Ultraviolet sensing and storage integrated device

Abstract

The utility model discloses an ultraviolet sensing and storage integrated device. The ultraviolet sensing and storage integrated device comprises a substrate, an n-type epitaxial layer, a first epitaxial layer, a transparent electrode, a first electrode, a second electrode and a storage unit, the first epitaxial layer exposes a first region of the n-type epitaxial layer; the transparent electrode is located on one side of the first epitaxial layer away from the substrate; the transparent electrode covers the first surface of the first epitaxial layer and forms Schottky contact with the first epitaxial layer; the first electrode is located in the first region, forms ohmic contact with the n-type epitaxial layer, and is insulated from the transparent electrode and the first epitaxial layer; the second electrode is in direct contact with the transparent electrode; the storage unit is located on one side of the transparent electrode away from the substrate; the storage unit comprises a third electrode; the third electrode is in direct contact with the transparent electrode and is spaced from the second electrode. According to the technical scheme of the embodiment of the utility model, in-situ transmission of signals can be realized, and the power consumption of devices is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a semiconductor technical field especially relates to a ultraviolet sensing integration device. BACKGROUND

[0002] The wavelength of ultraviolet light is less than 400nm, has energy high, anti -interference strong etc. advantage, has very important application on disinfection and sterilization, nondestructive testing, fluorescent analysis etc. civilian and military ultraviolet reconnaissance, missile early warning.

[0003] The traditional ultraviolet detection device usually adopts "von neumann type" structure, that is, the sensing, storage, calculation three units are physically separated, are interconnected through the external lead interconnection, need to pass through the information conversion of digital to analog converter between different units to can carry out the interactive transmission of information, causes the additional power loss and signal loss etc. problem with the increase of interconnection length in the process of signal transmission, will greatly increase the transmission power consumption and limit the overall processing efficiency. UTILITARIAN CONTENT

[0004] The utility model provides a kind of ultraviolet sensing integration device, to realize the in situ transmission of signal, reduce the power consumption of device.

[0005] The ultraviolet sensing integration device provided by the utility model includes:

[0006] Substrate;

[0007] N-type epitaxial layer, located at one side of substrate;

[0008] First epitaxial layer, located at the side of n-type epitaxial layer away from substrate;First epitaxial layer exposes the first region of n-type epitaxial layer;

[0009] Transparent electrode, located at the side of first epitaxial layer away from substrate;First epitaxial layer includes opposite first surface and second surface, and first surface is located at the side of second surface away from substrate;Transparent electrode covers first surface, and forms Schottky contact with first epitaxial layer;

[0010] First electrode, located at the side of n-type epitaxial layer away from substrate, and located in first region;First electrode forms ohmic contact with n-type epitaxial layer, and is insulated from transparent electrode and first epitaxial layer;

[0011] Second electrode, located at the side of transparent electrode away from substrate, and directly contacts with transparent electrode;

[0012] Storage unit, located at the side of transparent electrode away from substrate;Storage unit includes third electrode;Third electrode directly contacts with transparent electrode, and is spaced apart from second electrode.

[0013] Optionally, the storage unit may also include a storage function layer and a fourth electrode;

[0014] The storage layer is located on the side of the third electrode furthest from the substrate;

[0015] The fourth electrode is located on the side of the storage layer away from the substrate.

[0016] Optionally, the ultraviolet sensing and storage integrated device includes multiple storage cells arranged in an array on a transparent electrode.

[0017] Optionally, the plurality of storage cells include at least one of RRAM, PCM, and FeRAM.

[0018] Optionally, the first electrode, the second electrode, and the third electrode are arranged in the same layer.

[0019] Optionally, the ultraviolet sensing and storage integrated device also includes a passivation layer;

[0020] The passivation layer is located between the first epitaxial layer and the first electrode, and covers the sidewalls of the first epitaxial layer and the transparent electrode.

[0021] Optionally, the first epitaxial layer and the n-type epitaxial layer form a PN junction or a heterojunction.

[0022] Optionally, the ultraviolet sensing and storage integrated device also includes a buffer layer;

[0023] The buffer layer is located between the substrate and the n-type epitaxial layer.

