Temperature control of multi-segment susceptor

Abstract

A system for processing a semiconductor substrate includes a substrate support assembly configured to support the semiconductor substrate. The substrate support assembly includes M resistive heaters respectively disposed in M segments in a layer of the substrate support assembly, where M is an integer greater than 1. The layer is adjacent to the semiconductor substrate. The substrate support assembly includes N temperature sensors disposed at N locations in the layer, where N is an integer greater than 1 and less than or equal to M. The system also includes a controller configured to control one or more of the M resistive heaters based on a temperature sensed by one of the N temperature sensors and an average temperature of one or more of the M sections.

Description

This application is a divisional application of the invention patent application with application number 202080058573.3, application date June 22, 2020, and invention name “Temperature Control of Multi-Zone Base”. CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 62 / 865,621, filed on June 24, 2019. The entire disclosure of the above-referenced application is incorporated herein by reference. Technical Field

[0002] The present invention relates generally to substrate processing systems and, more particularly, to temperature control of multi-zone susceptors. Background Art

[0003] The background description provided here is for the purpose of generally presenting the context of the present disclosure. No admission is made, either explicitly or implicitly, that the work of the presently designated inventors is prior art to the present disclosure to the extent that it is described in this background section and in aspects of the specification that were not determined to be prior art at the time the application was filed.

[0004] Substrate processing systems can be used to perform etching, deposition, and / or other processing of substrates (e.g., semiconductor wafers). Examples of processes that can be performed on substrates include, but are not limited to, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), atomic layer etching (ALE), plasma-enhanced atomic layer deposition (PEALD), and / or other etching, deposition, and cleaning processes. During processing, a substrate is positioned on a substrate support (e.g., a susceptor, electrostatic chuck (ESC), etc.) within a processing chamber of the substrate processing system. A process gas mixture is introduced into the processing chamber to process the substrate. In some examples, a plasma can be ignited to enhance chemical reactions within the processing chamber.

[0005] During substrate processing, the temperature of the substrate can be controlled using resistive heaters placed in a substrate support. In some examples, the resistive heaters are placed in two or more independently controlled zones. Maintaining thermal uniformity in the zones heated by the resistive heaters typically requires direct temperature measurement or individually calibrated indirect temperature measurement (e.g., using a known correlation between heater resistance and temperature) in each zone. Summary of the Invention

[0006] A system for processing a semiconductor substrate includes: a substrate support assembly configured to support the semiconductor substrate; the substrate support assembly includes: M resistive heaters disposed in M ​​sections of a layer of the substrate support assembly, where M is an integer greater than 1; the layer is adjacent to the semiconductor substrate; the substrate support assembly includes: N temperature sensors disposed at N locations in the layer, where N is an integer greater than 1 and less than or equal to M; the system also includes: a controller configured to control one or more of the M resistive heaters based on a temperature sensed by one of the N temperature sensors and an average temperature of one or more of the M sections.

[0007] In other features, the M segments include: a first circular segment located at a central region of the layer; a second annular segment surrounding the first circular segment; a first group of segments located in a first annular region surrounding the second annular segment; and a second group of segments located in a second annular region surrounding the first annular region.

[0008] In another feature, the first set of segments is rotated at an angle relative to the second set of segments.

[0009] In another feature, the first set of segments is rotated relative to the second set of segments by an angle of forty-five degrees.

[0010] In another feature, the first and second annular regions have different widths.

[0011] In another feature, the second annular section has a different width than each of the first and second annular regions.

[0012] In another feature, each of the first and second sets of segments includes four segments.

[0013] In other features, the N temperature sensors include: a first temperature sensor located within the first circular segment; a first pair of temperature sensors located at a first boundary between the second annular segment and the first group of segments along a first diameter of the layer; and a second pair of temperature sensors located at a second boundary between the first group of segments and the second group of segments along a second diameter of the layer. The first temperature sensor is located at the intersection of the first and second diameters.

[0014] In other features, the positions of the first and second pairs of temperature sensors correspond to vertices of a parallelogram; and the first and second diameters form diagonals of the parallelogram.

[0015] In another feature, the controller is configured to control one of the M resistive heaters independently of other of the M resistive heaters.

[0016] In another feature, the controller is configured to control one or more of the M resistive heaters based on a target temperature profile of the semiconductor substrate.

