Silicon-on-germanium photodetector and thermal control method for silicon-on-germanium photodetector

Abstract

The application discloses a silicon-based germanium photoelectric detector and a thermal control method of the silicon-based germanium photoelectric detector, wherein the silicon-based germanium photoelectric detector comprises a silicon-based germanium photoelectric detector body and at least one temperature sensor integrated in the silicon-based germanium photoelectric detector body; the temperature sensor is arranged at intervals from a depletion zone of the silicon-based germanium photoelectric detector body and is distributed on at least one side of a light absorption zone of the silicon-based germanium photoelectric detector body, and the temperature sensor does not interfere with light path transmission of the silicon-based germanium photoelectric detector. The application integrates the temperature sensor in the silicon-based germanium photoelectric detector, realizes real-time and accurate monitoring of a working temperature on the premise of not influencing core photoelectric performance of the detector, provides reliable temperature feedback for a subsequent temperature control and signal adjustment system, and thus lays a foundation for stable and efficient operation of the entire photoelectric detection system.

Description

Technical Field

[0001] This application relates to the technical field of optical communication, and in particular to a silicon-based germanium photodetector and a thermal control method for the silicon-based germanium photodetector. Background Technology

[0002] In recent years, ultra-wideband optical transmission technology has expanded its operating band from the traditional C-band (1530nm–1565nm) to the C+L band to meet the urgent needs of ultra-large-scale data centers and telecom operators for low-cost expansion of fiber optic communication capacity. Germanium, as a typical indirect bandgap semiconductor material, has an optical absorption cutoff wavelength of approximately 1550nm. Its absorption coefficient decreases significantly in the L-band range, making it difficult to meet the absorption efficiency requirements for long-wavelength optical signals in high-baud-rate optical communication scenarios.

[0003] Existing technologies typically enhance the light absorption capability of germanium photodetectors in the L-band by heating them. However, current solutions generally lack accurate real-time monitoring of the detector chip temperature. The integration of discrete optical components can easily lead to temperature deviations between the temperature monitoring point and the actual operating area of ​​the detector, reducing the accuracy of temperature measurements and consequently affecting the stability of the device's performance. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this application is to provide a silicon-based germanium photodetector and a thermal control method for the silicon-based germanium photodetector, in order to solve the technical problem that the prior art lacks the ability to accurately monitor the temperature of the working area of ​​the silicon-based germanium photodetector chip in real time, which makes it impossible to accurately control the heating process of the silicon-based germanium photodetector, and ultimately affects the stability of the device's working performance.

[0005] The first aspect of this application provides a silicon-based germanium photodetector, including a silicon-based germanium photodetector body and at least one temperature sensor integrated within the silicon-based germanium photodetector body. The temperature sensor is spaced apart from the depletion region of the silicon-based germanium photodetector body and is distributed on at least one side of the light absorption region of the silicon-based germanium photodetector body. The temperature sensor does not interfere with the optical path transmission of the silicon-based germanium photodetector.

[0006] This embodiment integrates a temperature sensor into a silicon-based germanium photodetector, enabling real-time and accurate monitoring of the operating temperature without affecting the core photoelectric performance of the detector. This provides reliable temperature feedback for the subsequent temperature control and signal conditioning system, thus laying the foundation for the stable and efficient operation of the entire photoelectric detection system.

[0007] In some embodiments of this application, the temperature sensor is a PN junction type temperature sensor.

[0008] This embodiment employs a PN junction temperature sensor, which is highly compatible with the standard semiconductor fabrication process of silicon-based germanium photodetectors, enabling integration without adding complex processes or extra costs. The PN junction temperature sensor features fast response, high temperature measurement accuracy, and a compact structure, allowing for real-time temperature detection within a small area to provide accurate and reliable temperature feedback for the system.

[0009] In some embodiments of this application, the PN junction of the PN junction temperature sensor is formed on the same layer as the P-region and N-region of the PIN junction in the silicon-based germanium photodetector body.

[0010] This embodiment, through the above design, can fully reuse existing process layers and photolithography steps, significantly simplifying the process flow, reducing fabrication costs, and improving device integration and structural consistency. This approach does not occupy additional usable area, does not affect the detector's photoelectric performance, and ensures that temperature detection is closer to the actual operating temperature.

