Method, apparatus, and non-transitory computer-readable medium for dynamic, localized temperature control for epitaxial deposition reactors

Abstract

A method and apparatus for improving film growth uniformity on a semiconductor substrate. The film growth uniformity is improved by adjusting the amount of power delivered to the substrate by a spot heater as the substrate is rotated. Thus, the amount of power delivered to the substrate by the spot heater changes as the portion of the substrate being heated by the spot heater changes. The change in power delivered by the spot heater depends on a temperature correction factor applied by a controller.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to apparatus and methods for semiconductor processing, and more particularly to the use of thermal process chambers and spot heaters. [Background technology]

[0002] Semiconductor substrates are processed for a wide range of applications, including the fabrication of integrated devices and microdevices. During processing, the substrate is placed on a substrate support within a process chamber. The substrate support is supported by a support shaft that is rotatable about a central axis. Precise control of a heat source, such as multiple heat lamps disposed below or above the substrate, allows the substrate to be heated within very tight tolerances. Precise control of the substrate temperature aids in the deposition of a uniform layer on the substrate.

[0003] Even with control of heat lamps in a process chamber, it is often difficult to achieve uniform film deposition on a substrate. Non-uniformity includes areas of greater or lesser deposition on the substrate. Non-uniformity can be caused by one or more factors, such as uneven heat distribution within the substrate support and substrate, and uneven precursor flow rates. Therefore, improvements in heating devices and methods for semiconductor processing are needed. Summary of the Invention

[0004] The present disclosure generally relates to a method for adjusting a temperature profile of a substrate during processing suitable for use during semiconductor manufacturing. The method includes determining a first angular position of the substrate. A plurality of temperature correction factors are provided to a spot heater controller. A first radiation beam having a first power is irradiated onto the first angular section of the substrate using the spot heater. The first power is determined using a first temperature correction factor of the plurality of temperature correction factors. After irradiating the first angular section of the substrate, the substrate is rotated about a central axis. After rotating the substrate, a second radiation beam having a second power is irradiated onto a second angular section of the substrate using the spot heater. The second power is determined using a second temperature correction factor of the plurality of temperature correction factors. The second power is different from the first power.

[0005] In another embodiment, an apparatus for processing a substrate suitable for use during semiconductor manufacturing is described. The apparatus includes a chamber body, a substrate support disposed within the chamber body, a chamber lid, a chamber floor, an upper window disposed between the chamber lid and the substrate support, a lower window disposed between the substrate support and the chamber floor, a plurality of upper lamps disposed between the upper window and the chamber lid, a plurality of lower lamps disposed between the lower window and the chamber floor, one or more spot heaters disposed on the chamber lid and configured to direct a radiation beam toward the substrate support, and a controller. The controller is configured to control the one or more spot heaters and is programmed to determine an angular position of the substrate and to adjust a power output of the one or more spot heaters using a set of temperature correction coefficients such that a power output of the one or more spot heaters varies as the spot heaters heat multiple angular portions of the substrate.

[0006] In yet another embodiment, a non-transitory computer-readable medium is described that stores instructions that, when executed by a processor, cause a computer system to determine an angular position of a substrate, receive a temperature correction curve, and adjust a power output of one or more spot heaters, wherein adjusting the power output includes using the temperature correction curve to vary the power output of the one or more spot heaters as the spot heaters heat multiple angular portions of the substrate along a first radial position of the substrate.

[0007] So that the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the present disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the accompanying drawings, It should be noted, however, that the accompanying drawings illustrate only exemplary embodiments and therefore should not be considered as limiting the scope of the embodiments, which may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0008] [Figure 1A] FIG. 1 is a schematic diagram of a deposition chamber according to one embodiment of the present disclosure. [Figure 1B] FIG. 2 is a schematic diagram of a deposition chamber according to another embodiment of the present disclosure. [Figure 2] FIG. 1C is a schematic diagram of a spot heater disposed on the deposition chamber of either FIG. 1A or FIG. 1B according to one embodiment of the present disclosure. [Figure 3] FIG. 2 is a schematic plan view of a spot heating irradiation path according to one embodiment of the present disclosure. [Figure 4] 1 is a flowchart of a method for determining an adjusted spot heater intensity to improve film uniformity on a substrate. [Figure 5] 10 is a flowchart of a method for processing a substrate while adjusting the intensity of spot heater irradiation. [Figure 6] 1 is a graph showing film growth thickness measured on a substrate during a calibration operation. [Figure 7] 7 is a graph showing correction factors for reducing the film growth non-uniformity of FIG. 6. [Figure 8A] 10 is a graph showing the corrected signal output of a spot heater angularly offset by 90 degrees from the angular position sensor. [Figure 8B] 10 is a graph showing the corrected signal output of a spot heater angularly offset by 180 degrees from the angular position sensor. DETAILED DESCRIPTION OF THE INVENTION

[0009] For ease of understanding, like reference numerals have been used where possible to designate like elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0010] The present disclosure generally relates to apparatus and methods for semiconductor processing, and more particularly to the use of thermal process chambers and spot heaters. More particularly, the present disclosure is directed to spot heaters utilized in epitaxial deposition chambers to improve film growth uniformity on a substrate, and methods of utilizing spot heaters. In some cases, non-uniformities in precursor flow rates and substrate support structure result in non-uniform film growth on a substrate within a process chamber. Non-uniformities in a radial direction from the center of the substrate can be corrected by utilizing a spot heater to provide a focused radiation beam irradiation in an annular ring on the substrate. In some embodiments, the spot heater includes an actuating base to irradiate the substrate with radiation in a pattern other than an annular ring. However, it has been found that non-uniform film growth can also occur at different angular positions of the same radial position on the substrate.