[0017] In still other features, a substrate support assembly for supporting a semiconductor substrate includes: a baseplate including a layer adjacent to the semiconductor substrate; the substrate support assembly including: M resistive heaters disposed in M ​​segments of the layer, where M is an integer greater than 1; the M segments including: a first circular segment located at a central region of the layer; a second annular segment surrounding the first circular segment; a first group of segments located in a first annular region surrounding the second annular segment; and a second group of segments located in a second annular region surrounding the first annular region; and the substrate support assembly including: N temperature sensors disposed at N locations in the layer, where N is an integer greater than 1 and less than or equal to M. The N temperature sensors include: a first pair of temperature sensors located at a first boundary between the second annular segment and the first group of segments along a first diameter of the layer; a second pair of temperature sensors located at a second boundary between the first group of segments and the second group of segments along a second diameter of the layer; and a first temperature sensor located in the first circular segment and at the intersection of the first and second diameters.

[0018] In other features, the positions of the first and second pairs of temperature sensors correspond to vertices of a parallelogram; and the first and second diameters form diagonals of the parallelogram.

[0019] In another feature, the first set of segments is rotated at an angle relative to the second set of segments.

[0020] In another feature, the first set of segments is rotated relative to the second set of segments by an angle of forty-five degrees.

[0021] In another feature, the first and second annular regions have different widths.

[0022] In another feature, the second annular section has a different width than each of the first and second annular regions.

[0023] In another feature, each of the first and second sets of segments includes four segments.

[0024] In other features, a system for processing a semiconductor substrate includes: the substrate support assembly; and a controller configured to control one or more of the M resistive heaters based on a temperature sensed by one of the N temperature sensors and an average temperature of one or more of the M segments.

[0025] In another feature, the controller is configured to control one of the M resistive heaters independently of other of the M resistive heaters.

[0026] In another feature, the controller is configured to control one or more of the M resistive heaters based on a target temperature profile of the semiconductor substrate.

[0027] In other features, a system includes: the substrate support assembly; and a controller configured to control one or more of the M resistive heaters using a temperature sensed by one of the N temperature sensors in conjunction with open-loop control of the M zones. The open-loop control of the M zones includes correlating power supplied to each of the M zones with a measured temperature of the semiconductor substrate.

[0028] In other features, a system includes: the substrate support assembly; and a controller configured to control the first resistive heater relative to the second resistive heater based on a temperature sensed by one of the N temperature sensors and a resistance ratio of a first resistive heater among the M resistive heaters to a second resistive heater among the M resistive heaters.

[0029] Further scope of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0031] Figure 1A is a functional block diagram of an example of a substrate processing system;

[0032] Figure 1B A heater section of a substrate support is shown according to the present disclosure;

[0033] Figure 2 Shows the settings Figure 1B temperature sensors in the heater sections shown;

[0034] Figure 3A and 3BA functional block diagram showing an example of a heating system according to the present disclosure is shown;

[0035] Figure 4 is a flow chart of a method for setting heater zones and temperature sensors according to the present disclosure;

[0036] Figure 5 is a flow chart of a first method for controlling a heater zone according to the present disclosure; and

[0037] Figure 6 is a flow chart of a second method for controlling a heater zone according to the present disclosure.

[0038] Among the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0039] While the present disclosure includes specific examples related to temperature control of multiple zones in a substrate support of a substrate processing system, the systems and methods described herein may be applied to temperature control in other types of components that use zoned resistive heating.

[0040] In film deposition processes such as atomic layer deposition (ALD), the properties of the deposited film vary in spatial (i.e., xy coordinates in a horizontal plane) distribution. For example, a substrate processing tool may have a corresponding specification for film thickness non-uniformity (NU), which may be measured as the full range, half range, and / or standard deviation of a set of measurements taken at predetermined locations on the surface of a semiconductor substrate. In some examples, NU can be reduced by addressing the direct cause of NU and / or introducing countervailing NU to compensate for and eliminate existing NU. In other examples, material may be intentionally deposited and / or removed non-uniformly to compensate for known non-uniformities of other (e.g., previous or subsequent) steps in the process. In these other examples, a predetermined non-uniform deposition / removal profile may be calculated and used.

[0041] Various properties of deposited ALD films can be affected by the substrate temperature during deposition. Systems and methods according to the present disclosure are configured to adjust the temperature distribution across the substrate to reduce the thickness NU. For example, the temperature distribution can be adjusted to compensate for the known NU of a particular substrate processing tool (referred to as profile compensation), to produce a predetermined NU profile for a particular process (referred to as profile tuning), and so on.

