Algorithm for accurately converting large-range optical signal into current

Abstract

Embodiments disclosed herein include a method of calibrating a tool for converting a photonic signal to an electrical signal. In one embodiment, the method includes connecting a calibration module to a calibration current source, finding a transfer function for multiple modes with the calibration module, and storing the transfer function in a lookup table.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Patent Application No. 17 / 862,278, filed on July 11, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments relate to the field of semiconductor manufacturing and, in particular, to processes and apparatus for calibrating pyrometers and emissometers. Background Art

[0004] Temperature control is a critical parameter for many process operations in the semiconductor industry. For example, in order to obtain process uniformity in applications such as thermal oxidation, heat treatment, etc., temperature control on the surface of a substrate (e.g., a silicon wafer) is critical. Due to the complexity of semiconductor processing tools, temperature readings for such processes are typically achieved using non-contact temperature measurement systems. Non-contact measurement tools may include pyrometers, emissometers, etc. In general, temperature measurement tools include a photodiode that receives an optical signal from the surface of the substrate being measured. For example, an infrared signal may be received by a photodiode.

[0005] Typically, the photocurrent is converted into a digital (electrical) signal. In semiconductor processing, the photocurrent has a large range. For example, the photocurrent can span multiple orders of magnitude (e.g., ten orders of magnitude). In certain cases, the photocurrent can be between 10 -14 Ampere (A) and 10 -4 The analog to digital converter (ADC) used with such a system can have high resolution, but the sensitivity of the ADC is limited over the entire dynamic range of the ADC. Summary of the invention

[0006] Embodiments disclosed herein include methods of calibrating a tool for converting photonic signals into electrical signals. In one embodiment, the method includes connecting a calibration module to a calibration current source, finding transfer functions for a plurality of modes using the calibration module, and storing the transfer functions in a lookup table.

[0007] In one embodiment, a tool for converting a photon signal into an electrical signal is provided. In one embodiment, the tool includes a photodiode, a signal scaling module, an ADC, a selector module, and a current calculation module.

[0008] In one embodiment, a method for converting a photon signal into an electrical signal includes receiving an optical signal with an ADC, selecting a mode based on a position of the optical signal within a dynamic range of the ADC, setting an integration time and range of the mode, and calculating a current based on a transfer function of the mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is an illustration of a pyrometer for measuring the temperature of a hot body with a non-contact solution according to one embodiment.

[0010] Figure 2A is an illustration of various modules in a pyrometer including an integrated calibration module for a pair of photodiodes according to one embodiment.

[0011] Figure 2B is an illustration of various modules in a pyrometer including an integrated calibration module for a single photodiode according to one embodiment.

[0012] Figure 3 is a process flow diagram of a process for calibrating a pyrometer according to one embodiment.

[0013] Figure 4 is a process flow diagram of a process for using a calibrated pyrometer according to one embodiment.

[0014] Figure 5 is a block diagram of a pyrometer including an integrated calibration module according to one embodiment.

[0015] Figure 6 is a process flow diagram of a process for assembling and calibrating a pyrometer according to one embodiment.

[0016] Figure 7 is a cross-sectional view of a semiconductor processing tool including one or more pyrometers according to one embodiment.

[0017] Figure 8 A block diagram of an exemplary computer system that may be used in conjunction with a processing tool is shown according to one embodiment. DETAILED DESCRIPTION

[0018] The systems described herein include processes and devices for calibrating pyrometers and emission meters. In the description below, many specific details are set forth in order to provide a thorough understanding of the embodiments. It is apparent to those skilled in the art that the embodiments can be practiced without these specific details. In other cases, well-known aspects are not described in detail in order to unnecessarily obscure the embodiments. In addition, it should be understood that the various embodiments shown in the drawings are illustrative representations and are not necessarily drawn to scale.

[0019] As described above, the use of non-contact temperature measurement solutions is to provide improved process uniformity across the substrate surface. The non-contact temperature measurement solution may include an emission meter and a pyrometer. As used herein, any reference to one of an emission meter or a pyrometer may be considered to also include both an emission meter and a pyrometer. That is, the embodiments described herein may be applied to both an emission meter and a pyrometer.

