Window edge heater for high power plasma processing applications.

Abstract

A window support system for a plasma processing chamber includes a window support frame configured to surround an opening. The window support frame has a top surface, a bottom surface, an inner surface, and an outer surface. Each of the inner surface and the outer surface extend between the top surface and the bottom surface. A passageway is formed in the outer surface. The top surface is configured to mechanically and thermally couple with a periphery of the window that is substantially conductive to radio frequency power. The window support system also includes a heating element disposed within the passageway of the window support frame. The heating element is configured to substantially surround the window support frame.

Description

[Background technology]

[0001] Plasma processing systems are used to fabricate semiconductor devices (e.g., chips / dies) on semiconductor wafers. In plasma processing systems, the semiconductor wafers are exposed to various types of plasmas to produce a predetermined change in the state of the semiconductor wafer, such as by depositing material, and / or removing material, and / or embedding material, and / or modifying material. During plasma processing of the semiconductor wafer, radio frequency (RF) power is transmitted through a process gas in a chamber to turn the process gas into a plasma for exposure to the semiconductor wafer. Reactive components of the plasma, such as radicals and ions, react with materials on the semiconductor wafer to achieve a predetermined effect on the semiconductor wafer. In some plasma processing systems, RF power is transmitted from an antenna or coil through a window (e.g., an RF transparent ceramic structure) to a processing region in the chamber to turn the process gas into a plasma for exposure to the semiconductor wafer.

[0002] In some plasma processing applications, a sufficiently high RF power is transmitted from the antenna / coil to the chamber in combination with a sufficiently high chamber pressure to cause a large temperature gradient from center to edge across the window, which can lead to mechanical failure (e.g., cracking and / or breakage) of the window. For example, plasma processing operations at high power (e.g., greater than about 2.5 kilowatts of antenna / coil power) can result in a large temperature gradient across the window due to high plasma temperatures at the chamber side of the window, heat losses from the edge and top surface (non-chamber side) of the window, and heat losses from the edge of the window to the chamber body. The large temperature gradient from center to edge across the window can cause stress in the brittle ceramic material of the window, leading to catastrophic failure of the window. Also, large windows, e.g., for processing 300 millimeter substrates, will have larger temperature gradients and correspondingly increased stress. Furthermore, the large temperature gradient across the window can cause non-uniformities on the wafer (e.g., similar to the so-called first wafer effect). In this regard, various embodiments described herein arise. Summary of the Invention

[0003] In an exemplary embodiment, a window support system for a plasma processing chamber is disclosed. The window support system comprises a window support frame configured to surround an opening. The window support frame has a top surface, a bottom surface, an inner surface, and an outer surface. Each of the inner surface and the outer surface extends between the top surface and the bottom surface. A flow passage is formed within the outer surface. The top surface is configured to mechanically and thermally couple with a periphery of the window that is substantially conductive to radio frequency power. The window support system also comprises a heating element disposed within the flow passage. The heating element is configured to substantially surround the window support frame.

[0004] In an exemplary embodiment, a plasma processing system is disclosed. The plasma processing system includes a chamber having a wall surrounding a plasma processing region. The plasma processing system also includes an adapter structure configured to interface with a top of the chamber wall. The adapter structure is configured to surround a first opening. The adapter structure has a flange portion surrounding the first opening and projecting into the first opening. The plasma processing system also includes an insulator member disposed on the flange portion of the adapter structure. The insulator member is formed as a continuous convoluted structure. The plasma processing system also includes a window support frame disposed on the insulator member. The window support frame is configured to surround a second opening. The window support frame has a top surface, a bottom surface, an inner surface, and an outer surface. Each of the inner surface and the outer surface extends between the top surface and the bottom surface. The window support frame includes a flow passage formed within the outer surface. The plasma processing system also includes a heating element disposed within the flow passage of the window support frame. The heating element is configured to substantially surround the window support frame. The plasma processing system also includes a window disposed in the window support frame, the convoluted periphery of the window being in thermal contact with the window support frame, the window being substantially transparent to radio frequency power.

[0005] In an exemplary embodiment, a method for controlling a temperature of a window of a plasma processing chamber is disclosed. The method includes supplying heat to the convoluted periphery of the window by operating a heating element that dissipates heat to a window support frame on which the convoluted periphery of the window is disposed. The method also includes monitoring the temperature of the convoluted periphery of the window. The method also includes adjusting the supplied heat based on the monitored temperature to achieve and maintain a set temperature on the convoluted periphery of the window.

[0006] Other aspects and advantages of the embodiments disclosed herein will become more apparent from the following detailed description and accompanying drawings. [Brief description of the drawings]

[0007] [Figure 1A] FIG. 1A is a vertical cross-sectional view through a portion of an exemplary substrate plasma processing system, in accordance with some embodiments.

[0008] [Figure 1B] FIG. 1B is a top view of a substrate plasma processing system according to some embodiments.

[0009] [Figure 2A] FIG. 2A is a top view of a substrate plasma processing system with the coil and window removed, according to some embodiments.

[0010] [Figure 2B] FIG. 2B is a vertical cross-sectional view through a window support system shown in the AA view of FIG. 2A according to some embodiments.

[0011] [Figure 2C] FIG. 2C is a horizontal cross-sectional view through the window support system shown in the BB view of FIG. 2B, according to some embodiments.

[0012] [Diagram 3] FIG. 3 is a vertical close-up perspective view of a window support system according to some embodiments.

