Germanium-silicon photoelectric detector array and signal reading method thereof

Abstract

The invention belongs to the field of photoelectric detection, and discloses a germanium-silicon photoelectric detector array and a signal reading method thereof, and the germanium-silicon photoelectric detector array comprises a plurality of macro pixel units which are sequentially arranged side by side according to a set interval; each macro pixel unit comprises a plurality of pixel units and an output bus, the pixel units are sequentially arranged from top to bottom according to a set interval, the output end of each pixel unit is electrically connected with the output bus, and the voltage input end of each pixel unit is connected with a bias voltage output module. Providing a bias voltage for each pixel unit to enable each pixel unit to work in a bias state; inputting an optical signal to a detector of each pixel unit to generate a light current, and performing signal conversion and amplification on the light current to obtain an amplified voltage signal; and the voltage signal is output to the output bus after passing through the driver. According to the technical scheme, layout, wiring and hardware resources can be saved, and meanwhile the adverse effect caused by the power supply crosstalk problem is reduced.

Description

Technical Field

[0001] The invention belongs to the field of photoelectric detection, and in particular relates to a germanium silicon photoelectric detector array and a signal readout method thereof. Background Art

[0002] Photodetectors are devices that convert optical signals into electrical signals. They are also one of the core technologies in the fields of optical communications, data centers, lidar, and three-dimensional computer vision. Among them, light in the short-wave infrared (SWIR) spectrum has the advantages of low loss, strong penetration, low scattering, and eye safety in optical transmission and optical detection applications. Therefore, SWIR communication and detection systems are widely used in various fields. At present, SWIR detectors mainly use two material system solutions: III-V semiconductors represented by indium gallium arsenide devices (InGaAs) and germanium silicon (Ge-on-Si) devices. Among them, InGaAs materials have a high spectral absorption range, low dark current, and high bandwidth; but at the same time, their preparation cost is also high, which limits the application of InGaAs materials in the field of imaging and communication. The germanium silicon process introduces germanium materials compatible with the CMOS process on the silicon substrate, so that the germanium silicon device can absorb photons and generate photon-hole pairs in the short-wave infrared spectrum. Compared with III-V semiconductor materials, photodetectors based on the germanium silicon process have the characteristics of low preparation cost and good compatibility with the CMOS process.

[0003] However, when the detectors are integrated into a large array, due to the huge number of photodetectors, setting up a separate power supply and interface for each photodetector will consume a lot of wiring and hardware resources and is difficult to implement. The existing technical solutions usually use the same power supply to provide bias voltage for all photodetector devices. When using a photodetector array based on germanium silicon process as a sensor, due to its large dark current, the bias voltage may drift or fluctuate to a certain extent, thereby affecting the bias state of other detector units, generating power supply crosstalk, and affecting the overall performance of the detector array. Summary of the invention

[0004] The object of the present invention is to provide a germanium silicon photodetector array and a signal readout method thereof to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above-mentioned purpose, the present invention provides a germanium silicon photodetector array, comprising a plurality of macro-pixel units arranged in parallel in sequence according to a set spacing; each of the macro-pixel units comprises a plurality of pixel units and an output bus, and each of the pixel units is arranged in sequence from top to bottom according to the set spacing, and the output end of each of the pixel units is electrically connected to the output bus, and the voltage input end of each of the pixel units is connected to a bias voltage output module.

[0006] Optionally, the pixel units have the same structure, and all include a detector, a signal conversion module and a driving module;

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

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

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

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

[0011] Providing a bias voltage to each pixel unit through a bias voltage output module, so that each pixel unit operates in a bias state;

[0012] Inputting a light signal into the detector of each pixel unit to generate a photocurrent, inputting the photocurrent into the signal conversion module for signal conversion and amplification to obtain an amplified voltage signal; the amplified voltage signal is output to the output bus after passing through the driver.