[0011] The embodiments described herein enable the amount of radiation delivered to a substrate by one or more spot heaters to be continuously adjusted as the angular position of the substrate relative to the radiation beam changes. Thus, spot heaters may be used to correct uneven film growth at different angular positions on the substrate by delivering a higher amount of radiation to cooler spots on the substrate and a lower amount of radiation to hotter spots on the substrate. In some embodiments, local thickness variations on the substrate are corrected by deposition followed by etching of excess material. Spot heating of localized locations on the substrate during an etch operation can increase material removal rates and help improve overall profile uniformity.

[0012] In some embodiments, localized, variable spot heating is used to improve the uniformity of the selective growth operation. Selective growth is utilized to grow a single material only on the desired irradiated semiconductor area, and not on adjacent areas, such as dielectric areas. After the selective growth operation, film growth on undesired areas, such as dielectric areas, is removed in an etch back operation.

[0013] Selective heating of different angular positions on the substrate can therefore eliminate thermal non-uniformities or non-uniformities in precursor flow caused by the substrate support. The methods described herein can also reduce the amount of substrate support components that are rejected due to manufacturing variations. The substrate throughput of different process chambers, such as the deposition chambers described herein, can also be more closely matched while in situ. Thus, differences in thickness and material composition between substrates processed in different process chambers are reduced while using several process chambers in the same mass production process.

[0014] Adjusting the amount of radiation delivered to different portions is performed using a plurality of temperature correction coefficients. The temperature correction coefficients are determined by measuring layer deposition thicknesses deposited on test substrates during maintenance operations of the process chamber. The layer deposition thickness measurements are then used to determine the temperature correction coefficients. The temperature correction coefficients are applied during subsequent substrate processing operations in the process chamber and determine the amount of power delivered to the spot heater and the subsequent spot heater signal (radiation delivery) to the substrate, such that the spot heater signal varies continuously as the relative angular position of the substrate from the radiation beam and the spot heater changes.

[0015] 1A is a schematic diagram of one type of process chamber 100 according to one embodiment of the present disclosure. The process chamber 100 is a deposition chamber, such as an epitaxial deposition chamber. The process chamber 100 is utilized to grow an epitaxial film on a substrate, such as a substrate 102. The process chamber 100 creates a cross-flow of precursors across a top surface 150 of the substrate 102.

[0016] The process chamber 100 includes an upper body 156, a lower body 148 disposed below the upper body 156, and a flow module 112 disposed between the upper body 156 and the lower body 148. The upper body 156, the flow module 112, and the lower body 148 form a chamber body. Disposed within the chamber body are a substrate support 106, an upper dome 108, a lower dome 110, a plurality of upper lamps 141, and a plurality of lower lamps 143. As shown, a controller 120 is in communication with the process chamber 100 and is used to control processes, such as those described herein. The substrate support 106 is disposed between the upper dome 108 and the lower dome 110. The plurality of upper lamps 141 are disposed between the upper dome 108 and the lid 154. The lid 154 includes a plurality of sensors 153 disposed therein for measuring the temperature within the process chamber 100. A plurality of lower lamps 143 are disposed between the lower dome 110 and the floor 152. The plurality of lower lamps 143 form a lower lamp assembly 145.

[0017] A processing volume 136 is defined between the upper dome 108 and the lower dome 110. The processing volume 136 has a substrate support 106 disposed therein. The substrate support 106 includes an upper surface on which the substrate 102 is disposed. The substrate support 106 is attached to a shaft 118. The shaft 118 is coupled to a translation assembly 121. The translation assembly 121 includes one or more actuators and / or adjustment devices for moving and / or adjusting the shaft 118 and / or the substrate support 106 within the processing volume 136. The translation assembly 121 includes a rotary actuator 122 that rotates the shaft 118 and / or the substrate support 106 about a longitudinal axis A of the process chamber 100. The translation assembly 121 further includes a vertical actuator 124 for raising and lowering the substrate support 106 in the z-direction. The translation assembly includes a tilt adjustment device 126 used to adjust the planar orientation of the substrate support 106 and a lateral adjustment device 128 used to laterally adjust the position of the shaft 118 and substrate support 106 within the processing volume 136.

[0018] The substrate support 106 may include lift pin holes 107 disposed therein. The lift pin holes 107 are sized to accommodate lift pins 132 for lifting the substrate 102 from the substrate support 106 either before or after a deposition process is performed. The lift pins 132 may rest on lift pin stops 134 when the substrate support 106 is lowered from a processing position to a transfer position.

[0019] The flow module 112 includes multiple process gas inlets 114, multiple purge gas inlets 164, and one or more exhaust gas outlets 116. The multiple process gas inlets 114 and the multiple purge gas inlets 164 are disposed on a side of the flow module 112 opposite the one or more exhaust gas outlets 116. One or more flow guides 146 are disposed below the multiple process gas inlets 114 and the one or more exhaust gas outlets 116. The flow guides 146 are disposed above the purge gas inlets 164. A liner 163 is disposed on an inner surface of the flow module 112 to protect the flow module 112 from reactant gases used during the deposition process. The process gas inlets 114 and the purge gas inlets 164 are positioned to flow gases parallel to an upper surface 150 of a substrate 102 disposed within the processing volume 136. The process gas inlets 114 are fluidly connected to a process gas source 151. The purge gas inlet 164 is fluidly connected to the purge gas source 162. The one or more exhaust gas outlets 116 are fluidly connected to the exhaust pump 157. Each of the process gas source 151 and the purge gas source 162 can be configured to supply one or more precursor gases or process gases into the processing volume 136.

