CN207320147U - A kind of AlGaN ultraviolet detectors with two-dimensional electron gas denoising shading ring - Google Patents

Abstract

The utility model discloses a kind of AlGaN ultraviolet detectors with two-dimensional electron gas denoising shading ring, which includes substrate, GaN or AlN cushions, the highly doped backside conductive layers of GaN, undoped GaN layer, the active depletion regions of N-shaped AlGaN and p-type AlGaN snowslide knots from bottom to up；Two-dimensional electron gas trench mask structure is formed between undoped GaN layer and the active depletion regions of N-shaped AlGaN；Snowslide inactivity of yang-qi pole is provided with above p-type AlGaN snowslide knots；Detector further includes each electrode structure.The dark current that active area periphery can be greatly reduced in the application and back end produces, improves the signal-to-noise ratio and detection efficient of detector.Device forms 2DEG raceway groove equipotential faces as leakage current and the shielding construction of noise using GaN/AlGaN two-dimensional structures, the noise current of active area periphery and backing substrate is filtered out by 2DEG raceway groove equipotentials face ground connection, help to realize the ultraviolet detector of low noise high-gain, high s/n ratio and detection efficient.

Description

A kind of AlGaN ultraviolet detectors with two-dimensional electron gas denoising shading ring

Technical field

The utility model belongs to field of semiconductor devices, and in particular to a kind of with two-dimensional electron gas denoising shading ring AlGaN ultraviolet detectors.

Background technology

Ultraviolet detection technology is the another dual-use detecting technique after infrared acquisition and Laser Detection Technique. AlGaN material becomes the leader of UV materials with unique physics, chemistry, electrology characteristic.AlGaN, which belongs to direct band gap, partly to be led Body, with the change of Al components in alloy material, band gap consecutive variations between 3.4eV -6.2eV, the corresponding peak value of its band gap Response wave length scope is 200nm -365nm, therefore AlGaN is one of ideal material for making ultraviolet detector.AlGaN material system Ultraviolet detector quantum efficiency height, high sensitivity, the UV, visible light of work suppress than big, and the day that can work in low background completely is blind Wave band (240-280nm).AlGaN ultraviolet detectors can be applied to play early warning, precise guidance, ultraviolet secret communication, biochemical analysis, The field such as naked light detection, biological medicine analysis, offshore oil prison, ozone concentration monitoring, solar ultraviolet Index Monitoring, ultraviolet imagery, Real-time detection or effectively tracking can be carried out to the airbound target that a large amount of ultraviolet radioactives are discharged in wake flame or plumage cigarette, faint Target is detected under background.

Low noise, high-gain are two key indexes of high-performance ultraviolet avalanche photodetector.Avalanche photodetector Noise and gain can be realized by the regulation and control of effective ratio to carrier-electronics, hole collision ionization rate, referred to as Ionization by collision engineering.Research finds that the avalanche breakdown process of single carrier (electronics or hole) triggering has relatively low excess noise The factor；And the gain of higher can then be obtained by using the big carrier of impact ionization coefficient as carrier is triggered.For GaN materials Material, hole collision ionization coefficient is more than electron impact ionization coefficient, therefore is had by the GaN avalanche photodetectors that hole is triggered The avalanche gain of higher.But the avalanche photodetector of existing APD structures and PIN structural all there are device active region periphery and Noise caused by leakage current and dark excitation current that backing tape is come, have impact on the signal-to-noise ratio and detection efficient of detector.

Utility model content

For problems of the prior art, gone the purpose of this utility model is to provide one kind with two-dimensional electron gas Make an uproar the AlGaN ultraviolet detectors of shading ring, the dark current that active area periphery can be greatly reduced in it and back end produces, improves detection The signal-to-noise ratio and detection efficient of device.

To achieve the above object, the utility model uses following technical scheme：

A kind of AlGaN ultraviolet detectors with two-dimensional electron gas denoising shading ring, the detector include from bottom to up In substrate, GaN or AlN cushions, the highly doped backside conductive layers of GaN, undoped GaN layer, the embedded undoped GaN layer top The p-type AlGaN snowslide knots of the active depletion regions of N-shaped AlGaN of the heart and the embedded active depletion region central upper portions of N-shaped AlGaN； Two-dimensional electron gas trench mask structure is formed between undoped GaN layer and the active depletion regions of N-shaped AlGaN；P-type AlGaN snowslide knots Top be provided with snowslide inactivity of yang-qi pole；The contact position of undoped GaN layer and the active depletion regions of N-shaped AlGaN, across the two dimension Electron gas channel shielding construction is provided with ground plane ground loop；The top of the highly doped backside conductive layers of GaN, undoped GaN Highly doped GaN back sides noise absorbent electrode is buried in being circumferentially provided with for layer.

Further, the substrate is Si, SiC or Sapphire Substrate.

Further, the extraction of all electrodes uses Ti, Al, Ni, Au alloy in the detector；Or Ti, Al, Ti, Au Alloy；Or the Ohmic contact that Ti, Al, Mo, Au alloy make is formed.

The utility model has following advantageous effects：

The dark current that active area periphery can be greatly reduced in the application and back end produces, improves signal-to-noise ratio and the spy of detector Survey efficiency.Device forms 2DEG raceway groove equipotential faces as leakage current and the shielding knot of noise using GaN/AlGaN two-dimensional structures Structure, the noise current of active area periphery and backing substrate is filtered out by 2DEG raceway groove equipotentials face ground connection, helps to realize low noise The ultraviolet detector of sound pitch gain, high s/n ratio and detection efficient.