[0020] Typically, non-contact temperature measurement solutions include an analog-to-digital converter (ADC). The ADC may have high resolution, but lacks sensitivity over the entire dynamic range. Therefore, embodiments disclosed herein include pyrometer and / or emission meter solutions that include hardware, firmware, and / or software that allow internal calibration processing to be implemented. For example, the dynamic range of the ADC can be utilized with multiple modes. Each mode may include an integration time and a range. The integration time may be an integration time set for the ADC for recording numerical values, and the range may be a value used by a signal scaling module. In one embodiment, each mode may be associated with a transfer function including two or more coefficients (e.g., coefficients k and b). When a particular mode is selected, the calibration current is calculated using the associated transfer function coefficients. For example, the coefficient k may be multiplied by the ADC value, and the coefficient b may be an offset. In some embodiments, dark current values ​​may also be used to more accurately measure temperature.

[0021] Reference now Figure 1 , shows a diagram of a processing system 100 according to one embodiment. The processing system 100 may include a pyrometer 120 and a thermal body 121. The pyrometer 120 measures the temperature of the thermal body 121 using a non-contact measurement process. For example, thermal energy 122 (e.g., infrared electromagnetic radiation) may be emitted by the thermal body 121 and propagate toward the pyrometer 120. The pyrometer 120 may include one or more photodiodes to convert the optical thermal energy 122 into a digital signal that may be used to calculate the temperature of the thermal body 121. As will be described in more detail below, the pyrometer 120 may include an integrated calibration module to properly calibrate the pyrometer 120.

[0022] In one embodiment, the thermal body 121 may include any number of components used in a semiconductor manufacturing process. For example, the thermal body 121 may be a semiconductor substrate, such as a silicon wafer or any other semiconductor wafer. In other embodiments, the thermal body 121 may be a glass substrate, a ceramic substrate, etc. The temperature of components of a semiconductor processing tool may also be measured using the pyrometers described herein. For example, the thermal body 121 may include a chamber lid, a clamping surface, etc. More generally, the thermal body 121 may be any object whose temperature is desired to be measured. That is, the pyrometers 120 disclosed herein are not limited to semiconductor processing environments.

[0023] In one embodiment, the pyrometer 120 can be integrated into a semiconductor processing tool. For example, a rapid thermal processing (RTP) chamber (e.g., a thermal oxidation chamber) can utilize one or more pyrometers 120. However, it should be understood that any type of semiconductor processing tool can benefit from the non-contact temperature measurement provided by the pyrometer 120 described herein. Figure 7 An example of a particular processing chamber utilizing one or more pyrometers 120 is shown in greater detail.

[0024] Now refer to Figure 2A , shows a schematic diagram of a pyrometer 220 according to one embodiment. In one embodiment, the pyrometer 220 may include a pair of photodiodes 223 A and 223 B The photodiode 223 may be adapted to convert an optical signal into an electrical signal. For example, the photodiode 223 A and 223 B Can be configured to detect infrared electromagnetic radiation emitted by a hot body such as a semiconductor wafer.

[0025] In one embodiment, the photodiode 223 can be coupled to a measurement system. The measurement system can include a signal scaling module 226 and an ADC 227. In the illustrated embodiment, a single scaling module 226 and ADC 227 are shown. However, in other embodiments, each photodiode 223 can be coupled to a different signal scaling module 226 and ADC 227. In one embodiment, the signal scaling module 226 can be responsible for changing (e.g., amplifying) the signal provided by the photodiode 223 before it reaches the ADC 227. The ADC 227 can have any suitable ADC architecture, sampling rate, dynamic range, etc.

[0026] The pyrometer 220 may also include a calibration module 228. That is, the calibration module 228 may be integrated into the pyrometer 220 itself. A or 224 B The calibration module 228 is used in conjunction with the calibration current source 225. The calibration current source 225 may include a battery, etc. The calibrated current source 225 may then be used to develop a transfer function for each operating mode of the ADC 227. For example, each mode may include an integration time for the ADC 227 and a range for the signal scaling module 226. The transfer function may include two coefficients for calculating an accurate temperature report. After the calibration is completed, the switch 224 A and 224 B The calibration current source 225 can be disconnected to return the input to the photodiode 223.A and 223 B A more detailed description of the calibration system and method for calibrating the pyrometer 220 is described in more detail below.

