阅读说明：本技术 双色光电探测器及其制备方法 (Double-color photoelectric detector and preparation method thereof ) 是由 张晓东 张凯 张宝顺 于 2019-08-28 设计创作，主要内容包括：本发明揭示了一种双色光电探测器及其制备方法,所述双色光电探测器包括衬底、位于衬底上的pn异质结、及位于pn异质结上的电极,所述pn异质结包括位于衬底上的n型半导体层及位于n型半导体层上的p型半导体层,所述电极包括与n型半导体层电连接的第一电极及与p型半导体层电连接的第二电极,n型半导体层和p型半导体层通过范德华力形成pn异质结。本发明的双色光电探测器采用n型材料和p型材料通过范德华力形成pn异质结,优选地采用BP二维材料和β-Ga_2O_3材料通过范德华力形成BP/β-Ga_2O_3异质结,p型的BP材料进行中红外探测,n型的β-Ga_2O_3材料进行日盲紫外探测,该器件具有制备成本低廉、工艺简单和性能优越等优点,满足在红外、紫外探测技术领域的迫切需求。(The invention discloses a bicolor photoelectric detector and a preparation method thereof, the bicolor photoelectric detector comprises a substrate, a pn heterojunction and an electrode, wherein the pn heterojunction is positioned on the substrate, the electrode is positioned on the pn heterojunction, the pn heterojunction comprises an n-type semiconductor layer and a p-type semiconductor layer, the n-type semiconductor layer is positioned on the substrate, the p-type semiconductor layer is positioned on the n-type semiconductor layer, the electrode comprises a first electrode and a second electrode, the first electrode is electrically connected with the n-type semiconductor layer, the second electrode is electrically connected with the p-type semiconductor layer, and the n-type semiconductor layer and the p-type semiconductor layer form. The two-color photoelectric detector of the invention adopts n-type material and p-type material to form pn heterojunction through Van der Waals force, preferably adopts BP two-dimensional material and beta-Ga 2 O 3 Formation of BP/beta by Van der Waals forces‑Ga 2 O 3 Heterojunction, p-type BP material for mid-infrared detection, n-type beta-Ga 2 O 3 The material is used for solar blind ultraviolet detection, and the device has the advantages of low preparation cost, simple process, superior performance and the like, and meets the urgent requirements in the technical field of infrared and ultraviolet detection.)

1. A dual-color photodetector comprising a substrate, a pn heterojunction on the substrate, and an electrode on the pn heterojunction, the pn heterojunction comprising an n-type semiconductor layer on the substrate and a p-type semiconductor layer on the n-type semiconductor layer, the electrode comprising a first electrode electrically connected to the n-type semiconductor layer and a second electrode electrically connected to the p-type semiconductor layer, the n-type semiconductor layer and the p-type semiconductor layer forming a pn heterojunction by Van der Waals forces.

2. The dual-color photodetector of claim 1, wherein the material of the n-type semiconductor layer is Ga of a β -crystal phase₂O₃The material of the p-type semiconductor layer is black phosphorus, and preferably, the black phosphorus is doped with arsenic.

3. The dual-color photodetector of claim 1, wherein a dielectric layer is disposed on a portion of the n-type semiconductor layer, and the second electrode is disposed on the p-type semiconductor layer and the dielectric layer.

4. The dual color photodetector of claim 3, wherein said dielectric layer is SiO₂、Si₃N₄、Al₂O₃One or more of (a).

5. The bi-color photodetector of claim 1, wherein the pn heterojunction has a passivation layer disposed thereon, and the first and second electrodes are at least partially exposed from the passivation layer.

6. The bi-color photodetector of claim 1, wherein said first and second electrodes are interdigitated electrodes disposed to cross each other.

