Disclosure of Invention
The invention aims to solve the technical problems in the prior art, and particularly creatively provides a hybrid integrated double-spectrum multispectral short-wave infrared detector.
In order to achieve the above object, the present invention provides a hybrid integrated dual-spectral multispectral short-wave infrared detector, which sequentially comprises, along the incident direction of light:
a MEMS optical filtering or interference chip on which an electrode is formed;
a dual-spectrum multispectral infrared detector unit or array is arranged below the MEMS optical filtering or interference chip, and the dual-spectrum multispectral infrared detector is connected with the MEMS optical filtering or interference chip in a mounting or coupling mode;
a signal processing chip or a reading circuit chip is arranged below the dual-spectrum multispectral infrared detector unit or array, the dual-spectrum multispectral infrared detector is connected with the signal processing chip or the reading circuit chip in a lead bonding or flip-chip welding mode, and part of the dual-spectrum multispectral infrared detector and the signal processing chip or the reading circuit chip is exposed to form an electrode;
the MEMS optical filtering or interference chip electrode is interconnected with the electrode of the signal processing chip or the reading circuit chip through a lead;
the back of the signal processing chip or the reading circuit chip is a data and power interface.
The MEMS optical filtering or interference chip and the micro-assembly integration of the dual-spectrum multispectral infrared detector realize flexible single-chip wide-spectrum multispectral detection, and compared with other dual-multicolor detectors, such as optical filter optical window filtering, on-chip integrated microstructure dielectric film filtering, REC resonance detectors and the like, the spectral resolution and modulation flexibility of the multispectral detection are obviously improved.
The hybrid integration of the special IC chip for ASICs or ROICs and the multispectral detector can realize the chip production, is beneficial to the development of portable spectrum sensing application, can manufacture a multispectral focal plane image sensor, and meets the application requirements of low-cost and smart imaging spectrometers.
In a preferred embodiment of the present invention, a bispectral multispectral infrared detector comprises:
an InP substrate;
forming InP of a first conductivity type as a lower contact layer of a first absorption layer structure on the InP substrate;
intrinsic In is formed on the lower contact layer of the first absorption layer structurex1Ga1-x1As As the first absorption layer, wherein 0<x1<1, the first absorption layer covers part of the lower contact layer, the first absorption layer is preferably In0.53Ga0.47As;
InP of a second conductivity type is formed as a common contact layer over the first absorption layer;
a lattice-adapted buffer layer is formed on the common contact layer, the bottom layer of the lattice-adapted buffer layer is lattice-matched with the common contact layer, the upper layer of the lattice-adapted buffer layer is lattice-matched with the second absorption layer, and the lattice-adapted buffer layer covers part of the common contact layer;
forming In of intrinsic or first conductive type on the lattice-adapted buffer layerx2Ga1-x2As As the second absorption layer, wherein 0<x2<1,x2>x1;
Forming In of a first conductivity type over the second absorption layerx3Al1-x3An upper contact layer of As, wherein 0<x3<1; and x2-0.1<x3<x2+0.1;
Electrodes are formed on the lower contact layer, the exposed portion of the common contact layer, and the upper contact layer.
The invention adopts a design scheme of a two-color detector, combines a standard wavelength response PIN detector (PD1) with an extended wavelength response PIN detector (PD2), utilizes PD1 to respond to a spectral band below 1.7 mu m, and utilizes PD2 to respond to a spectral band between 1.7 and 2.5 mu m. The PD1 and the PD2 share a P electrode to form a back incident type n-i-P-i-n type device structure, and the modulation of a response spectrum is realized through the switching of electrode bias.
The invention greatly improves the quantum efficiency of the spectrum band below 1.7 mu m, obviously reduces the dark current and obviously improves the detection sensitivity.
According to the distribution characteristics of spectrum signals, the spectrum below 1.7 mu m is mainly based on light reflection detection, the spectrum range of 1.7-2.5 mu m is mainly based on heat radiation detection, and the detector structure not only meets the detection requirement of wide spectrum, but also can meet the two-color detection requirement of part of specific applications, and is flexible to apply.
In a preferred embodiment of the invention, an etch stop layer, preferably In, is formed between the InP substrate and the lower contact layer0.53Ga0.47As. The invention can effectively expand the spectral response range of the InGaAs detector, the working wavelength covers the wide spectral range of 0.95-2.5 μm, if the InP substrate is completely stripped, the working wavelength can effectively cover the near infrared-short wave infrared wide spectral range of 0.75-2.5 μm, and the widest response spectrum can cover the visible short spectral range of 0.4-2.5 μm.