[0013] [Figure 4] FIG. 4 is a diagram of an example controller, according to some embodiments.

[0014] [Diagram 5] 4 is a flow chart of a method for controlling a temperature of a window of a plasma processing chamber, in accordance with some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In the following description, some specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that embodiments of the present disclosure may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail in order to avoid unnecessarily obscuring the present disclosure.

[0016] Disclosed herein are systems and methods for providing and using a heating structure in which a TCP (transformer coupled plasma) window is installed to reduce the center-to-edge temperature gradient across the TCP window when performing plasma processing operations at high power and pressure. For ease of explanation, the TCP window that separates the antenna / coil from the plasma processing area in the plasma processing chamber is referred to herein as the window. By heating the bottom peripheral edge region of the window, heat loss to the chamber body is reduced or eliminated, and the temperature of the window peripheral edge region is increased to reduce the center-to-edge temperature gradient across the window, and the stresses built up in the window are correspondingly reduced. Also, by heating the peripheral edge region of the window, the first wafer effect is reduced. The first wafer effect refers to the process difference that occurs in the substrate due to the window having a lower temperature during processing of the first substrate than during processing of subsequent substrates.

[0017] FIG. 1A illustrates a vertical cross-sectional view through a portion of an exemplary substrate plasma processing system 100, according to some embodiments. FIG. 1B illustrates a top view of the substrate plasma processing system 100, according to some embodiments. The substrate plasma processing system 100 comprises a chamber 101 that encloses a plasma processing region 103. A substrate support structure 105 is disposed within the chamber 101 exposed to the plasma processing region 103. The substrate support structure 105 is configured to support a substrate 107 during processing of the substrate 107 by a plasma 109 generated above the substrate support structure 105. In some embodiments, the substrate support structure 105 is an electrostatic chuck configured to generate an electrostatic force that holds the substrate 107 to the substrate support structure 105.

[0018] The substrate plasma processing system 100 also includes an adaptor structure 111 on top of the chamber 101. In some embodiments, the adaptor structure 111 is removable from the chamber 101, and one or more seals 113 are disposed between the adaptor structure 111 and the chamber 101. In some embodiments, the one or more seals 113 are configured to provide a vacuum-tight seal between the adaptor structure 111 and the chamber 101. In some other embodiments, the adaptor structure 111 is integrally formed as part of the chamber 101 such that the one or more seals 113 are not required to maintain a full vacuum in the plasma processing region 103. The adaptor structure 111 is configured to surround an opening 112. The adaptor structure 111 has a flange portion 111F that surrounds the opening 112 and protrudes into the opening 112. The adaptor structure 111 is configured to support a window support frame 115 on the flange portion 111F. The window support frame 115 is configured to support a window 117. In some embodiments, the window 117 is configured as a ceramic structure. In some embodiments, the window 117 is configured as a generally disk-shaped ceramic structure. In some embodiments, the window 117 is configured as a ceramic showerhead structure including an array of internal gas passages configured to receive process gases provided from a process gas source outside the chamber 101 and distribute the process gases to the plasma processing region 103 as indicated by arrows 119. The window 117 is substantially transparent to RF power such that RF power originating from a coil (or antenna 121) positioned above the window 117 can pass through the window 117 to the plasma processing region 103. It should be appreciated that in various embodiments, the window 117 can be formed of any material (e.g., ceramic, quartz, etc.) that is substantially transparent to RF power and is chemically, mechanically, and thermally compatible with the conditions to which the window 117 will be exposed in the plasma processing region 103.

[0019] A coil (or antenna) 121 is positioned above the window 117 to deliver RF power through the window 117 to the plasma processing region 103. In some embodiments, the coil 121 has a planar spiral shape (see FIG. 1B). For example, in the cross-sectional view of FIG. 1A, coil portion 121A extends outwardly from the plane and coil portion 121B extends inwardly from the plane. It should be understood that in various embodiments, the coil 121 can have essentially any configuration, so long as the coil 121 is configured to deliver RF power through the window 117 to the plasma processing region 103. In some embodiments, the coil 121 is electrically connected to receive RF power from the RF power source 123 through an impedance matching network 125, as shown by electrical connection 127. In some embodiments, the impedance matching network 125 is a network of capacitors and / or inductors configured to minimize reflections of RF power from the coil 121 such that RF power delivery to the plasma 109 is optimized.

[0020] The RF power delivered from the coil 121 to the plasma processing region 103 converts the process gas / mixture into a plasma 109 within the plasma processing region 103. The plasma 109 is generated to cause changes to the substrate 107 in a controlled manner. In various fabrication processes, the changes to the substrate 107 may be alterations to materials or surface conditions in the substrate 107. For example, in various fabrication processes, the changes to the substrate 107 may include one or more of etching material from the substrate 107, depositing material onto the substrate 107, and / or altering materials present on the substrate 107. The process gas / mixture used and process by-product materials are exhausted from the plasma processing region 103 as indicated by arrow 129. It should be understood that the plasma processing system 100 may be any type of plasma processing system in which RF power is delivered to the process gas / mixture in the plasma processing region 103 to generate a plasma 109 above the substrate 107 supported on the substrate support structure 105.