7. The bi-color photodetector of claim 1, wherein the substrate is one of sapphire, silicon, or silicon carbide.

8. A preparation method of a two-color photodetector is characterized by comprising the following steps:

providing a substrate;

epitaxially growing an n-type material on the substrate to form an n-type semiconductor layer;

epitaxially growing a dielectric layer on the n-type semiconductor layer;

etching part of the dielectric layer to the n-type semiconductor layer, and directionally transferring the p-type material to an etching area to form a pn heterojunction;

a first electrode electrically connected to the n-type semiconductor layer and a second electrode electrically connected to the p-type semiconductor layer are deposited on the pn-heterojunction.

9. The method according to claim 8, wherein the n-type material is Ga in a beta crystal phase₂O₃The p-type material is black phosphorus, and Ga of beta crystalline phase₂O₃And black phosphorus forms a pn heterojunction by van der waals forces.

10. The method according to claim 8, wherein the step of forming a first electrode electrically connected to the n-type semiconductor layer and a second electrode electrically connected to the p-type semiconductor layer on the pn heterojunction comprises:

etching part of the dielectric layer through the mask until reaching the n-type semiconductor layer to form an interdigital etching area;

depositing an interdigital first electrode on the interdigital etching area;

and depositing interdigitated second electrodes on the p-type semiconductor layer.

Technical Field

The invention belongs to the technical field of photoelectric information, and particularly relates to a bicolor photoelectric detector and a preparation method thereof.

Background

The research and application of photoelectric information are important components in the fields of electronic information, optics, semiconductor technology and the like, and photoelectric detectors are the basis of human beings utilizing photoelectric information, particularly infrared detectors and ultraviolet detectors, and are widely applied to various aspects of military, civil and the like.

The application of the infrared detector brings great convenience to daily life of people, and the most common is infrared induction, such as an induction faucet, an induction door, an induction lamp and the like, and other applications such as infrared night vision/imaging, infrared search and tracking, infrared accurate guidance, remote sensing resource investigation, mineral resource exploration, aviation detection, environment monitoring, meteorological satellite, nondestructive inspection, gas analysis, underground coal mine temperature measurement, hidden fire source detection and the like are also provided.

The middle wavelength infrared ray (3-5 mu m) and the long wavelength infrared ray (8-15 mu m) are important wave bands of an atmospheric window and thermal imaging, and currently, infrared detection is realized by mainly utilizing materials such as InGaAs, AlAsSb, GaSb, InSb, InAsSb, HgCdTe and the like in combination with structures such as quantum wells, superlattices, quantum dots and the like, but the material epitaxial growth difficulty of the detector is high, low-temperature refrigeration is required for device work, the integration level is low and the like, and the multispectral detection is difficult to break through in a short period.

The ultraviolet detector has important applications in the fields of relevant military fields such as ultraviolet communication, biochemical analysis, early missile early warning and the like, medical and biomedical fields such as skin lesion detail diagnosis, cancer cell detection, microorganism detection, leukocyte detection and the like, fire detection, ozone monitoring, offshore oil monitoring, public security reconnaissance, astronomical observation, ultraviolet disinfection, ultraviolet curing and polymerization, spectral analysis, particle detection and the like.

The natural advantages of the solar blind ultraviolet band (200-280 nm) make the research on the detector focus, and the wide band gap semiconductor material-gallium oxide (Ga)₂O₃) The forbidden band width is as high as 4.2-5.2 eV, just in timeCan respond to the wave band, has low cost and stable physicochemical properties, and becomes a research hotspot in recent years.

At present, the research of the detector is developing towards the directions of multi-spectrum, high sensitivity, high resolution, low power consumption, miniaturization, integration and intellectualization, but due to the compatibility problem of different photosensitive materials, an integrated infrared-ultraviolet dual-color detector with great application potential is yet to be researched.

Therefore, in view of the above technical problems, it is necessary to provide a two-color photodetector and a method for manufacturing the same.

Disclosure of Invention

In view of the above, the present invention provides a two-color photodetector and a method for manufacturing the same, so as to implement two-color detection of infrared and ultraviolet.