[0011] In some embodiments of this application, the PN junction temperature sensor is a PN junction of a diode or a base-emitter junction of a bipolar junction transistor.

[0012] This embodiment uses the PN junction of a diode or the base-emitter junction of a bipolar junction transistor, which has high temperature sensitivity and good signal output linearity. It can accurately acquire temperature signals and will not interfere with the photoelectric response characteristics of the photodetector, which is conducive to achieving high on-chip integration and stable system temperature control.

[0013] In some embodiments of this application, the distance between the temperature sensor and the depletion region of the silicon-based germanium photodetector body ranges from 100nm to 1000nm.

[0014] This embodiment, through the above parameter settings, ensures that the sensor is close enough to the light-absorbing area, making temperature detection more accurate and the response more timely, while effectively controlling the interference of parasitic parameters on the photoelectric performance of the detector, achieving the best balance between temperature measurement accuracy and device electrical performance.

[0015] In some embodiments of this application, the silicon-based germanium photodetector body has a vertical PIN junction structure, and the depletion region is the depletion region of the vertical PIN junction.

[0016] In some embodiments of this application, the silicon-based germanium photodetector body has a horizontal PIN junction structure, and the depletion region is the depletion region of the horizontal PIN junction.

[0017] The two embodiments described above employ vertical PIN junction structures and horizontal PIN junction structures, respectively, enabling the silicon-based germanium photodetector of this application to be adapted to different device designs and process requirements, thereby improving the versatility of the solution.

[0018] In some embodiments of this application, the silicon-based germanium photodetector further includes a heating resistor integrated within the silicon-based germanium photodetector body, and a heating electrode electrically connected to the heating resistor.

[0019] This embodiment integrates a heating resistor and a heating electrode within a silicon-based germanium photodetector, enabling active temperature control within the device and rapid compensation for performance drift at low temperatures. Furthermore, this structure boasts high integration and fast heating response, accurately maintaining the detector's operating temperature and enhancing its stability under various operating conditions.

[0020] In some embodiments of this application, the heating resistor is made of at least one of titanium nitride and polycrystalline silicon.

[0021] This embodiment uses titanium nitride and / or polycrystalline silicon as heating resistors, which is compatible with the fabrication process of silicon-based germanium photodetectors. Integration is achieved without adding complex processes, thereby improving the reliability and lifespan of the detector.

[0022] A second aspect of this application provides a thermal control method for a silicon-based germanium photodetector, wherein the silicon-based germanium photodetector is as described above, comprising: Acquire the temperature data detected by the temperature sensor in the silicon-based germanium photodetector; Based on the temperature data, heating control is performed on the silicon-based germanium photodetector to adjust the operating temperature of the silicon-based germanium photodetector to the target temperature range.

[0023] The thermal control method provided in this application, based on real-time temperature data acquisition by an on-chip temperature sensor, performs closed-loop heating control on the detector, stabilizing the operating temperature within the target range. This method effectively suppresses the impact of temperature drift on device performance, ensuring stable and reliable photoelectric response, while achieving precise and adaptive temperature regulation, thus improving the overall operational stability and environmental adaptability of the detector.

[0024] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 The diagram shown is a schematic representation of the silicon-based germanium photodetector described in an embodiment of this application.

[0027] Figure 2 The diagram shown is a schematic representation of the surface-incident optical path transmission of the silicon-based germanium photodetector described in this application embodiment.

[0028] Figure 3 The diagram shown is a schematic diagram of the optical path transmission of the silicon-based germanium photodetector described in the embodiments of this application.

[0029] Figure 4 The diagram shown is a schematic diagram of a silicon-based germanium photodetector with a horizontal PIN junction as described in an embodiment of this application.

[0030] Figure 5 Displayed as Figure 4 Top view of the structure shown.

[0031] Figure 6 The diagram shown is a schematic diagram of a silicon-based germanium photodetector with a vertical PIN junction as described in an embodiment of this application.

[0032] Figure 7 The diagram shows a flow chart of the thermal control method for a silicon-based germanium photodetector as described in an embodiment of this application.