[0021] In some embodiments, the substrate 107 is a semiconductor wafer that has undergone a fabrication procedure. However, it should be understood that in various embodiments, the substrate 107 can be essentially any type of substrate that undergoes a plasma-assisted fabrication process. For example, in some embodiments, the substrate 107 can be formed of silicon, sapphire, GaN, GaAs, or SiC, and / or other substrate materials, including glass panels / substrates, metal foils, metal sheets, polymeric materials, and the like. Also, in various embodiments, the substrate 107 can vary in appearance, shape, and / or size. For example, in some embodiments, the substrate 107 is a semiconductor wafer having an outer diameter of 200 mm, 300 mm, 450 mm, or another size. Also, in some embodiments, the substrate 107 is a non-circular substrate (e.g., a rectangular substrate, particularly for flat panel displays).

[0022] The top view of the substrate plasma processing system 100 shown in FIG. 1B shows the cooling device 131 disposed within the adapter structure 111. In some embodiments, the adapter structure 111 is formed of a highly thermally conductive material (e.g., aluminum or other similar thermally conductive material) that has sufficient mechanical strength to support the window 117 and is chemically compatible with the plasma process performed in the plasma processing region 103. In some embodiments, the cooling device 131 is disposed within a groove or passage 133 formed within the adapter structure 111. In some embodiments, the groove / passage 133 is rolled / machined / cast into the top surface of the adapter structure 111. However, it should be understood that in other embodiments, the cooling device 131 can be embedded in the adapter structure 111 in a different manner (e.g., via a slot formed in the outer surface of the adapter structure 111). The groove / passage 133 and the cooling device 131 are configured to substantially surround the window 117. The cooling device 131 is in thermal contact with the adapter structure 111 to provide thermal conduction from the adapter structure 111 to the cooling device 131. In some embodiments, the cooling device 131 is configured as a tube formed of a thermally conductive material (e.g., aluminum, copper, or other similar material) through which a cooling fluid is flowed. In some embodiments, the cooling fluid is water. However, in other embodiments, the cooling fluid may be essentially any flowable fluid having suitable heat transfer properties for removing heat from the adapter structure 111 and transporting the removed heat to an external heat sink. In some embodiments, rather than having a separate co-located cooling device 131, the adapter structure 111 is formed to have an internal flow passage through which a cooling fluid may be flowed to remove heat from the adapter structure 111 itself. In some embodiments, the internal flow passage is configured to substantially surround the window 117 such that heat is removed from the adapter structure 111 by a substantially uniform cooling fluid about the periphery of the window 117.

[0023] FIG. 2A shows a top view of the substrate plasma processing system 100 with the coil 121 and the window 117 removed, according to some embodiments. The substrate plasma processing system 100 includes a window support system 134 for the plasma processing chamber 101. The window support system 134 includes a window support frame 115, a heating element 137 disposed around the window support frame 115, and a thermal insulator member 139 disposed between the window support frame 115 and the adapter structure 111. The window support frame 115 is configured to surround an opening 140. FIG. 2B shows a vertical cross section through the window support system 134, as shown in the AA view of FIG. 2A, according to some embodiments. The window support frame 115 has a top surface 115T, a bottom surface 115B, an inner surface 115I, and an outer surface 115O. Each of the inner surface 115I and the outer surface 115O extends between the top surface 115T and the bottom surface 115B. A top surface 115T of the window support frame 115 is configured to mechanically and thermally couple with the periphery (edge ​​region) of the window 117. The window 117 is disposed on the window support frame 115 such that the convoluted periphery of the window 117 is in thermal contact with the window support frame 115.

[0024] In some embodiments, a vacuum-tight seal is established between the window 117 and a top surface 115T of the window support frame 115. In some embodiments, the top surface 115T of the window support frame 115 has a groove 115G configured to receive a seal member 141 to establish a vacuum-tight seal between the window support frame 115 and the window 117. It should be understood that in various embodiments, different sealing mechanisms may be used to establish a vacuum-tight seal between the window support frame 115 and the window 117, so long as the window 117 is in a thermally conductive relationship with the window support frame 115.

[0025] In some embodiments, the shape of the window support frame 115 is configured to generally match the shape of the outer peripheral region of the window 117. In some embodiments, the window support frame 115 is generally ring-shaped and the window 117 has a right cylindrical shape. In these embodiments, the outer peripheral portion of the window 117 disposed in direct thermal conductive relationship with the window support frame 115 is the outer annular portion of the bottom surface 117B of the window 117. In some embodiments, the window support frame 115 is secured to the adapter structure 111. For example, FIG. 2A shows the window support frame 115 secured to the adapter structure 111 by several fasteners 145-1 through 145-4. In some embodiments, the vacuum pressure generated within the plasma processing region 103 is sufficient to hold the window support frame 115 to the adapter structure 111 such that the fasteners (e.g., 145-1 through 145-4) are not used.

[0026] The window support frame 115 has a radial thickness 161 (see FIG. 2B) measured between its inner surface 115I and outer surface 115O. The radial thickness 161 is measured along a line extending through a center point 163 (see FIG. 2A) of the opening 140 surrounded by the window support frame 115. In some embodiments, to achieve and maintain a set temperature along the outer perimeter region of the window 117, the radial thickness 161 of the window support frame 115 is sized as small as possible while ensuring that the window support frame 115 can support the window 117 and while providing an adequate amount of surface contact area between the window support frame 115 and the window 117 for thermal conduction from the heating element 137 to the window 117 through the window support frame 115.