In order to achieve the above object, an embodiment of the present invention provides the following technical solutions:

a bicolor photodetector comprises a substrate, a pn heterojunction and an electrode, wherein the pn heterojunction is positioned on the substrate and comprises an n-type semiconductor layer and a p-type semiconductor layer, the n-type semiconductor layer is positioned on the substrate, the p-type semiconductor layer is positioned on the n-type semiconductor layer, the electrode comprises a first electrode and a second electrode, the first electrode is electrically connected with the n-type semiconductor layer, the second electrode is electrically connected with the p-type semiconductor layer, and the n-type semiconductor layer and the p-type semiconductor layer form the pn heterojunction through Van der Waals force.

In one embodiment, the n-type semiconductor layer is made of Ga with a beta crystal phase₂O₃The material of the p-type semiconductor layer is black phosphorus, and preferably, the black phosphorus is doped with arsenic.

In one embodiment, a dielectric layer is disposed on a portion of the n-type semiconductor layer, and the second electrode is disposed on the p-type semiconductor layer and the dielectric layer.

In one embodiment, the dielectric layer is SiO₂、Si₃N₄、Al₂O₃One or more of (a).

In one embodiment, a passivation layer is disposed on the pn heterojunction, and the first and second electrodes are at least partially exposed from the passivation layer.

In one embodiment, the first electrode and the second electrode are interdigitated electrodes disposed to cross each other.

In one embodiment, the substrate is one of sapphire, silicon, or silicon carbide.

The technical scheme provided by another embodiment of the invention is as follows:

a method of fabricating a bi-color photodetector, the method comprising:

providing a substrate;

epitaxially growing an n-type material on the substrate to form an n-type semiconductor layer;

epitaxially growing a dielectric layer on the n-type semiconductor layer;

etching part of the dielectric layer to the n-type semiconductor layer, and directionally transferring the p-type material to an etching area to form a pn heterojunction;

a first electrode electrically connected to the n-type semiconductor layer and a second electrode electrically connected to the p-type semiconductor layer are deposited on the pn-heterojunction.

In one embodiment, the n-type material is Ga having a beta crystal phase₂O₃The p-type material is black phosphorus, and Ga of beta crystalline phase₂O₃And black phosphorus forms a pn heterojunction by van der waals forces.

In one embodiment, the step of forming a first electrode electrically connected to the n-type semiconductor layer and a second electrode electrically connected to the p-type semiconductor layer on the pn heterojunction includes:

etching part of the dielectric layer through the mask until reaching the n-type semiconductor layer to form an interdigital etching area;

depositing an interdigital first electrode on the interdigital etching area;

and depositing interdigitated second electrodes on the p-type semiconductor layer.

Compared with the prior art, the invention has the following beneficial effects:

the two-color photoelectric detector of the invention adopts n-type material and p-type material to form pn heterojunction through Van der Waals force, preferably adopts BP two-dimensional material and beta-Ga₂O₃Formation of BP/beta-Ga by van der Waals forces₂O₃HeterojunctionP-type BP material for mid-infrared detection, n-type beta-Ga₂O₃The material is used for solar blind ultraviolet detection, and the device has the advantages of low preparation cost, simple process, superior performance and the like, and meets the urgent requirements in the technical field of infrared and ultraviolet detection.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic cross-sectional view of a dual color photodetector according to an embodiment of the present invention;

FIG. 2 is a schematic plan view of a dual-color photodetector according to an embodiment of the present invention;

fig. 3a to 7a are sectional structure process flow diagrams of a method for manufacturing a two-color photodetector according to an embodiment of the present invention;

fig. 3b to 7b are process flow diagrams of a planar structure of a method for manufacturing a two-color photodetector according to an embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to embodiments shown in the drawings. The embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to the embodiments are included in the scope of the present invention.

The invention discloses a bicolor photoelectric detector which comprises a substrate, a pn heterojunction and an electrode, wherein the pn heterojunction is positioned on the substrate, the electrode is positioned on the pn heterojunction, the pn heterojunction comprises an n-type semiconductor layer and a p-type semiconductor layer, the n-type semiconductor layer is positioned on the substrate, the p-type semiconductor layer is positioned on the n-type semiconductor layer, the electrode comprises a first electrode and a second electrode, the first electrode is electrically connected with the n-type semiconductor layer, the second electrode is electrically connected with the p-type semiconductor layer, and the n-type semiconductor layer and the p-type semiconductor layer form the.

