CN1598502A

CN1598502A - Gallium nitrogen base visible / ultraviolet clouble-colour photoelectric detector

Info

Publication number: CN1598502A
Application number: CN 03151054
Authority: CN
Inventors: 李向阳; 王平
Original assignee: Shanghai Institute of Technical Physics of CAS
Current assignee: Shanghai Institute of Technical Physics of CAS
Priority date: 2003-09-18
Filing date: 2003-09-18
Publication date: 2005-03-23

Abstract

The invention discloses a visible/ultraviolet double-color photoelectric detector based on gallium nitride group. The detector includes two photoelectric diodes integrated on the substrate with extending growth, one is a photoelectric diode of visible light, and another is ultraviolet photoelectric diode. It uses gallium nitride group materials of Aln, AlGaN, GaN, InGaN, whose forbidden band widths are lessened gradually, and the forbidden width changes along with the chemical component, through controlling the materials and component, thus controls the forbidden width, realizes the selection of device sensitive waveband, achieves the double-color photoelectric detection. The accuracy and reliability are excellent.

Description

Gallium nitrate based visible/ultraviolet clouble-colour photoelectric detector

Technical field

The present invention relates to photodetector, specifically be meant the gallium nitrate based bi-coloured light electric explorer that to survey visible waveband and ultraviolet band simultaneously.

Background technology

In recent years, gallium nitrate based photoelectric devices such as GaN, AlGaN, InGaN are subjected to people's attention, and wherein relatively more outstanding is luminescent device and photoelectric detector.Since gallium nitrate based photodetector have radiation resistance good, can be used for advantage such as hot environment, add that it can accomplish insensitive this remarkable advantage of visible light wave range, make it become a research and development focus.

The external gallium nitrate based unit ultraviolet detector of having reported has multiple, and as guide type, MS type, PIN type and optical transistor type etc., the array focus planardetector also has report.As document: " the Solar-Blind AlGaNHeterostructure Photodiodes " that " MRS Internet J.Nitride Semicond.Res.5; 9 (2000). " reported, adopt heterojunction PIN structure, its response wave length is 250-290nm, and peak response is near 270nm; The also PIN structures that adopt of focus planardetector more, the detection wavelength coverage that realizes is also narrow, as 128 * 128 focal plane devices that document " MRS Internet J.Nitride Semicond.Res.5,6 (2000). " is reported, its response wave band is at 320-365nm.The research of domestic GaN sill has been carried out for many years, and the photoelectric device research and development mainly concentrates on the light emitting diode field at present, and shorter mention is to ultraviolet detector.

But the structure of above-mentioned all these detectors all can only realize the detecting function of a certain wavelength coverage.When they are used for the photodetection instrument, need adopt the photodetector of different-waveband at different incident light wave segment limits.When system needs the multiband complex probe, just may need two kinds or two or more photodetectors, so just increased the complicacy of photodetection instrument system; When needs multiband optics passage registration, the requirement of minute adjustment to be proposed also to the optical system of instrument.

Use the bi-coloured light electric explorer, not only can make system have the effect of passage nature registration, and on a focal plane, realize the photodetection of two wave bands simultaneously, can omit colour esensitized equipment, simplified system, improve different-waveband image registration accuracy and reliability.Aspect infrared light detecting, medium wave is infrared/the existing report of array device of LONG WAVE INFRARED double-color detector.As seen/do not appear in the newspapers as yet in all kinds of at home and abroad documents of gallium nitrate based double-colored photoelectric detector of ultraviolet band.

Summary of the invention

There is the single problem of detecting band based on above-mentioned existing gallium nitrate based detector, the purpose of this invention is to provide a kind of gallium nitrate based bi-coloured light electric explorer that can survey visible waveband and ultraviolet band simultaneously.

Gallium nitrate based bi-coloured light electric explorer of the present invention comprises substrate, it is characterized in that: by vertical successively integrated two photodiodes of epitaxial growth, one of them is a visible light photodiode 2 on substrate 1, and another is a ultraviolet light photo diode 3.If incident light is the positive incident from device, then on substrate, generate visible light photodiode 2 earlier, the back generates ultraviolet light photo diode 3.If it is incident light is the back surface incident from device, also, then just in time opposite promptly from the substrate incident of device.

The present invention utilizes gallium nitride-based material: the energy gap of AlN, AlGaN, GaN, InGaN reduces successively, and their energy gap changes with chemical composition, by control material and component, thereby control energy gap, realize choosing of device sensitive band, reach the purpose of double-colored photodetection.