[0027] In one embodiment, the pyrometer 220 may also include a selector 229. The selector 229 may be used to select a mode for operating the ADC 227 and the signal scaling module 226. The selector 229 may select a mode based on different parameters. In one embodiment, the selector 229 may be selected to couple to the first photodiode 223. A mode of the ADC 227 providing the best performance, or for coupling to the second photodiode 223 B In other embodiments, the selector 229 may use the first photodiode 223 to select the mode that provides the best performance for the ADC 227. A or the second photodiode 223 B For example, any photodiode 223 having the highest or lowest signal strength may be used to select the desired mode.

[0028] In one embodiment, the pyrometer 220 may also include a calculator module 230. The calculator module 230 may use a transfer function for a given mode in order to generate an accurate report of the temperature observed by the pyrometer. In one embodiment, the transfer function is stored in a lookup table or memory (not shown) on the pyrometer 220. The transfer function may include a first coefficient (k) that is multiplied by the ADC 227 reading and a second coefficient (b) that is an offset value. The calculator module 230 may take the form of I=k*ADC+b.

[0029] In some embodiments, the dark current value may also be stored in a lookup table or memory. The dark current may be subtracted from the calculated value in order to determine the exact value of the temperature. In such embodiments, the calculator module 230 may take the form of I=k*ADC+b-dark current. The dark current may be the current value flowing through the pyrometer 220 when the pyrometer 220 is in a dark environment. That is, in the case where the photodiode 223 is tuned to detect infrared radiation, the photodiode 223 may be placed in a housing that is opaque to infrared radiation in order to measure the dark current. Without subtracting the dark current, noise in the system may cause inaccurate temperature readings. The dark current may be independent of the mode.

[0030] Now refer to Figure 2B , shows a schematic diagram of a pyrometer 220 according to another embodiment. Figure 2B The pyrometer 220 in may be substantially similar to Figure 2AThe pyrometer 220 in FIG. 1 is different in that the number of photodiodes 223 is the same. Instead of two photodiodes 223, there is only a single photodiode 223. A and 223 B Although one photodiode 223 and two photodiodes 223 are shown A and 223 B , but it should be understood that the pyrometer 220 may have any number of photodiodes 223 (eg, one or more photodiodes).

[0031] In the illustrated embodiment with a single photodiode 223, the selector 229 is less complex. The selector 229 only needs to consider a single photodiode 223, rather than selecting between two photodiodes 223. Thus, the mode selected by the selector 229 will optimize the performance of the single photodiode 223. Furthermore, since only a single photodiode 223 is provided, connections between components are reduced since only a single channel is required.

[0032] Reference now Figure 3 , shows a process flow diagram of a process 340 for calibrating a pyrometer according to one embodiment. In one embodiment, the pyrometer being calibrated may include one or more photodiodes, such as the examples described in more detail above. In addition, calibration hardware, firmware and / or software may be integrated within the pyrometer.

[0033] In one embodiment, process 340 may begin with operation 341, which includes connecting a calibration module to a calibration current source. In one embodiment, the input line of the calibration module may be implemented by a switch. During the calibration operation, the switch may be positioned so that the input line is electrically coupled to the calibrated current source. In one embodiment, the calibration current source is a current source with a known current. In one embodiment, the calibration current source may be implemented using a battery integrated with the pyrometer. However, in other embodiments, the current source may be disposed external to the pyrometer. In one embodiment, the calibration current source may provide a single current value. In other embodiments, the calibration current source may be configured to provide a plurality of different current values. The use of a calibration current source allows the calibration module to know what the input current should be so that the effects (noise, etc.) caused by the circuit system of the pyrometer can be determined.

[0034] In one embodiment, the process 340 may continue with operation 342, which includes finding a transfer function for multiple modes. In one embodiment, each mode may correspond to a pairing of an integration time of the ADC and a range of a signal scaling module. In order to increase the sensitivity of the ADC over the entire dynamic range of the ADC, multiple modes are used. A selector will select a specific mode based on the location of the signal within the dynamic range of the ADC. In one embodiment, the transfer function for each mode may include a pair of coefficients. The first coefficient (k) will be multiplied by the ADC output, and the second coefficient (b) is an offset value.

[0035] In one embodiment, the transfer function can be calculated using any known processing operation. For example, the transfer function can be a pair of coefficients (k and b) that cause the measured current to be equal to the current of the calibration current source. In this way, the impact of the circuit system, modules, and components on the output can be taken into account to provide a more accurate temperature measurement. In addition, it should be understood that the circuit system, modules, and components can have different impacts depending on the amount of current provided by the system. Therefore, different modes are used to calibrate the entire dynamic range of the ADC.