[0033] Specific element symbols: 1-Silicon-based germanium photodetector, 10-Silicon-based germanium photodetector body, 101-Insulating buried layer, 102-PN junction in PIN junction, 103-Germanium layer, 11-Temperature sensor, 111-Temperature sensor input terminal, 112-Temperature sensor output terminal, 12-Heating resistor, 13-Heating electrode, 14-Gate, 15-Source, 16-Depletion region. Detailed Implementation

[0034] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0035] It should be noted that when a component is referred to as being "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] As information technology advances towards ultra-high capacity information transmission and ultra-high density information storage, silicon-based photonic integrated chips, as a core technology for overcoming the bandwidth and speed bottlenecks of traditional integrated circuits, have become a research hotspot in the field of optical communication. Among these, coherent receivers, as key components of high-speed optical communication systems, place stringent demands on detector performance. Silicon-based germanium detectors, due to the excellent compatibility of germanium materials with silicon processes and their infrared detection capabilities, have become the core device of coherent receivers. In recent years, to meet the demand for low-cost expansion of fiber optic capacity from ultra-large-scale data centers and telecom operators, ultra-wideband optical transmission has expanded the frequency band from the traditional C-band (1530nm~1565nm) to the C+L band. The application of the L-band (1565nm~1625nm) has increased the single-fiber capacity from 32Tbps to 64Tbps, achieving a significant leap in fiber optic transmission capacity. Market data shows that the demand for ultra-large-scale data center interconnect (DCI) is continuously driving the rapid growth of the L-band coherent transceiver market.

[0038] However, germanium, as an indirect bandgap semiconductor, has an absorption cutoff wavelength of approximately 1550 nm. Its absorption coefficient drops significantly in the L-band, making it difficult to meet the long-wavelength absorption requirements of high baud rate scenarios. This has become a key bottleneck restricting the application of silicon-based photonic integrated chips in L-band coherent communication. Research shows that as input power increases, the photocurrent in the germanium region increases, generating a thermal effect that narrows the bandgap, enhances absorption, and subsequently induces nonlinear growth in photocurrent. This phenomenon provides a solution for actively heating to regulate device performance. However, while improving L-band absorptivity, thermal accumulation can also degrade device performance. The thermal effect under high photocurrent can also alter device characteristics and affect system stability. Furthermore, the additional heating power consumption increases system energy consumption, contradicting the trend towards low-power optical communication.

[0039] Based on this, this application improves upon the silicon-based germanium photodetector and its thermal control method in related technologies. The silicon-based germanium photodetector 1 of this application can calculate the PN junction temperature by real-time acquisition of the PN junction forward voltage value and combining it with a pre-calibrated voltage drop and temperature correlation model; it can also calculate the corresponding theoretical voltage value based on the target temperature, providing a reference for temperature control. Simultaneously, the detector can also design a hardware compensation circuit based on the fitted temperature compensation formula, or integrate a lookup table algorithm and linear calculation program in the MCU to achieve precise temperature compensation at the system level, further ensuring the device's performance stability across the entire temperature range.

[0040] refer to Figure 1 As shown, the silicon-based germanium photodetector 1 of this application embodiment includes a silicon-based germanium photodetector body 10 and a temperature sensor 11 integrated within the silicon-based germanium photodetector body 10. The temperature sensor 11 can be set to one or multiple based on actual needs.

[0041] The temperature sensor 11 needs to be spaced apart from the depletion region 16 of the silicon-based germanium photodetector body 10. At the same time, the temperature sensor 11 also needs to be distributed on at least one side of the light absorption region of the silicon-based germanium photodetector body 10. This ensures that the temperature sensor 11 integrated in the silicon-based germanium photodetector body 10 does not interfere with the optical path transmission of the silicon-based germanium photodetector body 10 (i.e., does not affect the optical path transmission of the silicon-based germanium photodetector body 10), and thus ensures that the setting of the temperature sensor 11 does not affect the normal operation of the silicon-based germanium photodetector body 10.

[0042] Furthermore, silicon-based germanium photodetectors are currently mainly divided into two types: surface-incident and light-guided. Figure 2 This is a schematic diagram of the surface-incident optical path transmission of the silicon-based germanium photodetector described in the embodiments of this application. Figure 3 This is a schematic diagram of the optical path transmission of the silicon-based germanium photodetector described in an embodiment of this application. Figure 2 and Figure 3 Taking the spatial rectangular coordinate system in the silicon-based germanium photodetector 1 as an example, the distribution of the temperature sensor 11 on at least one side of the light absorption region of the silicon-based germanium photodetector body 10 will be described in detail.