In another preferred embodiment of the present invention, the first conductivity type is N-type, the second conductivity type is P-type, and the conductivity type of the lattice-adapted buffer layer is P-type, preferably Be-doped. Be doping is more favorable to improving the epitaxial crystal quality of buffer layer, helps promoting the epitaxial quality of second absorbing layer, improves and extends wavelength response sensitivity.
In another preferred embodiment of the invention, the lattice-adapted buffer layer is of a multilayer structure, InAlAs or InAsP material with linearly-graded or graded components is adopted, and through component modulation, the bottom layer is lattice-matched with the common contact layer, and the upper layer is lattice-matched with the second absorption layer. The epitaxial growth quality of the second absorption layer is improved.
In another preferred embodiment of the present invention, a bispectral multispectral infrared detector comprises:
a substrate;
the absorption structure comprises a first absorption layer structure, a second absorption layer structure, … …, an ith absorption layer structure, … … and an Nth absorption layer structure which are sequentially formed on the substrate from bottom to top, wherein N is a positive integer larger than 1, and i is a positive integer larger than 1 and smaller than or equal to N;
each absorption layer structure is provided with a lower contact layer, an absorption layer and an upper contact layer, and the contact layers of two adjacent absorption layer structures are shared;
the absorption wavelengths of the N absorption layers become longer gradually in the upward direction from the substrate.
The invention adopts the structural design of a multicolor detector, and can realize multicolor synchronous detection in a wide spectral band range.
In a preferred embodiment of the invention, an etch barrier layer is formed between the substrate and the first absorber layer structure. By arranging the corrosion barrier layer, the substrate can be completely stripped, the detectable spectral range is widened, and the expansion of the visible light wave band is realized.
In a further preferred embodiment of the invention, a filter layer is formed between two adjacent absorption layer structures, the absorption wavelength of the filter layer being between the absorption wavelengths of the two absorption layer structures with which it is in contact. The degree of freedom of detection spectrum range modulation is greatly increased, and narrow-band-pass multi-color detection can be realized.
In another preferred embodiment of the invention, N is 2.
In another preferred embodiment of the present invention, a bispectral multispectral infrared detector comprises:
an InP substrate; forming InP of a first conductivity type as a lower contact layer of a first absorption layer structure on the InP substrate; intrinsic In is formed on the lower contact layer of the first absorption layer structurex4Ga1-x4Asy4P1-y4As a first absorption layer, wherein 0<x4<1,0<y4<1 and y4 ═ 2.2 × (1-x4), the first absorbent layer covering part of the lower contact layer; InP of a second conductivity type is formed as a common contact layer over the first absorption layer; intrinsic In is formed on the common contact layerx5Ga1-x5Asy5P1-y5Or Inx6Ga1-x6As As the second absorption layer, wherein 0<x5<1,0<y5<1 and y5 ═ 2.2 × (1-x 5); x4<x5;0.53<x6<0.6; the second absorption layer covers part of the common contact layer and is lattice-matched with the InP; InP of a first conductivity type is formed as an upper contact layer over the second absorption layer; at the lower contact layer, exposed part of the common contact layer andan electrode is formed on the upper contact layer.
The invention adopts the structural design of a double-color detector and utilizes InxGa1-xAsyP1-yThe band gap of the absorption layer is adjusted, so that the double-color detection in the spectral band range of 0.95-1.7 mu m can be realized, and the range of the double-color spectral band can be continuously modulated.
In another preferred embodiment of the present invention, an etch stop layer (preferably In) is formed between the InP substrate and the lower contact layer0.53Ga0.47As). The provision of the etch stop layer facilitates the stripping of the InP substrate, which, if completely stripped, will effectively cover a broad spectral range of 0.6-1.7 μm. The detectable spectral range is extended.
In another preferred embodiment of the present invention, the structure of the common contact layer is replaced by the following structure: an InP first electron barrier layer of a second conductivity type is formed on the first absorption layer, and In of the second conductivity type is formed on the InP first electron barrier layerx7Ga1-x7Asy7P1-y7A filter layer of which 0<x7<1,0<y7<1 and y7 ═ 2.2 × (1-x 7); x4<x7<x 5; and an InP second electronic barrier layer of a second conduction type is formed on the filter layer, the second electronic barrier layer covers part of the filter layer, and electrodes are formed on the lower contact layer, the exposed part of the filter layer and the upper contact layer.
