A germanium-silicon photodetector array and a signal readout method thereof

Abstract

The application belongs to the field of photoelectric detection, and discloses a germanium-silicon photoelectric detector array and a signal reading method thereof, which comprises a plurality of macro-pixel units arranged in parallel according to a set interval; each of the macro-pixel units comprises a plurality of pixel units and an output bus, the pixel units are arranged from top to bottom according to a set interval, the output ends of the pixel units are electrically connected with the output bus, and the voltage input ends of the pixel units are connected with a bias voltage output module. Bias voltage is provided to each pixel unit, so that each pixel unit works in a bias state; an optical signal is input into the detector of each pixel unit to generate a photoelectric current, signal conversion and amplification are performed on the photoelectric current to obtain an amplified voltage signal; and the voltage signal is output to the output bus after passing through a driver. The technical scheme can save layout wiring and hardware resources, and reduce the adverse effects caused by power supply crosstalk.

Description

Technical Field

[0001] This invention belongs to the field of photoelectric detection, and in particular relates to a germanium-silicon photodetector array and its signal readout method. Background Technology

[0002] Photodetectors are devices that convert optical signals into electrical signals and are one of the core technologies in fields such as optical communication, data centers, lidar, and 3D computer vision. Short-wave infrared (SWIR) light offers advantages in optical transmission and detection applications, including low loss, high penetration, low scattering, and eye safety, making SWIR communication and detection systems widely used in various fields. Currently, SWIR detectors mainly employ two material systems: group III-V semiconductors represented by indium gallium arsenide (InGaAs) and germanium-silicon (Ge-on-Si) devices. InGaAs has a wide spectral absorption range, low dark current, and high bandwidth; however, its manufacturing cost is also high, limiting its application in imaging and communication. Germanium-silicon technology introduces germanium material compatible with CMOS processes onto a silicon substrate, enabling germanium-silicon devices to absorb photons and generate photon-hole pairs in the short-wave infrared spectrum. Compared to group III-V semiconductor materials, photodetectors based on germanium-silicon technology have advantages such as lower manufacturing costs and better compatibility with CMOS processes.

[0003] However, when detectors are integrated into large-scale arrays, the sheer number of photodetectors necessitates the provision of separate power supplies and interfaces for each detector, which would consume substantial wiring and hardware resources, making it impractical. Existing solutions typically use a single power supply to provide bias voltage for all photodetector devices. When using photodetector arrays based on germanium-silicon technology as sensors, their high dark current can cause bias voltage drift or fluctuations, affecting the bias state of other detector units, generating power supply crosstalk, and impacting the overall performance of the detector array. Summary of the Invention

[0004] The purpose of this invention is to provide a germanium-silicon photodetector array and its signal readout method to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides a germanium-silicon photodetector array, comprising a plurality of macropixel units arranged in parallel at a predetermined spacing; each macropixel unit includes a plurality of pixel units and an output bus, the pixel units are arranged in descending order at a predetermined spacing, the output terminal of each pixel unit is electrically connected to the output bus, and the voltage input terminal of each pixel unit is connected to a bias voltage output module.

[0006] Optionally, each of the pixel units has the same structure, including a detector, a signal conversion module, and a driving module;

[0007] The detector, signal conversion module, and drive module are connected in sequence. The voltage input terminal of the detector is electrically connected to the bias voltage output module. The output terminal of the drive module is electrically connected to the output bus.

[0008] Optionally, the detector is a balanced detector.

[0009] Optionally, the signal conversion module employs a transimpedance amplifier.

[0010] A signal readout method, applied to the aforementioned germanium-silicon photodetector array, includes:

[0011] The bias voltage output module provides a bias voltage to each pixel unit, so that each pixel unit operates in a bias state.

[0012] An input optical signal is sent to the detector of each pixel unit to generate a photocurrent. The photocurrent is then input to the signal conversion module for signal conversion and amplification to obtain an amplified voltage signal. The amplified voltage signal is then output to the output bus after passing through a driver.