The invention also discloses a preparation method of the bicolor photoelectric detector, which comprises the following steps:

providing a substrate;

epitaxially growing an n-type material on the substrate to form an n-type semiconductor layer;

epitaxially growing a dielectric layer on the n-type semiconductor layer;

etching part of the dielectric layer to the n-type semiconductor layer, and directionally transferring the p-type material to an etching area to form a pn heterojunction;

a first electrode electrically connected to the n-type semiconductor layer and a second electrode electrically connected to the p-type semiconductor layer are deposited on the pn-heterojunction.

The present invention is further illustrated by the following specific examples.

Referring to fig. 1 and 2, a two-color photodetector according to an embodiment of the present invention includes a substrate 10, a pn heterojunction on the substrate, and an electrode on the pn heterojunction, wherein the pn heterojunction includes an n-type semiconductor layer 20 on the substrate and a p-type semiconductor layer 40 on the n-type semiconductor layer, the electrode includes a first electrode 51 electrically connected to the n-type semiconductor layer 20 and a second electrode 52 electrically connected to the p-type semiconductor layer 40, and the n-type semiconductor layer is made of a material of Ga in a β -crystal phase₂O₃The material of the p-type semiconductor layer is black phosphorus, and the n-type semiconductor layer 20 and the p-type semiconductor layer 40 form a pn heterojunction by van der waals force. The dielectric layer 30 is provided on a partial region of the n-type semiconductor layer 20, and the second electrode 52 is provided on the p-type semiconductor layer 40 and the dielectric layer 30.

The substrate in this embodiment may be a sapphire substrate, a silicon substrate, or a silicon carbide substrate, and the dielectric layer is SiO₂、Si₃N₄、Al₂O₃And the like.

Further, in the present embodiment, the passivation layer 60 is disposed on the pn heterojunction, and the first electrode 51 and the second electrode 52 are at least partially exposed from the passivation layer 60.

Preferably, the first electrode 51 and the second electrode 52 are interdigital electrodes arranged to cross each other in this embodiment.

Ultra-wideband gap oxide semiconductor-gallium oxide (Ga) compared with third generation semiconductor material₂O₃) The material has the advantages of larger forbidden band width, higher breakdown field strength, transparency and conductivity, capability of growing by a melt method, lower cost and the like, and becomes a research hotspot in the fields of semiconductor materials, devices and the like.

Ga₂O₃The material has five known crystal phases of alpha, beta, gamma, delta and epsilon, wherein beta-Ga₂O₃The structure is most stable and can be mutually converted with other four kinds of gallium oxide. beta-Ga₂O₃The single crystal material is the first choice material for preparing high-performance ultraviolet detector, but beta-Ga is prepared₂O₃Single crystal materials are difficult and expensive. In terms of application, beta-Ga₂O₃The critical field intensity of the GaN-based high-voltage power amplifier is more than 20 times of that of Si and more than 2 times of that of GaN and SiC, and the GaN-based high-voltage power amplifier has great application potential on high-power and high-voltage equipment; in addition, as a solar blind ultraviolet detecting material, Ga₂O₃Compared with AlGaN, MgZnO, diamond and other materials, the material has more obvious advantages.

beta-Ga in the present example₂O₃The material can be grown on a homogeneous substrate or a heterogeneous substrate by CVD, MOCVD, LPCVD, MBE, or the like.

The BP (black phosphorus) material has direct band gap characteristics independent of the number of layers, the forbidden bandwidth (1.51 eV-0.3 eV) is adjustable along with the thickness in a large range, the band from visible light to intermediate infrared light is covered, and the characteristics of high mobility, heterogeneous integration and the like are achieved, so that the BP material is a photoelectric detection material with high responsivity, high frequency response and wide response spectrum and has a great application prospect in the field of photoelectronic devices, and has great research value and development potential; more importantly, the same group element arsenic is doped into BP, the forbidden band width can be further adjusted to be 0.15eV, and black arsenic phosphorus (B-AsP) has important development prospect in the aspect of medium and far wave infrared (8 mu m) photoelectric detection.