[0043] The light absorption region of the silicon-based germanium photodetector 1 is the germanium layer 103, and its optical path transmission is of two types: reference. Figure 2 As shown, in the surface-incident silicon-based germanium photodetector 1, light is incident along the Z-axis (perpendicular to the chip surface), directly irradiating the germanium absorption layer, passing perpendicularly through the top dielectric layer, and entering the germanium region to excite photogenerated carriers to complete photoelectric conversion; Reference Figure 3As shown, the light from the waveguide end face of the photoconductive silicon-based germanium photodetector 1 is coupled into the waveguide along the X-axis (horizontal direction) and propagates laterally within the germanium absorption layer along the planar waveguide. Due to the longer interaction distance with the germanium material in the horizontal direction, more complete light absorption is achieved.

[0044] To avoid interference from the distribution of temperature sensors 11 on the two types of optical transmission (surface incidence type and light guide type), in this embodiment, temperature sensors 11 are preferably disposed on one or both sides of the light absorption region (germanium layer 103) along the Y-axis direction; that is, with the germanium layer as the origin, they are located in the side regions of the positive Y-axis direction and the negative Y-axis direction respectively, to ensure that the vertical incidence or lateral transmission path of light is not affected.

[0045] In one specific embodiment of this application, Figure 2 and Figure 3 The lower surface of the germanium layer 103 is provided with a PN junction 102 in the PIN junction, and the lower surface of the PN junction 102 in the PIN junction is provided with an insulating buried layer 101. The temperature sensor 11 is provided on the upper surface of the insulating buried layer 101, and in this embodiment, two temperature sensors 11 are provided. Figure 2 and Figure 3 The placement of the temperature sensor 11 is only one embodiment in which the temperature sensor 11 is preferably placed on both sides of the light absorption region (germanium layer 103). In other embodiments, the temperature sensor 11 may be placed at other positions on both sides of the light absorption region (germanium layer 103), and there is no fixed limitation on it here.

[0046] The distribution of the temperature sensor 11 on the silicon-based germanium photodetector body 10 can be configured in other reasonable ways without affecting the optical path transmission of the silicon-based germanium photodetector body 10. This application does not impose any fixed restrictions on it.

[0047] In a preferred embodiment of this application, to facilitate compatibility with the fabrication process of the silicon-based germanium photodetector body 10 and avoid introducing complex processes, the temperature sensor 11 is configured as a PN junction type temperature sensor. Further, the PN junction type temperature sensor can be configured as the PN junction of a diode, or as the base-emitter junction of a bipolar junction transistor. Both have the characteristics of high temperature sensitivity and good output signal linearity, enabling accurate acquisition of temperature signals without interfering with the photoelectric response characteristics of the photodetector, which is beneficial for achieving high on-chip integration and stable system temperature control.

[0048] In a preferred embodiment of this application, reference is made to Figure 4 and Figure 6As shown, to facilitate compatibility with the fabrication process of the silicon-based germanium photodetector body 10, the PN junction of the PN junction temperature sensor can be formed in the same layer as the P-region and N-region of the PIN junction in the silicon-based germanium photodetector body 10. This arrangement can be achieved by fully reusing existing process layers and photolithography steps during the formation of the silicon-based germanium photodetector body 10. This arrangement significantly simplifies the process flow for forming the PN junction temperature sensor in the silicon-based germanium photodetector 1, reduces fabrication costs, and simultaneously improves the device integration and structural consistency of the silicon-based germanium photodetector 1.

[0049] In a specific embodiment of this application, reference is made to Figures 4 to 6 As shown, a PN junction 102 in a PIN junction is disposed on the lower surface of the germanium layer 103, and an insulating buried layer 101 is disposed on the lower surface of the PN junction 102 in the PIN junction. Two temperature sensors 11 are disposed on the upper surface of the insulating buried layer 101. The silicon-based germanium photodetector body 10 also includes a gate 14 electrically connected to the P-doped region of the PN junction 102 in the PIN junction, a source 15 electrically connected to the n-doped region of the PN junction 102 in the PIN junction, and a temperature sensor input terminal 111 and a temperature sensor output terminal 112 of the temperature sensor 11.

