Synchronization between a temperature measuring device and a plurality of radiation sources

Abstract

Methods, systems, apparatuses, and devices measure a temperature of a substrate by switching one or more sources between an active state and an inactive state. When in the active state, the one or more sources heat at least a portion of the substrate. When in the inactive state, the one or more sources cause substantially no radiation or a negligible amount of radiation. A temperature measurement device is synchronized with the switching between the active state and the inactive state such that the temperature measurement device measures a temperature of at least a portion of the substrate substantially only when the one or more sources are in the inactive state.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 064,968, filed August 13, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This invention relates to the handling and / or processing of workpieces (e.g., semiconductor wafers and substrates). Background Technology

[0004] In the fabrication of semiconductor devices, various processing steps are performed where a wafer is heated to a desired temperature over a timescale of seconds or less by a heat source, which can be in the form of a high-intensity radiation source such as an LED, laser, or lamp. In some cases, the wafer undergoes thermal processing to perform various manufacturing steps, including, for example, dopant activation, thermal oxidation, metal reflow, and chemical vapor deposition. In other cases, the wafer may be heated as a byproduct of certain processing operations, such as heating the wafer due to exposure to plasma. Wafer temperature is monitored / measured, for example using a radiation thermometer, to track the temperature distribution of the wafer during processing. Summary of the Invention

[0005] The present invention relates to a method, apparatus, device, and system for measuring / monitoring parameters of a workpiece / substrate, including the temperature of the workpiece / substrate and the reflectivity and / or emissivity of the workpiece / substrate.

[0006] In some embodiments, the device includes an apparatus and / or one or more sensors configured to measure temperature by measuring thermal radiation emitted from a substrate or workpiece heated by a plurality of radiation sources. The apparatus and / or sensors operate synchronously with a plurality of radiation sources, which switch between a first (“activated”) state and a second (“deactivated”) state. In the first (“activated”) state, the plurality of radiation sources irradiate the substrate to heat it; in the second (“deactivated”) state, the plurality of radiation sources do not emit radiation or emit negligible amounts of radiation, such that any such radiation emitted by the plurality of radiation sources is not detected by the apparatus (and / or sensors) or is insufficient to measurably affect the measurements performed by the apparatus (and / or sensors). In a preferred embodiment, the synchronization of the device (and / or sensor) with multiple radiation sources enables the device and / or sensor to measure temperature (or thermal radiation) only when the multiple radiation sources are inactive. More preferably, this temperature / thermal radiation measurement is started / begins precisely when the multiple radiation sources are switched from an active state to an inactive state, and the precise measurement of the substrate / workpiece temperature / thermal radiation is stopped when the multiple radiation sources are switched from an inactive state to an active state. In a particularly preferred embodiment, when the multiple radiation sources are switched to an inactive state, the device and / or sensor precisely begins measuring the substrate temperature / thermal radiation, and when the device and / or sensor stops measuring the substrate temperature and / or thermal radiation, the multiple radiation sources are accurately / precisely switched back to an active state.

[0007] In some embodiments, a first sensor operates synchronously with multiple radiation sources to monitor / measure an intensity parameter that varies with the intensity of thermal radiation emitted by the substrate during periods when the multiple radiation sources are inactive, and generates a temperature indication electronic signal corresponding to the intensity parameter. In some embodiments, the synchronization is provided by a controller that controls the switching of the multiple radiation sources between two states. In other embodiments, the synchronization is provided by a second sensor configured to measure / monitor an intensity parameter that varies with the intensity of radiation emitted by the multiple radiation sources, and generates an intensity indication electronic signal corresponding to the intensity parameter. In some embodiments, a decrease in the intensity indication signal is used to synchronize the measurement performed by the first sensor with the switching of the multiple radiation sources between two states.

[0008] In a further embodiment, the device (and / or sensor) additionally measures radiation during periods when multiple radiation sources are switched to an active state in order to capture radiation reflected by the substrate in response to irradiation by the multiple radiation sources. In such an embodiment, the captured reflected radiation can be used to measure or calculate the reflectivity and / or emissivity of the substrate.

[0009] According to a teaching of an embodiment of the present invention, a method for measuring the temperature of a substrate is provided. The method includes: switching between one or more sources: an active state, wherein the one or more sources heat at least a portion of the substrate, and an inactive state, wherein the one or more sources substantially do not cause radiation or cause negligible amounts of radiation; and measuring the temperature using a temperature measuring device synchronized with the switching between the active state and the inactive state, such that the temperature measuring device measures the temperature of the at least a portion of the substrate substantially only when the one or more sources are in the inactive state.

[0010] Optionally, the one or more sources irradiate the substrate to heat the substrate during the active state.

[0011] Optionally, the one or more sources include a plurality of light-emitting diodes or a plurality of laser sources, which are configured to irradiate the substrate.

[0012] Optionally, the one or more sources include plasma, which is configured to bombard the substrate with a plurality of charged particles during the active state.

[0013] Optionally, the temperature measuring device is synchronized with the switching between the active state and the inactive state via a synchronization signal, the synchronization signal corresponding to at least one of the following: the inactive state, the transition from the active state to the inactive state, or the transition from the inactive state to the active state.

[0014] Optionally, the synchronization signal is provided by an intensity sensor configured to sense radiation emitted by the one or more sources.

[0015] Optionally, the synchronization signal is provided by a controller associated with the one or more sources, the controller controlling the switching of the one or more sources between the active state and the inactive state.

[0016] Optionally, the temperature measuring device includes a sensor that senses radiation emitted by the source and synchronizes the switching between the active and inactive states of the one or more sources by recognizing a decrease in the emitted radiation corresponding to the activation of the inactive state.

[0017] Optionally, the temperature measuring device is synchronized with the switching between the active state and the inactive state, such that the temperature measuring device begins to perform temperature measurement at or after the time when one or more sources switch from the active state to the inactive state, and the temperature measuring device stops performing temperature measurement of the substrate at or before the time when one or more sources switch from the inactive state to the active state.

[0018] Optionally, the temperature measuring device is synchronized with the switching between the active state and the inactive state, such that when the temperature measuring device stops performing temperature measurement, the one or more sources switch from the inactive state to the active state.

[0019] Optionally, the active state is associated with at least one irradiation time interval, each of which is a time interval during which the one or more sources emit radiation at an output power or average output power that is high enough to heat the substrate throughout the time interval; and the inactive state is associated with at least one measurement time interval, each of which is a time interval during which the one or more sources do not emit radiation, or emit radiation at an output power that is low enough to be negligible for the temperature measuring device.

[0020] According to one embodiment of the teachings of the present invention, a system for measuring the temperature of a substrate is also provided. The system includes: one or more sources configured to be associated with the substrate, the sources being switchable between: an active state, wherein the sources heat at least a portion of the substrate, and an inactive state, wherein the sources cause substantially no radiation or cause negligible amounts of radiation; a controller including at least one processor and configured to switch the sources between the active and inactive states; and a temperature measuring device configured to measure a temperature of the at least a portion of the substrate, the temperature measuring device and the switching between the active and inactive states being synchronized with each other, such that the temperature measuring device measures the temperature of the at least a portion of the substrate substantially only when the sources are in the inactive state.

[0021] Optionally, the at least one temperature measuring device is synchronized with the switching of the one or more sources via a synchronization signal, the synchronization signal corresponding to at least one of the following: the inactive state, a transition from the active state to the inactive state, or a transition from the inactive state to the active state.

[0022] Optionally, the synchronization signal is provided to the at least one temperature measuring device via the controller.

[0023] Optionally, the system further includes at least one intensity sensor configured to sense radiation emitted by the one or more sources.

[0024] Optionally, the at least one intensity sensor provides the synchronization signal to the at least one temperature measuring device.

[0025] Optionally, the at least one temperature measuring device measures radiation and synchronizes with the switching of the one or more sources by recognizing a drop in radiation measurement corresponding to the activation of the inactive state.

[0026] Optionally, the one or more sources irradiate the substrate to heat the substrate during the active state.

[0027] Optionally, the one or more sources may include a plurality of light-emitting diodes or a plurality of laser sources.

[0028] Optionally, the one or more sources include plasma, which is configured to bombard the substrate with a plurality of charged particles during the active state.

[0029] Optionally, the temperature measuring device is synchronized with the switching between the active state and the inactive state, such that the temperature measuring device begins to perform temperature measurement at or after the time when one or more sources switch from the active state to the inactive state, and the temperature measuring device stops performing temperature measurement of the substrate at or before the time when one or more sources switch from the inactive state to the active state.

[0030] Optionally, the switching between the active state and the inactive state is synchronized with the temperature measuring device, such that when the temperature measuring device stops performing temperature measurement, the controller switches the one or more sources from the inactive state to the active state.

[0031] Optionally, the active state is associated with at least one irradiation time interval, each of which is a time interval during which the one or more sources emit radiation at an output power or average output power that is high enough to heat the substrate throughout the time interval; and the inactive state is associated with at least one measurement time interval, each of which is a time interval during which the one or more sources do not emit radiation, or emit radiation at an output power that is low enough to be negligible for the temperature measuring device.

[0032] According to one embodiment of the teachings of the present invention, a method is also provided, comprising: switching between one or more sources: an active state, wherein the one or more sources heat the substrate, and an inactive state, wherein the one or more sources substantially do not cause radiation or cause a negligible amount of radiation; and using a means synchronized with the switching between the active state and the inactive state to measure thermal radiation emitted by the substrate, such that the means measures the thermal radiation emitted by the substrate substantially only when the one or more sources are in the inactive state.

[0033] Optionally, the method further includes: calculating the temperature of the substrate based on the measured thermal radiation.

[0034] Optionally, the device is synchronized with the switching between the active state and the inactive state, such that the device begins performing thermal radiation measurements at or after the time when one or more sources are switched from the active state to the inactive state, and the device stops performing thermal radiation measurements at or before the time when one or more sources are switched from the inactive state to the active state.

[0035] Optionally, the device is synchronized with the switching between the active state and the inactive state, such that when the device stops performing thermal radiation measurements, the one or more radiation sources are switched from the inactive state to the active state.