[0027] In some embodiments, the window support frame 115 is disposed on the insulation member 139 and has a vertical height 165 defined to provide a substantially coplanar orientation between the top surface 115T of the window support frame 115 and the top surface 111T of the adapter structure 111 when the insulation member 139 is disposed on the flange portion 111F of the adapter structure 111. Thus, in these embodiments, the vertical height 165 of the window support frame 115 is less than the vertical height 167 of the adapter structure 111. In these embodiments, the vertical height 169 of the flange portion 111F of the adapter structure 111 is defined such that the sum of the vertical height 169 of the flange portion 111F, the vertical height 171 of the insulation material 139, and the vertical height 165 of the window support frame 115 is substantially equal to the vertical height 167 of the adapter structure 111. However, it should be understood that in some other embodiments, the vertical height 165 of the window support frame 115 is defined such that the top surface 115T of the window support frame 115 is above or below the top surface 111T of the adapter structure 111.

[0028] FIG. 2C shows a horizontal cross-section through the window support system 134, shown as the BB view of FIG. 2B, according to some embodiments. In some embodiments, a passage 115C is formed in the outer surface 115O of ​​the window support frame 115. The passage 115C is configured to receive the heating element 137. The heating element 137 is disposed within the passage 115C. The heating element 137 is configured to substantially surround the window support frame 115. In some embodiments, the heating element 137 is secured within the passage 115C by a spring force applied from the heating element 137 to the window support frame 115. In some embodiments, the heating element 137 is secured within the passage 115C by potting, brazing, or any other type of process or connection technique that provides for the establishment of a reliable mechanical and thermal connection between the heating element 137 and the window support frame 115. The heating element 137 is in direct thermal conduction relationship with the window support frame 115. In some embodiments, the heating element 137 is an electrical resistance heating element. In some embodiments, the passageway 115C has a cross-sectional shape that generally matches the cross-sectional shape of the heating element 137. In some embodiments, the heating element has a generally circular cross-sectional shape. In some embodiments, the heating element 137 is capable of increasing the temperature of the periphery of the window 117 by at least 150° C. through thermal conduction to the window 117 through the window support frame 115.

[0029] In some embodiments, a thermocouple thread 115tc is formed along a portion of the passage 115C. In some embodiments, a thermocouple device 143 is inserted into the thermocouple thread 115tc. Thus, in some embodiments, the thermocouple device 143 is disposed between the heating element 137 and the window support frame 115. In some embodiments, the thermocouple thread 115tc extends over less than one-quarter of a circumferential distance around the window support frame 115. In some embodiments, the thermocouple thread 115tc extends over less than one-eighth of a circumferential distance around the window support frame 115. In some embodiments, the thermocouple thread 115tc extends far enough along the passage 115C of the window support frame 115 to allow the thermocouple device 143 to be located between the heated portion of the heating element 137 and the window support frame 115. In some embodiments, instead of or in addition to the thermocouple device 143, the heating element 137 itself is configured to include one or more embedded thermocouple devices having corresponding electrical connections extending from the heating element 137 and the window support frame 115. Also, in some embodiments, a plurality of thermocouple devices are disposed around the passage 115C of the window support frame 115 between the heating element 137 and the window support frame 115. In some embodiments, four or more thermocouple devices are disposed around the passage 115C of the window support frame 115. In some embodiments, a plurality of thermocouple devices are disposed at approximately equal intervals around the opening 140 surrounded by the window support frame 115. In these embodiments, each of the plurality of thermocouple devices has a respective electrical connection extending from the window support frame 115.

[0030] It should be appreciated that the window support frame 115 is configured to provide heat transfer between the heating element 137 and the periphery (edge ​​region) of the window 117. In some embodiments, the heating element 137 is configured to substantially surround the window support frame 115 and accordingly substantially surround the window 117 disposed therein such that heat is transferred from the heating element 137 to the window 117 substantially uniformly along the periphery of the window 117. In some embodiments, the window support frame 115 is formed of a material having a high thermal conductivity (e.g., on the order of or higher than aluminum) that is chemically compatible with the plasma processes performed in the plasma processing region 103. In some embodiments, the window support frame 115 is formed of a material having a thermal conductivity of at least 200 watts per meter per kelvin. In some embodiments, the window support frame 115 is formed of aluminum. In some embodiments, the window support frame 115 is formed of copper. In some embodiments, the window support frame 115 is formed of titanium. In some embodiments, the window support frame 115 is formed from an aluminum alloy, a copper alloy, a titanium alloy, or another material that has a thermal conductivity similar to aluminum, or copper, or titanium.

[0031] 3 shows a vertical close-up perspective view of the window support system 134 according to some embodiments. In some embodiments, the insulation member 139 is formed as a continuous convoluted structure. In some embodiments, the insulation member 139 is disposed on the upper surface 146 of the flange portion 111F of the adapter structure 111. The insulation member 139 is configured to thermally isolate the bottom surface 115B of the window support frame 115 from the adapter structure 111 (or from the upper structure of the chamber 101 in some embodiments where the upper structure is equivalent to the adapter structure 111 but integral with the chamber 101). In some embodiments, the insulation member 139 is formed of a material that provides for the establishment of a vacuum-tight seal between the insulation member 139 and the window support frame 115, and provides for the establishment of a vacuum-tight seal between the insulation member 139 and the adapter structure 111 (or the upper structure of the chamber 101). In some embodiments, one or more seal members 147 are disposed between the insulator member 139 and the adapter structure 111 (or the upper structure of the chamber 101) to facilitate establishment of a vacuum-tight seal between the insulator member 139 and the adapter structure 111 (or the upper structure of the chamber 101). Also, in some embodiments, the adapter structure 111 (or the upper structure of the chamber 101) includes respective grooves 149 for receiving the seal members 147.