[0042] For example, during an ALD process (e.g., deposition of an oxide film), a substrate is disposed on a substrate support such as an ALD pedestal. Typically, an ALD pedestal comprises a single segment. An ALD pedestal according to the present disclosure comprises a multi-segment (e.g., 2 to 10 or more segments) heater layer. The heater layer may be embedded within an upper layer of the pedestal. The heater layer may comprise a polyimide and silicone heater layer, which is at least partially encapsulated in an upper aluminum layer (e.g., an upper layer configured to support / contact a substrate disposed on a substrate support). In this example, the arrangement of the aluminum upper layer may serve as a Faraday cage. In other examples, the upper layer may be a ceramic layer (e.g., Al2O3, AlN, etc.). Each segment of the heater layer controls the temperature of a corresponding segment of the pedestal. The upper layer is disposed on a base (e.g., a substrate) of the pedestal, and heat may be transferred from the upper layer to the substrate (which may be cooled).

[0043] The arrangement (e.g., number, shape, geometry, etc.) of the segments can be configured to compensate for the known film thickness NU resulting from the ALD process. These segments can include, but are not limited to: two or more radial (i.e., annular) segments of varying widths; two or more segmented radial segments (i.e., radial segments comprising multiple interval / azimuthal segments); an outer radial segment adjacent to and / or overlapping the substrate edge; and an outer radial segment configured to adjust the temperature of the carry ring (e.g., to control / correct the radial profile for deposition and / or removal by trimming).

[0044] In one example, the segments include ten segments, including a central segment, an inner mid-radius segment, four outer mid-radius segments (i.e., an outer mid-radius segment containing four intervals), and four outer edge segments (i.e., an outer edge segment containing four intervals). In some examples, the radial segments may include more than four intervals (e.g., more than eight). Furthermore, the azimuthal segments of adjacent radial segments may not align. Alternatively, the azimuthal segments of one radial segment may have different rotational orientations (i.e., clockwise orientations) relative to adjacent radial segments.

[0045] Each of these sections includes a resistive heater. The resistive heater includes a resistive element made of a material having a high temperature coefficient of resistance (TCR). Therefore, throughout this disclosure, the resistive heater is also referred to as a high TCR heater or a high TCR heater element. In some examples, the heater element has a high TCR of greater than 0.001 per degree Celsius. By way of example only, molybdenum, tungsten (W), copper, or nickel heater elements may be used. In other examples, the heater element has a lower TCR of less than 0.001 per degree Celsius. By way of example only, a stainless steel (SST) alloy may be used.

[0046] The temperatures of the heater zones are controlled (i.e., the power supplied to the resistive heaters in the multiple zones is controlled) to achieve a target temperature profile (also known as a thermal map) for the substrate during processing. One method of controlling the temperature of multiple zones is open-loop control, which correlates the power supplied to each zone with the measured temperature of the wafer. However, this method has several disadvantages when used alone. For example, one disadvantage is that open-loop control lacks data about any load changes that may occur in the environment surrounding the wafer and that may cause changes in substrate temperature. Another disadvantage is that when moving from one temperature set point to another, the response time is slower than when closed-loop control is used. That is, when changing the power supplied to one or more zones to cause a desired temperature change, the time it takes for the actual temperature change to occur may be much slower than when closed-loop control is used.

[0047] In contrast, closed-loop control (e.g., PID control) uses a feedback loop to control the power supplied to each zone, which offers two benefits. First, compared to open-loop control, closed-loop control makes temperature control more robust to other stimuli (e.g., any load changes). Second, when moving from one temperature setpoint to another, the response time is faster than with open-loop control. In other words, when changing the power supplied to one or more zones to induce a desired temperature change, the actual temperature change takes place more quickly than with open-loop control.

[0048] If there is a correlation between the wafer temperature and the thermocouples (TC), using multiple zones in the susceptor with a thermocouple (TC) in each zone may be sufficient to control the temperature distribution on the wafer. Alternatively, the minimum number of TCs that provides a local temperature of a selected zone and an average temperature of the zone can be used to control the temperature distribution on the wafer, as described below.

[0049] The present disclosure relates to a temperature control scheme that combines local temperature measurements of the susceptor surface (e.g., using TC or resistance thermometers, also known as resistance temperature sensors (RTDs)) with average temperature of the segments or with open-loop control, as described below. Specifically, the proposed temperature control scheme combines local temperature measurements of fewer than all segments (e.g., using TC or RTD or similar methods) with open-loop current / voltage control of the segments that do not include TC. TC provides the local temperature of the segment, which represents the temperature at a point location in the segment. Furthermore, when combined with the local temperature measurements, the average temperature measurements of the heater elements in these segments are used to accurately set the susceptor surface temperature to a specified temperature profile.