[0024] Optionally, the orthogonal projection of the first electrode on the substrate surrounds the orthogonal projection of the transparent electrode on the substrate;

[0025] The orthogonal projection of the second electrode onto the substrate surrounds the area where the memory cell is located.

[0026] Optionally, the projection shape of the transparent electrode on the substrate is circular or polygonal.

[0027] The technical solution of this utility model embodiment integrates the storage unit on the transparent electrode (output electrode) of the sensing unit in situ through a leadless direct connection, so that the third electrode of the storage unit is in direct contact with the transparent electrode of the sensing unit. This allows the current signal from the sensing unit to be directly transmitted to the storage unit through the transparent electrode and the third electrode for signal storage. In this way, information interaction and transmission between sensing and storage can be carried out without additional external interconnects and digital-to-analog converters, realizing in-situ signal transmission. Ultimately, this can greatly reduce the energy consumption of the product in the process of information sensing, storage and processing.

[0028] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Figure 1 is a top view structural schematic diagram of an ultraviolet sensing and storage integrated device provided by the embodiments of the present application;

[0031] Figure 2 is a cross-sectional structural schematic diagram of the ultraviolet sensing and storage integrated device along AA' in the middle; Figure 1

[0032] Figure 3 is another top view structural schematic diagram of an ultraviolet sensing and storage integrated device provided by the embodiments of the present application. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0034] Various modifications and changes can be made to the present application without departing from the spirit or scope of the present application, which will be apparent to those skilled in the art. Therefore, the present application is intended to cover the modifications and changes falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided in the present application can be combined with each other without contradiction.

[0035] ​First of all, it should be noted that the technical terms or scientific terms used in the utility model should be understood as the usual meaning by the person skilled in the art unless otherwise defined. The "first", "second" and similar words used in the utility model do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" and similar words mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connected" or "connected" and similar words are not limited to physical or mechanical connection, but can include electrical connection, whether direct or indirect. "Up", "down", "left" and "right" and similar words are only used to represent the relative positional relationship, which may also change accordingly when the absolute position of the described object changes. In addition, the shapes and sizes of the components in the drawings do not reflect the true proportion, but only aim to illustrate the content of the utility model.

[0036] Figure 1 is a top view structural schematic diagram of an ultraviolet sensing and storage integrated device provided by an embodiment of the utility model, Figure 2 is a cross-sectional structural schematic diagram of the ultraviolet sensing and storage integrated device taken along AA' in the Figure 1 , as shown in Figure 1 and Figure 2 , the ultraviolet sensing and storage integrated device 100 provided by the embodiment of the utility model includes a substrate 10, an n-type epitaxial layer 20, a first epitaxial layer 30, a transparent electrode 40, a first electrode 50, a second electrode 60 and a storage unit 70; the n-type epitaxial layer 20 is located on one side of the substrate 10; the first epitaxial layer 30 is located on the side of the n-type epitaxial layer 20 away from the substrate 10; the first epitaxial layer 30 exposes a first region Q1 of the n-type epitaxial layer 20; the transparent electrode 40 is located on the side of the first epitaxial layer 30 away from the substrate 10; the first epitaxial layer 30 includes opposite first and second surfaces F1 and F2, and the first surface F1 is located on the side of the second surface F2 away from the substrate 10; the transparent electrode 40 covers the first surface F1 and forms a Schottky contact with the first epitaxial layer 30; the first electrode 50 is located on the side of the n-type epitaxial layer 20 away from the substrate 10 and is located in the first region Q1; the first electrode 50 forms an ohmic contact with the n-type epitaxial layer 20 and is insulated from the transparent electrode 40 and the first epitaxial layer 30; the second electrode 60 is located on the side of the transparent electrode 40 away from the substrate 10 and directly contacts the transparent electrode 40; the storage unit 70 is located on the side of the transparent electrode 40 away from the substrate 10; the storage unit 70 includes a third electrode 71; the third electrode 71 directly contacts the transparent electrode 40 and is spaced apart from the second electrode 60.

[0037] In the embodiment, the substrate 10, the n-type epitaxial layer 20, the first epitaxial layer 30, the transparent electrode 40, the first electrode 50 and the second electrode 60 constitute a sensing unit of the device, and realize the sensing function of the device.

