CN216354238U

CN216354238U - Black silicon-based ultraviolet photoelectric sensor

Info

Publication number: CN216354238U
Application number: CN202122838548.1U
Authority: CN
Inventors: 张晶茹
Original assignee: Shanxi Guangwei Maritime Technology Co ltd
Current assignee: Shanxi Guangwei Maritime Technology Co ltd
Priority date: 2021-11-18
Filing date: 2021-11-18
Publication date: 2022-04-19
Anticipated expiration: 2031-11-18

Abstract

The utility model relates to the field of photoelectric sensors, in particular to a black silicon-based ultraviolet photoelectric sensor, which comprises a silicon substrate, a black silicon structure, an alumina film, a P-type doped region, an N-type doped region, an electrode and an ohmic contact region, wherein the silicon substrate is an N-type high-resistance silicon wafer and forms a PIN-type photoelectric detector structure together with the P-type doped region and the N-type doped region, and the black silicon structure is formed by compounding a nano structure and a chimney-shaped or honeycomb-shaped micro structure and is arranged on the front surface of the silicon substrate; the aluminum oxide film is deposited on the surface of the black silicon structure through an atomic layer deposition technology, the electrodes are divided into a Ti electrode and an Au electrode, and the ohmic contact area is arranged on the front surface of the silicon substrate and is in contact with the edge of the black silicon structure to ensure conduction. The utility model can realize the detection of near ultraviolet wave band and has high quantum efficiency, the micron structure is arranged into chimney shape and honeycomb shape, the energy band structure of silicon material is changed, and the prepared black silicon reflectivity is obviously reduced.

Description

Black silicon-based ultraviolet photoelectric sensor

Technical Field

The utility model relates to the field of photoelectric sensors, in particular to a black silicon-based ultraviolet photoelectric sensor.

Background

The purpose of the photodetector is to effect conversion of light into two different signal forms of electricity, which is also typically accompanied by conversion of energy forms from light energy to electrical energy. The device has the advantages of high efficiency, low power consumption, small volume, vibration resistance and the like, and is widely applied to the fields of early warning, guidance, night vision, long-distance detection, medical diagnosis and the like. Among all the photodetectors, the silicon-based photodetector is the most developed and mature device in process technology, and occupies an important position due to its excellent reproducibility, low manufacturing cost, and good compatibility with semiconductor processes. Because silicon is an indirect band gap material, the band gap width is 1.12eV, and the corresponding cut-off wavelength is 1.1 μm, so that the silicon absorbs almost zero light waves with the wavelength of more than 1.1 μm and is in a transparent state, the existing silicon-based photoelectric detector is mostly used for detecting visible light and near infrared bands, although other photoelectric detectors made of semiconductor materials such as germanium (Ge), gallium arsenide (GaAs), indium gallium arsenide (InGaAs) and the like can make up the defects of the traditional silicon-based photoelectric detector, the silicon-based photoelectric detector cannot be widely applied due to high price and poor process compatibility. In view of the fact that the current silicon-based photoelectric detection of the near ultraviolet band has few reports and the ultraviolet detection is widely applied to astronomy, missile early warning, pollution monitoring, ultraviolet communication and the like. Therefore, the performance improvement and optimization on the basis of the traditional silicon material to realize the high-performance ultraviolet photoelectric detection is a breakthrough with both market value and practical application value.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems, the utility model provides a black silicon-based ultraviolet photoelectric sensor which can detect near ultraviolet bands and has high quantum efficiency.

In order to achieve the purpose, the utility model adopts the technical scheme that:

a black silicon-based ultraviolet photoelectric sensor comprises a silicon substrate, a black silicon structure, an alumina film, a P-type doped region, an N-type doped region, an electrode and an ohmic contact region, wherein the silicon substrate is an N-type high-resistance silicon wafer and forms a PIN-type photoelectric detector structure together with the P-type doped region and the N-type doped region, and the black silicon structure is formed by compounding a nano structure and a chimney-shaped or honeycomb-shaped micron structure and is arranged on the front surface of the silicon substrate; the aluminum oxide film is deposited on the surface of the black silicon structure through an Atomic Layer Deposition (ALD) technology, the electrodes are a Ti electrode and an Au electrode, and the ohmic contact area is arranged on the front surface of the silicon substrate and is in contact with the edge of the black silicon structure to ensure conduction.

Further, the resistance of the silicon substrate is more than 10000 omega cm.

Furthermore, the Ti electrode is arranged on the periphery of the black silicon structure, and the Au electrode is arranged on the back surface of the silicon substrate.

Furthermore, the silicon substrate is provided with a high-resistance intrinsic layer I layer, and the P-type doped region and the N-type doped region are respectively doped with boron ions and phosphorus ions at low concentration and are arranged on the upper surface and the lower surface of the silicon substrate.

