Visible light and short wave infrared dual-band detector

Abstract

The invention relates to a visible light and short wave infrared dual-band detector which comprises a tube shell, a cover plate, a thermoelectric refrigerating unit, a short wave infrared chip set, a multilayer ceramic substrate with a cavity, a microlens array, a silicon-based visible light chip, an antireflection film and cofferdam glue. The cover plate with a window is welded to the upper end of the tube shell. The multilayer ceramic substrate with a cavity is fixed on a bottom plate of the tube shell, the thermoelectric refrigerating unit is arranged on the bottom surface of the ceramic cavity, the short-wave infrared chip set is arranged on the thermoelectric refrigerating unit in the ceramic cavity, the micro-lens array is arranged on the photosensitive surface of the silicon-based visible light chip, the antireflection film is manufactured on the backlight surface of the silicon-based visible light chip, and the silicon-based visible light chip is arranged in the antireflection film. The periphery of the short-wave infrared reading circuit chip is coated with the cofferdam glue, and the silicon-based visible light chip with the antireflection film is fixed on the cofferdam glue, so that pixels of the silicon-based visible light chip and pixels of the indium gallium arsenic short-wave infrared photosensitive chip are aligned up and down and are in one-to-one correspondence; filling glue is filled between the antireflection film and the photosensitive surface of the indium gallium arsenic short wave infrared photosensitive chip, and the silicon-based visible light chip and the indium gallium arsenic short wave infrared chip are connected with the ceramic substrate through lead bonding wires.

Description

Technical Field

[0001] The invention relates to the field of photoelectric detectors, and in particular to a visible light and short-wave infrared dual-band detector. Background Art

[0002] Multi-(wide) spectrum and high-resolution photoelectric detection is the development trend of detectors, which has a subversive effect on the miniaturization, low power consumption, high precision and high anti-interference ability of photoelectric instruments and equipment. The energy of night sky light such as moonlight, atmospheric glow and starlight in the dark environment is mainly concentrated in the visible-short-wave infrared band (0.4-1.7μm). In order to achieve high-quality imaging in low-light night vision environment, visible-short-wave infrared dual-band detectors have become a research hotspot. Visible-short-wave infrared detectors can combine the advantages of visible light detectors and infrared light detectors, and have a subversive impact on many visible-infrared fusion application fields. They can be used in automotive laser radar, deep space exploration, earth mineral resource exploration, soil monitoring, vegetation moisture content and atmospheric composition changes, crop yield estimation and disaster prevention and mitigation, and many other fields.

[0003] In order to achieve visible-shortwave infrared detection, the prior art includes the following technical solutions:

[0004] 1. Expand the response band of the photosensitive chip. For example, by removing the InP substrate to extend the response band of the InGaAs infrared detector, its response cutoff can be expanded from 0.9μm to about 0.5μm, covering the visible light band. In this technology, visible light and short-wave infrared need to respond to different pixels. For example, one short-wave infrared pixel is set in every four sub-pixels, which actually sacrifices the resolution of the entire array;

[0005] 2. Detection of different wavebands is achieved through device integration technology. For example, patent CN 108346713 B discloses a visible-short-wave infrared detector, that is, a visible light detector is formed on the back of a silicon substrate, and a short-wave infrared detector is formed on the front of the silicon substrate. The problem with this technology is that the process is complex and the process flow is long. The failure of each device will lead to the overall scrapping, and the two detectors share a readout circuit, which makes circuit design difficult.

[0006] Chip-level stacking packaging is widely used in the integrated circuit industry to achieve high-density integration. The upper and lower chips are interconnected by flip-chip soldering or wire bonding, or each is led out by wire bonding. In the optoelectronics field, stacking packaging becomes more difficult because the photosensitive chip needs to receive incident light from the window and the lower chip has a low external quantum efficiency due to the shading of the upper chip. There are few reports on visible-short-wave infrared stacking packaging.

[0007] In conventional integrated device technology, the silicon process of visible light detectors is incompatible with the compound semiconductor process of short-wave infrared, making it difficult to integrate and manufacture visible-short-wave infrared detectors. Patent CN 108346713 B reports a visible-short-wave infrared detector compatible with silicon semiconductor process, which manufactures visible light detectors and short-wave infrared detectors on the front and back sides of the readout circuit respectively, but its readout circuit design is difficult, the device process flow is complicated, and the yield is low.