[0036] In one embodiment, process 340 may continue with operation 343, which includes storing the transfer function in a lookup table. In one embodiment, the transfer function may be stored in a lookup table provided in a memory accessible to the pyrometer. For example, a memory die or other memory architecture may be integrated into the pyrometer. That is, the memory source may be provided on a board that houses the electronics for the pyrometer.

[0037] Reference now Figure 4 , shows a process flow diagram of a process 450 for measuring temperature with a pyrometer according to one embodiment. In one embodiment, the pyrometer can be similar to any pyrometer described in more detail herein. More specifically, the pyrometer can be a pyrometer that includes an integrated calibration module to provide calibration of the pyrometer.

[0038] In one embodiment, process 450 may begin with operation 451, which includes receiving an optical signal with an ADC. In one embodiment, the optical signal may first be processed with a photodiode. The photodiode may convert the optical signal (e.g., an infrared signal) into an electrical signal. The electrical signal may then pass through a signal scaling module before reaching the ADC. In one embodiment, the pyrometer includes a single photodiode. In other embodiments, the pyrometer may include two or more photodiodes. In such embodiments, each photodiode may report an electrical signal to a different channel of the ADC or to two different ADCs.

[0039] In one embodiment, process 450 may continue with operation 452, which includes selecting a mode based on the location of the electrical signal within the dynamic range of the ADC. That is, the dynamic range of the ADC may be segmented into multiple discrete segments. The segmentation of the dynamic range allows different parameters to be applied to the signal to optimize the accuracy and sensitivity of the ADC. In one embodiment, the mode may include the integration time of the ADC and the range of the signal scaling module.

[0040] In one embodiment, the mode may be selected based on the output of a channel of the ADC coupled to the first photodiode or based on the output of a channel of the ADC coupled to the second photodiode. In other embodiments, the mode may be selected based on which ADC channel is highest or lowest. It should be understood that while separate channels of a single ADC are contemplated herein, similar embodiments may be used when each photodiode has a separate ADC.

[0041] In one embodiment, process 450 may continue with operation 453, which includes setting the integration time and range of the mode. In one embodiment, the integration time may be applied to the ADC and the range may be applied to the signal scaling module. The values ​​of the integration time and range may be stored in a memory integrated into the pyrometer.

[0042] In one embodiment, process 450 may continue with operation 454, which includes calculating the current based on the transfer function of the mode. The transfer function for the mode may be stored in a lookup table. The transfer function may be determined using a calibration process, such as the process described in more detail above. The transfer function may include a pair of coefficients (k and b). In one embodiment, the calculation may include using the coefficients to calculate the current. For example, the equation may be as follows: I=k*ADC+b.

[0043] In some embodiments, the calculation may also include an adjustment for dark current in the system. In such embodiments, the equation may be as follows: I = k*ADC + b - dark current. Dark current values ​​may also be stored in a lookup table. Dark current may be determined during calibration of the pyrometer, during assembly of the pyrometer, or at any other time.

[0044] Reference Figure 5 , shows a plan view of a pyrometer 520 according to one embodiment. In one embodiment, the pyrometer 520 may include a board 519. The board 519 may be a printed circuit board, etc. In one embodiment, a plurality of modules and / or components may be coupled to the board 519.

[0045] In one embodiment, a photodiode 523 may be disposed on the board 519. The photodiode 523 may include an optical element to detect an optical signal (e.g., an infrared electromagnetic radiation signal) from a thermal body. In the illustrated embodiment, a single photodiode 523 is shown. However, it should be understood that embodiments may include two or more photodiodes 523. The photodiode 523 converts the optical signal into an electrical signal.

[0046] In one embodiment, the pyrometer 520 may also include a signal scaling module 526 and an ADC 527. The signal scaling module 526 and the ADC 527 may be used to convert the electrical analog signal into a digital signal that may be used to calculate the current obtained by the photodiode 523. The signal scaling module 526 and the ADC 527 may include multiple channels to accommodate multiple photodiodes 523.

[0047] In one embodiment, the pyrometer 520 may include a mode selector module 529. The mode selector module 529 may be used to select an appropriate mode to accurately measure the signal from the photodiode 523. The mode may include an integration time of the ADC 527 and a range of the signal scaling module 526. The integration time of the ADC 527 and the range of the scaling module 526 may be stored in a lookup table accessible by the mode selector 529. For example, the lookup table may be provided in the memory 531.