The utility model has the following beneficial effects:

the micron structure is arranged into a chimney shape and a honeycomb shape, so that the energy band structure of the silicon material is changed, and the reflectivity of the prepared black silicon is obviously reduced; the PIN structure is formed by doping low-concentration boron ions and phosphorus ions on the upper surface and the lower surface of the silicon substrate, so that the width of a depletion region is increased, the recombination of current carriers is reduced, and the quantum efficiency is improved. The spectrum range of the photoelectric sensor adopting the black silicon-based PIN type structure is expanded to near ultraviolet light, and because the energy of the near ultraviolet light is large, carrier multiplication can be caused, so that the photoelectric sensor has higher response and quantum efficiency to the near ultraviolet light, and even can exceed 100%.

Drawings

Fig. 1 is a schematic structural diagram of a black silicon-based ultraviolet photoelectric sensor according to an embodiment of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "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 only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

As shown in fig. 1, the black silicon-based ultraviolet photoelectric sensor according to the embodiment of the present invention includes a silicon substrate 1, a black silicon structure 2, an alumina thin film 3, a P-type doped region 4, an N-type doped region 5, an electrode 6, and an ohmic contact region 7, where the silicon substrate 1 is an N-type high-resistance silicon wafer, the resistance of which is greater than 10000 Ω · cm, and provides a high-resistance intrinsic layer I layer, the P-type doped region and the N-type doped region are doped with boron ions and phosphorus ions at low concentrations, respectively, and are disposed on the upper and lower surfaces of the silicon substrate 1, the P-type doped region 4, and the N-type doped region 5 together form a PIN-type photodetector structure, and the black silicon structure 2 is formed by combining a nano structure and a chimney-like or honeycomb-like micro structure and is disposed on the front surface of the silicon substrate 1; the aluminum oxide film 3 is deposited on the surface of the black silicon structure 2 through an atomic layer deposition ALD technology to play a role in passivation and reflection reduction, the electrodes are divided into Ti electrodes and Au electrodes, the Ti electrodes are arranged on the periphery of the black silicon structure, the Au electrodes are arranged on the back of the silicon substrate and are prepared through a sputtering stripping method, and the ohmic contact region 7 is arranged on the front of the silicon substrate 1 and is in contact with the edge of the black silicon structure 2 to ensure conduction.

When the preparation is implemented specifically, the photoetching technology is utilized to pattern the front surface of the high-resistance N-type silicon wafer, a chimney-shaped and/or honeycomb-shaped micron structure is obtained on the front surface of the silicon wafer by using a Bosch etching method, and then the photoetching patterning is utilized to etch the nano structure on the basis of the micron structure to obtain a micro-nano black silicon structure; respectively doping boron ions and phosphorus ions with low concentration on the front surface and the back surface of the silicon wafer by an ion implantation method; then magnetron sputtering Ti and Au on the front surface and the back surface of the silicon wafer to respectively obtain an upper electrode and a lower electrode, wherein photoetching patterning is carried out on the front surface of the silicon wafer; then Atomic Layer Deposition (ALD) of alumina; and finally scribing to obtain the black silicon-based PIN type ultraviolet photoelectric detector structure.

In the specific implementation, in the preparation process of the black silicon, a micro-structure is prepared by using a Bosch etching method, and then a nano-structure is prepared by using a plasma etching method to obtain the black silicon with the micro-nano composite structure, wherein the micro-structure is arranged into a chimney shape and a honeycomb shape, the energy band structure of the silicon material is changed, and the reflectivity of the prepared black silicon is obviously reduced; the PIN structure is formed by doping low-concentration boron ions and phosphorus ions on the upper surface and the lower surface of the silicon substrate, so that the width of a depletion region is increased, the recombination of current carriers is reduced, and the quantum efficiency is improved. The spectrum range of the photoelectric sensor adopting the black silicon-based PIN type structure is expanded to near ultraviolet light, and because the energy of the near ultraviolet light is large, carrier multiplication can be caused, so that the photoelectric sensor has higher response and quantum efficiency to the near ultraviolet light, and even can exceed 100%.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the utility model. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A black silicon-based ultraviolet photoelectric sensor is characterized in that: the silicon substrate (1) is an N-type high-resistance silicon wafer, the P-type doping region (4) and the N-type doping region (5) form a PIN-type photoelectric detector structure together with the N-type doping region (5), and the black silicon structure (2) is formed by compounding a nano structure and a chimney-shaped or honeycomb-shaped micro structure and is arranged on the front surface of the silicon substrate (1); the aluminum oxide film (3) is deposited on the surface of the black silicon structure (2) through an atomic layer deposition technology, the electrodes are Ti electrodes and Au electrodes, and the ohmic contact region (7) is arranged on the front surface of the silicon substrate (1) and is in contact with the edge of the black silicon structure (2) to ensure conduction.

2. A black silicon based uv photosensor according to claim 1 wherein: the resistance of the silicon substrate is more than 10000 omega cm.

3. A black silicon based uv photosensor according to claim 1 wherein: the Ti electrode is arranged on the periphery of the black silicon structure, and the Au electrode is arranged on the back of the silicon substrate.