Research On Dual-band Infrared Detection Materials And Devices Based On GaSb

Infrared detection technology,especially dual-band infrared detection technology,plays an important role in military and civil fields because of its wide detection band range,rich feature information,strong resolution,anti-jamming and other advantages.In the field of infrared detector,according to the atmospheric window,it is usually divided into short wave infrared(1-3?m),medium wave infrared(3-5?m)and long wave infrared(8-14?m).In this paper,GaSb bulk was used as short wave infrared absorption materials,InAs/GaSb type-? superlattices was used as medium wave and long wave infrared absorption materials,four kinds of GaSb based short/mid,short/long,mid/mid and mid/long dual-band infrared detection materials and devices have been realized by energy band simulation,molecular beam epitaxy and device fabrication.The surface morphology,crystal structure of epitaxial materials and photoelectric properties of dual-band infrared detector were studied.The main research contents are as follows:(1)Optimized epitaxial growth parameters of GaSb buffer layer and InAs/GaSb type-? superlattices.Including growth temperature,?/? beam ratio and growth time of InSb interface.The optimized GaSb buffer layer and InAs/GaSb type-?superlattices surface root mean square roughness RMS are 1.8A and 1.97A,respectively.The FWHM of zero-order superlattice satellite peak is 41.22arcsec,and the strain value of substrate peak is 0.0347%.The annealing experiments of InAs/GaSb type-II superlattices show that the maximum temperature of superlattices should not exceed Tc+75?.The GaSb bulk was grown at low temperature Tc+60?,and the optimized beam ratio was Sb/Ga=7,RMS is 1.79A.(2)The growth parameters were confirmed by regrowth of 10/1/5/1 and 18/3/5/3 M structure superlattices.The temperature of doping source furnace and the corresponding doping concentration were studied.The epitaxial growth of high quality short/mid,short/long,mid/mid and mid/long dual-band infrared detector is realized by the basis of material epitaxial experiment,structural design and energy band simulation.The zero order satellite peaks of superlattices with different structures in the four devices are overlapped.The FWHM of overlapped zero-order peaks are 17.57arcsec,38.77arcsec,36.34arcsec and 27.92arcsec,respectively.The strain values with substrate peak are 0.0905%,0.0215%,0.1224%and 0.030%respectively.(3)Four kinds of dual-band devices were fabricated and their electrical and optical properties were tested.The test results are as follows:The cutoff wavelengths of two channels of short/mid dual-band devices are 1.6?m and 5.02?m,respectively.The maximum impedance value of the device RA and the dark current density value J are 1.86×106?·cm2 and 4.12×10-7 A·cm-2 respectively.The optical cross-talk of short wave and medium wave channels are 0.0049 and 0.295 respectively.The peak quantum efficiency are 35.86%and 25.47%,respectively.The peak specific detectivity are 7.63×10¹¹ cm·Hz^1/2/W and 4.05×1010cm·Hz^1/2/W,respectively.The comparison between sulfuration process and passivation process was made,the side wall resistivity of sulfuration and passivated devices are 4.49×107?·cm and 6.83×106?·cm,respectively.The cutoff wavelengths of two channels of short/long dual-band devices are 1.64?m and 11.06?m,respectively.The maximum impedance value of the device RA is 3.75×107 ?·cm2,The peak responsivity of short-wave and long-wave channels are 0.7A/W and 1.5A/W,respectively.The peak quantum efficiencies were 0.6%and 17%,respectively.The peak specific detectivity is 1.4×109cm·Hz^1/2/W at 1.5?m for short-wave channel,and 1.052×10¹¹cm·Hz^1/2/W at 5?m for long-wave channel.The cutoff wavelengths of two channels of mid/mid dual-band devices are 3.7?m and 5.0?m,respectively.The maximum impedance value of the device RA is 4.69×106?·cm2,The peak responsivity of 3.7?m and 5.0?m channels are 0.7A/W and 1.5A/W,respectively.The peak quantum efficiencies were 2.37%and 35.06%,respectively.The peak specific detectivity are 1.453×10¹² cm·Hz^1/2/W and 9.936×10¹³ cm·Hz^1/2/W,respectively.The cutoff wavelengths of two channels of mid/long dual-band devices are 4.8?m and 10.5?m,respectively.The maximum impedance value of the device RA is 2.48×105 ?·cm2,The peak responsivity of mid-wave and long-wave channels are 0.2664 A/W and 0.5169 A/W,respectively.The peak quantum efficiencies are 8.12%and 13.12%,respectively.The peak specific detectivity are 2.04×10¹²cm·Hz^1/2/W and 3.95×10¹²cm·Hz^1/2/W,respectively.