[0036] According to one embodiment of the teachings of the present invention, a method for measuring the temperature of a substrate periodically irradiated by a plurality of radiation sources is also provided, the plurality of radiation sources being switchable between an active state and an inactive state, wherein in the active state, the plurality of radiation sources irradiate the substrate to heat at least a portion of the substrate; and in the inactive state, the plurality of radiation sources emit substantially no radiation or emit negligible amounts of radiation. The method includes: performing a temperature measurement on at least a portion of the substrate by means of the temperature measuring device during a period in which the plurality of radiation sources are in an inactive state, based on a synchronization signal received by a temperature measuring device, the synchronization signal indicating at least one of the following: i) a period in which the plurality of radiation sources are in the active state, ii) a period in which the plurality of radiation sources are in the inactive state, iii) a period in which the plurality of radiation sources transition from the active state to the inactive state, or iv) a period in which the plurality of radiation sources transition from the inactive state to the active state, such that the temperature measuring device begins performing temperature measurement at or after the time when one or more radiation sources are switched from the active state to the inactive state, and the temperature measuring device stops performing temperature measurement on the substrate at or before the time when one or more radiation sources are switched from the inactive state to the active state.

[0037] Optionally, the method further includes terminating the temperature measurement through the temperature measuring device during the period when the plurality of radiation sources are in the activated state.

[0038] Optionally, the temperature measuring device includes at least one sensor for sensing thermal radiation emitted by the substrate and generating a temperature indication signal in response to the sensed radiation, and the method further includes: decoupling signal amplification electronics from the at least one sensor before or during the switching of the plurality of radiation sources from the inactive state to the active state.

[0039] Optionally, the synchronization signal is provided to the temperature measuring device via a controller that switches the plurality of radiation sources between an active and inactive state.

[0040] Optionally, the synchronization signal is provided by an intensity sensor configured to sense radiation emitted by the plurality of radiation sources.

[0041] According to one embodiment of the teachings of the present invention, a temperature measuring device is also provided for measuring the temperature of a substrate periodically irradiated by a plurality of radiation sources, the plurality of radiation sources being switchable between an active state and an inactive state, wherein in the active state, the plurality of radiation sources irradiate the substrate to heat at least a portion of the substrate; and in the inactive state, the plurality of radiation sources emit substantially no radiation or emit negligible amounts of radiation. The temperature measuring device includes: a sensor that senses thermal radiation emitted by the substrate during a period when the plurality of radiation sources are in the inactive state, based on a synchronization signal received by the temperature measuring device, and generates a temperature indication signal in response to the sensed thermal radiation, the synchronization signal indicating at least one of the following: i) a period when the plurality of radiation sources are in the active state, ii) a period when the plurality of radiation sources are in the inactive state, iii) a period when the plurality of radiation sources change from the active state to the inactive state, or iv) a period when the plurality of radiation sources change from the inactive state to the active state, such that the temperature measuring device begins to perform temperature measurement at or after the time when one or more radiation sources are switched from the active state to the inactive state, and stops performing temperature measurement of the substrate at or before the time when one or more radiation sources are switched from the inactive state to the active state.

[0042] According to one embodiment of the teachings of the present invention, a temperature measuring device is also provided for measuring the temperature of a substrate periodically irradiated by a plurality of radiation sources configured to switch between an active state and an inactive state, wherein in the active state, the plurality of radiation sources irradiate the substrate to heat the substrate; and in the inactive state, the plurality of radiation sources emit substantially no radiation or emit negligible amounts of radiation. The temperature measuring device includes a sensor that senses thermal radiation emitted by the substrate and generates a temperature indication signal in response to the sensed thermal radiation, wherein the temperature measuring device is synchronized with the switching of the plurality of radiation sources between the active state and the inactive state, such that the sensor generates the temperature indication signal only during the periods when the plurality of radiation sources are in the inactive state.

[0043] According to one embodiment of the teachings of the present invention, an apparatus is also provided, the apparatus being configured to operate together with or as part of a heat treatment system for processing a substrate, the heat treatment system having a plurality of switchable radiation sources configured to switch between an active state and an inactive state, wherein in the active state the plurality of radiation sources irradiate the substrate to heat at least a portion of the substrate; and in the inactive state the plurality of radiation sources emit substantially no radiation or emit negligible amounts of radiation. The device includes: a first sensor for sensing thermal radiation emitted by the substrate and generating a temperature indication signal in response to the sensed thermal radiation; a second sensor for sensing radiation emitted by the plurality of radiation sources and generating a synchronization signal corresponding to the inactive state; an amplifier circuit; and a controllable switch associated with the first sensor and the amplifier circuit and configured to switch between: an open position, wherein the amplifier circuit is decoupled from the first sensor, and an closed position, wherein the amplifier circuit communicates with the first sensor only during the period when the plurality of radiation sources are in the inactive mode.

[0044] According to one embodiment of the teachings of the present invention, an apparatus is also provided, the apparatus being configured to operate together with or as part of a thermal processing system for processing a substrate, the thermal processing system having a plurality of switchable radiation sources configured to switch between an active state and an inactive state, wherein in the active state, the plurality of radiation sources irradiate the substrate to heat at least a portion of the substrate; and in the inactive state, the plurality of radiation sources emit substantially no radiation or emit negligible amounts of radiation. The apparatus includes: a temperature measuring device including at least one sensor for sensing thermal radiation, generating a signal corresponding to the sensed thermal radiation, detecting a decrease in the signal corresponding to a time period during which the plurality of radiation sources transition from the active state to the inactive state, and causing a temperature measurement of the at least a portion of the substrate based on the sensed thermal radiation and the detected decrease in the signal.

[0045] According to one embodiment of the teachings of the present invention, a method is also provided, comprising: switching one or more radiation sources between: an active state, wherein the one or more radiation sources irradiate a substrate to heat the substrate, and an inactive state, wherein the one or more radiation sources emit substantially no radiation or emit negligible amounts of radiation; performing, via means synchronized with the switching between the active state and the inactive state: a first radiation measurement during the inactive state, the first radiation measurement including radiation corresponding to thermal emission from the substrate, and a second radiation measurement during the active state, the second radiation measurement including: radiation corresponding to thermal emission from the substrate; and radiation reflected by the substrate in response to radiation emitted by the one or more radiation sources; and calculating at least one of a reflectivity or an emissivity of the substrate based on the first radiation measurement and the second radiation measurement.

[0046] Unless otherwise defined herein, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although several methods and materials similar to or equivalent to those described herein may be used in the practice or testing of several examples of this invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification (including definitions) shall prevail. Furthermore, the materials, methods, and examples are illustrative only and are not intended to impose any necessary limitations. Attached Figure Description

[0047] Some embodiments of the present invention are illustrated herein by way of example only and with reference to the accompanying drawings. Detailed reference is made to the drawings, with emphasis placed on the details shown by way of example and for the purpose of illustrative discussion of several embodiments of the invention. In this regard, the description taken in conjunction with the drawings will make it clear to those skilled in the art how embodiments of the invention can be practiced.

[0048] Now turn your attention to the accompanying drawings, in which similar reference numerals or characters denote corresponding or similar parts. In the accompanying drawings:

[0049] Figure 1 It is a schematic diagram of a system with a measuring device having sensors for measuring / monitoring / tracking the thermal radiation and temperature of a substrate, heated by a switchable radiation source that can switch between an active and inactive state, and synchronized with an embodiment of the invention, wherein the switching of the radiation source between the active and inactive state is provided by a controller that controls the switching of the radiation source.

[0050] Figure 2 yes Figure 1 A block diagram of the controller;

[0051] Figure 3 yes Figure 1 A schematic diagram of the measuring device;

[0052] Figure 4 This is a graph showing the wavelength of radiation emitted by an example radiation source for heating a substrate and the wavelength of radiation to which the measuring device is sensitive.

[0053] Figure 5 It is a graph showing the wavelength of radiation emitted by an exemplary narrowband radiation source for heating a substrate and the wavelength of radiation to which the measuring device is sensitive.

[0054] Figure 6 yes Figure 5 A close-up view of the low-radiation region shows the overlap between some low-intensity broadband radiation emitted by the radiation source and the wavelengths that the measurement device is sensitive to, as well as the overlap with the wavelengths of thermal radiation emitted by the substrate when heated to various example temperatures.

[0055] Figure 7 It is a graph showing the change of the activation and deactivation states of the radiation source over time, and a graph showing the temperature distribution trend of the substrate heated by the radiation source in the activation state.

[0056] Figure 8 This is a schematic diagram of a system with a measuring device according to another embodiment, the measuring device having a sensor for measuring / monitoring the thermal radiation and temperature of a substrate, heated by a switchable radiation source, which is synchronized with the switching of the radiation source. The synchronization of the present invention is provided by an intensity sensor that measures the radiation intensity of the radiation source.

[0057] Figure 9 It is similar to Figure 8 A schematic diagram of the system, in which the intensity sensor is integrated as part of the measuring device;

[0058] Figure 10 It is similar to Figure 1 A schematic diagram of the system, but the measuring device includes an amplifier and a switch between the sensor and the amplifier, and the opening and closing of the switch is synchronized with the switching of the sensor. A radiation source between active and inactive states;

[0059] Figure 11 These are non-limiting examples of synchronization signals that can be used to provide synchronization between the measuring device and the switching of the radiation source;

[0060] Figure 12 This is a flowchart illustrating a process for measuring / monitoring substrate temperature according to an embodiment of the present invention;

[0061] Figure 13A and 13BThis is a schematic diagram of the controller disclosed herein, which can be used to control the pulse width modulation (PWM) voltage waveform of a radiation source; and

[0062] Figure 14 It is similar to Figure 1 A schematic diagram of the system, wherein the device measures the reflectivity and / or emissivity of the substrate by measuring the thermal radiation of the substrate when the radiation source is in an inactive state, and the radiation emitted by the substrate and the radiation reflected from the substrate when the radiation source is in an active state. Detailed Implementation

[0063] This invention relates to a method, apparatus, device, and system for measuring / monitoring the temperature of a workpiece / substrate.

[0064] The principles and operation of the methods, apparatus, devices and systems according to the present invention can be better understood by referring to the accompanying drawings and descriptions.

[0065] Before explaining at least one embodiment of the present invention in detail, it should be understood that the application of the present invention is not necessarily limited to the details of the construction and arrangement of components and / or methods set forth in the following description and / or illustrated in the drawings and / or examples. The present invention can have other embodiments, or can be practiced or performed in various ways.