[0050] From the perspective of the temperature measurement principle of temperature sensor 11, the closer the temperature sensor 11 is to the PIN junction of the silicon-based germanium photodetector body 10, the higher the sensitivity and response speed of the device's operating temperature detection, and the better the temperature measurement effect. However, at the same time, the smaller the distance between temperature sensor 11 and the PIN junction, the greater the parasitic parameters such as parasitic capacitance and parasitic resistance will be, which will affect the overall photoelectric performance of the silicon-based germanium photodetector body 10, such as response speed, dark current, and bandwidth.

[0051] Therefore, in a preferred embodiment of this application, the temperature sensor 11 and the depletion region 16 of the silicon-based germanium photodetector body 10 are spaced apart, and the distance between them is controlled within the range of 100nm to 1000nm. By setting the above-mentioned distance parameters appropriately, on the one hand, the temperature sensor 11 can be brought close enough to the light absorption region and the active detection region to ensure the real-time performance and detection accuracy of temperature acquisition, achieving accurate monitoring of the device's operating temperature; on the other hand, it can effectively suppress the parasitic parameter influence of the temperature sensor 11 on the PIN junction, reducing its interference with the photoelectric response characteristics of the detector, thereby achieving an optimal balance between temperature detection accuracy and the overall electrical and photoelectric performance of the device.

[0052] Depending on the different device structures and process requirements, the silicon-based germanium photodetector 1 of this application can adopt two preferred schemes in specific implementation. Both preferred schemes use an additional silicon PN junction as a temperature monitoring unit, and the core geometric dimensions remain consistent. The main difference lies in the different doping distribution patterns of the P-region and N-region in the silicon-based germanium photodetector body 10.

[0053] refer to Figure 4 and Figure 5 As shown, one preferred embodiment is a horizontal pin junction scheme. Specifically, the silicon-based germanium photodetector body 10 adopts a horizontal pin junction structure, and its depletion region 16 is the depletion region formed by the horizontal pin junction. (Reference) Figure 6 As shown, another preferred solution is a vertical PIN junction solution. Specifically, the silicon-based germanium photodetector body 10 adopts a vertical PIN junction structure, and its depletion region 16 is the depletion region formed by the vertical PIN junction.

[0054] By providing both vertical and horizontal PIN junction designs, the silicon-based germanium photodetector 1 of this application can flexibly adapt to different device layout designs, process requirements, and application scenarios, significantly improving the versatility and adaptability of the technical solution and expanding its scope of application.

[0055] Existing silicon-based germanium photodetectors mostly employ a separate optical component structure, which can easily lead to deviations in the ambient temperature detection during signal reception. The silicon-based germanium photodetector 1 described in this application, through its built-in temperature sensor 11, can accurately collect internal temperature data in real time, solving the temperature monitoring deviation problem caused by the separate optical structure. During the process of improving the L-band absorptivity of the detector using heating methods, the silicon-based germanium photodetector 1 can be controlled and heated based on accurate temperature data, ensuring its normal operation and practical application.

[0056] refer to Figures 4 to 6 As shown, in order to achieve heating control of the silicon-based germanium photodetector 1 in practical applications, a preferred embodiment of this application also integrates a heating resistor 12 inside the silicon-based germanium photodetector body 10, and a heating electrode 13 electrically connected to the heating resistor 12 is also provided inside the silicon-based germanium photodetector body 10.

[0057] By integrating a heating resistor 12 and a heating electrode 13 inside the silicon-based germanium photodetector 1, active temperature control within the device can be achieved, rapidly compensating for performance drift under low-temperature environments. This structure features high integration and rapid heating response, enabling precise stabilization of the detector's operating temperature and improving its reliability under different operating environments.

[0058] In a preferred embodiment of this application, the heating resistor 12 may be made of at least one of titanium nitride (TiN) and polycrystalline silicon. Using titanium nitride and / or polycrystalline silicon as the heating material is compatible with the fabrication process of the silicon-based germanium photodetector body 10, allowing for integration without adding complex processes, effectively improving the reliability and lifespan of the detector.