[0038] Optionally, the substrate 10 is a sapphire substrate or a silicon substrate, and the thickness ranges from 300 um to 500 um.

[0039] Optionally, the n-type epitaxial layer 20 is an n-type doped AlGaN layer (n-AlGaN), and the thickness ranges from 400 nm to 500 nm.

[0040] Optionally, the first epitaxial layer 30 and the n-type epitaxial layer 20 form a PN junction or a heterojunction, and constitute an ultraviolet light detection layer.

[0041] Optionally, the first epitaxial layer 30 is any one of AlN, p-Ga2O3 and p-GaN.

[0042] When the first epitaxial layer 30 and the n-type epitaxial layer 20 adopt the combination of AlN / n-AlGaN, the two form a heterojunction, and can detect ultraviolet light in the wavelength range of 200 nm to 250 nm. When the first epitaxial layer 30 and the n-type epitaxial layer 20 adopt the combination of p-Ga2O3 / n-AlGaN, the two form a PN junction, and can detect ultraviolet light in the wavelength range of 250 nm to 300 nm. When the first epitaxial layer 30 and the n-type epitaxial layer 20 adopt the combination of p-GaN / n-AlGaN, the two form a PN junction, and can detect ultraviolet light in the wavelength range of 300 nm to 350 nm.

[0043] Optionally, the transparent electrode 40 has high light transmittance to ensure the reception of light signals. In addition, in the embodiment, the transparent electrode 40 fully covers the first epitaxial layer 30, and forms a high-barrier Schottky contact with the first epitaxial layer 30, so that the switching response of the device can be significantly improved, and the turn-on voltage can be reduced. In addition, in the embodiment, the transparent electrode 40 also serves as an output end of the photocurrent (electric signal) in the sensing unit.

[0044] As a feasible implementation, optionally, the transparent electrode 40 adopts a Pt thin film with a high work function, and the thickness ranges from 5 nm to 20 nm.

[0045] The first electrode 50 specifically refers to a cathode of the sensing unit, and the second electrode 60 specifically refers to an anode of the sensing unit.

[0046] Optionally, the first electrode 50 and the second electrode 60 adopt any one of Ti / Au, Ti / Al / Ti / Au and Ti / Al / Ni / Au structures, and the thickness ranges from 400 nm to 500 nm.

[0047] Further, the storage unit 70 is used to realize the storage function of the device. In the embodiment, the storage unit 70 is integrated in situ on the transparent electrode 40 in a direct connection manner without lead, so that the third electrode 71 of the storage unit 70 is in direct contact with the transparent electrode 40 of the sensing unit, and the current signal from the sensing unit can be directly transmitted to the storage unit through the transparent electrode 40 and the third electrode 71 for signal storage. In this way, the information interaction and transmission between sensing and storage can be realized without additional external interconnection lines and digital-analog converters, the in-situ transmission of the signal is realized, and finally the energy consumption of the product in the information sensing, storage and processing process can be greatly reduced.

[0048] For the storage unit 70, since the output signal of the sensing unit is an analog signal, in the embodiment, the storage unit can adopt any type of storage device capable of storing analog quantities, and the embodiment of the utility model does not make limitation.

[0049] Optionally, one or more storage units 70 are arranged on the side of the transparent electrode 40 away from the substrate 10.

[0050] Referring to Figure 1 , as a feasible implementation manner, the ultraviolet sensing and storage integrated device 100 includes a plurality of storage units 70, and the plurality of storage units 70 are arranged in an array on the transparent electrode 40. In this way, the storage capacity can be increased, and in addition, it is also beneficial to increase the types of storage units according to the needs and improve the storage capacity.

[0051] Optionally, the plurality of storage units include at least one of RRAM (Resistive Random Access Memory, resistive random access memory), PCM (Phase Change Material, phase change material memory), and FeRAM (Ferroelectric Random Access Memory, ferroelectric random access memory). The above storage devices all support the storage of analog quantities, and one or more storage devices can be integrated above the transparent electrode 40 of the sensing unit according to actual needs, and the embodiment of the utility model does not make limitation.