[0032] In various embodiments, the insulator member 139 is formed of an insulator material that provides sufficient mechanical strength to support the window support frame 115 and the window 117, is chemically compatible with the materials present in the plasma processing region 103, and is thermally compatible with the temperature of the window support frame 115 generated by the heating element 137. In some embodiments, the insulator member 139 is formed of a plastic material. In some embodiments, the insulator member 139 is formed of a ceramic material. In some embodiments, the insulator member 139 is formed of a stainless steel material. In some embodiments, the insulator member 139 is formed of polyetheretherketone (PEEK). For electrical efficiency and performance of the window support system 134, as well as thermal efficiency and performance of the window support system 134, it is preferred that as much heat power as possible from the heating element 137 be transferred through the window support frame 115 to the window 117. As such, in some embodiments, the window support frame 115 is sized and positioned such that there is essentially no direct conductive heat transfer to the adapter structure 111 (or to the superstructure of the chamber 101). FIG. 2B illustrates an example embodiment in which a gap 151 exists between the exterior surface 115O of ​​the window support frame 115 and the adapter structure 111 when the window support frame 115 and the insulation member 139 are both disposed on the top surface 146 of the flange portion 111F of the adapter structure 111. The gap 151 extends around the entire periphery of the exterior surface 115O of ​​the window support frame 115 such that there is no direct thermal conduction between the exterior surface 115O of ​​the window support frame 115 and the adapter structure 111. In some embodiments, the gap 151 is an air gap. In some embodiments, an insulation material is disposed in at least a portion of the gap 151. In some embodiments, the insulation material disposed in the gap 151 is the same material from which the insulation member 139 is formed. In some embodiments, the insulation material disposed in the gap 151 is integrally formed with the insulation member 139. In some embodiments, a heat reflector is disposed in at least a portion of the gap 151, where the heat reflector is configured to reflect heat emanating from the heating element 137 back to the window support frame 115. In some embodiments, the heat reflector disposed in the gap 151 is integrally formed with the insulation member 139 .

[0033] In some embodiments, the inner surface 115I of the window support frame 115 is coated with a protective coating. In some embodiments, the protective coating of the window support frame 115 is a plasma-resistant coating. In some embodiments, the protective coating of the window support frame 115 is one or more of an anodized coating, a ceramic coating, and a yttrium-based coating. In other embodiments, the protective coating of the inner surface 115I of the window support frame 115 can be essentially any type of plasma-resistant coating used in the semiconductor fabrication industry. Also, in some embodiments, the surface of the adapter structure 111 exposed to the plasma processing region 103 is coated with a protective coating. In some embodiments, the protective coating of the adapter structure 111 is a plasma-resistant coating. In some embodiments, the protective coating of the adapter structure 111 is one or more of an anodized coating, a ceramic coating, and a yttrium-based coating. In other embodiments, the protective coating of the adapter structure 111 can be essentially any type of plasma-resistant coating used in the semiconductor fabrication industry. In some embodiments, the protective coating of the adapter structure 111 is the same as the protective coating of the window support frame 115 .

[0034] As shown in FIGS. 2A and 3, a temperature measuring device 153 is disposed on a connection block 115X of the window support frame 115. The connection block 115X is configured to support a first lead end 137A and a second lead end 137B of the heating element 137. In some embodiments, the temperature measuring device 153 is electrically connected to the controller 155 via an electrical connection 157. In this manner, the controller 155 receives a signal from the temperature measuring device 153 indicative of a measured temperature of the connection block 115X. In some embodiments, the temperature measuring device 153 is used to monitor for an overheating condition that may cause the controller 155 to disconnect the heating element 137 from the power source. In some embodiments, the connection block 115X is configured to include a passage for inserting the thermocouple device 143 into the thermocouple passage 115tc such that the thermocouple device 143 can be inserted and removed from the thermocouple passage 115tc when the heating element 137 is secured within the passage 115C of the window support frame 115. In some embodiments, the first lead end 137A and the second lead end 137B of the heating element 137 are electrically connected to a power source. The controller 155 is configured and programmed to control the power supply to the heating element 137, which in turn provides control of the temperature of the window support frame 115, which in turn provides control of the temperature of the outer peripheral region of the window 117. In some embodiments, the temperature measurements made by the thermocouple device 143 are used to control the heating element 137. For example, in some embodiments, the controller 155 is configured to implement a PID (Proportional Integral Derivative) control system that uses the temperature measurements of the thermocouple device 143 to actively control the heating element to achieve and maintain a set operating temperature of the outer peripheral region of the window 117. In some embodiments, the set operating temperature of the outer peripheral region of the window 117 is programmed into the controller 155. In some embodiments, the set operating temperature of the outer peripheral region of the window 117 is about 150° C. In some embodiments, the set operating temperature of the outer peripheral region of the window 117 is greater than about 150° C. The heating element 137 has an operable power range capable of achieving and maintaining a set operating temperature along the peripheral region of the window 117. In some embodiments, the output power of the heating element 137 is approximately 3 kilowatts.However, it should be understood that in various other embodiments, the output power of the heating element 137 is less than 3 kilowatts or greater than 3 kilowatts.