[0020] One or more spot heaters 170 are disposed on the lid 154. In some embodiments, there are multiple spot heaters 170, such as two spot heaters 170, three spot heaters 170, or four spot heaters 170 disposed on the lid 154. Each spot heater 170 includes a concentrated radiation supply unit 172 and a holder 174. The concentrated radiation supply unit 172 is mechanically coupled to the holder 174, such that the radiation supply unit 172 is attached to the lid 154 using the holder 174. The holder 174 is configured to adjust the orientation of the concentrated radiation supply unit 172. In some embodiments, the holder 174 is configured to change the orientation of the radiation supply unit 172 between process runs or periodically during a single process run.

[0021] The concentrated radiation supply unit 172 includes one of a laser or a concentrated lamp. In some embodiments, the laser is the end of an optical fiber, and the laser source is disposed separately from the one or more spot heaters 170, such as in a spot heater control box 176. The concentrated radiation supply unit 172 may include one or more optical elements, such as mirrors, lenses, or metasurface devices. The optical elements may help to increase or decrease the concentration of radiation in the radiation beam emitted from the one or more spot heaters 170 toward the substrate 102.

[0022] The one or more spot heaters 170 are configured to emit a radiation beam having a diameter of less than about 25 mm, such as less than about 20 mm, less than about 10 mm, less than about 5 mm, less than about 3 mm, or less than about 2 mm. Each spot on the substrate 102 that is irradiated at one time is irradiated with a power range of about 0.5 W to about 100 W, such as about 1 W to about 100 W, or about 2 W to about 100 W. Adjusting the size of the irradiated spot on the substrate 102 also adjusts the power density of the irradiation. Thus, the power density of each of the radiation beams as they intersect the top surface 150 of the substrate 102 is about 3 W / cm. 2 greater than approximately 5W / cm 2greater than approximately 5W / cm 2 ~Approx. 1500W / cm 2 , about 5W / cm 2 ~about 500W / cm 2 , about 5W / cm 2 ~About 300W / cm 2 etc., about 2W / cm 2 The power density is configured to be greater than 1000 W. The power density is high enough to affect the growth rate and composition of the growing film, but low enough to prevent damage to the wafer and susceptor.

[0023] Each of the one or more spot heaters 170 is directed toward a different portion of the substrate 102, such that the first spot heater 170 is directed toward a first radial position of the substrate 102 and the second spot heater 170 is directed toward a second radial position of the substrate 102.

[0024] The spot heater control box 176 is configured to provide power to each of the spot heaters 170, such that the spot heater control box 176 provides power and / or radiation to the spot heaters 170 through one or more wires or optical fibers. The spot heater control box 176 may include a variable voltage source or a variable amperage source to control the intensity of the radiation beam of each of the one or more spot heaters 170. The spot heater control box 176 further includes one or more laser sources. The laser source is configured to emit a laser having a wavelength of about 700 nm to about 2000 nm, such as about 750 nm to about 1800 nm, or about 760 nm to about 1700 nm.

[0025] An angular position sensor 178 is disposed within the process chamber 100 and configured to determine the angular position of one or both of the substrate 102 and the substrate support 106. In the embodiment of FIGS. 1A and 1B , the angular position sensor 178 is disposed adjacent to the shaft 118 and configured to measure the angular position of the shaft 118 relative to the longitudinal axis A. The angular position sensor 178 may be configured to measure when one or more signalers on the shaft 118 pass by a sensing path of the angular position sensor 178. In some embodiments, the one or more signalers include a notch, a bar code, a reflector, or a bump on the side of the shaft 118. The angular position sensor 178 may be an optical position sensor or a resistive position sensor.

[0026] In some embodiments, the angular position sensor 178 is located within the flow module 112 or above the substrate support 106, such as disposed through the lid 154 as one of the sensors 153. The angular position sensor 178 may then be configured to measure a notch location within the edge of the substrate 102 or a notch in the substrate support 106. The angular position sensor 178 is coupled to the controller 120 or one of the microcontrollers, such as the microcontroller 180 of FIG. 1B.

[0027] The controller 120 includes a central processing unit (CPU) 159, a memory device 135, and support circuits 158. The controller 120 may control the process chamber 100 directly or through other computers or controllers, such as a spot heater control box 176 or a microcontroller 180 (FIG. 1B), associated with specific support system components. The controller 120 may be one of any form of general-purpose computer processor that can be used in an industrial environment to control various chambers and subprocessors. The support circuits 158 include cache, power supplies, clock circuits, input / output circuits and subsystems, etc. Processing steps may be stored in the memory device 135 as software routines that can be executed or called to transform the controller 120 into a special-purpose controller for controlling the operation of the process chamber 100. The controller 120 may be configured to perform any of the methods described herein.