[0050] The high TCR-based average zone temperature measurement method can be used with multiple (e.g., 10) zones and can provide the ability to perform closed-loop control of all zones. In the high TCR-based method, the resistance of the high TCR heater element in a zone can be measured. A lookup table or formula can be used to relate resistance to temperature to provide an average temperature in the zone. The high TCR-based method can provide an average temperature for the zone, which can be used as is or in combination with local temperature measurements. These and other aspects of the present disclosure are described in detail below.

[0051] Now refer to Figure 1A and 1B , shows an example of a substrate processing system 100 including a substrate support (e.g., an ALD pedestal) 104 according to the present disclosure. The substrate support 104 is disposed within a processing chamber 108. During processing, a substrate 112 is disposed on the substrate support 104. In some examples, the substrate support 104 can be configured to minimize contact with the substrate 112 (e.g., only the outer edge of the substrate 112 can contact the upper surface of the substrate support 104, the substrate 112 can be disposed on a minimum contact area (MCA) feature, etc.). In other examples, the substrate support 104 can be configured to provide backside gas clamping.

[0052] The gas delivery system 120 includes gas sources 122-1, 122-2, ..., and 122-N (collectively, gas sources 122), which are connected to valves 124-1, 124-2, ..., and 124-N (collectively, valves 124) and mass flow controllers 126-1, 126-2, ..., and 126-N (collectively, MFCs 126). The MFCs 126 control the flow of gas from the gas sources 122 to a manifold 128, where the gases are mixed. The output of the manifold 128 is supplied to a manifold 136 via an optional pressure regulator 132. The output of the manifold 136 is input to a multi-injector showerhead 140. Although manifolds 128 and 136 are shown, a single manifold may also be used.

[0053] The substrate support 104 comprises a plurality of sections. Figure 1BAs shown, the substrate support 104 includes a central section 144, an inner intermediate radius section 148, four outer intermediate radius sections (i.e., an outer intermediate radius section 152 including four intervals 152-1, 152-2, 152-3, and 152-4), and four outer edge sections (i.e., an outer edge section 156 including four intervals 156-1, 156-2, 156-3, and 156-4). The intervals of the outer edge sections 156 are offset from (i.e., rotated relative to) the intervals of the outer intermediate radius section 152 (e.g., 45°). In some examples, the substrate support 104 may include a second outer edge section 158 located radially outward from the outer edge section 156. For example, the inner diameter of the second outer edge section 158 may be greater than the diameter of the substrate 112. As described below, the temperature of the substrate support 104 may be controlled through the use of individually controllable resistive heaters 160 disposed in each of these sections.

[0054] In some examples, outer edge segment 156 may overlap and / or extend beyond (i.e., in a radial direction) the outer edge of substrate 112. For example, for a 300 mm substrate, the radius of outer edge segment 156 may be greater than 300 mm. Furthermore, the width of outer edge segment 156 (i.e., the distance from the inner radius to the outer radius) may be less than the widths of inner intermediate radius segment 148 and outer intermediate radius segment 152. For example, the width of outer edge segment 156 may be approximately 10 mm (e.g., + / - 2 mm), while the widths of inner intermediate radius segment 148 and outer intermediate radius segment 152 may each be approximately 40 mm (e.g., + / - 2 mm). The relatively narrow width of outer edge segment 156 may facilitate fine-tuning at the outer edge of substrate 112.

[0055] In some examples, the substrate support 104 may include a coolant channel 164. Cooling fluid is supplied to the coolant channel 164 from a fluid reservoir 168 and a pump 170. Pressure sensors 172 and 174 may be disposed in the manifold 128 or manifold 136, respectively, to measure pressure. A valve 178 and a pump 180 may be used to evacuate reactants from the process chamber 108 and / or control the pressure within the process chamber 108.

[0056] The controller 182 includes a dosage controller 184 that controls the dosage provided by the multi-injector showerhead 140. The controller 182 also controls the delivery of gases from the gas delivery system 120. The controller 182 utilizes the valve 178 and the pump 180 to control the pressure and / or reactant evacuation in the process chamber. The controller 182 controls the temperature of the substrate support 104 and the substrate 112 as described below.

