Day Blind Algan-based Pin Uv Detector Technology Research

As the third generation of semiconductor material, GaN is direct band-gap semiconductor. It has wide band gap, small permittivity, high speed electronic saturation, physical and chemical properties and stability, so it's valuable in the UV detector field, especially the ternary AlGaN, the range of the response in the wavelength is 200³65nm, it's an ideal material for solar blind UV detector. AlGaN based UV detector has wide application needs in missile early warning, weapons guidance, space exploration, UV newsletter and so on. This article includes research of the material growth of solar blind AlGaN PIN UV detector, the characterization of the material, ICP etching, Ohmic contact and other production crafts and process.We use MOCVD method taking the AlN material as the model layer on the sapphire, having successfully grown high Al component Al_xGa_1-xN layer with PIN structure, using XRD diffraction and projective spectra to test AlGaN epitaxial layer, show the quality of the epitaxial layer, the cut off the spectra 280nm, the layer quality and peak value can meet the demands of the device. The device structure design uses the way of light coming from the back. SixNy masks is growen by PECVD. The ICP etching method etches the epitaxial layer from P type to N type, By choosing the suitable etching condition, Cl₂/Ar/BCl₃ as etching gas. the etching speed can reach 200nm/min, the select ration of Si₃N₄ and AlGaN is 2.5. The Ohmic contact of N electrode is Ti/Al/Ni/Au muti-layer metal structure, P electrode is Cr/Au metal structure, annealing 60s under the temperature of 550℃in Oxygen environment, achieving a certain quality of P type Ohmic contact, contact resistance is 5.0×10^-1Ω.cm². There has a large distance from literature repot. We also study out the craft process of the solar blind AlGaN PIN UV detector, lays a solid foundation for the development of the solar blind AlGaN PIN UV detector.