[0028] To facilitate control of the spot heaters 170 and associated radiation delivery to the substrate 102, the CPU 159 may be one of any form of general-purpose computer processor that can be used in an industrial environment, such as a programmable logic controller (PLC) for controlling various chambers and sub-processors. A memory device 135 is coupled to the CPU 159, and the memory device 135 is non-transitory and may be one or more of readily available memory, such as random access memory (RAM), read-only memory (ROM), a floppy disk drive, a hard disk, or any other form of digital storage, local or remote. Support circuits 158 are coupled to the CPU 159 for supporting the processor in a conventional manner. Process gas flow and heating instructions are generally stored in the memory device 135, typically as software routines. The software routines may also be stored and / or executed by a second CPU located remotely from the hardware being controlled by the CPU.

[0029] The memory device 135 is a form of a computer-readable storage medium containing instructions that, when executed by the CPU 159, facilitate operation of the spot heater 170. The instructions in the memory device 135 are in the form of a program product, such as a program that implements the methods of the present disclosure. The program code may conform to any one of several different programming languages. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The programs in the program product define the functions of the embodiments (including the methods described herein).

[0030] In some embodiments, the program performs machine learning functions. Various data features include process parameters such as processing time, temperature, pressure, voltage, polarity, power, gas species, and precursor flow rates. Relationships between features are identified and defined to capture data and enable analysis by machine learning algorithms to adapt the process being performed by the process chamber 100 and spot heaters 170. The machine learning algorithms may employ supervised or unsupervised learning techniques. Examples of machine learning algorithms implemented by the program include, but are not limited to, linear regression, logistic regression, decision trees, state vector machines, neural networks, naive Bayes, k-nearest neighbors, k-means, random forests, dimensionality reduction algorithms, and gradient boosting algorithms, among others.

[0031] Exemplary computer-readable storage media include, but are not limited to, (i) non-writable storage media on which information is permanently stored (e.g., a read-only memory device in a computer, such as a CD-ROM disk readable by a CD-ROM drive, a flash memory, a ROM chip, or any type of solid-state non-volatile semiconductor memory), and (ii) writable storage media on which changeable information is stored (e.g., a floppy disk in a diskette drive or hard disk drive, or any type of solid-state random access semiconductor memory type). Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are embodiments of the present disclosure. In some embodiments, controller 120 is an etherCAT controller.

[0032] 1B is a schematic diagram of another embodiment of process chamber 100. In the embodiment of FIG. 1B, a microcontroller 180 is utilized to control spot heater 170, and thus the microcontroller is coupled to both a spot heater control box 176 and an angular position sensor 178. Microcontroller 180 is further coupled to controller 120, and thus microcontroller 180 separates control of spot heater 170 from controller 120, but still receives input or power from primary controller 120. Microcontroller 180 is similar to controller 120 and may include a CPU, memory, and support circuitry.

[0033] A dedicated microcontroller, such as microcontroller 180, provides faster response times and avoids signal latency on a large controller network, such as controller 120. Controller 120 receives signals from numerous sensors within process chamber 100 while sending control signals to many different components and devices on the network. It is estimated that cycle times using a simple microcontroller reduce possible cycle times to less than 1 microsecond. Cycle times using microcontroller 180 are therefore up to at least 1000 times faster.

[0034] Faster cycle times allow for more precise control of spot heating on the substrate 102. Shorter times between successive signals to the laser allow for faster modulation of power, so that very small angular position changes of the substrate 102 can receive different irradiance power levels. Faster control times using a microcontroller allow for precise irradiance level control, even at high wafer / susceptor rotation speeds.

[0035] 2 is a schematic diagram of a spot heater 170 disposed on the process chamber 100 of either FIG. 1A or FIG. 1B. The spot heater 170 is further shown with a radiation beam 202 directed from the spot heater 170 toward the top surface 150 of the substrate 102. As described herein, the diameter of the radiation beam 202 is less than about 10 mm, such as less than about 5 mm, less than about 3 mm, or less than about 2 mm, at the point of contact with the substrate 102 and / or substrate support 106.

[0036] 3 is a schematic plan view of spot heater irradiation paths 302, 304, 306, and 308 on the upper surface 150 of the substrate 102. The spot heater irradiation paths 302, 304, 306, and 308 are formed using one or more spot heaters 170, such as one of the first spot heater 170a, the second spot heater 170b, or the third spot heater 170c. Each of the spot heater irradiation paths 302, 304, 306, and 308 is disposed at a different radial position on the substrate 102 from the axis A. The spot heater irradiation paths 302, 304, 306, and 308 include the first spot heater irradiation path 302, the second spot heater irradiation path 304, the third spot heater irradiation path 306, and the fourth spot heater irradiation path 308. Each of the spot heater irradiation paths 302, 304, 306, 308 includes a centerline that is the center of the annular portion of the spot heater irradiation path 302, 304, 306, 308.

[0037] Each of the spot heater irradiation paths 302, 304, 306, and 308 is disposed at a different radial position such that the first spot heater irradiation path 302 is disposed at a first radial distance R1 from the axis A of the substrate 102, the second spot heater irradiation path 304 is disposed at a second radial distance R2 from the axis A of the substrate 102, the third spot heater irradiation path 306 is disposed at a third radial distance R3 from the axis A of the substrate 102, and the fourth spot heater irradiation path 308 is disposed at a fourth radial distance R4 from the axis A of the substrate 102. The fourth radial distance R4 is greater than the third radial distance R3. The third radial distance R3 is greater than the second radial distance R2. The second radial distance R2 is greater than the first radial distance R1.

