阅读说明：本技术 一种双响应GaN紫外探测器及其制备方法 (Double-response GaN ultraviolet detector and preparation method thereof ) 是由 仇志军 叶怀宇 张国旗 于 2019-09-16 设计创作，主要内容包括：本发明公开了一种双响应GaN紫外探测器及其制备方法,包括：1)衬底上依次生长GaN缓冲层和n型掺杂GaN层；2)所述n型掺杂GaN层上生长m层不同In组分本征掺杂In<Sub>x</Sub>Ga<Sub>1-x</Sub>N结构,其中m≥3；3)所述m层不同In组分本征掺杂In<Sub>x</Sub>Ga<Sub>1-x</Sub>N结构上生长p型掺杂GaN层；4)刻蚀所述p型掺杂GaN层和所述m层不同In组分本征掺杂In<Sub>x</Sub>Ga<Sub>1-x</Sub>N层；5)沉积钝化层；6)刻蚀所述钝化层并沉积金属电极。本发明的GaN探测器是PIN结构探测器,能够实现快速、准确、高灵敏度的紫外光探测；其次,本发明的探测器能够在输出光电信号的同时发出白光指示信号,实现了人眼可见的探测提示以及光信号测量。(The invention discloses a double-response GaN ultraviolet detector and a preparation method thereof, wherein the double-response GaN ultraviolet detector comprises the following steps: 1) sequentially growing a GaN buffer layer and an n-type doped GaN layer on the substrate; 2) growing m layers of intrinsic doped In with different In components on the n-type doped GaN layer x Ga 1‑x N structure, wherein m is more than or equal to 3; 3) the m layers of different In components are doped with In x Ga 1‑x Growing a p-type doped GaN layer on the N structure; 4) etching the p-type doped GaN layer and the m layer of intrinsic doped In with different In components x Ga 1‑x N layers; 5) depositing a passivation layer; 6) and etching the passivation layer and depositing a metal electrode. The GaN detector is a PIN structure detector, and can realize rapid, accurate and high-sensitivity ultraviolet detection; secondly, the detector of the invention can emit white light indicating signals while outputting photoelectric signals, thereby realizing detection prompt visible to human eyes and optical signal measurement.)

1. A double-response GaN ultraviolet detector and a preparation method thereof are characterized in that: comprises that

1) Sequentially growing a GaN buffer layer and an n-type doped GaN layer on the substrate;

2) growing m layers of intrinsic doped In with different In components on the n-type doped GaN layer_xGa_1-xN structure, wherein m is more than or equal to 3;

3) the m layers of different In components are doped with In_xGa_1-xGrowing a p-type doped GaN layer on the N structure;

4) etching the p-type doped GaN layer and the m layer of intrinsic doped In with different In components_xGa_1-xN layers;

5) depositing a passivation layer;

6) and etching the passivation layer and depositing a metal electrode.

2. The method for preparing a dual-response GaN ultraviolet detector as claimed in claim 1, wherein: the thickness of the GaN buffer layer in the step 1) is 0.2-4 mu m.

3. The method for preparing a dual-response GaN ultraviolet detector as claimed in claim 1, wherein: the thickness of the n-type doped GaN layer in the step 1) is 0.25-1 μm, and the doping concentration is 1 × 10¹⁸cm^-3～5×10¹⁸cm^-3The doping element is silicon.

4. The method for preparing a dual-response GaN ultraviolet detector as claimed in claim 1, wherein: m in said 2)Intrinsic doping of In for different In composition of layer_xGa_1-xThe thickness of the N structure is 0.1-1 μm.

5. The method of claim 1, wherein: in the 2), m is 3; the 3 layers of In_xGa_1-xIn the N structure, the In component x is 0.38-0.4, 0.27-0.3 and 0.07-0.1 In sequence, and the thickness of each layer is 30-300 nm.

6. The method for preparing a dual-response GaN ultraviolet detector as recited in claim 1, wherein: the thickness of the p-type doped GaN layer in the step 3) is 0.5-2.5 μm.

7. The method for preparing a dual-response GaN ultraviolet detector as recited in claim 1, wherein: the p-type doping concentration in the step 3) is 1 multiplied by 10¹⁸cm^-3～5×10¹⁸cm^-3The doping element is magnesium.

8. The method for preparing a dual-response GaN ultraviolet detector as recited in claim 1, wherein: the thickness of the passivation layer in the step 5) is 20 nm-200 nm; the passivation layer is made of aluminum oxide.

9. A dual response GaN ultraviolet detector made according to the method of claims 1-8.

Technical Field

The invention relates to the field of semiconductor photoelectric devices, in particular to a double-response GaN ultraviolet detector and a preparation method thereof.

Background

The traditional ultraviolet detector has the working principle that after photoelectric materials absorb external ultraviolet light, photo-generated electron pairs are generated in the materials, and photo-generated voltage or photo-current signals are output under the action of built-in potential or scanning bias voltage, but the photo-generated signals can be read out by professional semiconductor analysis equipment or a signal processing circuit at the rear end, and then information such as ultraviolet radiation intensity and the like can be finally obtained. However, with the development of demand and the popularization of detectors, for many simple tests, only the external ultraviolet light intensity needs to be known schematically, and complicated circuit structures or devices are not needed for optical signal detection. Therefore, ultraviolet detectors with novel structures are required to meet the requirements of accurate, rapid and high-sensitivity optical signal detection and simple qualitative tests, and the strength information of optical signals of people can be indicated through some information visible to the naked eyes.