[0048] In one embodiment, the pyrometer 520 may also include a calibration module 528. The calibration module 528 is used to calibrate the signal obtained from the photodiode 523. The calibration module 528 can generate a plurality of transfer functions. Each transfer function can be associated with one of the above modes. The transfer function can include a pair of coefficients (k and b). The calculator module 530 can use these coefficients to calculate a calibration value of the current using equations such as those described in more detail above.

[0049] In one embodiment, the calibration module 528 can be configured to selectively couple to the calibration current source 525. The calibration current source 525 can provide a known current value to facilitate calibration of the pyrometer 520. Specifically, the calibration module 528 has a known current from the calibration current source 525 and receives an input current from the system through the circuit system of the pyrometer 520. The difference between the calibration current and the input current can then be determined, and the calibration module 528 generates coefficients of a transfer function to convert the input current to a value equal to the calibration current. In one embodiment, the calibration current source 525 provides a single current. In other embodiments, the calibration current source 525 can provide multiple different current values.

[0050] Reference now Figure 6, shows a process flow diagram of a process 660 for assembling a pyrometer according to one embodiment.

[0051] In one embodiment, process 660 may begin with operation 661, which includes assembling a board without a photodiode. The board may include components or modules such as a signal scaling module, an ADC, a calibration module, a calibration current source, a selector module, and a calculator module.

[0052] In one embodiment, process 660 may continue with operation 662, which includes calibrating the circuit board. The calibration may be similar to any of the calibration processes described in more detail above. For example, a calibration current source may provide an input current having a known value to the calibration module, which input current passes through the electronic component. The calibration module detects the level of the current and compares the level to the known calibration current level. The calibration module then develops a transfer function having coefficients (k and b) that are used to convert the measured current to the known calibration current. The transfer function is then stored in a lookup table for use during pyrometer operation.

[0053] In one embodiment, process 660 may continue with operation 663, which includes determining the dark current of the circuit board. The dark current may be measured by providing a temporary photodiode to the board and measuring the resulting current provided by the system when the pyrometer is placed in a dark enclosure (e.g., opaque to infrared radiation). The value of the dark current may be stored in a lookup table of the pyrometer. After determining the dark current, the temporary photodiode may be removed. In one embodiment, the dark current is independent of the mode.

[0054] In one embodiment, process 660 may continue with operation 664, which includes assembling the photodiode onto the board. The photodiode may be connected to the board at a physical location different from the location where the rest of the board is assembled. For example, a partially assembled board may be assembled at a first facility, and the photodiode may be assembled onto the board at a second facility.

[0055] In one embodiment, process 660 may continue with operation 665, which includes calibrating the board a second time. In one embodiment, the second calibration may be used to check the electronics and ensure that everything is working properly. In some embodiments, the second calibration process may not use a calibration module.

[0056] Reference now Figure 7, shows a cross-sectional view of a processing chamber 770 according to one embodiment. In one embodiment, chamber 770 may include any type of semiconductor manufacturing chamber that may require precise substrate temperature control. In the illustrated embodiment, chamber 770 is shown without plasma capability. However, it should be understood that chamber 770 may also include the ability to use plasma in order to achieve various processing states.

[0057] In one embodiment, chamber 770 may include chamber body 710. Chamber body 710 may include any suitable material, such as stainless steel, etc. In one embodiment, a coating (not shown) may be disposed on an inner surface of chamber body 710. For example, the coating may be a chamber drying or protective layer. In one embodiment, gas 711 may enter chamber 770 via a first portion of chamber body 710, and gas 712 may exit the tool via a second portion of chamber body 710. Although gases 711 and 712 are shown entering and exiting via chamber body 710, it should be understood that gases may enter or exit the chamber body via any portion of chamber body 770 depending on the type of chamber 770 used.

[0058] In one embodiment, a substrate support 705 and a pedestal 707 are disposed in the chamber. The substrate support 705 and the pedestal 707 are configured to hold and / or fix a substrate 709. For example, the substrate 709 may be a semiconductor substrate, such as a silicon wafer. The substrate 709 may have any suitable dimensions. For example, the diameter of the substrate 709 may be 300 mm, 450 mm, or any standard wafer dimensions. In addition, other substrates 709 may be used in the chamber 770. For example, glass substrates, ceramic substrates, etc. may also be used in some embodiments. In one embodiment, the substrate support 705 and the pedestal 707 may be configured to rotate. Rotation allows for improved temperature uniformity on the substrate 709.

