elements 112 and 113 are electrically connected in parallel, and thus the total current is divided between these two heating elements, and they emit a lower amount of heat. The relatively high power heat generation in the first and third sections 121, 123 serves to compensate for heat losses at the edges 131, 132 of the plane 130.

[0060] Figure 2 Schematically shows a top view of a first example of a resistance heating element 1 according to the present invention. Figure 2 As shown, the resistive heating element 1 has a substantially circular geometry that is particularly suitable for use in substrate processing systems in which the substrate is a substantially circular disk, such as a silicon wafer.

[0061] The resistance heating element 1 according to this example comprises the following components connected in series one after another:

[0062] Input contact 2;

[0063] A conductive electrode, comprising:

[0064] a first section 3, which provides a portion of the outer ring;

[0065] a second section 4 , which is arranged in a region inside the outer ring, wherein the second section 4 is split into two independent electrically conductive electrode branches 41 , 42 ; and

[0066] a third section 5, which provides the remainder of the outer ring;

[0067] Output contact 6.

[0068] It should be noted that the two independent conductive electrode branches 41, 42 are recombined in the second section 4 before the conductive electrodes reach the third section 5. Accordingly, the two independent conductive electrode branches are confined within the second section 4 in this example.

[0069] In this example, the third section 5 is substantially symmetrical with respect to the center point CP of the resistive heating element to the first section 3. Furthermore, the second section 4 is substantially completely split into two independent conductive electrode branches 41,42.

[0070] Although the thickness of the conductive electrode can vary along its path, in this example, the resistive heating element 1 has a substantially constant thickness in a direction perpendicular to the plane of the drawing. In this example, the resistive heating element 1 is made of a carbon-carbon composite (CCC) material having a thickness of approximately 3 mm. The slots 7 defining the path of the conductive electrode are cut from a sheet of CCC material using, for example, a water jet cutter.

[0071] like Figure 2 As schematically shown, the two independent conductive electrode branches 41, 42 each have a first tortuous path from the outer ring of the resistive heating element toward the center point CP in a first quarter of the circular area of the resistive heating element, and then have a second tortuous path from the center of the resistive heating element toward the outer ring in a second quarter of the circular area of the resistive heating element, adjacent to the first quarter.

[0072] like Figure 2 As shown, the turns in the tortuous path of the conductive electrode are provided with cutouts 8. The cutouts 8 in the turns of the tortuous path are configured to prevent cold spots in the temperature distribution across the resistive heating element.

[0073] exist Figure 2 In the specific example of , one or more of the turns comprises two cutouts 8 extending at angles α1, α2, α3 relative to each other. This angle α1, α2, α3 is an angle greater than 0 degrees and less than 180 degrees. Figure 2 In the example of FIG, the angles α1, α2, α3 between the two cutouts 8 at the bend are substantially 45 degrees, 90 degrees or 135 degrees. Figure 2 In the example shown in FIG. 5 , substantially each turn portion includes two cutouts 8 , except for the turn portion closest to the center point CP of the resistance heating element.

[0074] Furthermore, the width of the two independent conductive electrode branches 41, 42 of the conductive electrode, in a direction parallel to the plane, varies along the path. As the path progresses toward the center point CP of the resistive heating element, the conductive electrode becomes wider, and the heat generated by a given current flowing through the conductive electrode decreases. This allows for fine-tuning of the resistive heating to achieve optimal, uniform heat distribution for a specific application.

[0075] Figure 3 A partial cross-sectional view of a first example of a substrate processing system 10 according to the present invention is schematically shown. Figure 3 The cross section of φ ranges from the center point P to the peripheral edge of the substrate handling system 10. Accordingly, the left hand side of the cross section is equal to the mirror image in the line 20 passing through the center point CP.

[0076] The substrate processing system 10 includes a first heating element 11 and a second heating element 12. Each of the first heating element 11 and the second heating element 12 preferably includes Figure 2 The resistive heating element 1 is shown. The substrate processing system 10 further includes a processing compartment 13 arranged between the first heating element 11 and the second heating element 12. The processing compartment 13 includes a top wall 14 and a bottom wall 15, which are made of a thermally conductive material, in this particular example, Shapal (AlN). The bottom wall 15 is configured to support a substrate to be processed, such as a silicon wafer. In addition, the processing compartment 13 is configured to allow a process gas or vapor to be introduced into the processing compartment 13. The substrate processing system 10 is arranged inside a processing chamber (not shown).

[0077] like Figure 3 Schematically shown, the first heating element 11 is arranged against a side of the top wall 14 facing outside the processing compartment 13 , and the second heating element 12 is arranged against a side of the bottom wall 15 facing outside the processing compartment 13 .