[0059] This application integrates a temperature sensor 11 inside a silicon-based germanium photodetector 1, enabling real-time and accurate monitoring of the device's internal operating temperature, effectively solving the temperature detection deviation problem caused by traditional separate optical structures. The temperature sensor 11 and the detector's depletion region 16 are appropriately spaced to avoid interfering with optical path transmission and core photoelectric performance. Employing a PN junction type temperature sensor, it is compatible with the detector's PIN junction process and can be integrated on the same layer without requiring additional complex processes. It offers high temperature measurement accuracy, fast response, and a compact structure, providing stable and reliable temperature feedback for the system and laying the foundation for precise temperature control.

[0060] Building upon this precise temperature detection, this application further integrates an on-chip heating resistor 12 and a heating electrode 13 to achieve active heating control within the device. The heating resistor 12 utilizes materials compatible with silicon-based processes, such as titanium nitride and polycrystalline silicon, exhibiting high integration and rapid heating response. It can quickly compensate for performance drift under low-temperature environments based on real-time temperature data, achieving closed-loop precise temperature control. Through the synergistic cooperation of temperature monitoring and active heating, this application can stabilize the detector's operating temperature, significantly improving the working stability, response consistency, and lifespan of the silicon-based germanium photodetector 1 under different environments. It demonstrates strong versatility and possesses high practical value and application prospects.

[0061] refer to Figure 7 As shown, in order to better implement the silicon-based germanium photodetector 1 in any of the above embodiments, a thermal control method for the silicon-based germanium photodetector is also provided in this application embodiment based on the silicon-based germanium photodetector 1.

[0062] This embodiment mainly utilizes the temperature sensor 11 built into the silicon-based germanium photodetector 1. By applying a forward injection current to the PN junction, the change in its forward voltage with temperature is measured, thereby obtaining the internal temperature information of the silicon-based germanium photodetector 1. Before this, it is necessary to obtain the relationship between the forward voltage drop of the PN junction of the temperature sensor in the silicon-based germanium photodetector 1 and the temperature.

[0063] The measurement principle is as follows: A constant injection current is maintained across the PN junction, and forward voltage drop data at different temperatures are collected. A relationship curve is then plotted, and the curve is fitted to determine its slope and intercept, ultimately establishing a quantitative correlation model between the forward voltage drop and temperature. The specific process for obtaining the PN junction forward voltage drop-temperature relationship is as follows: First, preset several typical temperature points (it is recommended to cover the actual operating temperature range of the device, such as...). The silicon-based germanium photodetector 1 was placed at various temperature points (40°C, 0°C, 25°C, 50°C, 85°C, 125°C) and kept sufficiently warm to ensure the system reached thermal equilibrium and that the PN junction temperature remained consistent with the ambient temperature. A constant forward current was then applied to the PN junction under test using a constant current source. To suppress self-heating, a short-time pulse power supply and a reduced duty cycle could be used to avoid power consumption accumulation leading to junction temperature drift. After the device temperature stabilized, the forward voltage drop of the PN junction was sampled multiple times and averaged to reduce the influence of random noise. The corresponding data were then compiled and recorded. To further compensate for self-heating errors, the measurement results under different injection currents could be compared, or the pulse duty cycle could be optimized through power consumption estimation. The collected data was linearly fitted, and the temperature coefficient (usually negative) was extracted. For higher accuracy over a wide temperature range, the original physical equation of the diode could be used for fitting, or a quadratic term could be introduced for correction.

[0064] To improve detection accuracy, two different constant injection currents can be applied to the same PN junction, and the absolute temperature can be calculated using the dual-current method (a common solution for BJT / diode temperature measurement), thereby effectively reducing the systematic error caused by the change in reverse saturation current.

[0065] Different precision models can be selected for data processing based on actual measurement needs: When using a simplified linear model, the PN junction temperature coefficient (unit: mV / °C) is obtained through least squares fitting, and a lookup table relationship or linear compensation formula between temperature and forward voltage drop is established under the target operating current, which can meet the requirements of conventional precision measurements. When using a refined model, the reverse saturation current is modeled based on the complete diode equation, and parameters such as the bandgap and ideality factor are obtained through multi-parameter fitting, significantly improving the measurement accuracy over a wide temperature range. For individual device differences, a batch calibration scheme can be adopted: if the consistency between batches is good, representative samples are selected to establish a universal calibration curve; if individual differences are significant, calibration parameters are stored separately for each device to achieve precise matching at the device level.