[0066] Now refer to the attached diagram, Figure 1-3 Various aspects of a workpiece handling system constructed and operated according to various aspects of this disclosure are illustrated, the system generally designated as 10. Generally, the workpiece handling system (hereinafter referred to as the "system") 10, for example when implemented as a heat treatment system, may be deployed in or as part of a heat treatment chamber, including equipment for providing temperature monitoring / measurement during the handling of the workpiece 12. Generally, the workpiece 12 may be a substrate of any sheet-like material, such as a semiconductor wafer, a semiconductor substrate, or a glass substrate. Without loss of generality, the workpiece will be interchangeably referred to hereinafter as substrate 12.

[0067] System 10 typically includes one or more controllable sources 14 deployed to be switchably activated to selectively heat a substrate, a controller 24 for controlling the sources 14, and a measuring device 16 for measuring one or more parameters of the substrate 12 based on emitted radiation, or reflected by the substrate 12 in response to irradiation and / or heating by the sources 14. According to a first aspect of this disclosure, the device 16 is configured to measure the temperature of the substrate 12 based on thermal radiation emitted by the substrate 12. In embodiments according to the first aspect of this disclosure, the device 16 may also be interchangeably referred to as a "temperature measuring device." According to a second aspect of this disclosure, the device 16 measures thermal radiation emitted by the substrate and radiation reflected from the substrate to determine the reflectivity and / or emissivity of the substrate 12.

[0068] According to certain preferred but non-limiting embodiments, one or more sources 14 are a plurality of electronically controllable and switchable radiation sources 14a-14j, collectively referred to as radiation sources 14, which in some embodiments may be implemented as an array of radiation sources deployed to irradiate the substrate 12 to heat the substrate 12. Although ten radiation sources are shown herein for illustrative purposes, the system 10 may include fewer or more than ten sources, depending on the heat treatment application. In such embodiments, radiation sources 14 may also be interchangeably referred to as “sources” or “heat sources.” Heat sources 14 are preferably configured to heat at least a portion or the entire substrate 12 to a desired temperature, for example, 175°C or higher, and in some cases 200°C or higher, and in others 300°C or higher, depending on the application. When used in the case of a rapid heat treatment system, radiation sources 14 may be configured to heat the substrate 12 to even higher temperatures, including 1000°C or higher.

[0069] Incidentally, although source 14 is implemented as a radiation source for irradiating substrate 12 to heat substrate 12, other embodiments are contemplated herein, in which a causal relationship is not necessarily present between the radiation generated by source 14 and the heating of substrate 12. For example, as will be discussed in later sections of this disclosure, certain types of sources can be switchably activated to heat substrate 12 and radiation generation (i.e., radiative emission) can occur as a side effect or incidental result of source 14 activation, which is not the cause of substrate heating. For most of the remainder of this disclosure, source 14 will be described in the context of a radiation source for irradiating substrate 12, and more generally as applicable, source 14 typically configured to be activated to heat substrate.

[0070] Considering the above, radiation source 14 is typically configured to switch between two operating states: an active state where radiation source 14 irradiates substrate 12 to heat substrate 12, and an inactive state where radiation source 14 irradiates substrate 12 to heat substrate 12. Radiation source 14 may not irradiate the substrate, either by not emitting radiation or by emitting a negligible amount of radiation during the duration of its inactive state. In some non-limiting embodiments, the intensity (i.e., power) emitted by source 14 may vary between a minimum intensity / power value and a maximum intensity / power value, thereby combining the controlled variability of the desired temperature of substrate 12 with the duration of radiation source emission 14 emitting radiation at minimum and maximum intensities. The minimum intensity / power value may be, for example, 0 Watts / cm². 2 And the maximum strength / power value can be, for example, 20 Watts / cm. 2 These minimum and maximum values ​​may vary depending on the application.

[0071] In the context of this document, the term "active state" is used interchangeably with the terms "activated state," "active," and "activated," and generally refers to the state in which source 14 heats substrate 12. In a particularly preferred but non-limiting embodiment where source 14 is a radiation source, an active state refers to the state in which the radiation source irradiates substrate 12 by emitting sufficiently high radiation over a given time period, said radiation being high enough to heat substrate 12. In such embodiments, an active state corresponds to a time interval or period during which radiation source 14 emits radiation at a sufficiently high output power or average output power (over the entire time interval / period) to measurably heat the substrate (preferably according to the desired temperature profile). The time interval (i.e., period) during which radiation source 14 is in an active state can be interchangeably referred to as an "irradiation time interval" or an "irradiation period." In the general case where the source 14 does not irradiate the substrate but still heats the substrate in the active state, the time interval during which the source 14 is in the active state can be equivalently referred to as the "active state time interval" or "active state period" and any other interchangeable term for "active state" used in conjunction with the terms "time interval" or "period".

[0072] Similarly, in the context of this document, the term "inactive state" is used interchangeably with the terms "deactivated state," "inactive," and "deactivated," and generally refers to a state in which the radiation source 14 does not irradiate the substrate 12, or, more generally, causes substantially no radiation or causes a negligible amount of radiation. In embodiments where the source 14 is a radiation source that irradiates the substrate 12 during the active state, when in the inactive state, the radiation source 14 does not (i.e., stops) emit radiation, or emits a negligible amount of radiation (from the perspective view of device 16), or emits a residual low level of radiation immediately after switching from the active state to the inactive state. In such embodiments, the inactive state corresponds to a time interval or period during which the radiation source 14 emits radiation at an output power or average output power (over the entire time interval / period), which is zero (i.e., the radiation source 14 does not emit any radiation) or low enough that the radiation source 14 emits a negligible amount of radiation (i.e., a very low non-zero output power amount, e.g., << 1 Watt / cm). 2The time interval during which radiation source 14 is in an inactive state can be interchangeably referred to as a "measurement time interval" or a "measurement period". In the general case where source 14 does not irradiate the substrate but still heats the substrate when in an active state, the time interval during which source 14 is in an inactive state can be equivalently referred to as an "inactive state time interval" or an "inactive state period", and any other interchangeable term for "inactive state" can be used in combination with the terms "time interval" or "period".

[0073] A single measurement time interval corresponds to the time period between the first time instance and the second time instance, where the first time instance is the time instance in which the radiation source 14 is in an inactive state, and the second time instance is the time instance in which the radiation source 14 is in an active state continuously after being in an inactive state.

[0074] In the context of this document, the term “negligible radiation” generally refers to any amount of radiation that the temperature measuring device 16 cannot detect and is insufficient to significantly affect the temperature measurement of the substrate 12 performed by the temperature measuring device 16.

[0075] Controller 24 is electrically connected to radiation source 14 and is used to drive radiation source 14 to turn on and off, thereby controlling radiation source 14 to switch between an active and inactive state at a suitable switching rate. In some embodiments, the switching rate may be static / constant and may be pre-programmed into controller 24. In other embodiments, the switching rate may be dynamic. The switching rate may depend on the heating rate and the desired temperature to which substrate 12 will be heated, which may depend on the specific heat treatment application. Controller 24 is preferably also configured to regulate the intensity / power of radiation emitted by radiation source 14 when in an active state. Furthermore, as will be discussed in further detail in subsequent sections of this disclosure, controller 24 may employ various techniques to control the switching between active and inactive states, as well as the radiation intensity output of radiation source 14. In a preferred but non-limiting embodiment, controller 24 employs pulse width modulation (PWM) to control the switching of radiation source 14 and radiation intensity output.

[0076] Figure 2This is a schematic block diagram of controller 24, showing processor 26, which may be one or more computer processors (e.g., microprocessors, microcontrollers, signal processors, etc.) coupled to a computer storage medium, schematically represented as memory 28. Such a processor includes or can communicate with a computer-readable medium (e.g., memory 28) storing computer program code or instruction sets that, when executed by the processor, cause the processor to perform actions. Types of computer-readable media include, but are not limited to, electronic, optical, magnetic, or other storage or transmission devices capable of providing computer-readable instructions to the processor. Memory 28 can be any type of memory used for storing data and information, and may also store computer program code or instruction sets for execution by processor 26.

[0077] In some embodiments, individual radiation sources 14a-14j can be independently controlled by controller 24, allowing controller 24 to independently and selectively turn each radiation source on and off. In other embodiments, radiation sources 14 are collectively turned on and off by controller 24, such that when controller 24 issues an "on" control command, all radiation sources 14 are turned on simultaneously, and when controller 24 issues an "off" control command, all radiation sources 14 are turned off simultaneously.

[0078] Temperature measuring device 16 (also referred to as a “temperature measuring device” or simply a “device”) is used to measure a portion of the temperature of substrate 12, which may be a part of substrate 12 or the entire substrate 12. In some embodiments, temperature measuring device 16 is implemented as a radiation thermometer, such as a temperature probe, which may be a separate component independent of radiation source 14 and controller 24 of system 10, or may be integrated with other components of system 10.

[0079] In some preferred embodiments, the radiation source 14 is deployed relative to the substrate 12 to irradiate the substrate 12 from a wide range of angles, thereby heating the entire substrate 12. In such embodiments, the radiation source 14 may be configured as a heat source array.

[0080] In a particularly preferred but non-limiting set of embodiments, source 14 is implemented as a plurality of electronically switchable light-emitting diodes (LEDs) (optionally deployed in an array), or as an arrangement of laser sources configured to emit radiation in a specific wavelength range and preferably from a wide range of angles, in order to heat substrate 12 to a desired temperature. LEDs and lasers offer several advantages in thermal processing compared to incandescent lamps and other types of lamps, particularly in the precision of their electronic control. Furthermore, LEDs and lasers can be rapidly switched on and off, allowing LEDs to switch from zero power to full power (and vice versa) in fractions of a second.

[0081] However, it should be noted that the radiation output of the LED, laser, or other radiation source may at least partially overlap with a particularly desired wavelength range used for measuring the temperature of the substrate 12 by the temperature measuring device 16. This can be achieved... Figure 4 As seen in the example, temperature measuring device 16 operates at approximately 950 nm, and the source emits peak radiation at approximately 870 nm but also radiation up to 950 nm. Therefore, the radiation emitted by the LED / laser / light source—when on—interferes with the temperature measurement of substrate 12. Even LEDs and laser heat sources operating far from the operating wavelength band of the temperature probe (e.g., close to 500 nm) still emit broadband radiation, albeit typically weaker, which can still overlap and interfere with the temperature measuring device 16 operating at nearby longer wavelengths, such as around 950 nm. This is in... Figure 5 As shown, radiation source 14 emits narrowband peak radiation close to 500 nm, but still emits broadband radiation strong enough to interfere with low thermal signal levels (in Figure 6 (As shown in the close-up view) When heated to various example temperature levels (175°C, 200°C, and 300°C in this example), the intensity is sufficient to interfere with the low thermal signal level emitted by substrate 12. Therefore, temperature measurements performed while radiation source 14 is active will obscure the temperature readings of substrate 12.