[0035] 4 illustrates an exemplary diagram of controller 155 according to some embodiments. In some embodiments, controller 155 includes processor 409, storage hardware unit (HU) 411 (e.g., memory), input HU 401, output HU 405, input / output (I / O) interface 403, I / O interface 407, network interface controller (NIC) 415, and data communication bus 413. Processor 409, storage HU 411, input HU 401, output HU 405, I / O interface 403, I / O interface 407, and NIC 415 are in data communication with each other through data communication bus 413. Examples of input HU 401 include a mouse, keyboard, stylus, data acquisition system, data acquisition card, etc. Examples of output HU 405 include a display device, speaker, device controller, etc. Examples of NIC 415 include a network interface card, network adapter, etc. In various embodiments, the NIC 415 is configured to operate according to one or more communication protocols and associated physical layers (such as Ethernet and / or EtherCat, among others). Each of the I / O interfaces 403 and 407 is defined to provide compatibility between different hardware units connected to the I / O interface. For example, the I / O interface 403 can be defined to convert signals received from the input HU 401 to a format, amplitude, and / or speed compatible with the data communication bus 413. Also, the I / O interface 407 can be defined to convert signals received from the data communication bus 413 to a format, amplitude, and / or speed compatible with the output HU 405. Although various operations described herein are performed by the processor 409 of the controller 155, it should be understood that in some embodiments, various operations can be performed by multiple processors of the controller 155 and / or multiple processors of multiple computing systems connected to the controller 155.

[0036] In various embodiments, the substrate plasma processing system 100 is integrated with electronics for controlling operations before, during, and after processing of the substrate 107. The electronics are implemented within a controller 155 configured and connected to control various components and / or subcomponents of the substrate plasma processing system 100, including the window support system 134. Depending on the substrate 107 processing requirements and / or the specific configuration of the substrate plasma processing system 100, the controller 155 is programmed to control any process and / or component disclosed herein, including, among others, supply of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, settings of the RF power system, settings of electrical signal frequencies, gas flow settings, fluid supply settings, position operation settings, settings of the bias voltage supply system, loading and unloading of the substrate 107 into and from the chamber 101, and / or loading and unloading of the substrate 107 into and from the chamber 101 and / or load locks connected to the substrate plasma processing system 100.

[0037] In various embodiments, the controller 155 is defined as electronic equipment having various integrated circuits, logic, memory, and / or software that, among other things, receive instructions, issue instructions, control device operations, enable cleaning operations, enable endpoint measurements, enable metrology measurements (light, heat, electricity, etc.), direct and control various tasks / operations. In some embodiments, the integrated circuits in the controller 155 include, among other things, firmware that stores program instructions, digital signal processors (DSPs), application specific integrated circuit (ASIC) chips, programmable logic devices (PLDs), one or more microprocessors and / or one or more microcontrollers that execute the program instructions (e.g., software). In some embodiments, the program instructions are communicated to the controller 155 in the form of various individual settings (or program files) that define operational parameters for performing processing on the substrate 107 in the substrate plasma processing system 100. In some embodiments, the operational parameters are included in a recipe defined by a process engineer to perform one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies on the substrate 107.

[0038] In some embodiments, the controller 155 is part of or connected to a computer that is integrated with, connected to, networked with, or a combination of the substrate plasma processing system 100. For example, in some embodiments, the controller 155 is implemented in all or part of a “cloud” or fab host computer system that allows remote access to control the processing of a substrate 107 by the substrate plasma processing system 100. The controller 155 allows remote access to the substrate plasma processing system 100 to provide for monitoring the progress of a fabrication operation, examining the history of past fabrication operations, examining trends or performance metrics from multiple fabrication operations, modifying process parameters, setting up subsequent processing steps, specifying operating parameters of the RF power supply system, specifying operating parameters of the bias voltage supply system, specifying operating parameters of the window support system 134, and / or initiating a new substrate fabrication process.

[0039] In some embodiments, a remote computer, such as a server computer system, provides the controller 155 with a process recipe over a computer network, including a local network and / or the Internet. The remote computer includes a user interface that allows for entry or programming of parameters and / or settings, which are then communicated from the remote computer to the controller 155. In some examples, the controller 155 receives instructions in the form of a configuration for processing the substrate 107 in the substrate plasma processing system 100. It should be understood that the configuration is specific to the type of process to be performed on the substrate 107 and the type of tools / apparatus / components to which the controller 155 connects or controls. In some embodiments, the controller 155 is distributed, for example, by including one or more separate controllers 155 that are networked and synchronized to operate toward a common purpose (e.g., operating the substrate plasma processing system 100 to perform a given process on the substrate 107). Examples of controllers 155 distributed for such purposes include one or more integrated circuits on the chamber that communicate with one or more integrated circuits located remotely (e.g., at the platform level or as part of a remote computer) and coupled to control the process in the chamber 101.