[0052] For any one of the above storage devices, a laminated structure design can be adopted. As shown in Figure 2 , optionally, the storage unit 70 further includes a storage function layer 72 and a fourth electrode 73; the storage function layer 72 is located on the side of the third electrode 71 away from the substrate 10; and the fourth electrode 73 is located on the side of the storage function layer 72 away from the substrate 10.

[0053] The storage function layer 72 realizes the storage of the signal, and the fourth electrode 73 serves as the output electrode of the ultraviolet sensing and storage integrated device and is electrically connected with the processor at the back end for subsequent signal processing.

[0054] Specifically, referring to Figure 2 The working principle of the ultraviolet sensing and storing integrated device provided by the embodiment is as follows: external ultraviolet incident light first passes through the transparent electrode 40 at the top of the device to enter the ultraviolet light detection layer composed of the first epitaxial layer 30 and the n-type epitaxial layer 20, and a voltage is input on the first electrode 50 and the second electrode 60, then the ultraviolet light generates electron-hole pairs in the ultraviolet light detection layer with the above-mentioned electric field and separates the electron-hole pairs, thereby generating a photoelectric current. Since the third electrode 71 of the storage unit 70 directly contacts the transparent electrode 40 of the sensing unit, the photoelectric current is directly transmitted to the storage unit 70 through the transparent electrode 40, and the photoelectric current is memorized and stored through the storage function layer 72, and finally the current is output to the back-end processor through the fourth electrode 73 of the storage unit 70.

[0055] It should be noted that the storage unit 70 is not sensitive to light in the utility model, and the storage unit 70 will not generate additional current when the incident ultraviolet light irradiates the storage unit 70.

[0056] In summary, the embodiment of the utility model integrates the storage unit in situ on the transparent electrode (output electrode) of the sensing unit in a leadless direct connection manner, so that the third electrode of the storage unit directly contacts the transparent electrode of the sensing unit, the current signal from the sensing unit can be directly transmitted to the storage unit through the transparent electrode and the third electrode, the signal is stored, in this way, the information interaction and transmission between sensing and storage can be performed without additional external interconnection lines and digital-to-analog converters, the in-situ transmission of the signal is realized, and finally the energy consumption of the product in the information sensing, storage and processing process can be greatly reduced.

[0057] Further, referring to Figure 2 As a feasible implementation manner, optionally, the first electrode 50, the second electrode 60 and the third electrode 71 are arranged in the same layer. In other words, the three can adopt the same material and are obtained in the same process, so that the preparation process can be simplified.

[0058] In other embodiments, optionally, the first electrode 50 and the second electrode 60 adopt the same material and are formed in the same process, and the third electrode 71 adopts other materials and is manufactured after the first electrode 50 and the second electrode 60 are formed. In this way, a more suitable metal can be selected to manufacture the bottom electrode (that is, the third electrode 71) of the storage unit, so as to ensure the performance of the storage unit.

[0059] Referring to Figure 2 Optionally, the ultraviolet sensing and storing integrated device 100 further comprises a passivation layer 80; the passivation layer 80 is located between the first epitaxial layer 30 and the first electrode 50 and covers the sidewalls of the first epitaxial layer 30 and the transparent electrode 40.

[0060] Specifically, the passivation layer 80 can play a role of protecting the first epitaxial layer 30 and the transparent electrode 40, and in addition, can also serve as an insulation layer between the first epitaxial layer 30 and the transparent electrode 40 and the first electrode 50, so as to ensure insulation between the first epitaxial layer 30 and the first electrode 50 and insulation between the transparent electrode 40 and the first electrode 50.

[0061] Optionally, the passivation layer is any one of SiO2, Si3N4 and Al2O3, and the thickness ranges from 500 nm to 1000 nm.

[0062] With reference to Figure 2 Optionally, the ultraviolet sensing integrated device 100 further comprises a buffer layer 90, and the buffer layer 90 is located between the substrate 10 and the n-type epitaxial layer 20. By arranging the buffer layer 90, the lattice mismatch between the n-type epitaxial layer 20 and the substrate 10 can be adjusted, so that the generation of grain boundaries and defects is reduced, and the growth quality of the epitaxial layer is improved.

[0063] Optionally, the buffer layer 90 is made of AlN, and the thickness ranges from 500 nm to 1000 nm.