[0057] Figure 2Shown are radial sections of the base. These radial sections are labeled R1, R2, ..., and R10. Thermocouples TC1, TC2, ..., and TC5 (depicted with solid circles) are arranged as shown. Although TC is used for illustration throughout the present invention, it should be understood that RTDs can replace TCs or be used in combination with TCs. Specifically, TC1 is located at the center of central section R1 (element 144). As shown, thermocouples TC2, TC3, TC4, and TC5 are arranged at the boundaries between these radial sections in a cross-shaped manner.

[0058] Specifically, as shown in the figure, two thermocouples TC3 and TC5 are arranged at opposite ends on the diameter on the boundary between radial section R2 (element 148) and radial sections R3, R4, R5 and R6 (element 152) in a cross form. As shown in the figure, two thermocouples TC3 and TC5 can be arranged along the first diameter of the base that passes through the center of radial sections R4 and R6. As shown in the figure, the first diameter also passes the junction of radial sections R7 and R8, and passes the junction of radial sections R9 and R10. As shown in the figure, two thermocouples TC3 and TC5 can be adjacent to or close to the center of radial sections R4 and R6 respectively.

[0059] As shown in the figure, other two thermocouples TC2 and TC4 are arranged at opposite ends on the diameter on the boundary between radial sections R3, R4, R5 and R6 (element 152) and radial sections R7, R8, R9 and R10 (element 156) in a cross form. As shown in the figure, other two thermocouples TC2 and TC4 can be arranged along the second diameter of the base that passes through the center of radial sections R3 and R5. As shown in the figure, the second diameter also passes the junction of radial sections R7 and R10, and passes the junction of radial sections R8 and R9. As shown in the figure, thermocouple TC2 can be located at the junction of radial sections R7 and R10, and thermocouple TC4 can be located at the junction of radial sections R8 and R9.

[0060] For example, the first and second diameters of the base can intersect at a ninety-degree angle or at another angle. For example, thermocouples TC2, TC3, TC4, and TC5 can be located at the vertices of a parallelogram, with the first and second diameters forming the diagonals of the parallelogram. As shown in the figure, thermocouple TC1 can be located at the intersection of the first and second diameters.

[0061] When arranged in this manner, thermocouples TC1, TC2, ..., and TC5 can capture the thermal interactions between the susceptor's segments and the local temperatures at two different diameters. By combining the average temperature of each segment obtained from the high-TCR heater element and the local temperature of a selected segment obtained from the TC in the selected segment, a thermal map of all segments can be constructed. Furthermore, by controlling the heater element using a combination of the local temperature of the selected segment and the average temperature of each segment, a target temperature distribution across the wafer can be achieved.

[0062] Local temperature measurements can be used to calibrate a high TCR heater (i.e., determine the temperature versus resistance relationship). For example, in an open-loop calibration method, the power input to segments R1 through R10 is increased by X% sequentially (i.e., R1, then R2, then R3, and so on), and the wafer temperature is measured. A sensitivity measure of the wafer temperature to the power value for each segment is defined (e.g., dT / dp, where T represents the wafer temperature and P represents the power expressed in voltage, current, or both). While collecting the wafer temperature data, the average temperature of each segment is also measured in parallel, and a sensitivity measure of the wafer temperature to the average temperature of each segment, dT / dT, is defined. heater-element Another sensitivity measure dT of the average segment temperature to the power value of each segment can also be defined heater-element Therefore, the controlled variable can be the power supplied to each zone or the average temperature of the zone. By controlling either or both, the temperature of the wafer can be controlled.

[0063] The use of average zone temperature as an additional (i.e., auxiliary) control variable (for improving the wafer temperature profile) or as the primary control variable can be time-dependent. In steady-state conditions, the wafer temperature can be controlled using open-loop control. When switching states (e.g., due to load changes), the average zone temperature can be used as the primary control variable. The average temperature of a zone can be obtained by analyzing resistance-temperature relationship data from high-TCR heater elements in that zone. For example, the average temperature can be an area-weighted average, where the area contains the high-TCR heater element.

[0064] In some cases, the additional step of calculating the average zone temperature can be avoided. For example, if it is desired to use the average zone temperature as an auxiliary variable (e.g., for transient response), the resistance ratio of the heater elements in the two zones can be used to increase or decrease the power supplied to the heater element in one of the two zones, rather than using the average temperature of the two zones as described below.