The p-InGaAsP filter layer is inserted as the common contact layer, so that the degree of freedom of modulation in the range of a two-color detection spectrum band is greatly increased, narrow-band-pass two-color detection can be realized, and the p-InP with wide band gap is used as the electronic barrier layer, so that the dark current of the detector is favorably reduced. The detector structure designed by the invention not only meets the detection requirement of bicolor wide spectral band, but also meets the narrow band-pass bicolor detection requirement of part of specific spectral identification application, and is flexible to apply.
In another preferred embodiment of the present invention, in the dual-spectral multispectral infrared detector:
the first absorption layer has a thickness of 2.0-3.5 μm and a band gap cut-off wavelength of λC1;
The second absorption layer has a thickness of2.0-3.5 μm, band gap cut-off wavelength λC2≤1.7μm,
The thickness of the filter layer is 2.0-3.5 μm, and the band gap cut-off wavelength λC1≤λCF≤λC2。
The detection effect is ensured by preventing the signal to be detected from being absorbed by the absorption layer passing through first.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.
In the description of the present invention, unless otherwise specified and limited, it is to be noted that the terms "mounted," "connected," and "connected" are to be interpreted broadly, and may be, for example, a mechanical connection or an electrical connection, a communication between two elements, a direct connection, or an indirect connection via an intermediate medium, and specific meanings of the terms may be understood by those skilled in the art according to specific situations.
The invention provides a hybrid integrated double-spectrum multispectral short-wave infrared detector, as shown in fig. 8, which is sequentially provided with the following components in the incident direction of light rays:
a MEMS (Micro-Electro-Mechanical System) optical filter or interference chip on which an electrode is formed; in this embodiment, the MEMS optical filter chip may be a Fabry-Perot tunable filter MEMS chip with an existing structure, and the MEMS interference chip may be an existing Michelson optical interference chip. The MEMS optical filtering or interference chip can be made by silicon-based, germanium-based or gallium arsenide-based process.
The MEMS optical filtering or interference chip is provided with a dual-spectrum multispectral infrared detector unit or array below, the dual-spectrum multispectral infrared detector and the MEMS optical filtering or interference chip are connected in an optical structure adhesive mounting or optical coupling mode, and the specific process can adopt the prior art.
And a signal processing chip or a reading circuit chip is arranged below the dual-spectrum multispectral infrared detector unit or array, the dual-spectrum multispectral infrared detector is connected with the signal processing chip or the reading circuit chip in a lead bonding or flip-chip bonding mode, and part of the signal processing chip or the reading circuit chip is exposed to form an electrode.
The MEMS optical filtering or interference chip electrode is interconnected with the electrode of the signal processing chip or the reading circuit chip through a lead; the electrical interconnection is realized through wire bonding, and the power supply bias voltage of the MEMS chip is modulated. The MEMS optical filtering or interference chip preferably adopts a silicon-based existing structure.
Specifically, an asic (Application Specific Integrated Circuit) signal processing chip/ROIC (read out Circuit) Readout Circuit chip having a detector signal output port and a MEMS chip power input modulation port may be used. In this embodiment, the ASIC chip mainly includes functional circuit units such as a bias power supply, a transimpedance amplifier, an ADC, a register, and a data interface; the ROIC adopts a CTIA type pixel reading circuit architecture, and the specific circuit structure design is matched with the impedance and the capacitive reactance characteristic of the detector.
The invention provides a bispectrum multispectral infrared detector, which aims to solve the problems of low quantum efficiency in the short wave direction and narrow spectral response range of the conventional extended short-wave infrared InGaAs detector and can obviously improve the detection sensitivity below the wavelength of 1.7 mu m.
In this embodiment, the dual-spectral multispectral infrared detector includes a substrate, which may be any semiconductor substrate selected, and may be, but is not limited to, a general group iv, group iii-v, group ii-vi semiconductor substrate, or a sapphire substrate, such as an InP substrate. Still include from the supreme first absorbed layer structure, second absorbed layer structure, … …, the ith absorbed layer structure, … …, the N absorbed layer structure that form in proper order down (set up from the substrate to the direction of extending survey the layer be from the supreme direction down) on the substrate, N is for being greater than 1 positive integer, i is for being greater than 1 and less than or equal to N's positive integer. The preferred N is 2. Each absorption layer structure is provided with a lower contact layer, an absorption layer and an upper contact layer, the contact layers of two adjacent absorption layer structures are shared, and the absorption wavelengths of the N absorption layers are gradually lengthened along the direction from the substrate to the top.