[0040] 5 illustrates a flow chart of a method for controlling a temperature of a window 117 of a plasma processing chamber 101, according to some embodiments. The method includes an operation 501 for providing heat to a convoluted periphery of a window 117 by operating a heating element 137 that dissipates heat to a window support frame 115 on which the convoluted periphery of the window 117 is disposed. In some embodiments, the window 117 is disposed in thermally conductive contact with a top surface 115T of the window support frame 115, the window support frame 115 being configured to surround an opening 140. The window support frame 115 has an inner surface 115I and an outer surface 115O. Each of the inner surface 115I and the outer surface 115O extends between a top surface 115T and a bottom surface 115B of the window support frame 115. The window support frame 115 also includes a passage 115C formed in the outer surface 115O. The heating element 137 is disposed within the passage 115C. The heating element 137 is configured to substantially surround the window support frame 115. The window 117 is substantially conductive to RF power. The method also includes an operation 503 for monitoring a temperature of the convoluted periphery of the window 117. The method also includes an operation 505 for adjusting the heat provided in operation 501 based on the temperature monitored in operation 503 to achieve and maintain a set temperature of the convoluted periphery of the window 117. In some embodiments, operation 503 monitors the temperature against a threshold. If the detected temperature exceeds the threshold, the controller 155 automatically stops (or interrupts) the supply of heat to the convoluted periphery of the window 117. This prevents accidental overheating of the window. In some embodiments, the heating element 137 operates to increase the temperature of the window support frame 115 and accordingly increase the temperature of the periphery region of the window 117 to a set temperature of about 150° C. or higher. In some embodiments, the method also includes directing a flow of cooling gas (e.g., air) to a central region of the top surface of window 117, as shown by arrow 159 in FIG. 1A, to further reduce the center-to-edge radial temperature gradient across window 117.

[0041] In some embodiments, the method includes disposing an insulation member 139 between the window support frame 115 and the adapter structure 111. In these embodiments, the adapter structure 111 is configured to support the insulation member 139 and the window support frame 115. The adapter structure 111 is also configured to extend around an exterior surface 115O of ​​the window support frame 115 without obstructing an opening 140 surrounded by the window support frame 115 and without contacting the window support frame 115. In some embodiments, the method also includes flowing a cooling fluid through a cooling device 131 disposed within the adapter structure 111. In some embodiments, the cooling device 131 is configured to extend around an exterior perimeter of the window support frame 115. In some embodiments, the cooling device 131 is a conduit through which the cooling fluid flows.

[0042] The window support system 134 provides thermal decoupling of the window 117 from the heat sink of the adapter structure 111 and / or the chamber 101. It should be appreciated that without the window support system 134 implemented, the heat sink provided by the adapter structure 111 and / or the chamber 101 would create temperature gradients large enough to cause thermal stress failure of the window 117 in some substrate plasma processing applications. The window support system 134 introduces a heat source to the outer periphery of the window 117. The heat source serves to mitigate heat loss from the edge of the window 117 to the adapter structure 111 and / or the chamber 101, thereby reducing the thermal gradients and correspondingly reducing stress in the window 117. In various embodiments, the window support system 134 is configured to be implemented in an existing plasma processing chamber body to preserve the existing geometric relationship between the window 117 and the plasma processing chamber body, thereby providing process compatibility. Also, implementing and using the window support system 134 avoids the need to attempt to heat the chamber body to protect the integrity of the window 117. Heating the chamber body raises many other issues, including complex implications with power requirements, safety concerns about having a hot (greater than 100° C.) chamber body, and compatibility with other equipment attached to the chamber (nanometers, valves, etc.).

[0043] In some embodiments, the window support system 134 provides integrity protection for the window 117 in high power plasma processing applications where the power of the coil 121 is about 2 kilowatts or more and the pressure in the plasma processing region 103 is about 100 millitorr or more. It should be appreciated that the window support system 134 provides an improvement over attempts to simply thermally isolate the window 117 from the adapter structure 111 and / or the chamber 101. Specifically, the window support system 134 completely eliminates the heat sink thermal effect on the window 117 caused by the adapter structure 111 and / or the chamber 101 and provides a heat source at the edge of the window 117. The window support system 134 is particularly useful for maintaining the structural integrity of larger diameter windows 117 that may be used when the substrate plasma processing system 100 is configured to process larger diameter substrates 107 (e.g., substrates 107 having a diameter of 300 millimeters or more). The larger diameter windows 117 require a lower center-to-edge temperature gradient to avoid cracking / breaking the window 117. The heat output by the window support system 134 increases the temperature around the edge of the window 117, correspondingly reducing the center-to-edge temperature gradient across the window 117. This allows the window 117 to withstand high power / voltage substrate plasma processing applications. As an additional benefit, the window support system 134 can be used to reduce or eliminate the first wafer effect.

[0044] The various embodiments described herein may be implemented in conjunction with a variety of computer system configurations (such as handheld hardware units, microprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, etc.). The various embodiments described herein may also be implemented in conjunction with distributed computing environments in which tasks are performed by remote processing hardware units connected through a computer network. It should also be understood that the various embodiments disclosed herein include the implementation of various computer-implemented operations on data stored in computer systems. These computer-implemented operations manipulate physical quantities. In various embodiments, the computer-implemented operations are implemented by either general-purpose or special-purpose computers. In some embodiments, the computer-implemented operations are implemented by a selectively operating computer and / or are directed by one or more computer programs stored in a computer memory or obtained over a computer network. When the computer programs and / or digital data are obtained over a computer network, the digital data may be processed by other computers on the computer network (e.g., a cloud of computer resources). The computer programs and digital data are stored as computer-readable code on a non-transitory computer-readable medium. A non-transitory computer readable medium is any data storage hardware unit (e.g., memory device) that stores data that can then be read by a computer system. Examples of non-transitory computer readable media include hard drives, network attached storage (NAS), ROM, RAM, compact disk ROM (CD-ROM), recordable CD (CD-R), rewriteable CD (CD-RW), digital video / versatile disk (DVD), magnetic tape, and other optical and non-optical data storage hardware units.In some embodiments, computer programs and / or digital data are distributed across multiple computer-readable media located in different computer systems within a network of connected computer systems for distributed execution and / or storage.