[0065] Several methods can be used to control the wafer temperature. For example, the least complex method involves controlling the power supplied to each segment based on the average temperature of each segment. The most complex method involves defining a least mean square (LMS) temperature target for the entire thermal map and controlling the power supplied to each segment using pulse width modulation (PWM).

[0066] In a medium-complexity hybrid approach, a minimum number of TCs is used in conjunction with the average zone temperature to control a particular zone. In a fourth approach, open-loop control can be used to control the zone temperature in steady state; and when switching states (e.g., when the load changes), the average zone temperature can be used as the primary control variable.

[0067] Here are some examples of hybrid approaches. In one example, Figure 2 In this example, TC1, TC2, and TC3 control the inputs to zones R1 and R2, respectively, and the baseline for all outer zones. The average zone temperature is used as the input to control the resistance ratio between the zones. Open-loop control is used to control the resistance ratio between the zones.

[0068] For example, consider outer segments R7, R8, R9, and R10. These segments have the same area. Assume that the resistance of the heater elements in these segments is equal. If these segments are desired to have the same target temperature, one of these segments (e.g., R8) is driven to the target temperature using the local temperature of segment R8. Segments R7, R9, and R10 are driven to the same resistance value corresponding to the target temperature. Assuming that these segments are initially at the same resistance value in the cold state or in the steady state after heating, if these segments are at the same resistance value in the hot state, then these segments will be at the same temperature (i.e., the target temperature).

[0069] Now assume that segment R10 will be hotter than segment R8. If the temperature ratio that will be achieved between segments R8 and R10 is known, segment R10 can be driven to have a higher resistance value than segment R8 so that the resistance ratio of segments R8 to R10 corresponds to the temperature ratio of segments R8 to R10. Therefore, when switching states (e.g., when the load changes), in addition to using a minimum number of TCs (local temperature measurements) to control specific segments, the average segment temperature can also be used to control the resistance ratio between these segments in the azimuthal direction. In another example of a hybrid approach, TC5 can control segment R6, while the average segment temperature can control segment R2.

[0070] Figure 3A Shows the control Figure 2 Controller 300 of heater zones R1 to R10 shown in FIG. Figure 1A182 to implement the controller 300. The heater driver 302 can be used to supply power to a selected TCR heater 304 under the control of the controller 300. For example, the TCR heater 304 can be used to implement the resistive heater 160 (shown in FIG. Figure 1A ). The current sensor 308 can be used to sense the current supplied by the heater driver 302 to the TCR heater 304. The voltage sensor 310 can be used to sense the voltage supplied by the heater driver 302 to the TCR heater 304. The controller 300 determines the resistance of each of the TCR heaters 304 based on the respective current and / or voltage measurements from the current sensor 308 and / or the voltage sensor 310.

[0071] Figure 3B Controller 300 is shown using resistance estimator 312 to monitor the duty cycle of a heater zone and estimate the resistance of the heater zone based on the corresponding duty cycle. In this example, the voltage or current is assumed to be constant, and the duty cycle of the current or voltage is varied. In other words, controller 300 estimates the resistance based on the known voltage or current and the duty cycle of the current or voltage. Therefore, in this example, current sensor 308 and voltage sensor 310 are omitted.

[0072] exist Figure 3A and 3B In FIG. 3 , the controller 300 controls the TCR heaters 304 in the heater zones R1 - R10. The controller 300 selects the heater zones (e.g., Figure 2 ). The heater driver 302 supplies power to the selected TCR heater 304. Figure 3A and 3B The operation of the controller 300 and other components is described below with reference to Figure 5 and 6 Describe in detail.

[0073] Figure 4 According to the present disclosure, a method 400 for setting up a plurality of zones (and corresponding heaters) and temperature sensors (e.g., TC and / or RTD) is shown. At 402, the method 400 includes setting up a high TCR heater element in a plurality of zones in an upper layer of a susceptor, wherein the upper layer of the susceptor is configured to support a substrate during processing. At 404, the method 400 includes setting up a plurality of zones as follows. The zones include a first zone (e.g., a first zone) in a central region of the upper layer of the susceptor. Figure 1B and 2 ), a second segment in the inner annular region surrounding the central region (e.g., Figure 1B and 2), a first set of segments in the outer annular region surrounding the inner annular region (e.g., Figure 1B and 2 ), and a second set of segments (e.g., segments R7, R8, R9, and R10 or segment 156) in the outer edge region surrounding the outer annular region. The second set of segments may be offset by an angle (e.g., 45°) relative to the first set of segments (e.g., as shown in FIG. Figure 1B shown).