[0064] In combination with Figure 1 and Figure 2 Optionally, the orthographic projection of the first electrode 50 on the substrate 10 surrounds the orthographic projection of the transparent electrode 40 on the substrate 10, and the orthographic projection of the second electrode 60 on the substrate 10 surrounds the region where the storage unit 70 is located.

[0065] Specifically, the first electrode 50 is annular, arranged on the mesa of the edge region of the n-type epitaxial layer 20, and surrounds the region where the first epitaxial layer 30 and the transparent electrode 40 are located. The second electrode 60 is also annular, arranged in the edge region of the first epitaxial layer 30, and the storage unit 70 is arranged in the central region of the first epitaxial layer 30, and the second electrode 60 surrounds the region where the storage unit 70 is located.

[0066] In combination with Figure 1 and Figure 2 Optionally, the projection of the transparent electrode 40 on the substrate 10 is in the shape of a polygon. Taking a quadrilateral as an example for illustration, correspondingly, the first electrode 50 and the second electrode 60 are both in the shape of a quadrilateral ring.

[0067] Figure 3 is a top view structural schematic diagram of another ultraviolet sensing integrated device provided by the embodiment of the present application, as Figure 3 shown, in other embodiments, optionally, the projection of the transparent electrode 40 on the substrate can be in the shape of a circle, and correspondingly, the first electrode 50 and the second electrode 60 are both in the shape of a circular ring.

[0068] The specific embodiments described above do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An integrated ultraviolet sensing and storage device, characterized in that, The ultraviolet sensing and storage integrated device comprises: a substrate; an n-type epitaxial layer on one side of the substrate; a first epitaxial layer on the side of the n-type epitaxial layer away from the substrate; the first epitaxial layer exposes a first region of the n-type epitaxial layer; a transparent electrode on the side of the first epitaxial layer away from the substrate; the first epitaxial layer comprises opposite first and second surfaces, the first surface is on the side of the second surface away from the substrate; the transparent electrode covers the first surface and forms a Schottky contact with the first epitaxial layer; a first electrode on the side of the n-type epitaxial layer away from the substrate and in the first region; the first electrode forms an ohmic contact with the n-type epitaxial layer and is insulated from the transparent electrode and the first epitaxial layer; a second electrode on the side of the transparent electrode away from the substrate and in direct contact with the transparent electrode; a storage unit on the side of the transparent electrode away from the substrate; the storage unit comprises a third electrode; the third electrode is in direct contact with the transparent electrode and is spaced apart from the second electrode.

2. The ultraviolet sensor-integrated device according to claim 1, wherein The storage unit further comprises a storage functional layer and a fourth electrode; the storage functional layer is on the side of the third electrode away from the substrate; the fourth electrode is on the side of the storage functional layer away from the substrate.

3. The ultraviolet sensor-integrated device according to claim 1, wherein The ultraviolet sensing and storage integrated device comprises a plurality of the storage units, and the plurality of the storage units are arranged in an array on the transparent electrode.

4. The ultraviolet sensor-integrated device according to claim 3, wherein The plurality of the storage units comprise at least one of RRAM, PCM, and FeRAM.

5. The ultraviolet sensor-integrated device according to claim 1, wherein The first electrode, the second electrode, and the third electrode are arranged in the same layer.

6. The ultraviolet sensor-integrated device according to claim 1, wherein The ultraviolet sensing and storage integrated device further comprises a passivation layer; the passivation layer is between the first epitaxial layer and the first electrode and covers the sidewalls of the first epitaxial layer and the transparent electrode.

7. The ultraviolet sensor-integrated device according to claim 1, wherein The first epitaxial layer and the n-type epitaxial layer form a PN junction or a heterojunction.

8. The ultraviolet sensor-integrated device according to claim 1, wherein The ultraviolet sensing and storage integrated device further comprises a buffer layer; the buffer layer is between the substrate and the n-type epitaxial layer.

9. The ultraviolet sensor-integrated device according to claim 1, wherein The orthogonal projection of the first electrode on the substrate surrounds the orthogonal projection of the transparent electrode on the substrate; The orthogonal projection of the second electrode on the substrate encloses the region where the storage unit is located.

10. The ultraviolet sensor-integrated device according to claim 1, wherein The projection of the transparent electrode on the substrate is circular or polygonal.

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