In a preferred embodiment of the present invention, a dual-spectral multispectral infrared detector comprises:
an InP substrate;
forming InP of a first conductivity type as a lower contact layer of a first absorption layer structure on the InP substrate;
intrinsic In is formed on the lower contact layer of the first absorption layer structurex1Ga1-x1As As the first absorption layer, wherein 0<x1<1, the first absorption layer covers part of the lower contact layer, the first absorption layer is preferably In0.53Ga0.47As;
InP of a second conductivity type is formed as a common contact layer over the first absorption layer;
a lattice-adapted buffer layer is formed on the common contact layer, the bottom layer of the lattice-adapted buffer layer is lattice-matched with the common contact layer, the upper layer of the lattice-adapted buffer layer is lattice-matched with the second absorption layer, and the lattice-adapted buffer layer covers part of the common contact layer;
forming In of intrinsic or first conductive type on the lattice-adapted buffer layerx2Ga1-x2As As the second absorption layer, wherein 0<x2<1,x2>x1;
Forming In of a first conductivity type over the second absorption layerx3Al1-x3An upper contact layer of As, wherein 0<x3<1, and x2-0.1<x3<x2+0.1;
Electrodes are formed on the lower contact layer, the exposed portion of the common contact layer, and the upper contact layer.
In a preferred embodiment of the present invention, the specific component selection and preparation process is as follows:
sequentially growing a p-on-N type PD1 structure and an N-on-p type PD2 structure layer on an InP single crystal substrate by utilizing an MOCVD or MBE epitaxial technology, wherein the InP substrate material adopts an Fe-doped I type semi-insulating substrate or an S-doped N type substrate;
preferably, N is grown on an InP single crystal substrate+-InP lower contact layer, N+The thickness of the-InP lower contact layer is 0.2-1.0 μm, and the doping concentration is more than or equal to 2E +18cm-3The donor impurity is Si; if the InP substrate needs to be stripped to expand the response spectrum, then N is+-inserting a layer of In between the InP lower contact layer and the InP substrate0.53Ga0.47As corrodes the barrier layer. If the substrate needs to be stripped, arranging the corrosion barrier layer; the corrosion barrier layer is not required to be provided if the substrate is not peeled.
In N+Epitaxially growing intrinsic i-In on top of the InP lower contact layer0.53Ga0.47The As first absorption layer has a thickness of 2.0-3.5 μm and a background carrier concentration of 1E +15cm or less-3。
A p-InP common contact layer is grown on the first absorption layer, the thickness is 0.5-1.0 μm, and the effective doping concentration is more than or equal to 1E +18cm-3The acceptor impurity is Zn.
Epitaxially growing a lattice-adapted buffer layer on the p-InP common contact layer, wherein the lattice-adapted buffer layer is of a multilayer structure, InAlAs or InAsP material with linearly-graded or gradually-graded components is adopted, the bottom layer is in lattice matching with the p-InP common contact layer through component modulation, and the upper layer is in lattice matching with the N common contact layer--InxGa1-xThe As second absorption layer is lattice matched, the epitaxial thickness is 1-10 μm, and the effective doping concentration is more than or equal to 1E +18cm-3And acceptor impurities are Zn or Be.
The extension wavelength detector adopts an n-on-p structure, so that the p-type lattice adaptation buffer layer can Be doped with Be, and compared with Si doping of the n-type buffer layer, the Be doping is more favorable for improving the epitaxial crystal quality of the buffer layer, is favorable for improving the epitaxial quality of the second absorption layer, and improves the response sensitivity of the extension wavelength.
Epitaxially growing N on lattice-adapted buffer layer--Inx2Ga1-x2An As second absorption layer, the In component of the second absorption layer is more than 0.53 and less than x2 and less than 0.83, the maximum band gap absorption cut-off wavelength is 2.6 μm (under the working condition of refrigeration and low temperature, the cut-off wavelength is not less than 2.5 μm), the epitaxial thickness is 1.5-2.5 μm,the doping concentration is 1-5E +16cm-3The donor impurity is Si.