[0013] The technical effects of the present invention are:

[0014] The present invention enables a plurality of detectors to share a set of device bias voltages. Compared with a solution in which 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 problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

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

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

[0019] Figure 3 FIG. 4 is a diagram of a balanced detector macro-pixel architecture in an embodiment of the present invention. DETAILED DESCRIPTION

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

[0021] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0022] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art generally understood by the present invention. Although the present invention describes only preferred methods, any method similar or equivalent to that described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0023] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

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

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] Embodiment 1

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

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

[0029] Providing a bias voltage to each pixel unit through a bias voltage output module, so that each pixel unit operates in a bias state;

[0030] Inputting a light signal into the detector of each pixel unit to generate a photocurrent, inputting the photocurrent into the signal conversion module for signal conversion and amplification to obtain an amplified voltage signal; the amplified voltage signal is output to the output bus after passing through the driver.

[0031] This embodiment allows several detectors to share a set of device bias voltages. Compared with the solution in which 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, and reducing the adverse effects of power supply crosstalk problems.

[0032] Figure 1 The diagram shows the detector array and the readout circuit architecture. The detector array is composed of s×t macro-pixel units. The output ends of the first column of macro-pixels are all connected to column bus 1; the output ends of the second column of macro-pixels are all connected to column bus 2; ...; the output ends of the t-th column of macro-pixels are all connected to column bus t. Each macro-pixel unit contains k pixel units, that is, the detector array contains a total of s×t×k pixel units.

[0033] Figure 2 The figure shows the architecture diagram of the macro pixel unit. The macro pixel unit is composed of k pixel units, wherein each pixel unit is composed of a detector unit, a signal conversion module and a driver. The two bias voltage ports of the detector unit are respectively connected to the bias voltage ports Vsup_an and Vsup_ca, and the output end is connected to the input end of the signal conversion module; the output end of the signal conversion module is connected to the input end of the driver, and the output end of the driver is connected to the output bus. The detector units in all pixel units in the macro pixel share a set of the same bias voltages, and the driver output ends in all pixel units in the macro pixel share a set of output buses.

[0034] The working process of the macro-pixel-based SiGe photodetector array and readout circuit is as follows: the detector unit is biased by Vsup_ca and Vsup_an. After receiving the light signal, the detector power supply generates a current signal, and the signal conversion module converts the current signal into a voltage signal; the voltage signal is output to the output bus after passing through the driver. The output signal in the macro-pixel unit is further output to the column bus.

[0035] Compared with the solution that all pixel units are powered by independent bias voltage sources, for a dual-port powered detector, the solution proposed in the present invention reduces the number of required bias voltage sources from s×t×k to s×t;

[0036] Compared with a solution in which all pixel units share the same set of bias voltage sources for power supply, the solution proposed in the present 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 is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A germanium silicon photodetector array, characterized in that: It comprises a plurality of macro pixel units which are arranged in parallel in sequence according to a set spacing; each of the macro pixel units comprises a plurality of pixel units and an output bus, each of the pixel units are arranged in sequence from top to bottom according to the set spacing, the output end of each of the pixel units is electrically connected to the output bus, and the voltage input end of each of the pixel units is connected to a bias voltage output module.

2. A germanium silicon photodetector array according to claim 1, characterized in that: The pixel units have the same structure, including a detector, a signal conversion module and a driving module; The detector, the signal conversion module and the driving module are connected in sequence, the voltage input end of the detector is electrically connected to the bias voltage output module; and the output end of the driving module is electrically connected to the output bus.

3. A germanium silicon photodetector array according to claim 2, characterized in that: The detector is a balanced detector.

4. The germanium silicon photodetector array according to claim 2, characterized in that: The signal conversion module adopts a transimpedance amplifier.

5. A signal readout method, applied to a germanium silicon photodetector array according to any one of claims 1 to 4, characterized in that: include: A bias voltage is provided to each pixel unit through a bias voltage output module, 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 photocurrent, and the photocurrent is input into the signal conversion module for signal conversion and amplification to obtain an amplified voltage signal; the amplified voltage signal is output to an output bus after passing through a driver.

Images