[0074] At 406, method 400 includes configuring a plurality of temperature sensors (eg, TCs and / or RTDs) that are less than the number of zones as follows: One TC is configured in a first zone (eg, Figure 2 TC1 in segment R1144 shown in FIG). The first pair of TCs ( Figure 2 TC3 and TC5) are arranged along the first boundary between the inner annular region (segment R2148) and the outer annular region (segment 152) and along the first diameter. The second pair of TC ( Figure 2 TC2 and TC4 (shown in FIG) are disposed along a second boundary between the outer annular region (segment 152) and the outer edge region (segment 156) and along a second diameter.

[0075] At 408 , method 400 includes placing first and second pairs of temperature sensors along a parallelogram whose diagonals are vertices of the first and second diameters. TC1 is placed at the intersection of the first and second diameters (ie, the intersection of the diagonals).

[0076] Figure 5 According to the present disclosure, a method for controlling a segment (e.g. Figure 1B and 2 The first method 500 of R1-R10 shown in FIG. Figure 3A and 3B The controller 300 and other components shown in FIG. 5 are executed. At 502, the method 500 utilizes Figure 2 Shown and referenced Figure 4 The temperature sensors are configured to measure the local temperature of selected (less than all) zones. At 504, method 500 measures the average temperature of each zone.

[0077] At 506, the method 500 determines whether the zones are in steady state. At 508, when the zones are in steady state, the method 500 utilizes open loop control to control the zones (ie, by correlating power supplied to each zone with measured wafer temperature).

[0078] At 510, method 500 determines whether one or more zones need to change state (e.g., due to a load change). If one or more zones do not need to change state (i.e., if the zones are in a steady state), method 500 returns to 508. At 512, if one or more zones need to change state, method 500 utilizes a combination of the measured local temperature of at least one (but not all) of the zones and the average temperature of all the zones to control the power supplied to the one or more zones.

[0079] Figure 6 According to the present disclosure, a method for controlling a segment (e.g. Figure 1B and 2 The second method 600 of R1-R10 shown in FIG. Figure 3A and 3B The controller 300 and other components shown in FIG. 6 are executed. At 602, the method 600 utilizes Figure 2 Shown and referenced Figure 4 The temperature sensors are positioned to measure the local temperature of selected (less than all) zones.

[0080] At 604, method 600 determines whether the zones are in steady state. At 606, when the zones are in steady state, method 600 utilizes open loop control to control the zones (ie, by correlating power supplied to each zone with measured wafer temperature).

[0081] At 608, method 600 determines whether one or more zones need to change state (e.g., due to a load change). If one or more zones do not need to change state (i.e., if the zones are in a steady state), method 600 returns to 606. At 610, if one or more zones need to change state, method 600 determines the resistance ratio between the two zones, one of which needs to change state, based on the expected temperature change of the zone that needs to change state.

[0082] At 612, method 600 utilizes a combination of the measured local temperature of at least one (but not all) of the segments and the resistance ratio between the two segments to control the power supplied to the segment that needs to change state. Thus, based on the combination of the measured local temperature of at least one (but not all) of the segments and the resistance ratio between the two segments, the power supplied to the segment that needs to change state is increased or decreased.

[0083] The foregoing description is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, as other modifications will become apparent upon studying the drawings, the description, and the appended claims.

[0084] It should be understood that one or more steps in the method can be performed in a different order (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure can be implemented in the features of any other embodiment and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the embodiments described are not mutually exclusive, and the permutation of one or more embodiments with each other remains within the scope of the present disclosure.

[0085] Various terms are used to describe spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless the relationship between a first and a second element is explicitly described as "direct," when such a relationship is described in the above disclosure, the relationship can be a direct relationship, in which there are no other intervening elements between the first and second elements, but can also be an indirect relationship, in which there are one or more intervening elements (spatially or functionally) between the first and second elements.

[0086] As used herein, the phrase “at least one of A, B, and C” should be construed to mean a logical (A or B or C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0087] In some implementations, the controller is part of a system, which can be part of the examples above. Such a system can include semiconductor processing equipment, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronics for controlling their operation before, during, and after processing of semiconductor wafers or substrates. Electronic devices can be referred to as "controllers" that can control various components or subcomponents of one or more systems.

[0088] Depending on the processing requirements and / or system type, the controller can be programmed to control any of the processes disclosed herein, including the delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer into and out of tools and other transfer tools and / or load locks connected to or interfaced with a particular system.