BP is a natural p-type semiconductor, which is in contrast to n-type beta-Ga₂O₃The materials are complementary, and the BP two-dimensional material does not need to consider lattice matching and has good compatibility, can form a pn junction through Van der Waals force, and is easy to prepare a two-dimensional heterojunction device, thereby obtaining the BP two-dimensional materialUnique performance is obtained.

The BP material in the present invention may be self-supporting, or may be on a metal substrate or a semiconductor material substrate, the substrate including silicon, sapphire, silicon carbide, gallium nitride, gallium oxide, diamond, etc.

The preparation method of the BP material can be a mechanical ball milling method, a high pressure method, a mineralization method, a bismuth melting method, a chemical vapor transport method and the like, and the methods are all the prior art and are not repeated herein.

The detector in the embodiment adopts a bottom-up ohmic contact metal-heterojunction-metal structure, p-type few-layer BP (back propagation) is used for middle infrared detection, and n-type beta-Ga₂O₃The material is subjected to ultraviolet detection, and the material interact to form a material based on BP/beta-Ga₂O₃A heterojunction intermediate infrared-solar blind ultraviolet double-color detector.

The heterogeneous integration method of the mid-infrared-solar blind ultraviolet double-color detector in the embodiment specifically comprises the following steps:

based on material growth, beta-Ga is prepared by adopting a bottom-up process₂O₃A two-color detector heterobonded with multilayer BPs. N-type beta-Ga on double-side polished sapphire substrate₂O₃And transferring and placing a few layers of BP single crystal slices on the substrate to form a pn heterostructure, then carrying out processes such as interdigital electrodes and the like, and improving the stability of the BP material by using methods such as atomic layer deposition of a dielectric film and the like.

After the basic device preparation process is completed, when a light source is incident from the top to the bottom from the front, BP can affect beta-Ga at the bottom layer₂O₃Performance is probed. Due to the optical, high-temperature and high-strength characteristics of the sapphire substrate material (widely applied to microwave communication, infrared detection, optical windows of orbital vehicles and the like), the sapphire substrate material adopts an inverted structure and carries out ultraviolet-infrared double-color light source detection by incidence from the back. The BP material is placed on the bottom layer by adopting heat-conducting silica gel and the like, so that the BP material is isolated from oxygen and water vapor and is not degraded, the inverted structure also ensures the stability of the device, improves the heat dissipation performance of the device and comprehensively improves the photoelectric response characteristic of the double-color detection device.

B in liquid phase, glove box or vacuum interconnection equipmentThe P two-dimensional material is directionally transferred, namely, the van der Waals force advantage is fully utilized to ensure that BP and beta-Ga₂O₃And forming a heterostructure to obtain heterogeneous integration of the bicolor detector.

In addition, different interdigital metal electrode types/thicknesses, metal periods and duty ratios are designed to influence the photoelectric characteristics of the detector in the middle infrared band and the solar blind ultraviolet band.

Specifically, the method for manufacturing the dual color photoelectric detector in the embodiment includes the following steps:

referring to fig. 3a, 3b, first a substrate 10 is provided on which Ga in the beta-crystalline phase is epitaxially grown₂O₃Forming an n-type semiconductor layer 20; a dielectric layer 30 is then epitaxially grown on the n-type semiconductor layer.

Referring to fig. 4a and 4b, a portion of the dielectric layer is etched to the n-type semiconductor layer 20 to form an interdigital etched region.

Referring to FIGS. 5a and 5b, a p-type semiconductor layer 40 is formed by directionally transferring p-type black phosphorus into interdigitated etched regions, the black phosphorus and the beta-phase Ga₂O₃Formation of BP/beta-Ga by Van der Waals forces₂O₃A heterojunction;

referring to fig. 6a and 6b, the dielectric layer 30 is etched partially through the mask to the n-type semiconductor layer 20 to form interdigitated etched regions.