[0078] Furthermore, the substrate processing system 10 includes a first thermal barrier 16, which is spaced apart from the first heating element 11 and disposed on a side of the first heating element 11 facing away from the processing compartment 13. Furthermore, the substrate processing system 10 includes a second thermal barrier 17, which is spaced apart from the second heating element 12 and disposed on a side of the second heating element 12 facing away from the processing compartment 13. Specifically, the first thermal barrier 16 and the second thermal barrier 17 include two layers 16a, 16b, 17a, 17b of heat-reflective and / or heat-insulating material. In this example, the first thermal barrier 16 and the second thermal barrier 17 include layers 16a, 16b, 17a, 17b comprising sheets of one or more of carbon-carbon composite (CCC), tungsten, molybdenum, or stainless steel.

[0079] The substrate processing system 10 further includes a third heat barrier 18 that forms a ring around the first heating element 11 and is spaced apart from the first heating element 11. The third heat barrier 18 is connected to the top wall 14 of the processing chamber 13 and extends in a direction perpendicular to the surface of the top wall 14. Figure 3In the example of FIG. 5 , the first heat barrier 16 is connected to the third heat barrier 18 at a position spaced apart from the top wall 14 and the first heating element 11 .

[0080] In addition, the substrate processing system 10 includes a fourth heat barrier 19 that forms a ring around the second heating element 12 and is spaced apart from the second heating element 12. The fourth heat barrier 19 is connected to the bottom wall 15 of the processing chamber 13 and extends in a direction perpendicular to the surface of the bottom wall 15. Figure 3 In the example of , the second heat barrier 17 is connected to the fourth heat barrier 19 at a position spaced apart from the bottom wall 15 and the second heating element 12. In this example, the third heat barrier 18 and the fourth heat barrier 19 are made of stainless steel or molybdenum.

[0081] It should be noted that the third thermal barrier 18 and the fourth thermal barrier 19 are connected to or are part of a process chamber or housing of the substrate processing system 10, which process chamber is preferably provided with a conduit for a cooling fluid, for example for cooling water. In such a substrate processing system 10, this is an additional reason for increased heat losses at the peripheral edges of the first heating element 11 and the second heating element 12. As described in more detail above, such heat losses are compensated by the outer rings 51, 52 of the first heating element 11 and the second heating element 12. The outer rings 51, 52 have a width w0 through which, in use, the entire drive current flows. Between the outer rings 51, 52 and the center point CP, the path of the conductive electrode is split into two independent conductive electrode branches electrically connected in parallel (see Figure 2 ), and therefore, in use, only a portion of the total drive current flows through the conductive electrode branches. Figure 2 In the example, the conductive electrode branches have substantially equal resistance, and accordingly, the total current is substantially divided in half when flowing through one of the conductive electrode branches.

[0082] like Figure 2 and Figure 3 As schematically shown, the width of each of the conductive electrode branches varies depending on the distance from the center point CP. By selecting an appropriate set of widths w1, w2, w3, w4, w5, the temperature of the first and second resistive heating elements 11, 12 can be optimized to provide a substantially uniform temperature distribution.

[0083] Figure 4 Schematically shows Figure 3 Simulation of the temperature profile in a substrate processing system, where:

[0084] The processing compartment 13 has a height of 10 mm;

[0085] The top wall 14 and the bottom wall 15 have a thickness of 3 mm and are made of Shapal;

[0086] The first and second resistance heating elements 11 and 12 have a thickness of 3 mm, a diameter of 110 mm, and the conductive electrode branches inside the outer rings 51, 52 include 5 coils, of which w1 = 7 mm, w2 = 9 mm, w3 = 19 mm, w4 = 20 mm and w5 = 18 mm.

[0087] like Figure 4 As shown schematically, the expected temperature variation across the heating elements 11, 12 is about 6 degrees around the operating temperature of about 1355 degrees, which is a variation of about 0.4%. Figure 4 R(m) in the graph is the distance from the center point CP.

[0088] The valley in the temperature curve can even be reduced by changing the width w3. Additionally or alternatively, each of the conductive electrode branches can be split again into two conductive electrode sub-branches electrically connected in parallel, which will cause the current flowing through the conductive electrode branch to be divided again into the two conductive electrode sub-branches in use.

[0089] Figure 5 is a top view of a second example of a resistance heating element 1 ' according to the invention, in which several minor changes have been made. Figure 2 When compared with the first example of the embodiment of the present invention, it is important to note that the first meandering path from the outer ring 3' of the resistance heating element towards the center point CP covers an area greater than one quarter of the circular area of the resistance heating element 1', and the subsequent second meandering path from the center of the resistance heating element towards the outer ring 3' covers an area less than one quarter of the circular area of the resistance heating element 1'. As a result, the radially arranged slots 7' are no longer as radially arranged as they were in the embodiment of the present invention. Figure 2 This allows adjusting the resistance heating elements 1 ' to the specific requirements and features of the substrate processing system (such as the position of the gas or vapor for processing the substrate in the substrate processing system and / or the position of the opening for introducing the substrate into the processing chamber or for removing the substrate from the processing chamber) and of course further homogenizing the temperature distribution over the area of the resistance heating element.

[0090] Furthermore, some of the slits 8 ′ are shaped differently to optimize the prevention of cold spots in the temperature distribution over the resistance heating element 1 ′.