Brief description of the drawings

Fig. 1 is the AlGaN UV detector structure schematic diagrames that the utility model has two-dimensional electron gas denoising shading ring；

Fig. 2 is that GaN/AlGaN has in AlGaN ultraviolet detectors of the utility model with two-dimensional electron gas denoising shading ring Source structure technique production process figure.

Embodiment

In the following, refer to the attached drawing, more fully illustrated the utility model, shown in the drawings of showing for the utility model Example property embodiment.However, the utility model can be presented as a variety of multi-forms, it is not construed as being confined to what is described here Exemplary embodiment.And these embodiments are to provide, so that the utility model is fully and completely, and by the utility model Scope is fully communicated to those of ordinary skill in the art.

As shown in Figs. 1-2, the utility model provides a kind of ultraviolet spies of AlGaN with two-dimensional electron gas denoising shading ring Device is surveyed, which includes substrate 1, GaN or AlN cushions 2, the highly doped backside conductive layers 3 of GaN, undoped GaN from bottom to up Layer 4, the active depletion regions 5 of N-shaped AlGaN of embedded undoped 4 central upper portion of GaN layer and the active depletion regions 5 of embedded N-shaped AlGaN The p-type AlGaN snowslides knot 6 of central upper portion；Two-dimensional electron gas is formed between undoped GaN layer 4 and the active depletion regions 5 of N-shaped AlGaN Trench mask structure 7；The top of p-type AlGaN snowslides knot 6 is provided with snowslide inactivity of yang-qi pole 8；Undoped GaN layer 4 has with N-shaped AlGaN The contact position of source depletion region 5, across two-dimensional electron gas trench mask structure 7 be provided with ground plane ground loop 9；GaN is highly doped The top of backside conductive layer 3, being circumferentially provided with for undoped GaN layer 4 bury highly doped GaN back sides noise absorbent electrode 10.

Substrate 1 is Si, SiC or Sapphire Substrate.

The extraction of all electrodes uses Ti, Al, Ni, Au alloy in detector；Or Ti, Al, Ti, Au alloy；Or Ti, The Ohmic contact that Al, Mo, Au alloy make is formed.

One layer of GaN or AlN cushion 2 of extension first on substrate 1 during the element manufacturing of the utility model, so that thereon Channel layer be subject to lattice mismatch influenced reduce, and on GaN or AlN cushions 2 one floor height of extension adulterate back side GaN conductive layers 3 (are used as back side noise absorbent electricity in subsequent technique by etching and making Ohmic contact by step on device active region periphery The extraction of pole), then grow the undoped GaN layer 4 of a thickness, as shown in Figure 2 processing step (deep trouth etching-AlGaN extensions- Cmp planarization) etch the active area that deep groove structure and epitaxial growth N-shaped AlGaN construction 2DEG conducting channels surround, Ran Hou Snowslide structure and extraction electrode are made in N-shaped AlGaN active areas.

During the device work of the utility model, 2DEG shielding raceway groove ring ground connection, buries highly doped GaN back sides noise absorbent electricity 10 additional one small back bias voltage of pole, and snowslide inactivity of yang-qi pole 8 connects a suitably negative avalanche bias, consumes whole N-shaped AlGaN active areas Uptake zone to the greatest extent as ultraviolet light.The equipotential ground plane that whole active absorbing area is formed by 2DEG raceway grooves face shields, and device removes Go the leakage current of the part outside active area and the generation of whole substrate to shield raceway groove by 2DEG and bury highly doped GaN to carry on the back Face noise absorbent electrode 10 filters out, and after photon incidence, is absorbed in the active depletion regions of N-shaped AlGaN and forms electron-hole pair, Electronics floats to 2DEG shielded layers and is guided, and the hole with high impact ionization coefficient continues to drift to snowslide interface initiation snow Multiplied signal is collapsed, so as to fulfill the ultraviolet detection signal of low noise high-gain.

It is described above simply to illustrate that the utility model, it is understood that the utility model be not limited to the above implementation Example, meets the various variants of the utility model thought within the scope of protection of the utility model.

Claims (3)

1. a kind of AlGaN ultraviolet detectors with two-dimensional electron gas denoising shading ring, it is characterised in that the detector is under It is supreme including substrate, GaN or AlN cushions, the highly doped backside conductive layers of GaN, undoped GaN layer, the embedded undoped GaN The p-type of the active depletion regions of N-shaped AlGaN of layer central upper portion and the embedded active depletion region central upper portions of N-shaped AlGaN AlGaN snowslide knots；Two-dimensional electron gas trench mask structure is formed between undoped GaN layer and the active depletion regions of N-shaped AlGaN；P-type Snowslide inactivity of yang-qi pole is provided with above AlGaN snowslide knots；The contact position of undoped GaN layer and the active depletion regions of N-shaped AlGaN, There is ground plane ground loop across the two-dimensional electron gas trench mask structure setting；The highly doped backside conductive layers of GaN it is upper Side, being circumferentially provided with for undoped GaN layer bury highly doped GaN back sides noise absorbent electrode.

2. the AlGaN ultraviolet detectors according to claim 1 with two-dimensional electron gas denoising shading ring, its feature exist In the substrate is Si, SiC or Sapphire Substrate.

3. the AlGaN ultraviolet detectors according to claim 1 with two-dimensional electron gas denoising shading ring, its feature exist In, in the detector extraction of all electrodes use Ti, Al, Ni, Au alloy；Or Ti, Al, Ti, Au alloy；Or Ti, Al, The Ohmic contact that Mo, Au alloy make is formed.