[0082] To prevent radiation from the radiation source 14 from obscuring the temperature readings of the substrate 12, the temperature measuring device 16 according to embodiments of this disclosure is synchronized with the switching between an active and inactive state of the radiation source 14, such that the temperature measuring device 16 begins performing temperature measurements at the same time as or shortly after the source 14 switches from an active state to an inactive state, and stops performing temperature measurements of the substrate 12 at the same time as or shortly before the source 14 switches from an inactive state to an active state. In this way, the only meaningful temperature measurement performed by the temperature measuring device 16 is performed during the period when the radiation source 14 is inactive. Note that the “short time” during which the device 16 does not measure temperature at the beginning and / or end of the inactive state is typically chosen to be a sufficiently long time interval to account for the synchronization signal and the exact time when the source 14 transitions to / from the inactive state. These small intervals added at the beginning and / or end of the inactive state when the device 16 is not measuring are to ensure that even in the face of uncertainty regarding the precise time of transition to / from the inactive state, the device 16 will always perform measurements only when the source 14 is inactive. Furthermore, in typical cases where device 16 requires a minimum amount of time to complete a temperature measurement, it may be considered to allow ensuring that device 16 measures the temperature in the middle. (Therefore, in practice, if there is sufficient time to complete the measurement before the next inactive-to-active transition of source 14, then only device 16 may be allowed to begin temperature measurement).

[0083] Each time the radiation source is placed in an inactive state, the temperature of substrate 12 decreases, resulting in a heating curve that qualitatively resembles... Figure 7 The heating curve is schematically shown in the diagram. In situations requiring strict control of temperature distribution, and / or in cases where the substrate cools rapidly during the inactive state interval, it is generally desirable to minimize the radiation interval when source 14 is inactive, in order to reduce the magnitude of temperature drops occurring during the inactive state interval. For this purpose, radiation source 14 can preferably be implemented as an LED, a laser, or other radiation source with a fast response time. (The rise / fall times of LEDs and lasers are typically on the order of 1 microsecond or faster). Using a radiation source with a fast response time allows temperature measurement to begin almost immediately after the inactive state begins, and allows the active state to be re-established almost immediately after the temperature measurement is completed. This differs from radiation sources with slower response times, such as incandescent radiation sources, whose rise / fall times are approximately a few 0.1 seconds or longer. Such slower response time radiation sources require a delay in the start of temperature measurement until the radiation level from the slow response time source decays to a level that no longer interferes with the temperature measurement. Similarly, a slow response time radiation source requires some time to fully return to the active state after the inactive state temperature measurement is completed. Therefore, by using LEDs, lasers, or other fast-response-time radiation sources, the temperature drop during the inactive state time interval can be made smaller.

[0084] In some preferred but non-limiting embodiments, pulse width modulation (PWM) control methods can be used to change the average power applied to the radiation source. Figure 13A and 13B An exemplary PWM voltage waveform for PWM control is shown. When using the PWM control method, there are two possible synchronization methods between the temperature probe and the radiation source:

[0085] a) When the temperature probe measurement time is long relative to the PWM cycle time T, the radiation source needs to be placed in an inactive state for one or more entire PWM cycles in order to capture the temperature measurement value. This situation occurs in... Figure 13A The diagram shows an inactive state (measurement time interval) before and after an active state interval in which a higher average power is applied to the radiation source.

[0086] b) When the temperature probe measurement time is short relative to the PWM cycle time T, temperature measurement can be performed within the inherent low-voltage intervals during each PWM cycle (whenever the PWM duty cycle < 100%). In this implementation, the inactive state naturally occurs within the PWM cycle, eliminating the need to insert special inactive state measurement intervals between PWM voltage pulses. This method... Figure 13Bis schematically shown in the figure. The method shown in the figure not only requires a fast temperature measurement time (<<T), but also requires a fast switching between the active and inactive states. As previously mentioned, LED and laser radiation sources are particularly suitable for such cases where fast switching is required.

[0087] It should be understood that achieving the inactive state does not require applying an exact zero voltage, current, power, or other appropriate excitation to the radiation source, but only requires applying a low enough excitation to ensure that the radiation source emits at a level below the value that would interfere with the temperature probe measurement.

[0088] The activation time interval and the measurement time interval will now be discussed in more detail. For clarity of illustration, the time intervals will be described in the non-limiting context where source 14 is a radiation source, whereby the activation time interval is equivalently referred to as the irradiation time interval. It is obvious that both the irradiation time interval and the measurement time interval can include multiple intervals. Generally, the irradiation time interval alternates with the measurement time interval corresponding to the activation / inactivation state switching of the radiation source 14, such that the radiation source 14 undergoes consecutive alternating cycles of activation and inactivation states, and such that there are interleaved irradiation time intervals and measurement time intervals between them. Figure 7 An example of the state of the radiation source 14 over time when the radiation source 14 cycles between the active and inactive states is shown, as well as the trend of the temperature distribution of the substrate 12 caused by the switching. From Figure 7 the example shown, it can be seen that the temperature of the substrate 12 increases (i.e., the substrate 12 "warms up") during the period when the radiation source 14 is in the active state, and decreases (i.e., during the period when the radiation source 14 is in the inactive state, the substrate 12 "cools down"). In the example shown, the substrate 12 temperature increases according to a non-linear function of time during each irradiation time interval.

[0089] Each irradiation time interval is long enough to provide sufficient time for the substrate 12 to heat up to a suitable temperature. It has been found that irradiation time intervals in the range of 0.25 to 10 seconds are particularly effective for heating semiconductor wafers, but the interval length can vary according to specific heat treatment applications. In addition, each measurement time interval is preferably shorter than the irradiation time interval, and is also preferably short enough to be compatible with the synchronization of the switching time of the radiation source 14, and the temperature of the substrate 12 is measured (by the temperature measuring device 16) while having a minimal impact on the temperature curve that changes over time. It has been found that measurement time intervals in the range of 0.01 to 0.1 seconds are particularly effective for measuring the temperature of semiconductor wafers heated at intervals of 0.25 to 10 seconds, but the measurement time interval length may vary depending on the specific processing application.

[0090] In some preferred embodiments, the device 16 continuously or nearly continuously measures the temperature (and / or thermal radiation) emitted by the substrate 12 throughout the entire duration of the measurement time interval.

[0091] Incidentally, it should be noted that the irradiation time interval does not necessarily need to be of equal length. Similarly, the measurement time interval does not necessarily need to be of equal length. For example, the irradiation time interval may increase or decrease continuously throughout the entire duration of the substrate heat treatment, and the measurement time interval may remain constant or may vary based on, for example, the length of each preceding irradiation time interval.

[0092] A schematic diagram of a temperature measuring device 16 according to certain embodiments of the present disclosure. In the illustrated embodiment, the temperature measuring device 16 includes a sensor 20 coupled to a processor 18. The processor 18 may be one or more computer processors (e.g., a microprocessor, microcontroller, signal processor, etc.). The sensor 20 is configured to detect / sensor / measure radiation (thermal radiation, radiation intensity) emitted by a substrate 12 and generate an electrical signal indicating temperature in response to the sensed thermal radiation. The sensor 20 is preferably sensitive to radiation within a specific wavelength range, which is selected to provide high sensitivity to temperature changes in the substrate 12, which will be heated by the radiation source 14 to a desired processing temperature within a desired range. In a non-limiting example, the sensor 20 is sensitive to radiation with a wavelength equal to or close to 1000 nm. The sensor 20 may be more than one sensor, such as a sensor array. The sensor 20 may measure the temperature of the substrate 12 based on the Stefan-Boltzmann law, the relationship between thermal radiation (irradiance) and temperature given by the Planck function, or using a lookup table (which may be stored in memory) associated with the processor 18.

[0093] In the illustrated embodiment, the temperature measuring device 16 further includes an optics element 23, schematically represented by a lens 23 (which may be a component of a lens, and may be refractive or reflective), for directing thermal radiation from the scene to the sensor 20. Alternatively, the optics element 23 may be implemented as one or more optical fibers (e.g., a bundle of optical fibers) or as a light tube. The optics element 23 is deployed to define a field of view corresponding to the area from which thermal radiation will reach. When the device 16 is deployed to measure the temperature / thermal radiation of the substrate 12, the device 16 is positioned such that the portion of the substrate 12 to be measured is within the field of view of the scene / area defined below by the optics element 23. Depending on the deployment configuration of the device 16 relative to the substrate 12, a "part of the substrate" may include one or more portions of the substrate 12 or may include the entire substrate 12.

[0094] In some embodiments, the processor 18, sensor 20, and optics 23 are housed in a single housing or mechanical body.

[0095] Incidentally, the thermal radiation emitted by substrate 12 is typically weak, so sensor 20, in response to sensing the thermal radiation, may generate a relatively weak temperature indication signal that requires some amplification by amplifier circuitry. Therefore, although not shown in the figures, the output of sensor 20 is preferably coupled to amplifier circuitry (e.g., a preamplifier) ​​that amplifies the signal generated by sensor 20.

[0096] Synchronization between the switching of the temperature measuring device 16 and the radiation source 14 can be provided in various ways. According to a set of non-limiting embodiments, such as... Figure 1 As shown, controller 24 is electrically associated (i.e., electrically connected) with temperature measuring device 16 and provides temperature measuring device 16 with a synchronization signal time interval and / or measurement time interval corresponding to irradiation. As will be discussed, the synchronization signal may correspond to an inactive state, and / or a transition from an active state to an inactive state, and / or a transition from an inactive state to an active state. Since controller 24 controls the switching rate of radiation source 14, controller 24 may also provide timing information to temperature measuring device 16, for example, in the form of a synchronization signal, such that temperature measuring device 16 measures only the temperature change of substrate 12 during the time period corresponding to the measurement time interval. Processor 18 may receive the synchronization signal and control the timing of sensor 20, such that sensor 20 measures thermal radiation only during the measurement time interval. In other embodiments, sensor 20 continuously measures thermal radiation intensity, and processor 18 controls a switch that switchably couples sensor 20 to amplifier circuitry to close the switch only during the measurement time interval, such that sensor 20 outputs a signal that communicates with amplifier circuitry only during the measurement time interval and does not communicate with amplifier circuitry during the irradiation time interval. Reference will be made to the following sections of this disclosure. Figure 10 Variants of the described implementation are discussed.