[0045] Although the above disclosure includes some details for clarity of understanding, it will be apparent that certain changes and modifications may be made within the scope of the appended claims. For example, it should be understood that one or more features from any embodiment disclosed herein may be combined with one or more features of any other embodiment disclosed herein. Thus, the present embodiments are considered to be illustrative rather than restrictive, and the claims are not limited to the details described herein, but may be modified within the scope of the described embodiments and their equivalents.

Claims

1. 1. A window support system for a plasma processing chamber, comprising: a window support frame configured to surround an opening, the window support frame having a top surface, a bottom surface, an inner surface, and an outer surface, each of the inner surface and the outer surface extending between the top surface and the bottom surface, a passageway formed within the outer surface, the top surface configured to be in mechanical and thermal communication with a periphery of a window that is substantially transparent to radio frequency power; a heating element disposed within the passageway, the heating element configured to substantially surround the window support frame; A window support system for a plasma processing chamber comprising:

2. 10. The window support system for a plasma processing chamber of claim 1, further comprising: A window support system for a plasma processing chamber comprising a thermocouple insertion passage formed along a portion of the passage.

3. 3. The window support system for a plasma processing chamber of claim 2, further comprising: A window support system for a plasma processing chamber comprising a thermocouple device inserted into the thermocouple passage.

4. 10. A window support system for a plasma processing chamber as recited in claim 1, comprising:

13. A window support system for a plasma processing chamber, wherein the window support frame is substantially ring-shaped, the window has a right cylindrical shape, and the periphery of the window is an outer annular portion of a bottom surface of the window.

5. 10. A window support system for a plasma processing chamber as recited in claim 1, comprising: A window support system for a plasma processing chamber, wherein the top surface of the window support frame includes a groove configured to receive a seal member to establish a vacuum-tight seal between the window support frame and the window.

6. 10. A window support system for a plasma processing chamber as recited in claim 1, comprising: A window support system for a plasma processing chamber, wherein the window support frame is formed from a material having a thermal conductivity of at least 200 watts per meter per Kelvin.

7. 10. A window support system for a plasma processing chamber as recited in claim 1, comprising: A window support system for a plasma processing chamber, wherein the window support frame is formed from aluminum.

8. 10. A window support system for a plasma processing chamber as recited in claim 1, comprising: A window support system for a plasma processing chamber, wherein the inner surface of the window support frame is coated with a plasma resistant coating.

9. 9. A window support system for a plasma processing chamber as recited in claim 8, comprising: The window support system for a plasma processing chamber, wherein the plasma resistant coating is one or more of an anodized coating, a ceramic coating, and a yttrium-based coating.

10. 10. The window support system for a plasma processing chamber of claim 1, further comprising:

11. A window support system for a plasma processing chamber comprising: an insulation member configured to thermally isolate a bottom surface of the window support frame from a structure of the plasma processing chamber, the insulation member being formed as a continuous convoluted structure.

11. 11. A window support system for a plasma processing chamber as recited in claim 10, comprising: A window support system for a plasma processing chamber, wherein the insulator member is formed of a plastic material.

12. 10. A window support system for a plasma processing chamber as recited in claim 1, comprising: A window support system for a plasma processing chamber, wherein the window support frame is sized and positioned such that there is essentially no direct conductive heat transfer to structures of the plasma processing chamber.

13. 1. A plasma processing system comprising: a chamber having a wall surrounding a plasma processing region; an adapter structure configured to interface with an upper portion of the wall of the chamber, the adapter structure being configured to surround a first opening and having a flange portion surrounding the first opening and projecting into the first opening; an insulation member disposed on the flange portion of the adapter structure, the insulation member being formed as a continuous convoluted structure; a window support frame disposed on the insulation member, the window support frame configured to surround a second opening, the window support frame having a top surface, a bottom surface, an inner surface, and an outer surface, each of the inner surface and the outer surface extending between the top surface and the bottom surface, the window support frame including a passageway formed in the outer surface; a heating element disposed within the passage of the window support frame, the heating element configured to substantially surround the window support frame; a window disposed in the window support frame such that a convoluted periphery of the window is in thermal contact with the window support frame, the window being substantially transparent to radio frequency power; A plasma processing system comprising:

14. 14. The plasma processing system of claim 13, further comprising: The adapter structure includes a cooling device configured to extend around the first opening, the cooling device being disposed in thermally conductive contact with the adapter structure.

15. 15. The plasma processing system of claim 14, further comprising: The plasma processing system, wherein the cooling device is a conduit through which a cooling fluid flows.

16. 16. The plasma processing system of claim 15, The conduit is disposed in a passage within the adapter structure.

17. 14. The plasma processing system of claim 13, further comprising: The plasma processing system, wherein the first opening in the adapter structure is sized larger than the window support frame such that a gap exists between the outer surface of the window support frame and the adapter structure.

18. 1. A method for controlling a temperature of a window in a plasma processing chamber, comprising: providing heat to a convoluted periphery of a window by operating a heating element that dissipates heat to a window support frame, the convoluted periphery of the window being disposed in the window support frame; monitoring a temperature of the convoluted periphery of the window; adjusting the supplied heat based on the monitored temperature to achieve and maintain a set point temperature at the convoluted periphery of the window; A method comprising:

19. 20. The method of claim 18 further comprising: directing a flow of cooling gas at a central region of a top surface of the window.

20. 20. The method of claim 18, The method, wherein the set temperature is about 150° C. or greater.

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