[0066] During the calibration and measurement process described above, it is essential to avoid systematic errors introduced by factors such as self-heating interference, contact and lead resistance, noise and drift, temperature uniformity deviation, and insufficient repeatability.

[0067] Based on the above, the thermal control method for silicon-based germanium photodetectors includes the following steps.

[0068] Step S101: Obtain the temperature data detected by the temperature sensor 11 in the silicon-based germanium photodetector 1.

[0069] A constant driving current is applied to the PN junction of the temperature sensor 11, and the voltage across the sensor is collected as the sampling voltage. Based on the pre-acquired PN junction forward voltage drop-temperature correspondence, the current temperature data is calculated through the sampling voltage and used as the real-time temperature information of the silicon-based germanium photodetector 1.

[0070] Step S102: Based on temperature data, perform heating control on the silicon-based germanium photodetector 1 to adjust the operating temperature of the silicon-based germanium photodetector 1 to the target temperature range.

[0071] Based on real-time temperature data, closed-loop heating control is implemented on the detector to stabilize its operating temperature within the target range, thereby achieving an optimal balance between improving light absorption performance and reducing system power consumption.

[0072] The thermal control method provided in this application embodiment achieves real-time temperature acquisition through an on-chip integrated temperature sensor 11 and performs closed-loop heating regulation of the detector, thereby stabilizing the device's operating temperature within the target range. This method can effectively suppress the impact of temperature drift on the device's photoelectric response, ensuring stable and reliable responsivity and operating point, while achieving precise and adaptive temperature control, thus improving the overall operational stability and environmental adaptability of the silicon-based germanium photodetector 1.

[0073] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0074] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0075] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0076] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0077] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A silicon-based germanium photodetector, characterized in that, It includes a silicon-based germanium photodetector body and at least one temperature sensor integrated within the silicon-based germanium photodetector body; The temperature sensor is spaced apart from the depletion region of the silicon-based germanium photodetector body and is distributed on at least one side of the light absorption region of the silicon-based germanium photodetector body. The temperature sensor does not interfere with the optical path transmission of the silicon-based germanium photodetector.

2. The silicon-based germanium photodetector according to claim 1, characterized in that, The temperature sensor is a PN junction type temperature sensor.

3. The silicon-based germanium photodetector according to claim 2, characterized in that, The PN junction of the PN junction temperature sensor is formed in the same layer as the P-region and N-region of the PIN junction in the silicon-based germanium photodetector body.

4. The silicon-based germanium photodetector according to claim 2, characterized in that, The PN junction temperature sensor is a PN junction of a diode or a base-emitter junction of a bipolar junction transistor.

5. The silicon-based germanium photodetector according to claim 1, characterized in that, The distance between the temperature sensor and the depletion region of the silicon-based germanium photodetector body ranges from 100nm to 1000nm.

6. The silicon-based germanium photodetector according to claim 1, characterized in that, The silicon-based germanium photodetector body has a vertical PIN junction structure, and the depletion region is the depletion region of the vertical PIN junction.

7. The silicon-based germanium photodetector according to claim 1, characterized in that, The silicon-based germanium photodetector body has a horizontal PIN junction structure, and the depletion region is the depletion region of the horizontal PIN junction.

8. The silicon-based germanium photodetector according to claim 1, characterized in that, It also includes a heating resistor integrated within the silicon-based germanium photodetector body, and a heating electrode electrically connected to the heating resistor.

9. The silicon-based germanium photodetector according to claim 8, characterized in that, The heating resistor is made of at least one of titanium nitride and polycrystalline silicon.

10. A thermal control method for a silicon-based germanium photodetector, characterized in that, The silicon-based germanium photodetector is the silicon-based germanium photodetector according to any one of claims 1-9, comprising: Acquire the temperature data detected by the temperature sensor in the silicon-based germanium photodetector; Based on the temperature data, heating control is performed on the silicon-based germanium photodetector to adjust the operating temperature of the silicon-based germanium photodetector to the target temperature range.

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