[0059] The pedestal 707 may include any type of clamping architecture to secure the substrate 709. In some embodiments, the pedestal 707 may include an electrostatic chucking (ESC) architecture. In such embodiments, the substrate 709 is secured to the pedestal 707 by electrostatic forces. Other embodiments may include a vacuum clamping architecture for the pedestal 707. In one embodiment, the pedestal 707 and the substrate support 705 may include a quartz material or another material that is at least substantially transparent to infrared radiation. Thus, the temperature of the back side of the substrate 709 may be obtained by the pyrometer 706.

[0060] In one embodiment, chamber 770 may include a cover 715. Cover 715 may sometimes be referred to as a chamber dome. Although shaped as a dome, it should be understood that cover 715 may have any configuration (e.g., a flat surface, etc.). Cover 715 may be formed of a material that is at least substantially transparent to infrared radiation. For example, cover 715 may include quartz, etc.

[0061] In one embodiment, the chamber 770 may further include a bottom cover 717. The bottom cover 717 may cover the bottom surface of the chamber 770. The bottom cover 717 may include a material that is at least substantially transparent to infrared radiation. Thus, the pyrometer 706 on the bottom side of the chamber 770 may be used to measure the temperature of the bottom surface of the substrate 709. In one embodiment, the bottom cover 717 may be coupled to the substrate support 705. More specifically, the substrate support 705 may pass through the bottom cover 717. The bottom cover 717 is coupled to the substrate support 705 in a configuration that allows the substrate support 705 to rotate freely.

[0062] In one embodiment, the plurality of lamps 735 may be disposed outside of the interior volume of the chamber 770. The interior volume of the tool may refer to the volume defined by the lid 715, the chamber body 710, and the bottom cover 717. That is, the lamps 735 are not disposed within the interior volume of the chamber 770 where substrate processing is performed. In one embodiment, the plurality of pyrometers 706 may be disposed through the bottom cover 717. The pyrometers 706 may be focused on the back side of the substrate 709. In one embodiment, the pyrometers 706 may be similar to any of the pyrometers described in more detail herein. For example, the pyrometers 706 may include an internal calibration module.

[0063] Reference now Figure 8, a block diagram of an exemplary computer system 800 of a processing tool according to one embodiment is shown. In one embodiment, the computer system 800 is coupled to the processing tool and controls the processing in the processing tool. The computer system 800 can be connected (e.g., networked) to other machines in a local area network (Local Area Network; LAN), an internal network, an external network, or an Internet network. The computer system 800 can run as a server or client machine in a client-server network environment, or as a peer node machine in a peer (or distributed) network environment. The computer system 800 can be a personal computer (personal computer; PC), a tablet PC, a set-top box (set-top box; STB), a personal digital assistant (Personal Digital Assistant; PDA), a cellular phone, a network device, a server, a network router, a switch or a bridge, or any machine capable of executing a set of instructions (sequential or otherwise) specifying the actions to be taken by the machine. Further, while a single machine is illustrated with respect to computer system 800, the term "machine" shall also be taken to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies described herein.

[0064] The computer system 800 may include a computer program product or software 822 having a non-transitory machine-readable medium having instructions stored thereon, which can be used to program the computer system 800 (or other electronic components) to perform processing according to the embodiment. Machine-readable media include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, machine-readable (e.g., computer-readable) media include machine-readable (e.g., computer) storage media (e.g., read-only memory (read only memory; "ROM"), random access memory (random access memory; "RAM"), magnetic disk storage media, optical storage media, flash memory elements, etc.), machine-readable (e.g., computer) transmission media (electrical, optical, acoustic or other forms of propagation signals (e.g., infrared signals, digital signals, etc.)), etc.

[0065] In one embodiment, the computer system 800 includes a system processor 802, a main memory 804 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM)), a static memory 806 (e.g., flash memory, static random access memory (SRAM), etc.), and an auxiliary memory 818 (e.g., a data storage device), which communicate with each other via a bus 830.

[0066] The system processor 802 represents one or more general processing devices, such as a microsystem processor, a central processing unit, etc. More specifically, the system processor can be a complex instruction set computing (CISC) microsystem processor, a reduced instruction set computing (RISC) microsystem processor, a very long instruction word (VLIW) microsystem processor, a system processor that implements other instruction sets, or a system processor that implements a combination of instruction sets. The system processor 802 can also be one or more special-purpose processing devices, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal system processor (DSP), a network system processor, etc. The system processor 802 is configured to execute processing logic 826 for performing the operations described herein.