[0008] It can be seen that in the current technology, visible-shortwave infrared detection either has difficulty in achieving high resolution, or has difficulties in device design, complex device technology, and long process flow, which easily leads to problems such as low yield. Summary of the invention

[0009] The purpose of the invention of this application is to provide a miniaturized visible light and short-wave infrared dual-band detector, which realizes high-resolution visible light and short-wave infrared joint imaging without increasing the overall design and process complexity.

[0010] In order to achieve the invention purpose of this application, this application adopts the following technical solutions:

[0011] The invention discloses a dual-band detector of visible light and short-wave infrared, comprising: a tube shell, a cover plate, a thermoelectric cooler, a short-wave infrared chipset and a multilayer ceramic substrate with a cavity. The cover plate is welded to the upper end of the tube shell, a window is opened on the cover plate, so that light is emitted from the window into the space surrounded by the cover plate and the tube shell. A multilayer ceramic substrate with a cavity is arranged at the lower end of the tube shell, a thermoelectric cooler is arranged in the cavity of the multilayer ceramic substrate with a cavity, and the short-wave infrared chipset is arranged on the thermoelectric cooler. The short-wave infrared chipset comprises: a short-wave infrared readout circuit chip and an indium gallium arsenide short-wave infrared photosensor chip. The short-wave infrared readout circuit chip is arranged on the thermoelectric cooler. The indium gallium arsenide short-wave infrared photosensor chip is interconnected on the top of the short-wave infrared readout circuit chip through an indium column. The short-wave infrared readout circuit chip is connected to the thermoelectric cooler through a wire bonding wire. The multilayer ceramic substrate with a cavity is connected, and a plurality of lead pins are welded on the bottom surface of the multilayer ceramic substrate, and they extend through the lower end of the bottom plate of the tube shell, wherein: the visible light and short-wave infrared dual-band detector also includes: a microlens array, a silicon-based visible light chip, an anti-reflection film and a cofferdam glue, the microlens array is arranged on the photosensitive surface of the silicon-based visible light chip, the anti-reflection film is made on the backlight surface of the silicon-based visible light chip, the cofferdam glue is coated on the periphery of the short-wave infrared readout circuit chip, the silicon-based visible light chip with the anti-reflection film is fixed on the cofferdam glue, so that the pixels of the silicon-based visible light chip and the pixels of the indium gallium arsenide short-wave infrared photosensitivity chip are aligned up and down and correspond one to one, and the anti-reflection film and the photosensitive surface of the indium gallium arsenide short-wave infrared photosensitivity chip are filled with filling glue, and the silicon-based visible light chip is connected to the multilayer ceramic substrate with a cavity through a wire bonding wire.

[0012] The visible light and shortwave infrared dual-band detector of the present invention, wherein: the cofferdam glue contains spherical spacers, the particle size of the spherical spacers is 15-200μm, and the distance between the photosensitive surface of the indium gallium arsenide shortwave infrared photosensor chip and the backlight surface of the silicon-based visible light chip is adjusted by the particle size of the above-mentioned spherical spacers.

[0013] The visible light and short-wave infrared dual-band detector of the present invention comprises: a step is arranged inside the cavity of the multilayer ceramic substrate with a cavity, and a short-wave infrared readout circuit chip is connected to a bonding point on the step through a wire bonding wire.

[0014] The visible light and short-wave infrared dual-band detector of the present invention, wherein: the silicon-based visible light chip is connected to the bonding point on the upper end of the multi-layer ceramic substrate through the lead bonding wire.

[0015] The visible light and short-wave infrared dual-band detector of the present invention, wherein: the aperture ratio of the silicon-based visible light chip is above 50%.

[0016] The visible light and short-wave infrared dual-band detector of the present invention, wherein: the silicon substrate of the silicon-based visible light chip is 200-300 μm.

[0017] The visible light and short-wave infrared dual-band detector of the present invention, wherein: the response band of the silicon-based visible light chip is 350nm-1050nm.

[0018] The visible light and short-wave infrared dual-band detector of the present invention, wherein: the microlens array is made of silicon nitride or sapphire material.

[0019] The visible light and short-wave infrared dual-band detector of the present invention can realize miniaturized visible-short-wave infrared simultaneous staring imaging without sacrificing device resolution, and the present invention does not increase the overall chip design and process complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a forward cross section of the visible light and short-wave infrared dual-band detector of the present invention;

[0021] Figure 2 It is a three-dimensional partial cross-sectional schematic diagram of the visible light and short-wave infrared dual-band detector of the present invention.