[0097] In another set of non-limiting embodiments, the sensor is sensitive to radiation emitted by the radiation source 14 and the substrate 12, and continuously senses / measures the intensity of thermal radiation. In such an embodiment, the processor 18 can be programmed to process the signal generated by the sensor 20 to identify a sudden drop in the signal indicating a decrease in the measured radiation intensity. This drop typically corresponds to a period when the radiation source 14 transitions to an inactive state. Therefore, the processor 18 can only generate, output, and / or store or write to memory (e.g., write to computer memory linked to the processor 18) upon the detected sudden drop in signal (which corresponds to the measurement time interval, i.e., when the radiation source 14 is in an inactive state), such that the temperature measuring device 16 only outputs the temperature measurement during the measurement time interval. The processor 18 can similarly be programmed to stop recording measurement data when a sudden increase in signal is detected, corresponding to the transition of the radiation source to an active state. Thus, the device of the present invention generates a temperature measurement of the substrate 12 based on the sensed radiation and the detected sudden drops and increases in the intensity of the sensed radiation. Alternatively, instead of identifying inactive states (which should be recorded) based on changes in the measured signal (sudden increases and decreases), the processor 18 can identify inactive state signal levels when the sensed radiation signal drops below a certain threshold.

[0098] Now for reference Figure 8 and Figure 9 A system and apparatus for synchronizing the switching between temperature measuring device 16 and radiation source 14, according to a further embodiment of the present disclosure, wherein an additional sensor is used to sense radiation emitted by radiation source 14. First, see... Figure 8 An intensity sensor 30 (there may be more than one intensity sensor) is used to sense radiation emitted by the radiation source 14 and is electrically associated with the temperature measuring device 16. The intensity sensor is sensitive to radiation within a specific wavelength range emitted by the radiation source 14, and the sensor 20 is sensitive to radiation within a specific wavelength range emitted by the substrate 12 when heated by the source 14. Although not shown, the intensity sensor 30 may be associated with optics for guiding the radiation from the scene (in this case, including the radiation source 14) to the radiation-directing sensor 30. Alternatively, the sensor 30 may be associated with dedicated optics for guiding the radiation from the radiation source 14 to the radiation-directing sensor 30.

[0099] The intensity sensor 30 generates a synchronization signal based on detecting / sensing radiation within a relevant wavelength range, specifically detecting / sensing radiation emitted by the radiation source 14. In some non-limiting embodiments, the intensity sensor 30 generates the synchronization signal when it detects / senses radiation emitted by the radiation source 14. In other non-limiting embodiments, the intensity sensor 30 generates the synchronization signal if it does not detect / sensor radiation within the relevant wavelength range.

[0100] Intensity sensor 30 provides a synchronization signal to temperature measuring device 16, which performs thermal radiation measurement (via sensor 20) based on the synchronization signal, such that sensor 20 measures thermal radiation (emitted by substrate 12) only during the measurement time interval (corresponding to the inactive period of radiation source 14). For example, processor 18 of temperature measuring device 16 can command sensor 20 to perform thermal radiation measurement in response to receiving the synchronization signal from intensity sensor 30.

[0101] Figure 9 Showing something similar to Figure 8 An alternative configuration, but in which the intensity sensor 30 is integrated as part of the temperature measurement device 16, so that sensors 20 and 30 are both deployed within a single housing or mechanical body. Here, as in Figure 8 In this process, intensity sensor 30 detects / senses / measures the radiation emitted by radiation source 14 to determine when radiation source 14 is inactive (corresponding to the measurement time interval) and / or when radiation source 14 is active (corresponding to the irradiation time interval). Each of sensors 20 and 30 may have a separate optics (i.e., sensor 20 may be coupled with...). Figure 3 The optical element 23 is associated with the sensor, and the sensor 30 may have a separate optical element, as shown in the reference above. Figure 8 (As mentioned). Alternatively, sensors 20 and 30 can share optics (e.g., Figure 3 The optical device 23 in the substrate can be deployed to direct the radiation from the radiation source 14 and the radiation-directing sensors 20 and 30 to the substrate 12.

[0102] exist Figure 9 In the embodiment shown, the processor 18 can receive a synchronization signal from the intensity sensor 30 and can command the sensor 20 to perform thermal radiation measurements based on the received synchronization signal.

[0103] Figure 10 Is with Figure 1In another similar embodiment, the difference being that the temperature measuring device 16 also includes an amplifier 22 for amplifying the temperature indication signal generated by the sensor 20, and a switch 21 for selectively positioning the sensor 20 in signal communication with the amplifier 22. The sensor 20 also continuously measures the intensity of thermal radiation and is sensitive not only to radiation within a specific wavelength range emitted by the radiation source 14 when the substrate 12 is heated by the source 14, but also to radiation within a specific wavelength range emitted by the radiation source 14. Nominally, the switch 21 can be in the open position, decoupling the sensor 20 from the amplifier 22 (i.e., not signaling with the amplifier 22). Therefore, when the switch 21 is in the open position, the output signal generated by the sensor 20 in response to any radiation measurement is not amplified. When the switch 21 is in the closed position, the sensor 20 is placed in signal communication with the amplifier 22, such that the output signal generated by the sensor 20 in response to any thermal radiation measurement is amplified by the amplifier 22. The switching of switch 21 between the open and closed positions is controlled by a control input received from controller 24 in the form of a synchronization signal, such that amplifier 22 is decoupled from sensor 20 for a small amount of time before or during the time it takes for radiation source 14 to switch from an inactive state to an active state. In the example shown, processor 18 acts as a relay, which actuates switch 21 to open and close based on the synchronization received from controller 24. Controller 24 provides a synchronization signal corresponding to the switching of radiation source 14 between an active and inactive state, such that when radiation source 14 is active, switch 21 is in the open position to decouple amplifier 22 from sensor 20, and when radiation source 14 is inactive, switch 21 is in the closed position. Therefore, switch 21 is primarily closed during the measurement time interval, such that amplifier 22 amplifies the signal generated by sensor 20 only during the measurement time interval, and switch 21 is primarily open during the irradiation time interval, such that the radiation intensity measurement performed by sensor 20 is not amplified and the temperature measurement performed by device 16 is effectively interrupted / terminated.

[0104] The synchronization signal used in the embodiments of this disclosure can take various forms, including, for example, a time-varying signal that is continuous for a specified duration, one or more pulse or step signals, or one or more trigger-type signals that may include pulse / step signals or digital signals. In a non-limiting example, the synchronization signal is a pulse or step that exhibits a high or low value when the radiation source 14 is active, and a low or high value when the radiation source 14 is inactive. In such an example, the temperature measuring device 16 measures the temperature (thermal radiation sensed via sensor 20) during time intervals when the synchronization signal has a low or high value (corresponding to an inactive time interval).

[0105] In another non-limiting example, for each inactive time interval, the synchronization signal may include a start trigger pulse indicating the start of the inactive time interval and an end trigger pulse indicating the end of the inactive time interval. In such an example, the temperature measuring device 16 begins measuring the temperature upon receiving the start trigger pulse and continues measuring the temperature until the end trigger pulse is received. In another similar non-limiting example, for each of the active time intervals, the synchronization signal may include a start trigger pulse indicating the start of the active time interval and an end trigger pulse indicating the end of the active time interval. In such an example, the temperature measuring device 16 begins measuring the temperature upon receiving the end trigger pulse (as associated with the end of an active time interval) and continues measuring the temperature until the start trigger pulse (as associated with the start of the next active time interval) is received. In another similar non-limiting example, a single trigger pulse may be used to indicate the transition of the radiation source to an inactive state, wherein the inactive state is pre-programmed to last for a duration equal to or slightly longer than the desired time for a single measurement by the temperature probe. At the end of this pre-programmed time interval, the radiation source automatically returns to the active state without sending a trigger pulse to indicate this transition.

[0106] Clearly, this paper also considers the combinations described above. For example, the synchronization signal may include high or low start and end trigger pulses indicating the start and end of an effective time interval, respectively, and may include low or high start and end trigger pulses indicating the start and end of a non-active time interval.

[0107] In some non-limiting embodiments, the synchronization signal can serve as a trigger signal for the temperature measuring device 16 to begin measuring the temperature of the substrate 12, while in other embodiments, the synchronization signal can serve as a trigger signal for the temperature measurement device 16 to stop measuring the temperature of the substrate 12. In other non-limiting embodiments, the receipt of the synchronization signal (via the temperature measuring device 16) triggers the temperature measuring device 16 to measure the temperature of the substrate 12, while in other embodiments, the temperature measuring device 16 is not triggered to measure the temperature of the substrate 12 without the receipt of the synchronization signal.

[0108] Continue to refer to Figure 4-10 Please refer to the following: Figure 11 The illustration shows an example state of a synchronization signal that can be used to provide synchronization between the temperature measuring device 16 and the radiation source 14 when switching between activation and inactivation. Here, when the signal changes from a "low" signal level (specified as...),... A L Increase to "high" signal level (specified as) A H These instances are sometimes labeled in the diagram. T INACThe measuring device 16 starts its temperature measurement simultaneously with the rising signal, and at a predetermined time interval (in... Figure 11 Designated as T MEAS Temperature measurement is completed within the time frame, after which radiation source 14 sometimes automatically returns to the active state, as marked in the diagram. T AC Therefore, the temperature measuring device 16 is able to measure the temperature of the substrate 12 only during the measurement time interval, that is, during the period when the radiation source 14 is inactive.

[0109] For example, a synchronization signal can be implemented as an electrical signal, where the "high" and "low" amplitude values ​​correspond to the high and low voltages used to generate the signal; for example, 5 volts represents "high" and 0 volts represents "low".

[0110] The synchronization between the temperature measuring device 16 and the radiation source 14 in active and inactive states, particularly when implemented as an LED or laser source, provides a significant advantage over conventional substrate temperature monitoring solutions by enabling the temperature measuring device 16 to measure temperature / thermal radiation only during the period when the radiation source 14 is inactive (and preferably during the entire period when the radiation source 14 is inactive). By doing so, the temperature measuring device is not affected by the glare from a much stronger thermal radiation source, which typically hinders the ability of temperature probes to accurately detect the typically small thermal radiation signals emitted from the substrate 12.