[0038] The angular position sensor 178 is shown at a first angular position about the axis A of the substrate 102. In some embodiments, the angular position sensor 178 is disposed at a zero angular position about the axis A. For clarity, the angular position sensor 178 is disposed radially outward of the substrate 102, however, it should be understood that the angular position sensor 178 may be disposed below the substrate 102 or above the substrate 102, as well as radially inward of the outer periphery of the substrate 102.

[0039] The first spot heater 170a is disposed at a first angle θ1 about axis A relative to the angular position sensor 178. The second spot heater 170b is disposed at a second angle θ2 about axis A relative to the angular position sensor 178. The third spot heater 170c is disposed at a third angle θ3 about axis A relative to the angular position sensor 178. The first angle θ1, second angle θ2, and third angle θ3 are exemplary and may be different from the angles shown. The first angle θ1 is approximately 90 degrees (°). The second angle θ2 is approximately 180°. The third angle θ3 is approximately 210°.

[0040] Each of the spot heater irradiation paths 302, 304, 306, and 308 is divided into a plurality of sectors 310a, 310b, and 310c. The plurality of sectors 310a, 310b, and 310c are portions of the spot heater irradiation paths 302, 304, 306, and 308 at different angular positions. Thus, the first angular position of the second spot heater irradiation path 304 is the first sector 310a. The second angular position of the second spot heater irradiation path 304 is the second sector 310b. The third angular position of the second spot heater irradiation path 304 is the third sector 310c. A plurality of additional sectors are disposed at other angular positions on the second spot heater irradiation path 304. Each of the first spot heater irradiation path 302, the third spot heater irradiation path 306, and the fourth spot heater irradiation path 308 is divided into similar sectors at different angular positions.

[0041] In embodiments in which the holder 174 of the spot heater 170 includes a motorized base, the radial position of the spot heating irradiation path can be continuously varied for each 360-degree rotation of the substrate 102. The range of radial position variation is limited to about 5 mm to about 10 mm, depending on the wafer rotation speed and the motor speed of the motorized base. The motorized base therefore enables a non-spherical spot heating irradiation path on the substrate 102. In some embodiments, the spot heating irradiation path is therefore oval or parabolic in shape. The non-spherical spot heating irradiation path allows for increased versatility in spot heating applications.

[0042] In some embodiments, one of the spot heating irradiation paths, such as the first spot heating irradiation path 302, can be at an outer radial position of the substrate 102, but also near the edge of the substrate 102. Due to thermal diffusion, spot heating the region outside the circumference of the substrate 102 further heats the edge of the substrate 102. Spot heating the region outside the circumference of the substrate 102 can therefore be utilized to target film thickness and composition variations primarily at the edge of the substrate 102, while sparing the interior of the substrate 102. In some embodiments, the spot heating irradiation path is within 10 mm of the outer periphery of the substrate, such as less than 10 mm from the outer periphery of the substrate, or less than 5 mm from the outer periphery of the substrate.

[0043] 4 is a flowchart of a method 400 for determining adjusted spot heater intensities to improve film uniformity on a substrate, such as substrate 102. Method 400 is stored in one of controller 120 in the embodiment of FIG. 1A or microcontroller 180 in the embodiment of FIG. 1B. Controller 120 and / or microcontroller 180 are configured to execute method 400 stored therein. Method 400 includes controlling spot heaters 170 and spot heater control box 176.

[0044] Method 400 first determines the amount of compensation desired at multiple points on the substrate before applying the compensation to the spot heater 170. A process, such as depositing a layer, is performed on the test substrate during operation 402. The process is one of a layer deposition process, an etch process, or a thermal treatment process. The substrate is the test substrate but is similar in size, shape, and composition to other substrates to be processed in the process chamber. Depositing or etching a layer on the test substrate is temperature dependent, and temperature non-uniformities within the substrate result in non-uniform film thickness on the test substrate. Temperature non-uniformities further result in differences in material and elemental composition of the layer across the profile of the substrate.

[0045] The thickness or material composition profile of the test substrate is measured during another operation 404 after depositing or etching a layer on the substrate. Because temperature mismatches result in non-uniform film thickness and non-uniform material composition, the thickness profile and / or material composition profile are used to determine an estimated temperature profile on the substrate. Thus, where there is less layer deposition, the temperature at that location is lower than the temperature at locations where there is more layer deposition. The material composition can also be used to determine processing temperatures at various locations on the substrate, such that higher or lower material concentrations indicate higher or lower processing temperatures at a particular location.

[0046] The thickness or material composition profile can be measured by moving the test substrate into a separate process chamber. The separate process chamber is configured to measure one or both of the thickness profile and the material composition profile of the test substrate. The thickness profile is measured using one of a non-contact thickness measurement device or a contact thickness measurement device. Non-contact thickness measurement devices include a camera, an ellipsometer, or an X-ray diffraction device. Contact thickness measurement devices include a line scanning tool. An ellipsometer measures changes in the optical properties of one or more light beams reflected from the surface of the test substrate to measure the material thickness. The thickness measurement device obtains the thickness profile of the test substrate. In some embodiments, the thickness measurement device is disposed inside a transfer chamber, a load-lock chamber, or a factory interface (not shown) mechanically coupled to a processing chamber. In some embodiments, the thickness measurement device is located in an in-line tool not coupled to a processing chamber.