Disclosure of Invention

Based on the development requirements, the invention innovatively provides the double-response GaN ultraviolet detector and the preparation method thereof, which not only can meet the requirement of accurate, rapid and high-sensitivity ultraviolet detection, but also can simply and conveniently realize the intensity display of optical signals visible to human eyes.

The method comprises the following steps:

1) sequentially growing a GaN buffer layer and an n-type doped GaN layer on the substrate;

2) growing m layers of intrinsic doped In with different In components on the n-type doped GaN layer_xGa_1-xN structure, wherein m is more than or equal to 3;

3) the m layers of different In components are doped with In_xGa_1-xGrowing a p-type doped GaN layer on the N structure;

4) etching the p-type doped GaN layer and the m layer of intrinsic doped In with different In components_xGa_1-xN layers; (ii) a

5) Depositing a passivation layer;

6) and etching the passivation layer and depositing a metal electrode.

Preferably, the thickness of the GaN buffer layer in the step 1) is 0.2-4 μm.

Preferably, the thickness of the n-type doped GaN layer in the step 1) is 0.25-1 μm, and the doping concentration is 1 × 10¹⁸cm^-3～5×10¹⁸cm^-3The doping element isSilicon.

Preferably, the m layers In 2) are doped with different In components_xGa_1-xThe thickness of the N structure is 0.1-1 μm.

Preferably, in 2), m is 3; the 3 layers of In_xGa_1-xIn the N structure, the In component x is 0.38-0.4, 0.27-0.3 and 0.07-0.1 In sequence, and the thickness of each layer is 30-300 nm.

Preferably, the thickness of the p-type doped GaN layer in the step 3) is 0.5-2.5 μm.

Preferably, the p-type doping concentration in the 3) is 1 × 10¹⁸cm^-3～5×10¹⁸cm^-3The doping element is magnesium.

Preferably, the thickness of the passivation layer in the step 5) is 20nm to 200 nm; the passivation layer is made of aluminum oxide.

The GaN-based light-emitting device prepared by the method is a double-response GaN ultraviolet detector.

When the p-type GaN layer absorbs ultraviolet photons, a large number of photo-generated electron pairs are formed In vivo, the photo-generated carrier pairs are separated under the action of an internal electric field, and then a large number of photo-generated carriers are injected into In_xGa_1-xN layer, and part of the injected photon-generated carriers are In_xGa_1-xThe N layers are subjected to transition recombination directly, and photons are emitted simultaneously. Because of the different In composition In_xGa_1-xThe N layers have different forbidden band widths and emit different lights, especially when the In component is 0.38-0.4, 0.27-0.3, and 0.07-0.1 In sequence_xGa_1-xPhotons emitted by direct transition in the N material are respectively red light (-630 nm), green light (-520 nm) and blue light (-400 nm), and when the light of the three colors is output simultaneously, the light can be converged into natural white light, so that the light can be used as a dual-response GaN ultraviolet detector. The traditional PN structure detector only measures an electric signal, and the detector can emit visible light except the electric signalBesides the response, the light signal also has response, so the double-response ultraviolet detector is provided. In addition, the detector is structurally a PIN structure, photogenerated carriers can be rapidly separated and accumulated at the two ends of P, N, a photogenerated voltage effect is generated, and the wide bandgap material has low dark current, so that the detector can achieve rapid and high-sensitivity light detection.

The invention has the advantages that:

A. the invention adopts a multilayer structure with different In components to obtain composite light which can be used for ultraviolet ray detection.

B. The specific In component multilayer structure of the invention respectively obtains red light, green light and blue light, and white light formed by compounding is enhanced along with the enhancement of the intensity of the blue light.

C. The double-response ultraviolet detector can simplify measuring equipment or a reading circuit, and simply and portably realizes visible ultraviolet detection for human eyes.

D. The ultraviolet detector is structurally a PIN photovoltaic detector, so that the ultraviolet detector has the characteristics of rapidness, accuracy and high sensitivity in photoelectric response.

E. The ultraviolet detector of the invention can simplify the measuring equipment in the field of qualitative measurement or detection, is convenient to use and is beneficial to the miniaturization of a system.

Drawings

In order to make the object, technical scheme and beneficial effect of the invention more clear, the invention provides the following drawings for explanation:

fig. 1 is a schematic diagram of the physical energy band structure of the present invention.

Fig. 2 is a schematic diagram of a two-dimensional cross-sectional structure according to the present invention.

Fig. 3, 4 and 5 are flow charts of the preparation process of the invention.

In FIG. 1, VBE-the valence band energy level, CBE-the conduction band energy level.

In FIG. 2, a sapphire substrate 1, a GaN buffer layer 2, an n-type doped GaN layer 3, and intrinsic doped In_xGa_1-xN layers 4, 5 and 6, a p-type doped GaN layer 7, an aluminum oxide passivation layer 8, a metal upper electrode 9 and a metal upper electrode 10.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.