[0111] In a particularly preferred synchronous implementation, synchronization enables the device 16 to begin temperature measurement precisely at the moment the radiation source 14 switches to the inactive state, and precisely at the moment the temperature probe completes its measurement, to return the radiation source to the active state. This synchronous implementation minimizes the duration of the inactive state, thereby reducing uncontrolled cooling of the substrate 12 that occurs during the inactive state intervals, such as… Figure 7 As illustrated schematically. Furthermore, reducing the inactive state time interval to an absolute minimum allows for more frequent inactive state measurement intervals to be inserted into the heating profile. This is particularly important when used in conjunction with a closed-loop temperature control scheme, where more frequent temperature measurements allow the temperature controller to perform control corrections more frequently, resulting in more stringent and robust temperature control.

[0112] However, it should be noted that the measurement and synchronization scheme disclosed herein can also be applied to situations where precise closed-loop control is not required, such as for data logging or collection purposes, or for issuing alarms or warnings if the measured temperature exceeds the preferred temperature range.

[0113] A flowchart of a process (i.e., method) 1200 for measuring / monitoring substrate temperature according to an embodiment of the disclosed subject matter is also referenced. Figure 1-11 . Figure 12 The process and subprocesses are performed by source 14, temperature measuring device 16 and their associated components, including sensor 20 and optional sensor 30. Figure 12 Some processes and subprocesses are computerized processes executed by controller 24 and / or processor 18. These processes and subprocesses are, for example, executed automatically and preferably in real time. It is assumed that during execution... Figure 12 Prior to the process, substrate 12 has been deployed in a substrate processing system, such as a heat treatment chamber, which includes a heat source and / or a radiation source (e.g., source 14), which in some embodiments is deployed to irradiate substrate 12 to heat the substrate, and a computer control device (e.g., controller 24) for turning the source on and off to control the switching between an active state and an inactive state, and in some embodiments controlling the radiation intensity level state emitted by the source when it is active.

[0114] Process 1200 begins at step 1202, where controller 24 switches source 14 to an active state, causing source 14 to heat substrate 12. In the context of heat treatment, source 14 is a radiation source that irradiates substrate 12 when switched to the active state in step 1202, thereby heating substrate 12 during the radiation time interval. In step 1204, controller 24 switches source 14 to an inactive state, causing source 14 to either not radiate or radiate a negligible amount of radiation. In the context of heat treatment, when switched to the inactive state in step 1204, source 14 no longer irradiates substrate 12, causing source 14 to emit no radiation or emit a negligible amount of radiation. Source 14 remains in an inactive state during the measurement time interval. In step 1206, temperature measuring device 16, deployed near substrate 12, begins measuring the temperature of the surrounding environment to measure the temperature of substrate 12 at the beginning (i.e., the end) of the measurement time interval (irradiation time interval). After the temperature measurement is completed, process 1200 then moves to step 1208 – which is generally the same as step 1202 – in which controller 24 switches source 14 to an active state, causing source 14 to heat substrate 12. Due to the synchronization between the temperature measuring device 16 and the switching of source 14 between active and inactive states, the temperature measuring device stops measuring the temperature of the surrounding environment, so that no thermal radiation is emitted by the substrate and no radiation (and in the case of heat treatment, emitted by source 14) is captured by the temperature measuring device 16. Process 1200 then returns to step 1204 and repeats itself until temperature monitoring terminates.

[0115] In some embodiments, process 1200 includes an additional step 1210 in which a synchronization signal (via controller 24 or via intensity sensor 30 deployed to measure the intensity of radiation emitted by radiation source 14) is provided to temperature measuring device 16, indicating when radiation source 14 is in an active or inactive state, such that temperature measuring device 16 can start and stop temperature measurement synchronously with the switching between active and inactive states.

[0116] Although embodiments of this disclosure have been described so far as having a temperature measuring device 16 synchronized with the switching rate of source 14, with source 14 electronically controlled by a dedicated controller 24 separate from the temperature measuring device 16, other embodiments are possible in which the controller is integrated as part of the temperature measuring device. Such embodiments may be particularly valuable when the temperature measuring device is implemented as a temperature probe integrated as part of a heat treatment system. In such embodiments, the processor of the temperature monitoring device can be configured to perform the functions of the controller 24 described above (e.g., see reference 14). Figure 1 and Figure 2 Furthermore, the controller 24 itself can be removed. Therefore, the processor of the temperature measuring device, such as processor 18, can control the switching of the radiation source 14 between an active and inactive state and direct it to the sensor 20 (or amplifier switch, e.g., ...). Figure 10 Switch 21 in the middle provides synchronization.

[0117] While the temperature control / monitoring / measurement methods, apparatus, and devices of this disclosure are particularly well-suited for use with radiation sources 14 implemented as multiple electronically controllable and switchable LEDs or lasers, they are also useful when deployed with radiation sources implemented as lamps or other incandescent sources. In such embodiments, it may be advantageous to add a time delay to the start time of the measurement interval to account for the time taken for residual radiative emission to dissipate after the lamp or other incandescent source is turned off. This delay may be dynamically included in a synchronization signal or may be programmed into the processor 18 of the temperature measuring device 16. Adding such a delay time to the start time of the measurement interval can also be used to compensate for delays introduced by other components of the system besides the radiation source itself, but this would cause the source with the time required for radiation to reduce its radiative output to a negligible level. For example, the radiation source power supply may also introduce delays or time dynamics to reduce the radiation output of the radiation source, and these delays and time dynamics can also be compensated for by adding a time delay to the start time of the measurement interval.

[0118] The various sensors described herein are electromagnetic radiation sensors, which are sensitive to radiation in specific bands or wavelength regions of the electromagnetic spectrum. These sensors may also be referred to as "detectors" and can be implemented in various ways, including, for example, photodetectors, photosensors, photodiodes, or any other type of sensing device that can convert sensed electromagnetic radiation into an electric current or other types of information-carrying signals. In some embodiments, sensor 20 and / or sensor 30 generate / produce analog signals in response to sensed radiation, while in other embodiments, sensor 20 and / or sensor 30 generate / produce digital signals in response to sensed radiation. In embodiments where the analog signal is generated by the sensor, an analog-to-digital converter circuit preferably communicates with the sensor signal to convert the analog signal into a digital signal.

[0119] As mentioned, according to the embodiments disclosed herein, the radiation source (e.g., an LED, a laser) has a peak emission wavelength that may differ from the wavelength at which the temperature measuring device operates. In embodiments where a sensor is used to detect the presence or absence of radiation emitted by a radiation source (e.g., intensity sensor 30) within a relevant wavelength range to generate a synchronization signal, it should be understood that such a sensor preferably operates at or near the peak emission wavelength of the radiation source. Furthermore, it should be understood that the wavelength values ​​and ranges shown above and in the accompanying drawings are merely exemplary and are generally provided to more clearly illustrate the temperature measurement / monitoring methods of embodiments of this disclosure. The teachings of embodiments of this disclosure can be applied to radiation emission and measurement at other wavelength values ​​and ranges, which should be apparent to those skilled in the art.

[0120] As described above, according to a second aspect of this disclosure, the device 16 is further configured to measure radiation in order to determine the reflectivity and / or emissivity of the substrate 12. As described above, the device 16 is generally configured to measure radiation from the substrate 12 (and the environment surrounding the substrate 12), and therefore can be combined with the above-described synchronous methods to determine and / or calculate and / or monitor and / or measure one or more parameters of the substrate 12 other than temperature, specifically including the reflectivity and / or emissivity of the substrate 12. The following paragraphs describe methods for determining the reflectivity and / or emissivity of the substrate 12 according to the aforementioned aspects of this disclosure; reference continues... Figure 1-13B And specifically refer to Figure 14 .

[0121] As an introduction, the reflectivity and transmittance of the substrate can be used to determine the emissivity of the substrate 12 by the following relationship (as a result of the first and second laws of thermodynamics): Emissivity = 1 - Reflectivity - Transmittance.

[0122] In the special case where the measuring device operates in a band where the substrate’s transmittance is practically zero (the band where the substrate is opaque), the emissivity can be determined by measuring the substrate’s reflectivity separately (because the transmittance is almost zero).

[0123] Therefore, if the reflectivity of substrate 12 can be determined within the effective opaque band of the substrate, the emissivity of substrate 12 can be easily calculated from said band. According to certain embodiments of the second aspect of this disclosure, the reflectivity of substrate 12 is first determined, and then the emissivity of substrate 12 is calculated based on the determined reflectivity.

[0124] According to some embodiments, the reflectivity of substrate 12 is determined based on measurements (performed by device 16) taken when radiation source 14 is in an inactive and active state. The following paragraphs describe a particular exemplary method by which the reflectivity of the substrate can be determined from measurements taken in both inactive and active states.

[0125] refer to Figure 14 When the radiation source is inactive, the measuring device 16 collects thermal radiation from the substrate 12. This radiation is indicated by wavy arrow 32. When the radiation source is switched to active mode, the measuring device 16 continues to collect thermal radiation emitted from the substrate 12, and additionally collects (a) radiation emitted by the radiation source 14 after reflection from the substrate 12, as indicated by thick dashed arrow 34, and (b) radiation emitted by the radiation source 14 that impacts the measuring device 16 without first being reflected from the substrate 12, as indicated by thin dashed arrow 35. It should be understood that... Figure 14 The arrows shown are merely exemplary paths that each type of radiation described in this paragraph may take.

[0126] make I inactive The intensity of radiation incident on device 16 when radiation source 14 is in an inactive state, and I active The power is the intensity of radiation incident on device 16 when the radiation source is in an active state with a specific power setting. P reflectivity Please note the difference between these two signals. I difference = I active - I inactive It does not depend on the intensity of thermal self-emission emitted by the substrate 12, but it does contain information about the intensity of radiation reflected from the substrate 12.

