| With the continuous development of the times,people constantly explore nature,and the technology of UV detection is also constantly improved and widely applied in civil and military fields.In the civil field,UV detection technology can be applied to environmental monitoring,flame detection and sky ultraviolet communication.In the military field,UV detection technology can be applied to intelligence transmission,missile warning and biochemical reagent detection.AlGaN material is a direct bandgap semiconductor.By adjusting the size of the aluminum component,the band gap can be continuously changed from 3.4 eV(GaN)to 6.2 eV(AIN),corresponding to the wavelength of 200 nm-365 nm of the ultraviolet light,which is in the range from near ultraviolet to deep ultraviolet.In addition,AlGaN material has excellent characteristics such as high electron saturation drift rate,high breakdown electric field,high thermal conductivity and high radiation resistance.So AlGaN material is the preferred material for the UV detection.This paper focuses on the fabrication and characterization of AIGaN-based Schottky-type multi-array UV detectors and metal-semiconductor-metal(MSM)structure UV detectors.The main results are as follows:(1)A2 × 2 Schottky multi-array UV detector was fabricated by semiconductor technology based on AlGaN material,and the I-V characteristics of the sample device were characterized.The dark current of a single pixel in a multicomponent device is not more than 10-9A under 50 V reverse bias,and it has good rectification characteristics.The photoelectric characteristics of each pixel in the same array are analyzed.Under 50 V reverse bias,the standard deviation coefficient of dark current of each pixel is 8.20%,the standard deviation coefficient of photocurrent is 2.55%,which is less than 10%,and under 5V reverse bias,the standard deviation coefficient of peak responsiveness is 3.28%.It shows that the photoelectric performance of each pixel in multi-element array device has good consistency.Therefore,the quadratic orthogonal detector is expected to be used in the fabrication of positioners to achieve target tracking and positioning.(2)In order to study the influence of interdigital s on the performance of MSM devices,we fabricated MSM UV detectors with interdigitated pitches of 5?m,10?m and 15?m on AlGaN materials,and the area of the interdigitated electrode area is 200?m×400?m From the measured experimental data,with the increase of interdigital pitch from 5 to 15 microns,the photocurrent decreases from 1.70×10-5 A to 2.44×10-6 A under 5 V bias,and the peak responsiveness decreases from 78.69mA/W to 50.42 mA/W under 8 V bias.Combining with the simulation of electric field distribution,we think that the main reasons for the decrease of peak photocurrent and responsiveness of MSM devices are:On the one hand,the electric field intensity between adjacent interdigital electrodes decreases with the increase of interdigital pitch,causing the drift velocity of carriers to become smaller,which leads to the decrease of photocurrent response of MSM devices;On the other hand,the depth of electric field distribution in MSM devices also decreases with the increase of interdigital pitch,which means that the thickness of the depletion layer in the absorption layer becomes thinner,so the number of carriers involved in drift motion decreases,which can also weaken the photocurrent response of the device. |
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