[0022] exist Figure 1 and Figure 2Among them, number 1 is a window; number 2 is a cover plate; number 3 is a microlens array; number 4 is a silicon-based visible light chip; number 5 is an anti-reflection film; number 6 is a cofferdam glue; number 7 is a step; number 8 is a lead pin; number 9 is a thermoelectric cooler; number 10 is a tube shell; number 11 is an indium column; number 12 is a short-wave infrared readout circuit chip; number 13 is an indium gallium arsenide short-wave infrared photosensor chip; number 14 is a ceramic substrate; number 15 is a filling glue; number 16 is a wire bonding wire. DETAILED DESCRIPTION

[0023] like Figure 1 and Figure 2 As shown, a visible light and short-wave infrared dual-band detector of the present invention includes: a cover plate 2, a thermoelectric cooler 9, a tube shell 10, a short-wave infrared chipset, a multilayer ceramic substrate 14 with a cavity, a microlens array 3, a silicon-based visible light chip 4, an anti-reflection film 5 and a cofferdam glue 6. A cover plate 2 is welded to the upper end of a tube shell 10, and a window 1 is opened on the cover plate 2, so that light is emitted from the window 1 into the space surrounded by the cover plate 2 and the tube shell 7. A multilayer ceramic substrate 14 with a cavity is arranged at the lower end of the tube shell 10, and a thermoelectric cooler 9 is arranged on the bottom surface of the ceramic substrate cavity. A short-wave infrared chipset is arranged on the thermoelectric cooler 9. The short-wave infrared chipset includes: a short-wave infrared readout circuit chip 12 and an indium gallium arsenide short-wave infrared photosensor chip 13. The short-wave infrared readout circuit chip 12 is arranged on the thermoelectric cooler 9. The indium gallium arsenide short-wave infrared photosensor chip 13 is interconnected directly above the short-wave infrared readout circuit chip 12 through an indium column 11. There is a step 7 on the inner side of the cavity of the multilayer ceramic substrate 14. The short-wave infrared readout circuit chip 12 is connected to the bonding point on the step 7 through a wire bonding wire 16. The cutoff wavelength of the indium gallium arsenide short-wave infrared photosensor chip 13 is 1.7 μm. A plurality of lead pins 8 are welded to the bottom surface of the multilayer ceramic substrate 14 and extend through the bottom end of the bottom plate of the tube shell 10.

[0024] The microlens array 3 is arranged on the photosensitive surface of the silicon-based visible light chip 4, the anti-reflection film 5 is made on the backlight surface of the silicon-based visible light chip 4, the dam glue 6 is coated on the periphery of the short-wave infrared readout circuit chip 12, and the silicon-based visible light chip 4 with the anti-reflection film 5 is fixed on the dam glue 6, so that the pixels of the silicon-based visible light chip 4 and the pixels of the indium gallium arsenide short-wave infrared photosensitive chip 13 are aligned up and down through the alignment mark and correspond one to one. The dam glue 6 contains spherical spacers, and the particle size of the spherical spacers is 15-200μm, for example: the spherical spacers are silicon oxide balls, and their diameters are 50μm or 20μm. The distance between the photosensitive surface of the indium gallium arsenide short-wave infrared photosensitive chip 13 and the backlight surface of the silicon-based visible light chip 4 is adjusted by the particle size of the spherical spacers. A filling glue 15 is filled between the anti-reflection film 5 and the photosensitive surface of the InGaAs short-wave infrared photosensor chip 13 , and the silicon-based visible light chip 4 is connected to the bonding point at the upper end of the ceramic cavity 14 through a wire bonding wire 16 .

[0025] The aperture ratio of the silicon-based visible light chip 4 is above 50%. For example, the aperture ratio of the silicon-based visible light chip 4 is 70% or 85%. The silicon-based visible light chip 4 is a common visible light chip, and its response band is 350nm - 1050nm. The microlens array 3 is made of silicon nitride or sapphire material. The microlens array focuses the incident light onto the pixel center, improving the quantum efficiency of the photosensitive sensor to ensure wide-spectrum transmission in the visible - short-wave infrared range.

[0026] On one side of the photosensitive surface of the indium gallium arsenide short-wave infrared photosensitive chip 13 and on one side of the backlight surface of the silicon-based visible light chip 4, there are aligned alignment marks, so that the pixels of the silicon-based visible light chip 4 and the pixels of the indium gallium arsenide short-wave infrared photosensitive chip 13 are vertically aligned and correspond one by one through the above alignment marks.