[0067] The computer system 800 may also include a system network interface device 808 for communicating with other devices or machines. The computer system 800 may also include a video display unit 810 (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and a signal generating device 816 (e.g., a speaker).

[0068] The secondary memory 818 may include a machine-accessible storage medium 832 (or more specifically, a computer-readable storage medium) on which is stored one or more sets of instructions (e.g., software 822) embodying any one or more of the methods or functions described herein. The software 822 may also reside, in whole or in part, within the main memory 804 and / or within the system processor 802 during execution of the software 822 by the computer system 800, the main memory 804 and the system processor 802 also constituting machine-readable storage media. The software 822 may also be sent or received over the network 820 via the system network interface device 808. In one embodiment, the network interface device 808 may operate using radio frequency coupling, optical coupling, acoustic coupling, or inductive coupling.

[0069] Although the machine-accessible storage medium 832 is shown as a single medium in the exemplary embodiment, the term "machine-readable storage medium" should be understood to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store one or more sets of instructions. The term "machine-readable storage medium" should also include any medium that can store or encode a set of instructions for execution by a machine and cause the machine to perform any one or more methods. Therefore, the term "machine-readable storage medium" should include, but is not limited to, solid-state memories and optical and magnetic media.

[0070] In the foregoing description, specific exemplary embodiments have been described. It will be apparent that various modifications may be made thereto without departing from the scope of the appended claims. Accordingly, the description and drawings are to be regarded in an illustrative rather than a restrictive sense.

Claims

1. A method for calibrating a tool for converting a photon signal into an electrical signal, comprising the steps of: Connect the calibration module to the calibration current source; finding transfer functions for a plurality of modes using the calibration module; as well as The transfer function is stored in a lookup table. 2 . The method of claim 1 , wherein a single mode of the plurality of modes comprises integrating time and range.

3. The method of claim 2, wherein the integration time is provided to an ADC in the tool, and wherein the range is provided to a signal scaling module in the tool. 4 . The method of claim 1 , wherein the transfer function comprises a first coefficient and a second coefficient, wherein the first coefficient is multiplied by an ADC value and the second coefficient is an offset value.

5. The method according to claim 1, wherein the step of calibrating further comprises the following steps: Find the dark current of the tool.

6. The method of claim 1, wherein the tool is a pyrometer or an emission meter.

7. A tool for converting an optical signal into an electrical signal, comprising: Photodiode; Signal scaling module; ADC; Selector module; as well as Current calculation module.

8. The tool of claim 7, wherein the selector module is configured to select a mode of operating the ADC and the signal scaling module.

9. The tool of claim 8, wherein the mode includes an integration time for the ADC and a range for the signal scaling module.

10. The tool according to claim 7, further comprising: Second photodiode.

11. The tool of claim 10, wherein the selector module is configured to select a mode of operating the ADC and the scaling module based on the ADC value of the photodiode or the ADC value of the second photodiode.

12. The tool of claim 10, wherein the selector module is configured to select a mode of operating the ADC and the scaling module based on which ADC value is higher, wherein the ADC values ​​include a first ADC value of the photodiode and a second ADC value of the second photodiode.

13. The tool according to claim 7, further comprising: Calibrate the module.

14. The tool according to claim 13, further comprising: Internal source of calibration current.

15. The tool of claim 14, wherein the calibration module calibrates the tool when the calibration module is connected to the internal source of the calibration current.

16. The tool of claim 7, wherein the tool is a pyrometer or an emission meter.

17. A method for converting a photon signal into an electrical signal, comprising the following steps: Receive the optical signal using ADC; selecting a mode based on a position of the optical signal within a dynamic range of the ADC; Setting the integration time and range of the mode; as well as The current is calculated based on the transfer function of the mode.

18. The method of claim 17, wherein the transfer function comprises first and second coefficients stored in a lookup table.

19. The method of claim 17, wherein the step of calculating the current further comprises the steps of: The dark current is subtracted from the current.

20. The method according to claim 17, further comprising the steps of: A second optical signal is received with the ADC, and wherein the step of selecting the mode further comprises the step of selecting a mode based on either the second optical signal or the optical signal, depending on which optical signal is greater.

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