Referring to fig. 7a, 7b, first interdigitated electrodes 51 are deposited on the interdigitated etched areas and second interdigitated electrodes 52 are deposited on the p-type semiconductor layer 40.

Finally a passivation layer 60 is grown over the pn-heterojunction and the electrodes and etched through the mask to expose at least part of the first electrode 51 and the second electrode 52, the final detector structure being shown with reference to figure 1.

According to the working principle of a photoelectric detector, the photoelectric detector can be divided into a photoconductive detector and a photovoltaic detector, the photovoltaic detector based on the photovoltaic effect of a semiconductor has the natural advantages of small dark current, high switching current ratio, high responsivity, high response speed and the like, and the most core part of the photovoltaic detector is a pn junction.

In theory, for photovoltaic semiconductor photoelectric detection deviceIn particular, pn structures are extremely important. While another n-type or p-type material is typically grown directly on a p-type or n-type semiconductor material by material growth, the two-dimensional material does not require lattice matching to be considered and a pn junction can be formed by van der waals forces. Thus, based on p-type few-layer BP two-dimensional material and n-type beta-Ga₂O₃The thin film material can construct a pn heterostructure, and further the preparation of the mid-infrared-solar blind ultraviolet double-color integrated detector is realized.

Using BP and beta-Ga₂O₃The film has the advantages of infrared and ultraviolet detection, and the few-layer BP two-dimensional material can react with beta-Ga through Van der Waals force₂O₃The thin film material forms a pn heterojunction. Thus, based on p-type few-layer BP two-dimensional material and n-type beta-Ga₂O₃The thin film material can construct a pn heterostructure, and the BP-beta-Ga with low preparation cost, simple process and excellent performance₂O₃An infrared-solar blind ultraviolet double-color integrated detector.

By utilizing the excellent crystal and optical characteristics of the sapphire material, the device process and packaging are carried out from bottom to top by taking the sapphire material as a substrate in the preparation of the device; when the device is tested, the stability of the device can be effectively ensured by taking the device as an incident window; BP material is placed on the bottom layer by adopting heat-conducting silica gel and the like, so that the BP material is isolated from oxygen and water vapor and is not degraded; in addition, the heterogeneous integrated structure can also improve the heat dissipation performance of the device and comprehensively improve the photoelectric response characteristic of the double-color detection device.

Besides the influence of the material factors, the device structure and the preparation process are also important aspects influencing the successful preparation of the bicolor integrated detector with excellent performance. Double side polishing of beta-Ga during device integration₂O₃Taking sapphire as a substrate, and transferring a BP material by a micro-nano processing technology to obtain BP/beta-Ga with excellent contact₂O₃The double-color detector is inverted by utilizing the optical and physical characteristics of a sapphire material, a light source enters from the back, the detection of infrared and ultraviolet double wave bands is responded simultaneously in the same optical system, and BP/beta-Ga with excellent performance is realized₂O₃Breakthrough of two-color integrated device.

It should be understood thatIn the above embodiments, the n-type material and the p-type material are represented by beta-Ga₂O₃Materials and BP two-dimensional materials are taken as examples for illustration, and in other embodiments, the materials are not limited to the materials in the above embodiments, and other types of n-type materials and p-type materials can be used, so that infrared and ultraviolet double-color detection can be realized.

According to the technical scheme, the invention has the following beneficial effects:

the two-color photoelectric detector of the invention adopts n-type material and p-type material to form pn heterojunction through Van der Waals force, preferably adopts BP two-dimensional material and beta-Ga₂O₃Formation of BP/beta-Ga by van der Waals forces₂O₃Heterojunction, p-type BP material for mid-infrared detection, n-type beta-Ga₂O₃The material is used for solar blind ultraviolet detection, and the device has the advantages of low preparation cost, simple process, superior performance and the like, and meets the urgent requirements in the technical field of infrared and ultraviolet detection.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.