The course of work of bi-coloured light electric explorer of the present invention is: when a branch of incident light that contains ultraviolet and visible composition enters device, photosignal between first photodiode electrode is the photon excitation by ultraviolet band, and the photosignal between second photodiode electrode is by the photon excitation of visible and long wave ultraviolet portion.Co-located is surveyed when so just having realized different wave length, promptly double-colored detection.

The great advantage of detector of the present invention is to realize the photodetection of two wave bands on a focal plane simultaneously, makes the photodetection instrument omit colour esensitized equipment, improves the different-waveband image registration accuracy and the reliability of instrument.

Description of drawings

Fig. 1 is the epitaxial layer structure synoptic diagram of device;

Fig. 2 is the vertical view of device;

Fig. 3 is the A-A cross-sectional view of Fig. 2.

The equivalent schematic diagram of Fig. 4 electronics

Embodiment

Below in conjunction with accompanying drawing, be embodiment in the back illumination mode, the present invention is described in further detail:

1. the material of device growth and annealing thereof: adopting the sapphire of twin polishing is substrate 1, epitaxial growth 0.01-0.1 micron thickness AlN cushion 4 at first, and the 0.1-0.5 micron thickness of growing successively then Si doping content is 10 ¹⁷N type AlGaN layer 5,0.1-0.5 micron thickness i type GaN layer 6,0.5-2.0 micron thickness Mg doping content are 10 ¹⁷P type GaN layer 7,0.1-0.5 micron thickness i type InGaN layer 8 and 0.1-0.5 micron thickness Si doping content are 10 ¹⁸n ⁺Type GaN layer 9.As shown in Figure 1, for the structure of each layer in can clearly illustrating to publish picture, there is not proportionate relationship in each layer thickness among the figure.After the material of sandwich construction is finished growth, carry out annealing in process, annealing temperature is at 440 ℃～780 ℃, and the time was at 20 minutes to 60 minutes.

2. table top is tied the technology fabricate devices: the method that adopts multistep photoetching and dry etching, make the material of surveying ultraviolet and visible light two subregions obtain etching, expose n type AlGaN layer 5 and p type GaN layer 7 respectively, on n type AlGaN layer 5 and uppermost n+ type GaN layer 9, respectively prepare a titanium aluminium

nickel gold electrode

13,12 then with common thin film techniques such as steaming, plating, sputters, preparation nickel gold common electrode 10 on p type GaN layer, in the edge and the side that are etched the zone, adopt the deielectric-coating 11 of insulation to carry out Passivation Treatment in addition.The ultraviolet light photo diode 3 of finishing ultraviolet detection in the device architecture that obtains like this is made of n type AlGaN layer 5, i type GaN layer 6 and p type GaN layer 7; During application, signal voltage or marking current are by output between nickel gold common electrode 10 and the titanium aluminium nickel gold electrode 13.The visible light photodiode 2 of finishing visible light detecting is made of n+ type GaN layer 9, i type InGaN layer 8 and p type GaN layer 7; During application, signal voltage or marking current are by output between nickel gold common electrode 10 and the titanium aluminium nickel gold electrode 12.The device inside structure as shown in Figures 2 and 3.The equivalent schematic diagram of the electronics of device such as Fig. 4.

Claims

One kind gallium nitrate based visible/ultraviolet clouble-colour photoelectric detector, comprise substrate (1), it is characterized in that: go up at substrate (1) and vertically be equipped with two photodiodes successively by epitaxial growth, one of them is visible light photodiode (2), and another is ultraviolet light photo diode (3); If incident light is the positive incident from device, then on substrate, put visible light photodiode (2), rearmounted ultraviolet light photo diode 3 earlier; If it is incident light is the back surface incident from device, also, then just in time opposite promptly from the substrate incident of device.
2. according to a kind of gallium nitrate based visible/ultraviolet clouble-colour photoelectric detector of claim 1, it is characterized in that: said visible light photodiode (2) is made of 0.1-0.5 micron thickness n+ type GaN layer, 0.1-0.5 micron thickness i type InGaN layer and 0.5-2.0 micron thickness p type GaN layer successively.
3. according to a kind of gallium nitrate based visible/ultraviolet clouble-colour photoelectric detector of claim 1, it is characterized in that: said ultraviolet light photo diode (3) is made of 0.1-0.5 micron thickness n type AlGaN layer, 0.1-0.5 micron thickness i type GaN layer and 0.5-2.0 micron thickness p type GaN layer.