[0047] The material composition of films across the surface of the test substrate is measured using non-contact methods, including ellipsometry and X-ray diffraction. For layers containing dopants such as boron and phosphorus, which have a significant effect on electrical properties, either resistivity measurements or carrier concentration measurements (e.g., Hall effect measurements) are used to determine the film's composition. Such composition data (composition vs. position) is then utilized to generate a concentration plot or graph similar to the exemplary thickness profile shown in FIG. 6.

[0048] In some embodiments, a thickness and / or material composition profile is obtained only for a specific radial location on the substrate. In one example, the thickness and / or material composition profile is obtained for radial locations greater than 20 mm from the center of the substrate. The thickness profile and / or material composition includes multiple thickness and / or material composition measurements at a single radial location, such as more than five thickness and / or material composition measurements, more than 10 thickness and / or material composition measurements, more than 15 thickness and / or material composition measurements, or more than 20 thickness and / or material composition measurements. FIG. 6 shows a graph 600 with multiple thickness measurements. The graph 600 includes 26 thickness measurements along a single radial location on the substrate. The thicknesses are measured in angstroms (A) and vary between approximately 875 A and approximately 950 A. In the embodiment of FIG. 6, the zero (0) measurement is at the same point on the substrate as the 26 measurements, and each measurement in between is at a different angular position on the substrate at the same radial location.

[0049] Once the thickness and / or material composition profile of the substrate is obtained in operation 404, a temperature correction factor is determined from the thickness and / or material composition profile in operation 406. The temperature correction factor depends on the amount of correction desired, the growth rate of the film on the substrate at different temperatures, the temperature of the process chamber, and the power of the spot heater. The temperature correction factor is obtained by inverting the thickness profile and / or material composition profile measurements and normalizing the thickness profile and / or material composition profile measurements. Inverting the thickness profile and / or material composition profile measurements includes subtracting each thickness value and / or material composition value from a first thickness value or a first material composition value. In some embodiments, the first thickness value and / or the first material composition value is the maximum thickness value and / or maximum material composition value among the thickness profile measurements and / or material composition measurements. Normalizing the thickness profile measurements and / or material composition measurements includes dividing the inverted thickness profile measurements and / or material composition measurements by the maximum value of the inverted thickness profile measurements and / or material composition measurements. An interpolation is then performed on the normalized thickness profile measurements or material composition profile measurements to obtain a normalized correction factor curve.

[0050] The interpolation of the normalized thickness profile measurements and / or material composition profile measurements can be one of linear, quadratic, or cubic interpolation. The normalized correction factor curve is then multiplied by a correction multiplier value to obtain a temperature correction curve. The correction multiplier value depends at least in part on other process conditions in the process chamber during deposition and / or etching within the substrate. In one example, the correction multiplier value is 4095 for a 12-bit correction value. Graph 700 in FIG. 7 shows an example of a temperature correction curve obtained as described in operation 406. In some examples, the correction factor value is equivalent to a difference in power applied to the spot heater, such as a difference in watts or joules emitted by the spot heater or by a laser coupled to the spot heater.

[0051] After determining the temperature correction factor curve and the temperature correction value, the signal output from the one or more spot heaters is adjusted as determined by the temperature correction factor value during operation 408. Adjusting the signal output of the one or more spot heaters is further described in method 500 of Figure 5. Determining the thickness profile, material composition profile, and / or temperature correction curve is performed during a maintenance procedure prior to processing of a substrate in the process chamber 100.

[0052] FIG. 5 illustrates a method 500 for processing a substrate while adjusting the intensity of spot heater illumination. Method 500 includes an operation 502 of detecting a position of the substrate. The position of the substrate detected during operation 502 is the angular position of the substrate. The angular position is determined using a position sensor, such as angular position sensor 178 of FIGS. 1A and 1B. The angular position is further determined by knowing the rate of rotation of the substrate support about axis A. Detecting the position of the substrate helps ensure that a temperature correction signal output by the spot heater during subsequent operation is provided to the correct angular position of the substrate. In some embodiments, the position of the substrate is known by recording when a notch or signaler on the substrate or the substrate support passes an angular position sensor.

[0053] After the angular position of the substrate is determined during operation 502, a temperature correction coefficient value and / or a temperature correction curve is provided to a spot heater controller, which may be one of the controller 120, the microcontroller 180, or the spot heater control box 176. The temperature correction coefficient value associated with the particular angular position of the substrate detected by the angular position sensor is provided to the spot heater controller.

[0054] In some embodiments, the spot heater controller already includes temperature correction factor values ​​and / or temperature correction curves stored therein, however, the temperature correction factor values ​​associated with the angular position of the substrate are retrieved from a set of temperature correction factor values ​​in the temperature correction curve.

[0055] After the temperature correction factor value is retrieved by the spot heater controller from either the internal spot heater controller memory or an external memory source, the signal output of one or more of the spot heaters is adjusted based on the temperature correction factor value during operation 506. Adjusting the signal output of the one or more spot heaters includes adjusting one or more of the power output, wavelength output, beam size, or beam angle. In embodiments where the signal output is a power output, the power output increases with increasing temperature correction factor values ​​and decreases with decreasing temperature correction factor values. The amount of power delivered to the substrate varies within a range from about 0% of the total power of the spot heater to 100% of the total power of the spot heater, from about 10% to about 95%, from about 20% to about 95%, etc. In some embodiments, the minimum power output by the spot heater during operation 506 is about 2 W / cm. 2 and therefore the power output delivered to the first angular section of the substrate is about 5 W / cm 2 greater than approximately 5W / cm 2 ~Approx. 1500W / cm 2 , about 5W / cm 2 ~about 500W / cm 2 , about 5W / cm 2 ~About 300W / cm 2 etc., about 2W / cm 2 The range of power output by the spot heater and delivered to the substrate depends on both the range of thickness variations on the substrate to be corrected and the sensitivity of the film growth thickness to the power delivered to the substrate. In addition to correcting for substrate thickness variations, the material composition of the substrate can also be adjusted using the same process.