Epitaxially growing N on the second absorption layer+-Inx3Al1-x3As upper contact top layer with In component same As that of the second absorption layer (i.e. x2 ═ x3), thickness of 0.2-1.0 μm, and doping concentration ≥ 1E +18cm-3The donor impurity is Si.
Manufacturing a detector device by adopting a mesa process, and forming a device mesa by utilizing dry etching or wet etching; the mesa of the device is made of SiNxOr Al2O3Passivating the dielectric film; electrodes (into which light to be measured is incident from the substrate) are formed on the lower contact layer, the exposed portion of the common contact layer, and the upper contact layer. The upper electrode, the lower electrode and the common electrode adopt Cr/Au double-layer metal or Ti/Pt/Au multi-layer metal.
And if the short-wave response wavelength range of the PD1 needs to be expanded, stripping the InP substrate by adopting selective wet etching.
The invention adopts the structural design of a bicolor detector, can effectively expand the spectral response range of the InGaAs detector, and the working wavelength covers the wide spectral range of 0.95-2.5 mu m, as shown in figure 2; if the InP substrate is completely stripped, the operating wavelength will effectively cover a broad spectral range of near-ir-short-wave ir of 0.75-2.5 μm, as shown in fig. 1.
In another preferred embodiment of the present invention, as shown in fig. 3 (the size of each region is only schematically shown in the figure, and the specific size can be designed according to the requirement of device parameters), the present invention provides a dual-band multispectral infrared detector, which solves the multiple-slice structure problem and the single/dual-color detection selection and control problem existing in the current similar detectors based on the band modulation principle of the InP/ingaas (p) material system. The bispectrum multispectral infrared detector comprises:
an InP substrate;
forming InP of a first conductivity type (preferably N-type) on the InP substrate as a lower contact layer of a first absorption layer structure;
intrinsic In is formed on the lower contact layer of the first absorption layer structurex4Ga1-x4Asy4P1-y4As a first absorbent layerWherein, 0<x4<1,0<y4<1 and y4 ═ 2.2 × (1-x4), the first absorbent layer covering part of the lower contact layer;
InP of a second conductivity type is formed as a common contact layer over the first absorption layer;
intrinsic In is formed on the common contact layerx5Ga1-x5Asy5P1-y5Or Inx6Ga1-x6As As the second absorption layer, wherein 0<x5<1,0<y5<1 and y5 ═ 2.2 × (1-x 5); x4<x5;0.53<x6<0.6; the second absorption layer covers part of the common contact layer and is lattice-matched with the InP;
InP of a first conductivity type is formed as an upper contact layer over the second absorption layer;
electrodes are formed on the lower contact layer, the exposed portion of the common contact layer, and the upper contact layer.
In this embodiment mode, In may be formed between the InP substrate and the lower contact layer0.53Ga0.47As corrodes the barrier layer.
In another preferred embodiment of the present invention, as shown in fig. 6, the structure of the common contact layer is replaced by the following structure:
an InP first electron barrier layer of a second conductivity type formed over the first absorption layer, and In formed over the first electron barrier layerx7Ga1-x7Asy7P1-y7A filter layer of which 0<x7<1,0<y7<1 and y7 ═ 2.2 × (1-x 7); x4<x7<x 5; and an InP second electronic barrier layer of a second conduction type is formed on the filter layer, the second electronic barrier layer covers part of the filter layer, and electrodes are formed on the lower contact layer, the exposed part of the filter layer and the upper contact layer.
According to the invention, a short-wave wavelength response PIN detector (PD1) and a long-wave wavelength response PIN detector (PD2) are combined, a P-on-n structure is adopted for PD1, an n-on-P structure is adopted for PD2, a P electrode is shared by PD1 and PD2 to form a back-incident n-i-P-i-n type device structure, and modulation of a response spectrum is realized through switching of electrode bias. As shown in fig. 6, a bicolor detection + on-chip filtering design scheme is adopted, and a p-InGaAsP filtering layer (common contact layer) is inserted between a short wavelength response PIN detector (PD1) and a long wavelength response PIN detector (PD2), so as to realize continuous modulation of a bicolor detection spectrum band.
In a preferred embodiment of the present invention, the specific component selection and preparation process is as follows:
by utilizing MOCVD or MBE epitaxial technology, a p-on-N type PD1 structure and an N-on-p type PD2 structure layer are sequentially grown on an InP single crystal substrate, and the InP substrate material adopts an Fe-doped I type semi-insulating substrate or an S-doped N type substrate.
