Material Growth And Performance Of Antimony-based Type-? Superlattices Mid-wavelength Infrared Photodetectors

The antimony-based type-? superlattice infrared photodetector has the advantages of the adjustable bandgap,large effective electron mass,good uniformity,fast response speed,and large-scale area array.In some aspects,the performance of this photodetector has exceeded the MCT detectors.It is considered to be a very promising third-generation infrared detector.Among them,the mid-wavelength superlattice infrared photodetector has a very wide application in industrial and military fields.The antimony-based type-? superlattice infrared photodetector can be manufactured by using the Molecular Beam Epitaxy(MBE)on a GaSb substrate through a standard etching process.However,there are many kinds of antimony-based compounds,and the optimal growth conditions of each compound are quite different.The growth conditions of different MBEs are also different.The optimal growth conditions for the growth of a certain compound in a different time will also shift.The quality of the interface between different materials will have a great impact on the performance of the photodetector.The research goal of this thesis is to realize the mid-wavelength infrared detector using the antimony-based type-? superlattices material system,to systematically study the influence on the material quality of the growth temperature,V/?I and interface sequence of MBE growth of superlattice low-dimensional materials,the preparation process of the photodetector and the optimization of the performance of the mid-wavelength photodetector.The main research contents and results are as follows:(1)Through the material test of the HRXRD and AFM,the position of the substrate peak and zero-order satellite peaks of the superlattice material,the FWHM of the zero-order peak,the number of the satellite peaks,the surface topography of the material and the RMS parameters were analyzed.The growth conditions of MBE epitaxial InAs/InAsSb materials were studied.And a method for systematically searching for optimal growth conditions of materials was obtained,which is simple and easy.The high-quality MW-InAs/InAsSb material was successfully grown with a lattice mismatch of 0arcsec,a FWHM of the first-order satellite peak of 46.8arcsec,and a RMS of 1.571?in the range of 10?m×10?m.This parameters indicated that the material was grown very well.(2)Using the device of HRXRD and TEM study the interface control methods of InAs/InAsSb and InAs/AlSb superlattices,respectively.Observing the intermixing of atoms in interfaces,finally,a conclusion that the interface quality obtained by the bulk material growth method is better than the growth interruption method and the V group element infiltration when grew the InSb interface was obtained.The conclusion is universal for InAs/InAsSb and InAs/AlSb.The growth interruption method and the V group element infiltration method are mainly used to fine tune the composition and stress of the material.(3)By using a standard detector process flow lithography,etching,passivation,vaporizing the metal electrode,and wire bonding to the antimony-based material,we have successfully produced the MW-InAs/InAsSb and the MW-InAs/GaSb infrared detectors.By inserting an M-type barrier into the PIN-type InAs/GaSb,the impedance of the device is increased from 440W·cm~2 to 13955W·cm~2;and by increasing the thickness of the active region from 1?m to 2?m,the quantum efficiency of the device is increased from 27.7%to 33.7%.