[0089] In general terms, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. The integrated circuits can include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software).

[0090] Program instructions may be instructions sent to a controller in the form of various individual settings (or program files) that define operating parameters for performing a particular process on or for a semiconductor wafer or system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0091] In some implementations, the controller can be part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller can be in the "cloud" or all or part of a wafer fab host system that can allow remote access to wafer processing. The computer can enable remote access to the system to monitor the current progress of manufacturing operations, review the history of past manufacturing operations, review trends or performance metrics for multiple manufacturing operations, change parameters of a current process, set processing steps to follow a current process, or start a new process.

[0092] In some examples, a remote computer (e.g., a server) can provide process recipes to the system over a network (which can include a local network or the Internet). The remote computer can include a user interface that enables input or programming of parameters and / or settings, which are then sent from the remote computer to the system.

[0093] In some examples, the controller receives instructions in the form of data that specify parameters for each process step to be performed during one or more operations. It should be understood that the parameters can be specific to the type of process to be performed and the type of tool with which the controller is configured to interface or control the tool.

[0094] Thus, as described above, the controller can be distributed, for example, by including one or more discrete controllers networked together and working toward a common purpose (e.g., processing and control as described herein). An example of a distributed controller for such a purpose is one or more integrated circuits on a chamber communicating with one or more integrated circuits remotely (e.g., at a platform level or as part of a remote computer), which combine to control processing on the chamber.

[0095] Example systems may include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used in the manufacture and / or preparation of semiconductor wafers.

[0096] As described above, depending on one or more processing steps to be performed by the tool, the controller can communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a host computer, another controller, or tools used in the material transport of wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

Claims

1. A substrate support assembly for supporting a semiconductor substrate, the substrate support assembly comprising: a baseplate comprising a layer adjacent to the semiconductor substrate; a plurality of resistive heaters disposed in respective sections in the layer, wherein the sections comprise: a first circular section located at a central region of the layer; a second annular segment surrounding the first circular segment; a first group of segments located in a first annular region surrounding the second annular segment; as well as a second group of segments located in a second annular region surrounding the first annular region; as well as a plurality of temperature sensors disposed in the layer, wherein the plurality of temperature sensors comprises: a first pair of temperature sensors located along a first diameter of the layer at a first boundary between the second annular segment and the first set of segments; a second pair of temperature sensors located along a second diameter of the layer at a second boundary between the first and second groups of segments; as well as A first temperature sensor is located in the first circular segment. 2 . The substrate support assembly of claim 1 , wherein the first temperature sensor is located in the first circular segment at the intersection of the first and second diameters.

3. The substrate support assembly of claim 1 , wherein: The positions of the first and second pairs of temperature sensors correspond to vertices of a parallelogram; and The first and second diameters form diagonals of the parallelogram.

4. The substrate support assembly of claim 1, wherein the first set of segments are rotated at an angle relative to the second set of segments.

5. The substrate support assembly of claim 1, wherein the first set of segments are rotated relative to the second set of segments by an angle of forty-five degrees. The substrate support assembly of claim 1 , wherein the first and second annular regions have different widths.

7. The substrate support assembly of claim 1, wherein the second annular section has a different width than each of the first and second annular regions.

8. The substrate support assembly of claim 1, wherein each of the first and second sets of segments comprises four segments.

9. A system for processing a semiconductor substrate comprising the substrate support assembly of claim 1 , the system further comprising: A controller is configured to control one or more of the resistive heaters based on a temperature sensed by one of the temperature sensors and an average temperature of one or more of the sections.

10. The system of claim 9, wherein the controller is configured to control one of the resistive heaters independently of the other of the resistive heaters.

11. The system of claim 9, wherein the controller is configured to control one or more of the resistive heaters based on a target temperature profile of the semiconductor substrate.

12. A system for processing a semiconductor substrate comprising the substrate support assembly of claim 1, the system further comprising: a controller configured to control one or more of the resistive heaters using a temperature sensed by one of the temperature sensors in conjunction with open loop control of the zones, Wherein the open-loop control of the segments includes correlating power supplied to each of the segments with a measured temperature of the semiconductor substrate.

13. A system for processing a semiconductor substrate comprising the substrate support assembly of claim 1, the system further comprising: A controller is configured to control the first resistive heater relative to the second resistive heater based on a temperature sensed by one of the temperature sensors and a resistance ratio of a first resistive heater to a second resistive heater of the resistive heaters.

Images