[0091] It should be understood that the above description is included to illustrate the operation of the preferred embodiment and is not meant to limit the scope of the invention. Based on the above discussion, many variations will be apparent to those skilled in the art, which will still be encompassed by the scope of the present invention.

[0092] In summary, the present invention relates to a heating element, a substrate processing system including such a heating element, and a method for processing a substrate in such a substrate processing system. The heating element includes a conductive electrode, wherein the conductive electrode extends along a path between an input contact and an output contact. The conductive electrode includes a section along the path in which the conductive electrode is split into at least two independent conductive electrode branches electrically connected in parallel. The conductive electrode and the at least two independent conductive branches comprise a heating element configured to generate heat and / or emit thermal radiation when current flows through the heating element.

Claims

1. A heating element for a substrate processing system, wherein: The heating element includes a conductive electrode, wherein the conductive electrode extends along a path between the input contact and the output contact, wherein the conductive electrode comprises a section along the path in which the conductive electrode is split into at least two independent conductive electrode branches electrically connected in parallel, and Wherein, the conductive electrode and the at least two independent conductive branches each include a heating component, and the heating component is configured to generate heat and / or emit thermal radiation when current flows through the heating component.

2. The heating element according to claim 1, wherein The heating member extends along the conductive electrode, preferably along substantially the entire length of the conductive electrode.

3. The heating element according to claim 1 or 2, wherein The heating element includes a resistive heating element.

4. The heating element according to claim 3, wherein The resistive heating element includes a cross-sectional area in a direction substantially transverse to a direction along a path from the input contact to the output contact, wherein the cross-sectional area varies along the path.

5. The heating element according to claim 4, wherein The path is arranged in a plane, wherein a thickness of the resistive heating element in a direction perpendicular to the plane is substantially constant, and wherein a width of the resistive heating element in a direction parallel to the plane varies along the path.

6. The heating element according to any one of claims 1 to 5, wherein The heating element comprises an edge, wherein the conductive electrode comprises a first segment adjacent to the edge, and a second segment, wherein the first segment and the second segment are electrically connected in series, wherein the first segment is arranged between the edge and the second segment, wherein the second segment of the conductive electrode comprises a section along the path in which the conductive electrode is split into at least two independent conductive electrode branches electrically connected in parallel.

7. The heating element according to claim 6, wherein The first section provides an outer ring substantially surrounding the second section of the heating element, or wherein, The electrically conductive electrode includes a second segment and two first segments electrically connected in series, wherein the second segment is disposed between the two first segments, wherein each of the two first segments provides a portion of an outer ring substantially surrounding the second segment of the heating element.

8. The heating element according to claim 6 or 7, wherein The second section is substantially completely split into at least two independent conductive electrode branches electrically connected in parallel.

9. A heating element according to any one of the preceding claims, wherein The conductive electrode comprises a carbon-based material, preferably a carbon-carbon composite (CCC) material.

10. A heating element according to any one of the preceding claims, wherein The heating element is a single zone heating element having only one input contact and only one output contact.

11. A substrate processing system comprising a first heating element and a second heating element according to any one of the preceding claims, wherein The first heating element and the second heating element are disposed in a process chamber, and wherein the first heating element and the second heating element are spaced apart to dispose a process compartment therebetween.

12. The substrate processing system according to claim 11, wherein: The process compartment comprises a top wall and a bottom wall, wherein the first heating element and the second heating element are arranged against surfaces of the top wall and the bottom wall, respectively, outside the process compartment, preferably wherein the top wall and the bottom wall comprise Shapal (AlN) plates.

13. The substrate processing system according to claim 12, wherein: The bottom wall of the processing compartment is configured to support a substrate to be processed.

14. The substrate processing system according to claim 11, 12 or 13, wherein: The substrate processing system further comprises a first thermal barrier and / or a second thermal barrier, wherein the first heat barrier is arranged spaced apart from the first heating element and at a side of the first heating element facing away from the processing compartment, wherein the second heat barrier is arranged spaced apart from the second heating element and at a side of the second heating element facing away from the processing compartment, Preferably, the first thermal barrier and / or the second thermal barrier comprises a sheet of one or more of carbon-carbon composite material (CCC), tungsten, molybdenum, and stainless steel.

15. The substrate processing system according to any one of claims 11 to 14, wherein: The substrate processing system further includes a third thermal barrier and / or a fourth thermal barrier, wherein the third thermal barrier is configured to provide a ring around the first heating element, wherein the third thermal barrier is arranged to be spaced apart from the first heating element, wherein the fourth thermal barrier is configured to provide a ring around the second heating element, wherein the fourth thermal barrier is arranged to be spaced apart from the second heating element, Preferably, the third thermal barrier and / or the fourth thermal barrier comprises a sheet of one or more of carbon-carbon composite material (CCC), tungsten, molybdenum, and stainless steel.

16. A method for processing a substrate in a substrate processing system according to any one of claims 11 to 15, wherein: The method comprises at least the following steps: - providing the substrate and arranging the substrate inside the processing compartment; - heating the substrate inside the processing compartment using the first heating element and the second heating element.

Images