Preferably, N is grown on an InP single crystal substrate+-InP lower contact layer, N+The thickness of the-InP lower contact layer is 0.2-1.0 μm, and the doping concentration is more than or equal to 2E +18cm-3The donor impurity is Si. In a more preferred embodiment of the present invention, if the InP substrate needs to be stripped to broaden the response spectrum, then N is the number+-inserting a layer of In between the InP lower contact layer and the InP substrate0.53Ga0.47As corrodes the barrier layer.
In N+Growing intrinsic i-In on top of the InP lower contact layerx1Ga1-x1Asy1P1-y1The first absorption layer has a thickness of 2.0-3.5 μm and a background carrier concentration of 1E +16cm or less-3Band gap cutoff wavelength of λC1。
As shown in FIG. 3, a p-InP common contact layer is grown on the first absorption layer, the thickness is 0.5-1.0 μm, and the effective doping concentration is more than or equal to 1E +18cm-3And acceptor impurities are Zn or Be.
As shown in FIG. 4, a first electron barrier layer of p-InP with a thickness of 0.5-1.0 μm and an effective doping concentration ≥ 1E +18cm is grown on the first absorption layer-3And acceptor impurities are Zn or Be. Growing p-In over a first electron barrier layerx4Ga1- x4Asy4P1-y4The thickness of the common contact layer/the filter layer is 2.0-3.5 mu m, and the effective doping concentration is more than or equal to 1E +18cm-3Acceptor impurities are Zn or Be; band gap cut-off wavelength lambdaC1≤λCF≤λC2. Growing a second p-InP electron barrier layer on the common contact/filter layer to a thickness of0.5-1.0 μm, effective doping concentration not less than 1E +18cm-3And acceptor impurities are Zn or Be.
Growing intrinsic i-In on p-InPx2Ga1-x2Asy2P1-y2A second absorption layer with a thickness of 2.0-3.5 μm and a background carrier concentration of 1E +16cm or less-3Band gap cut-off wavelength λC2Less than or equal to 1.7 mu m. Growing N on the second absorption layer+The thickness of the upper contact top layer of the-InP is 0.2-1.0 μm, and the doping concentration is more than or equal to 1E +18cm-3The donor impurity is Si.
Manufacturing a detector device by adopting a mesa process, and forming a device mesa by utilizing dry etching or wet etching; the mesa of the device is made of SiNxOr Al2O3Passivating the dielectric film; electrodes are formed on the lower contact layer, the exposed portion of the common contact layer, and the upper contact layer (see fig. 3), or electrodes are formed on the lower contact layer, the exposed portion of the filter layer, and the upper contact layer (see fig. 6). The upper electrode, the lower electrode and the common electrode adopt Cr/Au double-layer metal or Ti/Pt/Au multi-layer metal.
And if the short-wave response wavelength range of the PD1 needs to be expanded, stripping the InP substrate by adopting selective wet etching.
The invention adopts the structural design of a double-color detector and utilizes InxGa1-xAsyP1-yThe band gap of the absorption layer is adjusted, so that double-color detection in a spectral band range of 0.95-1.7 mu m can be realized, and the range of the double-color spectral band can be continuously modulated, as shown in figure 5; if the InP substrate is completely stripped, the operating wavelength will effectively cover a broad spectral range of 0.6-1.7 μm, as shown in fig. 4. The p-InGaAsP filtering layer is inserted as a common contact layer, so that the degree of freedom of modulation in the range of a two-color detection spectrum band is greatly increased, and narrow-band-pass two-color detection can be realized, as shown in fig. 7. And the p-InP with wide band gap is used as an electronic barrier layer, which is beneficial to reducing the dark current of the detector.
The invention adopts a mesa process to manufacture a detector device, and forms a device mesa by dry etching or wet etching; the mesa of the device adopts SiNx or Al2O3Passivating the dielectric film; the upper electrode, the lower electrode and the common electrode adopt Cr/Au double-layer metal or Ti/Pt/Au multi-layer metal.
It should be noted that the light incidence directions of fig. 3, 6, and 8 are different, the hierarchical description of the structure in the present invention is performed in the light incidence direction, and in particular, when the dual-spectrum multispectral infrared detector is operated, the dual-spectrum multispectral infrared detector is in an inverted structure, and light enters the device according to the light direction shown in fig. 8.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example" or "some examples" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.