[0056] The one or more spot heaters emit a radiation beam having a diameter of less than about 25 mm, such as less than about 20 mm, less than about 10 mm, less than about 5 mm, less than about 3 mm, or less than about 2 mm. Each spot on the substrate 102 that is irradiated at one time is irradiated with a power range of about 0.5 W to about 100 W, such as about 1 W to about 100 W, or about 2 W to about 100 W. Adjusting the size of the spot on the substrate 102 that is irradiated also adjusts the power density of the irradiation.

[0057] The wavelength of the radiation supplied to the substrate is from about 700 nm to about 2000 nm, such as from about 750 nm to about 1800 nm, such as from about 760 nm to about 1700 nm.

[0058] Different temperature correction coefficients are applied as the spot heater is scanned over the substrate to irradiate different portions of the substrate. A first temperature correction coefficient is provided to the spot heater controller while the substrate is disposed at a first angular position determined by the angular position sensor. The first temperature correction coefficient is utilized to adjust a first output signal of the spot heater so that a first angular section of the substrate is irradiated with a first radiation beam having a first power. The first power is determined using the first temperature correction coefficient value. The first angular position can be a first sector, such as first sector 310a, of a circle, such as second spot heater irradiation path 304, of the substrate.

[0059] The substrate is then rotated to a second angular position at the same radial location. While at the second angular position, a second temperature correction coefficient value is applied to the spot heater controller. The second temperature correction coefficient is utilized to adjust a second output signal of the spot heater so that a second angular section of the substrate is irradiated with a second radiation beam having a second power. The second power is determined using the second temperature correction coefficient value. When the second temperature correction coefficient is different from the first temperature correction coefficient, the second power is different from the first power. The second angular position can be a second sector of the annulus, such as second sector 310b, of the substrate, such as second spot heater irradiation path 304.

[0060] The substrate is then rotated to a third angular position at the same radial position. While at the third angular position, a third temperature correction coefficient value is applied to the spot heater controller. The third temperature correction coefficient value is used to adjust a third output signal of the spot heater so that a third angular section of the substrate is irradiated with a third radiation beam having a third power. The third power is determined using the third temperature correction coefficient value. When the third temperature correction coefficient value is different from either the first temperature correction coefficient value or the third temperature correction coefficient value, the third power is different from the first power and the second power. The third angular position can be a third sector of the annulus, such as third sector 310c, of the substrate, such as second spot heater irradiation path 304.

[0061] Additional angular positions are heated by the spot heaters at different power values ​​that correlate to additional temperature correction factor values. There can be more than 10 angular positions with more than 10 different power values, such as more than 15 angular positions with more than 15 different power values, or more than 20 angular positions with more than 20 different power values. In some embodiments, more than 100 temperature correction factor values ​​are determined from the temperature correction curve. In some embodiments, there are more than 200 temperature correction factor values, such as more than 300 temperature correction factor values. In some embodiments, each angular position is a portion of a circle, and thus the circle is divided into sectors with areas less than 60 degrees, such as less than about 45 degrees, less than about 30 degrees, less than about 15 degrees, less than about 10 degrees, less than about 5 degrees, less than about 3 degrees, less than about 2 degrees, or less than about 1 degree.

[0062] FIG. 8A is a graph 800 illustrating the corrected signal output of a spot heater angularly offset by 90 degrees from the angular position sensor. Thus, the angle of the section of spot heater illumination is offset by 90 degrees from the angular position sensor, similar to the first spot heater 170a in FIG. 3. When the illuminated area is disposed at an angle offset from the angle of the position sensor measurement, the correction signal output to the spot heater controller is similarly offset. As shown in FIG. 8B, the correction signal output and adjusted power output of the spot heater are adjusted by 90 degrees relative to the correction signal output when the location of the spot heater illumination is at the same angular position as the angular position sensor measurement.

[0063] Figure 8B is a graph 850 illustrating the corrected signal output of a spot heater that is angularly offset by 180 degrees from the angular position sensor. Thus, the angle of the section of the spot heater illumination is offset by 180 degrees from the angular position sensor, similar to the second spot heater 170b in Figure 3. As shown in Figure 8B, the corrected signal output and adjusted power output of the spot heater would be adjusted by 180 degrees relative to the corrected signal output if the location of the spot heater illumination were at the same angular position as the angular position sensor measurement.

[0064] The embodiments described herein allow for varying the power applied to a substrate by one or more spot heaters as the spot heaters irradiate different angular regions of the substrate during processing. Adjusting the amount of radiation imparted to the substrate for different angular regions allows for reducing or eliminating non-uniformities in the different angular regions. The change in power applied by the spot heaters is determined by a calibration operation in which the thickness of a grown or etched film is measured. The thickness is correlated with a temperature correction factor value, which is graphed and used to interpolate a temperature correction factor curve. The temperature correction factor curve provides a curve that can be followed to adjust the power and amount of radiation imparted to the substrate at different angular positions.