[0013] The technical effects of this invention are as follows:

[0014] This invention allows several detectors to share a set of device bias voltages. Compared with the scheme where all pixel units share the same set of bias voltage sources for power supply, the number of detectors on the same set of bias voltage sources is reduced, thereby saving layout wiring and hardware resources, while reducing the adverse effects of power supply crosstalk. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 This is a schematic diagram of the detector array and readout circuit architecture in an embodiment of the present invention;

[0018] Figure 2 This is a macro-pixel architecture diagram in an embodiment of the present invention;

[0019] Figure 3 This is a macropixel architecture diagram of the balanced detector in an embodiment of the present invention. Detailed Implementation

[0020] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0021] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0022] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods have been described herein, any methods similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe the methods associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0023] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0024] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] Example 1

[0027] like Figure 1 - Figure 3As shown, this embodiment provides a germanium-silicon photodetector array, including a plurality of macropixel units arranged in parallel according to a set spacing; each macropixel unit includes a plurality of pixel units and an output bus, each pixel unit is arranged in sequence from top to bottom according to a set spacing, the output terminal of each pixel unit is electrically connected to the output bus, and the voltage input terminal of each pixel unit is connected to a bias voltage output module.

[0028] A signal readout method, applied to the aforementioned germanium-silicon photodetector array, includes:

[0029] The bias voltage output module provides a bias voltage to each pixel unit, so that each pixel unit operates in a bias state.

[0030] An input optical signal is sent to the detector of each pixel unit to generate a photocurrent. The photocurrent is then input to the signal conversion module for signal conversion and amplification to obtain an amplified voltage signal. The amplified voltage signal is then output to the output bus after passing through a driver.

[0031] This embodiment allows several detectors to share a set of device bias voltages. Compared with the scheme where all pixel units share the same set of bias voltage sources for power supply, it reduces the number of detectors on the same set of bias voltage sources, thereby saving layout wiring and hardware resources, and reducing the adverse effects of power supply crosstalk.

[0032] Figure 1 The diagram shows the detector array and readout circuit architecture. The detector array consists of s×t macropixel units. The output terminals of the first column of macropixels are all connected to column bus 1; the output terminals of the second column of macropixels are all connected to column bus 2; ...; the output terminals of the t-th column of macropixels are all connected to column bus t. Each macropixel unit contains k pixel units, meaning the detector array contains a total of s×t×k pixel units.

[0033] Figure 2 The diagram shows the architecture of a macropixel unit. A macropixel unit consists of k pixel units, each comprising a detector unit, a signal conversion module, and a driver. The detector unit's two bias voltage ports are connected to bias voltage ports Vsup_an and Vsup_ca, respectively, and its output is connected to the input of the signal conversion module. The signal conversion module's output is connected to the driver's input, and the driver's output is connected to the output bus. All detector units within a macropixel share the same set of bias voltages, and all driver outputs within a macropixel share the same set of output buses.

[0034] The operation of the germanium-silicon photodetector array and readout circuit based on macropixels is as follows: The detector unit is biased by Vsup_ca and Vsup_an. After receiving the optical signal, the detector power supply generates a current signal, which is converted into a voltage signal by the signal conversion module. This voltage signal is then output to the output bus after passing through the driver. The output signal in the macropixel unit is further output to the column bus.

[0035] Compared to the scheme that uses an independent bias voltage source to power all pixel units, the scheme proposed in this invention reduces the number of required bias voltage sources from s×t×k to s×t for detectors with dual-port power supply.

[0036] Compared to the scheme where all pixel units share the same set of bias voltage sources for power supply, the scheme proposed in this invention reduces the number of detectors on the same set of bias voltage sources and reduces the adverse effects of power supply crosstalk.

[0037] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A germanium-silicon photodetector array, characterized in that, It includes several macro pixel units arranged in parallel according to a set interval; each macro pixel unit includes several pixel units and an output bus, each pixel unit is arranged from top to bottom according to a set interval, the output terminal of each pixel unit is electrically connected to the output bus, and the voltage input terminal of each pixel unit is connected to a bias voltage output module. Each pixel unit has the same structure, including a detector, a signal conversion module, and a driving module; The detector, signal conversion module, and drive module are connected in sequence. The voltage input terminal of the detector is electrically connected to the bias voltage output module. The output terminal of the drive module is electrically connected to the output bus.

2. The germanium-silicon photodetector array according to claim 1, characterized in that, The detector is a balanced detector.

3. The germanium-silicon photodetector array according to claim 1, characterized in that, The signal conversion module uses a transimpedance amplifier.

4. A signal readout method, applied to a germanium-silicon photodetector array according to any one of claims 1-3, characterized in that, include: The bias voltage output module provides a bias voltage to each pixel unit, enabling each pixel unit to operate in a biased state; the input light signal is sent to the detector of each pixel unit to generate a photocurrent, and the photocurrent is input to the signal conversion module for signal conversion and amplification to obtain an amplified voltage signal; the amplified voltage signal is then output to the output bus after passing through the driver.

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