[0027] The key points of the visible light and short-wave infrared dual-band detector of the present invention are as follows:

[0028] (1) Realize the vertical stacking of the indium gallium arsenide short-wave infrared photosensitive chip 13 and the silicon-based visible light chip 4 through spherical spacers, and the stacking does not affect the imaging function of the underlying indium gallium arsenide short-wave infrared photosensitive chip 13;

[0029] (2) Through the structure of vertical stacking and packaging, realize the simultaneous staring imaging of the indium gallium arsenide short-wave infrared photosensitive chip 13 and the silicon-based visible light chip 4 without sacrificing the resolution of the chips.

[0030] (3) In one package, realize the simultaneous imaging of the indium gallium arsenide short-wave infrared photosensitive chip 13 and the silicon-based visible light chip 4 without the need to separately set their respective filter structures, reducing the system complexity.

[0031] The above is only one implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any transformation that is easily conceivable by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A dual-band detector of visible light and short-wave infrared, comprising: A tube shell (10), a cover plate (2), a thermoelectric cooler (9), a short-wave infrared chipset and a multilayer ceramic substrate (14) with a cavity. The cover plate (2) is welded to the upper end of the tube shell (10). A window (1) is provided on the cover plate (2) so that light is emitted from the window (1) into a space surrounded by the cover plate (2) and the tube shell (7). A multilayer ceramic substrate (14) with a cavity is provided at the lower end of the tube shell (10). A thermoelectric cooler (9) is provided in the cavity of the multilayer ceramic substrate (14) with a cavity. The short-wave infrared chipset is arranged on a thermoelectric cooler (9), and the short-wave infrared chipset comprises: a short-wave infrared readout circuit chip (12) and an indium gallium arsenide short-wave infrared photosensor chip (13). The short-wave infrared readout circuit chip (12) is arranged on the thermoelectric cooler (9), and the indium gallium arsenide short-wave infrared photosensor chip (13) is interconnected on the top of the short-wave infrared readout circuit chip (12) through an indium column (11). The short-wave infrared readout circuit chip (12) is connected to a multilayer ceramic substrate (13) with a cavity through a wire bonding wire (16). 4), a plurality of lead pins (8) are welded on the bottom surface of a multilayer ceramic substrate (14) with a cavity, and extend through the lower end of the tube shell (10), characterized in that: the visible light and short-wave infrared dual-band detector also includes: a microlens array (3), a silicon-based visible light chip (4), an anti-reflection film (5) and a cofferdam glue (6), the microlens array (3) is arranged on the photosensitive surface of the silicon-based visible light chip (4), the anti-reflection film (5) is made on the backlight surface of the silicon-based visible light chip (4), and the cofferdam glue (6) is coated on the short-wave infrared On the periphery of the external readout circuit chip (12), a silicon-based visible light chip (4) with an anti-reflection film (5) is fixed on a cofferdam glue (6), so that the pixels of the silicon-based visible light chip (4) and the pixels of the indium gallium arsenide short-wave infrared photosensor chip (13) are aligned vertically and correspond one to one, and a filling glue (15) is filled between the anti-reflection film (5) and the photosensitive surface of the indium gallium arsenide short-wave infrared photosensor chip (13), and the silicon-based visible light chip (4) is connected to a multilayer ceramic substrate (14) with a cavity through a wire bonding wire (16).

2. The visible light and short-wave infrared dual-band detector according to claim 1, characterized in that: The cofferdam glue (6) contains spherical spacers, the particle size of the spherical spacers is 15-200 μm, and the distance between the photosensitive surface of the InGaAs short-wave infrared photosensitive chip (13) and the backlight surface of the silicon-based visible light chip (4) is adjusted by the particle size of the spherical spacers.

3. The visible light and short-wave infrared dual-band detector according to claim 2, characterized in that: A step (7) is provided inside the multilayer ceramic substrate (14) with a cavity, and a short-wave infrared readout circuit chip (12) is connected to a bonding point on the step (7) via a wire bonding wire (16).

4. The visible light and short-wave infrared dual-band detector as claimed in claim 3, characterized in that: The silicon-based visible light chip (4) is connected to a bonding point at the upper end of a multilayer ceramic substrate (14) with a cavity via a wire bonding wire (16).

5. The visible light and short-wave infrared dual-band detector according to claim 4, characterized in that: The aperture ratio of the silicon-based visible light chip (4) is above 50%.

6. The visible light and short-wave infrared dual-band detector according to claim 5, characterized in that: The silicon substrate of the silicon-based visible light chip (4) is 200-300 μm.

7. The visible light and short-wave infrared dual-band detector according to claim 6, characterized in that: The response waveband of the silicon-based visible light chip (4) is 350nm to 1050nm.

8. The visible light and short-wave infrared dual-band detector according to claim 7, characterized in that: The microlens array (3) is made of silicon nitride or sapphire material.

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