[0065] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof, which scope is determined by the appended claims.

Claims

1. 1. A method for adjusting a temperature profile of a substrate during processing suitable for use during semiconductor manufacturing, comprising: sending a plurality of temperature correction coefficients to the spot heater controller; using a spot heater to irradiate a first beam of radiation at a first angular section about a central axis of the substrate, the first power being determined using a first temperature correction coefficient of the plurality of temperature correction coefficients; rotating the substrate about a central axis; using the spot heater to irradiate a second beam of radiation having a second power at a second angular section about a central axis of the substrate, the second power being determined using a second temperature correction factor of the plurality of temperature correction factors, the second power being different from the first power; A method comprising:

2. The method of claim 1 , wherein both the first angle section and the second angle section are disposed at the same radial distance from a center of the substrate.

3. The method of claim 1 , wherein the substrate is rotated about a central axis of the substrate between the irradiating the first angular section and the irradiating the second angular section.

4. The method of claim 1 , wherein the temperature correction factor is determined using a thickness or composition of a film on a test substrate during a calibration operation.

5. 2. The method of claim 1, further comprising: determining a first angular position about a central axis of the substrate corresponding to the first angular section using a position sensor configured to determine an angular position about a central axis of the substrate or a substrate support on which the substrate is disposed.

6. The method of claim 5 , wherein the temperature correction factor is determined at each angular position about a central axis of the substrate.

7. The first power and the second power supplied to the first angle section and the second angle section, respectively, are about 2 W / cm ２ 7. The method of claim 6, wherein the power density is greater than

8. 8. The method of claim 7, further comprising using the spot heater to irradiate a third beam of radiation having a third power at a third angular section about a central axis of the substrate, wherein the third power is determined using a third temperature correction factor among the plurality of temperature correction factors, and the third power is different from the first power and the second power.

9. 1. An apparatus for processing a substrate suitable for use during semiconductor manufacturing, comprising: a chamber body; a substrate support disposed within the chamber body; Chamber lid and a chamber floor; and an upper window disposed between the chamber lid and the substrate support; a lower window disposed between the substrate support and the chamber floor; a plurality of upper lamps disposed between the upper window and the chamber lid; a plurality of lower lamps disposed between the lower window and the chamber floor; one or more spot heaters disposed on the chamber lid and configured to direct a radiation beam towards the substrate support; a controller configured to control the one or more spot heaters, determining an angular position of the substrate about a central axis; adjusting the power output of the one or more spot heaters using a set of temperature correction coefficients such that the power output of the one or more spot heaters varies as the one or more spot heaters heat multiple angular sections about a central axis of the substrate; a controller programmed to An apparatus comprising:

10. 10. The apparatus of claim 9, wherein the radiation beam of the one or more spot heaters has a diameter of less than about 10 mm.

11. The apparatus of claim 9 , further comprising a position sensor configured to determine an angular position about a central axis of the substrate or the substrate support on which the substrate is disposed.

12. The apparatus of claim 11 , wherein the one or more spot heaters are at a different angular position about a central axis of the substrate support than the position sensor.

13. 10. The apparatus of claim 9, wherein the controller is a spot heating microcontroller and is separate from a process chamber controller.

14. The apparatus of claim 9 , wherein each of the one or more spot heaters is positioned to direct the radiation beam to a different radial position of the substrate support.

15. A non-transitory computer-readable medium storing instructions that, when executed by a processor, determining an angular position about a central axis of the substrate; receiving a temperature correction curve; adjusting the power output of the one or more spot heaters using the temperature correction curve such that the power output of the one or more spot heaters varies as the one or more spot heaters heat a plurality of angular sections about a central axis of the substrate along a first radial position of the substrate; A non-transitory computer-readable medium for causing a computer system to execute the program.

16. 16. The medium of claim 15, wherein the radiation beam of the one or more spot heaters is directed toward the substrate and has a diameter of less than about 25 mm.

17. The medium of claim 15 , wherein determining the angular position about a central axis of the substrate is performed using a position sensor.

18. 18. The medium of claim 17, wherein the one or more spot heaters are at a different angular position about a central axis of the substrate than the position sensor, and the temperature correction curve is offset to account for differences between the angular position of the position sensor and the angular positions of the one or more spot heaters.

19. 16. The medium of claim 15, wherein the temperature correction curve is formed using a plurality of temperature correction coefficients, the plurality of temperature correction coefficients being determined by measuring film thicknesses or material compositions on a test substrate during a calibration operation.

20. 16. The medium of claim 15, wherein the power output of the one or more spot heaters is varied during a deposition operation in a process chamber to improve uniformity of a film growing at the first radial position on the substrate at different angular positions about a central axis of the substrate.

21. The method of claim 1, wherein the multiple temperature correction coefficients are obtained by inverting and normalizing thickness profile or multiple material composition profile measurements.

22. The controller is further programmed to receive a temperature correction curve; 10. The apparatus of claim 9, wherein the temperature correction curve is formed using a plurality of temperature correction coefficients, the plurality of temperature correction coefficients being determined by measuring film thicknesses or material compositions on a test substrate during a calibration operation and inverting and normalizing the film thicknesses or material compositions.

23. The medium described in claim 15, wherein the temperature correction curve is formed using multiple temperature correction coefficients, and the multiple temperature correction coefficients are determined by inverting and normalizing thickness profile or multiple material composition profile measurements.

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