[0127] In order to I differenceTo convert the reflectance to a value representing the reflectance of substrate 12, a calibration procedure needs to be performed. There are many possible methods to calibrate this measurement; one exemplary method is described below:

[0128] measure I difference when Known reflectivity ρ ref1 and ρ ref2 When the two substrates 12 are respectively placed in the system 10. The two substrates... I difference Called I diff1 and I diff2 (corresponding to reflectivity ρ respectively) ref1 and ρ ref2 (Measurements of the substrate). For example, in semiconductor processing applications, bare silicon wafers are often used as one of the reference substrates, having a known reflectivity at 950 nm wavelength and 30°C. ρ ref1 = 0.32. Another reference reflectivity could be, for example, in system 10 where substrate 12 has been completely removed, resulting in ρ ref2 = 0. (Note that in this case, in some system designs it may be necessary to also remove any reflective surfaces immediately behind substrate 12, even without substrate 12). The general reflectivity of any substrate placed in system 10 is then... ρ It can be calculated as follows:

[0129]

[0130] Where the constant C 1 and C 2. Based on calibration measurements:

[0131]

[0132]

[0133] The above equation applies to the case where the reflected radiation 34 collected by the measuring device 16 typically undergoes only one reflection from the substrate 12 before impacting the measuring device 16. In cases where the geometry of the system 10 causes the significant intensity of the reflected radiation 34 to undergo multiple reflections from the substrate 12 before impacting the measuring device 16, the above equation needs to be modified to account for the effects of these multiple reflections. These multiple reflection effects are referred to as the "cavity effect," and the formulas used to modify the above equation to explain these effects are well known to those skilled in the art.

[0134] Now consider the general case where all three of the following actions need to be performed when processing a given substrate 12: (a) heating the substrate to a desired temperature distribution, (b) measuring the substrate temperature (or thermal self-emission), and (c) measuring the substrate reflectivity (and the emissivity of opaque substrates). The required actions are: (a) placing the radiation source in an active state at a power setting that is intended to provide the desired substrate heating distribution, and (b) periodically deactivating the radiation source to measure the temperature (and...). I inactive (for reflectivity measurement), and (c) periodically putting the radiation source into an active state, power setting. P reflectivity To measure reflectance I active .

[0135] Please note that the substrate emissivity (and reflectivity) is expected to change very slowly with respect to substrate temperature; therefore, the three measurements described in the previous paragraph do not need to be performed at the same frequency. Typically, the majority (>80%) of the processing time is expected to be allocated to (a) heating the wafer to the desired temperature profile. The remaining <20% of the processing time will be allocated to measuring the temperature (thermal autoemissivity) and emissivity (reflectivity) of substrate 12, with temperature measurements performed more frequently than emissivity measurements. For example, if the substrate emissivity is considered to change very weakly as a function of temperature alone, it may be advantageous to measure the emissivity only once when the substrate enters the processing system 10, and then simply heat the substrate 12 and measure its temperature thereafter, without repeating the reflectivity measurement during the processing of the substrate. Alternatively, the emissivity of substrate 12 can be measured during substrate processing, for example, once every 10 temperature measurements.

[0136] Although the invention has been described in the context of heat treatment systems for heating and processing substrates, the temperature measurement / monitoring / tracking methods described herein are applicable to any heat treatment process that requires measurement of workpiece temperature / monitoring / tracking at least intermittently or periodically while being heated by one or more sources.

[0137] As previously mentioned, in some wafer processing systems, source 14 causes heating of substrate 12 and generates radiation. However, there is no causal relationship between the radiation generated when source 14 is active and the heating of substrate 12. In other words, in some cases, source 14 itself is not a radiation source that irradiates substrate 12 to heat it, and the fact that source 14 is active is not the cause of substrate heating, but rather a byproduct or side effect of some other aspect of the wafer process. Plasma etching or plasma deposition systems are an example of such processes, where the wafer is heated by the physical bombardment of charged particles in the plasma. These particle collisions and wafer collisions also generate radiation (i.e., radiation emission), which interferes with wafer temperature measurement. However, the generated radiation is not the cause of wafer heating, but a byproduct of particle bombardment. Nevertheless, to accurately measure / sense wafer thermal emission, it may be useful to be able to turn off the plasma to eliminate interfering plasma radiation during wafer temperature measurement.

[0138] Therefore, and as previously stated, the source 14 according to embodiments of this disclosure is not necessarily limited to a radiation source that irradiates the substrate, but is generally a source that causes heating of the substrate 12 when in an active state. Furthermore, the inactive state more generally corresponds to a state in which the source 14 substantially does not cause radiation or produces a negligible amount of radiation so as not to interfere with substrate temperature measurements. In some particularly preferred embodiments, the source 14 is, for example, a radiation source such as an LED or laser that irradiates the substrate to heat it, and can also be controlled to rapidly turn on and off so that the radiation source does not emit radiation or emits a negligible amount of radiation in the inactive state. In other embodiments, the source 14 causes heating of the substrate when in an active state, for example, when implemented as plasma in the case of a plasma etching or plasma deposition system. In such embodiments, when the source is in an inactive state, the source 14 substantially does not cause radiation or produces a negligible amount of radiation; in the example where the source is plasma, this refers to a state in which no charged particles bombard the wafer, such that charged particles do not collide with each other or with the wafer, resulting in no radiation or a negligible amount of radiation.

[0139] Various embodiments of this disclosure have been described for illustrative purposes, but these descriptions are not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein has been chosen to best explain the principles of the embodiments, their practical application, or technical improvements to technologies found in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

[0140] As used herein, the singular forms “a”, “an”, and “the” include plural references unless otherwise expressly stated in the text.

[0141] The term "exemplary" as used herein means "serving as an example, illustration, or illustration." Any embodiment described as "exemplary" is not necessarily to be construed as preferred or superior to other embodiments and / or as excluding the incorporation of features from other embodiments.

[0142] It should be understood that, for clarity, certain features of the invention described in the context of various embodiments may also be provided in combination in a single embodiment. Conversely, for brevity, different features of the invention described in the context of a single embodiment may also be provided individually or in any suitable sub-combination or applicable to any other described embodiments of the invention. Certain features described in different embodiments are not considered essential features of the embodiments unless the embodiment is invalid without the described element.

[0143] The appended claims are not intended to include the scope of multiple appendices, solely to comply with the formal requirements of jurisdiction that prohibit multiple appendices. It should be noted that all possible combinations of features implied by making the claims multiple-appendable are explicitly contemplated and should be considered part of the invention.

[0144] Although the invention has been described in conjunction with specific embodiments thereof, it will be apparent to those skilled in the art that many alternatives, modifications, and variations will be readily apparent. Therefore, it is intended to cover all such alternatives, modifications, and variations falling within the spirit and broad scope of the appended claims.

Claims

1. A method for measuring the temperature of a substrate, characterized in that, The method includes: Switch between one or more sources with multiple response times defined by multiple rise and fall times of less than 100 milliseconds: An active state, wherein the one or more sources heat at least a portion of the substrate, and A non-inactive state, wherein the one or more sources substantially do not cause radiation or cause a negligible amount of radiation; and Temperature measurement of at least a portion of the substrate is performed by a temperature measuring device, the temperature measuring device being synchronized with the switching between the active state and the inactive state, such that: i) During the plurality of response times, the one or more sources switch from the active state to the inactive state, and temperature measurement begins immediately after the one or more sources switch to the inactive state. ii) Immediately after the temperature measurement is completed, switch the one or more sources from the inactive state to the active state within the plurality of response times, and iii) The temperature measurement is performed only when the one or more sources are in the inactive state.

2. The method according to claim 1, characterized in that: The one or more sources irradiate the substrate to heat the substrate during the active state.

3. The method according to claim 1, characterized in that: The one or more sources include a plurality of light-emitting diodes or a plurality of laser sources, the plurality of light-emitting diodes or the plurality of laser sources being configured to irradiate the substrate.

4. The method according to claim 1, characterized in that: The one or more sources include plasma, which is configured to bombard the substrate with a plurality of charged particles during the active state.

5. The method according to claim 1, characterized in that: The temperature measuring device is synchronized with the switching between the active state and the inactive state via a synchronization signal, the synchronization signal corresponding to at least one of the following: the inactive state, the transition from the active state to the inactive state, or the transition from the inactive state to the active state.

6. The method according to claim 5, characterized in that: The synchronization signal is provided by an intensity sensor configured to sense radiation emitted by the one or more sources.

7. The method according to claim 5, characterized in that: The synchronization signal is provided by a controller associated with the one or more sources, which controls the switching of the one or more sources between the active state and the inactive state.

8. The method according to claim 1, characterized in that: The temperature measuring device includes a sensor that senses radiation emitted by the source and synchronizes with the switching between the active and inactive states of the one or more sources by recognizing a decrease in the emitted radiation corresponding to the activation of the inactive state.

9. The method according to claim 1, characterized in that: The active state is associated with at least one irradiation time interval, and each of the at least one irradiation time interval is a time interval during which the one or more sources emit radiation at an output power or average output power throughout the entire time interval, the output power or average output power being sufficiently high to heat the substrate; and the inactive state is associated with at least one measurement time interval, and each of the at least one measurement time interval is a time interval during which the one or more sources do not emit radiation, or emit radiation at an output power sufficiently low to be negligible for the temperature measuring device.

10. A system for measuring the temperature of a substrate, characterized in that, The system includes: One or more sources having multiple response times defined by multiple rise and fall times of less than 100 milliseconds, the one or more sources being configured to be associated with the substrate, the one or more sources being switchable between: an active state in which the one or more sources heat at least a portion of the substrate, and an inactive state in which the one or more sources substantially do not cause radiation or cause a negligible amount of radiation. A controller, the controller including at least one processor and configured to switch the one or more sources between the active state and the inactive state; and A temperature measuring device is configured to perform temperature measurement on at least a portion of the substrate. The temperature measuring device and the switching between the active and inactive states are synchronized with each other, such that: i) Within the response time, the one or more sources switch from the active state to the inactive state via the controller, and the temperature measurement begins immediately after the one or more sources switch to the inactive state. ii) Immediately after the temperature measurement is completed, the controller switches the one or more sources from the inactive state to the active state within the response time. iii) The temperature measurement is performed only when the one or more sources are in the inactive state.

11. The system according to claim 10, characterized in that: The at least one temperature measuring device is synchronized with the switching of the one or more sources via a synchronization signal, the synchronization signal corresponding to at least one of the following: the inactive state, a transition from the active state to the inactive state, or a transition from the inactive state to the active state.

12. The system according to claim 11, characterized in that: The synchronization signal is provided to the at least one temperature measuring device via the controller.

