High detection rate GaN-based Schottky ultraviolet detector using graphene

An ultraviolet detector, gallium nitride-based technology, applied in the direction of semiconductor devices, electrical components, circuits, etc., can solve the problems of unsatisfactory metal materials, detection rate impact, light transmittance drop, etc., to enhance the built-in electric potential field, The effect of increasing the detection rate and responsivity and increasing the quantum efficiency

CN104393093BActive Publication Date: 2017-02-01BEIJING UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2017-02-01

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Abstract

The invention provides a high-detectivity gallium-nitride-based Schottky ultraviolet detector using graphene. According to the basic structure, the high-detectivity gallium-nitride-based Schottky ultraviolet detector sequentially comprises heavily-doped n type gallium nitride, slightly-doped n type gallium nitride, a silicon dioxide insulating layer, metal electrodes and a graphene thin film from bottom to top. The metal electrodes have the transparent and electric conduction properties and have the half-metallic property. Under the condition that the metal electrodes make direct contact with the slightly-doped n type GaN, the potential barriers of about 0.5 ev can be formed. The formed potential barriers show that the portions, close to the metal electrodes, in the GaN can be bent, so that a spatial charge area is formed, the electron holes are separated, and the photoproduction electrodynamic potential and the photoproduction current are generated. The responsibility of the detector can be greatly improved by introducing the surface defect method. The high-detectivity gallium-nitride-based Schottky ultraviolet detector is simple in structure and process and high in efficiency; thus, the electron hole pair separation capacity is increased, the internal quantum efficiency of the detector is increased, and the detectivity and responsibility are increased.
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Description

Technical field

[0001] The invention relates to a novel gallium nitride-based Schottky-type ultraviolet detector structure and preparation method, and belongs to the technical field of semiconductor optoelectronic devices. Background technique

[0002] Ultraviolet detection technology has many applications, which can be used for polymer resin curing, water purification treatment, flame detection, biological effects, environmental pollution monitoring, and ultraviolet light storage. In terms of ultraviolet photodetectors, GaN materials have excellent properties: (1) GaN does not absorb visible light, and the made ultraviolet detectors can achieve visible light blindness without a filter system. (2) There is no need to make a shallow junction, This can greatly improve the quantum efficiency. (3) GaN has strong radiation resistance and can play a role in exploring the mysteries of the universe. GaN ultraviolet detectors are currently divided into the following types: photoconductiv...

Examples

Embodiment 1

[0029] Step 1. Use metal organic chemical vapor deposition (or molecular beam epitaxy system, liquid phase epitaxy technology, etc.) to sequentially produce heavily doped n-type gallium nitride 101 and lightly doped sapphire (or silicon wafer, silicon carbide, etc.) Hetero n-type gallium nitride 102.

[0030] Step 2. Cleaning, photolithography, and etching of the epitaxial wafer to form a mesa structure, such as heavily doped n-type gallium nitride 101 and lightly doped n-type gallium nitride 102.

[0031] Step 3: Growing a layer of silicon dioxide, and performing photolithography and etching to form a silicon dioxide insulating layer 103.

[0032] Step 4. Photoetch the electrode pattern, sputter or evaporate to produce the metal electrode 104.

[0033] Step 5: Transfer graphene to the surface of the device, photoetch the graphene pattern, and plasma etch the graphene to form a graphene film 105. The plasma etching gas is oxygen, the flow rate is 10-70L / min, the power is 50-100W, and...

Embodiment 2

[0038] Step 1. Use metal organic chemical vapor deposition (or molecular beam epitaxy system, liquid phase epitaxy technology, etc.) to sequentially fabricate heavily doped n-type gallium nitride 101 on sapphire (or silicon wafer, silicon carbide, etc.), lightly doped Hetero n-type gallium nitride 102.

[0039] Step 2. Use inductively coupled plasma to etch the surface of the epitaxial wafer to an etching depth of 10-50 nm to increase the surface defect density of the epitaxial wafer.

[0040] Step 3. Cleaning, photolithography, and etching of the epitaxial wafer to form a mesa structure, such as heavily doped n-type gallium nitride 101 and lightly doped n-type gallium nitride 102.

[0041] Step 4. Grow a layer of silicon dioxide, and perform photolithography and etching to form a silicon dioxide insulating layer 103.

[0042] Step 5. Photoetch the electrode pattern, sputter or evaporate to produce the metal electrode 104.

[0043] Step 6, transferring graphene to the surface of the de...