13. The system according to claim 11, characterized in that: The system further includes at least one intensity sensor configured to sense radiation emitted by the one or more sources.

14. The system according to claim 13, characterized in that: The at least one intensity sensor provides the synchronization signal to the at least one temperature measuring device.

15. The system according to claim 10, characterized in that: The temperature measuring device measures radiation and synchronizes with the switching of the one or more sources by recognizing a drop in radiation measurement corresponding to the activation of the inactive state.

16. The system according to claim 10, characterized in that: The one or more sources irradiate the substrate to heat the substrate during the active state.

17. The system according to claim 10, characterized in that: The one or more sources include multiple light-emitting diodes or multiple laser sources.

18. The system according to claim 10, characterized in that: The one or more sources include plasma, which is configured to bombard the substrate with a plurality of charged particles during the active state.

19. The system according to claim 10, characterized in that: The active state is associated with at least one irradiation time interval, and each of the at least one irradiation time interval is a time interval during which the one or more sources emit radiation at an output power or average output power throughout the entire time interval, the output power or average output power being sufficiently high to heat the substrate; and the inactive state is associated with at least one measurement time interval, and each of the at least one measurement time interval is a time interval during which the one or more sources do not emit radiation, or emit radiation at an output power sufficiently low to be negligible for the temperature measuring device.

20. A method for measuring thermal radiation emitted from a substrate, characterized in that, The method includes: Switch between one or more sources with multiple response times defined by multiple rise and fall times of less than 100 milliseconds: An active state, wherein the one or more sources heat the substrate, and A non-inactive state, wherein the one or more sources substantially do not cause radiation or cause a negligible amount of radiation; and The measurement of thermal radiation emitted by the substrate is performed by a thermal radiation measuring device, wherein the thermal radiation measuring device is synchronized with the switching between the active state and the inactive state, such that: i) During the response time, the one or more sources switch from the active state to the inactive state, and the measurement of thermal radiation begins immediately after the one or more sources switch to the inactive state. ii) Immediately after the thermal radiation measurement is completed, the one or more sources are switched from the inactive state to the active state within the response time, and iii) The measurement of thermal radiation is performed only when the one or more sources are in the inactive state.

21. The method according to claim 20, characterized in that: The method further includes: calculating the temperature of the substrate based on the measured thermal radiation.

22. A method for measuring the temperature of a substrate periodically irradiated by multiple radiation sources, characterized in that, The plurality of radiation sources can switch between an active state and an inactive state, wherein in the active state, the plurality of radiation sources irradiate the substrate to heat at least a portion of the substrate; and in the inactive state, the plurality of radiation sources emit substantially no radiation or emit negligible amounts of radiation, the plurality of radiation sources having a plurality of response times defined by a plurality of rise and fall times of less than 100 milliseconds, the method comprising: Based on a synchronization signal received by a temperature measuring device, during a period when the plurality of radiation sources are in an inactive state, a temperature measurement is performed on at least a portion of the substrate by the temperature measuring device, wherein the synchronization signal indicates at least one of the following: i) a period when the plurality of radiation sources are in the active state, ii) a period when the plurality of radiation sources are in the inactive state, iii) a period when the plurality of radiation sources change from the active state to the inactive state, or iv) a period when the plurality of radiation sources change from the inactive state to the active state. The synchronization signal synchronizes the temperature measuring device with the switching between the active state and the inactive state, such that: i) During the plurality of response time periods, the plurality of radiation sources switch from the active state to the inactive state, and the sensor immediately begins to sense thermal radiation after the plurality of radiation sources switch to the inactive state. ii) Immediately after the temperature measurement is completed, the plurality of radiation sources are switched from the inactive state to the active state within the plurality of response time periods, and iii) The thermal radiation is sensed by the sensor only when the plurality of radiation sources are in the inactive state, such that the sensor generates a temperature indication signal only during the period when the plurality of radiation sources are in the inactive state.

23. The method according to claim 22, characterized in that: The method further includes terminating the temperature measurement through the temperature measuring device during the period when the plurality of radiation sources are in the activated state.

24. The method according to claim 22, characterized in that: The temperature measuring device includes at least one sensor for sensing thermal radiation emitted by the substrate and generating the temperature indication signal in response to the sensed radiation, and the method further includes decoupling signal amplification electronics from the at least one sensor before or during the switching of the plurality of radiation sources from the inactive state to the active state.

25. The method according to claim 22, characterized in that: The synchronization signal is provided to the temperature measuring device through a controller that switches the plurality of radiation sources between an active state and an inactive state.

26. The method according to claim 22, characterized in that: The synchronization signal is provided by an intensity sensor configured to sense radiation emitted by the plurality of radiation sources.

27. A temperature measuring device for measuring the temperature of a substrate periodically irradiated by multiple radiation sources, characterized in that, The plurality of radiation sources can switch between an active state and an inactive state. In the active state, the plurality of radiation sources irradiate the substrate to heat at least a portion of the substrate. In the inactive state, the plurality of radiation sources emit substantially no radiation or emit negligible amounts of radiation. The plurality of radiation sources have multiple response times defined by multiple rise and fall times of less than 100 milliseconds. The temperature measuring device includes: A sensor senses thermal radiation emitted by the substrate during a period when the plurality of radiation sources are in the inactive state, based on a synchronization signal received by the temperature measuring device, and generates a temperature indication signal in response to the sensed thermal radiation. The synchronization signal indicates at least one of the following: i) a period when the plurality of radiation sources are in the active state; ii) a period when the plurality of radiation sources are in the inactive state; iii) a period when the plurality of radiation sources transition from the active state to the inactive state; or iv) a period when the plurality of radiation sources transition from the inactive state to the active state. The synchronization signal synchronizes the temperature measuring device with the switching between the active state and the inactive state, such that: i) During the plurality of response time periods, the plurality of radiation sources switch from the active state to the inactive state, and the sensor immediately begins to sense the thermal radiation after the plurality of radiation sources switch to the inactive state. ii) Immediately after the temperature measurement is completed, the plurality of radiation sources are switched from the inactive state to the active state within the plurality of response time periods, and iii) The thermal radiation is sensed by the sensor only when the plurality of radiation sources are in the inactive state, such that the sensor generates a temperature indication signal only during the period when the plurality of radiation sources are in the inactive state.

28. A temperature measuring device for measuring the temperature of a substrate periodically irradiated by multiple radiation sources, characterized in that, The plurality of radiation sources are configured to switch between an active state and an inactive state, wherein in the active state, the plurality of radiation sources irradiate the substrate to heat the substrate. In the inactive state, the plurality of radiation sources emit essentially no radiation or emit negligible amounts of radiation, and the plurality of radiation sources have multiple response times defined by multiple rise and fall times of less than 100 milliseconds. The temperature measuring device includes: A sensor senses thermal radiation emitted by the substrate and generates a temperature indication signal in response to the sensed thermal radiation, wherein the temperature measuring device is synchronized with the switching of the plurality of radiation sources between the active state and the inactive state, such that: i) During the plurality of response time periods, the plurality of radiation sources switch from the active state to the inactive state, and the sensor immediately begins to sense the thermal radiation after the plurality of radiation sources switch to the inactive state. ii) Immediately after the temperature measurement is completed, the plurality of radiation sources are switched from the inactive state to the active state within the plurality of response time periods, and iii) The thermal radiation is sensed by the sensor only when the plurality of radiation sources are in the inactive state, such that the sensor generates the temperature indication signal only during the period when the plurality of radiation sources are in the inactive state.

29. An apparatus configured to operate together with or as part of a heat treatment system for processing a substrate, characterized in that, The heat treatment system has multiple switchable radiation sources configured to switch between an active state and an inactive state. In the active state, the multiple switchable radiation sources irradiate the substrate to heat at least a portion of the substrate. In the inactive state, the multiple switchable radiation sources emit substantially no radiation or emit negligible amounts of radiation. The multiple switchable radiation sources have multiple response times defined by multiple rise and fall times of less than 100 milliseconds. The device includes: A first sensor is used to sense thermal radiation emitted by the substrate and generate a temperature indication signal in response to the sensed thermal radiation; A second sensor is used to sense radiation emitted by the plurality of switchable radiation sources and generate a synchronization signal corresponding to the inactive state; An amplifier circuit; and A controllable switch, associated with the first sensor and the amplifier circuit, and configured to switch between the following based on the synchronization signal: In the open position, the amplifier circuit is decoupled from the first sensor, and In a closed position, the amplifier circuit communicates with the first sensor only during the periods when the plurality of switchable radiation sources are in the inactive state. The synchronization signal synchronizes the first sensor with the switching between the active state and the inactive state, such that: i) During the plurality of response times, the plurality of switchable radiation sources switch from the active state to the inactive state, and the first sensor immediately begins to sense the thermal radiation after the plurality of switchable radiation sources switch to the inactive state. ii) Immediately after the temperature measurement is completed, the plurality of switchable radiation sources are switched from the inactive state to the active state within the plurality of response time periods, and iii) The thermal radiation is sensed by the first sensor only when the plurality of switchable radiation sources are in the inactive state, such that the sensor generates a temperature indication signal only during the period when the plurality of switchable radiation sources are in the inactive state.

30. A method for measuring thermal radiation emitted from a substrate, characterized in that, The method includes: Switch between one or more radiation sources with multiple response times defined by multiple rise and fall times of less than 100 milliseconds: An active state, wherein the one or more radiation sources irradiate a substrate to heat the substrate, and A non-active state, wherein the one or more radiation sources emit essentially no radiation or emit negligible amounts of radiation; To be performed by a device: A first radiation measurement during the inactive state, the first radiation measurement including radiation corresponding to the thermal emission of the substrate, and A second radiation measurement during the activation state, the second radiation measurement including: radiation corresponding to the thermal emission of the substrate; and radiation reflected by the substrate in response to radiation emitted by the one or more radiation sources. The device wherein the switching between the active state and the inactive state is synchronized, such that: i) During the plurality of response time periods, the one or more sources switch from the active state to the inactive state, and the first radiation measurement begins immediately after the one or more sources switch to the inactive state. ii) Immediately after the temperature measurement is completed, switch one or more sources from the inactive state to the active state within the plurality of response times, and iii) Perform the first radiation measurement only when the one or more sources are in the inactive state; and Based on the first radiation measurement and the second radiation measurement, at least one of a reflectivity or an emissivity of the substrate is calculated.

Images