Study On The Fabrication Of BIB Infrared Detector And Utilization Of Plasmon Effect

Infrared detection and Terahertz detection technology become more important in military, astronomy and imaging field as time goes on. Benefitting from high responsibility, broad response band, mature fabrication technique and convenience to be integrated with CMOS read-out circuit, BIB photodetectors have been the state-of-the-art choice for astronomical application from far-infrared and THz detection during the last three decades. However, the technique about infrared detector is still being blocked by several developed countries since it's dominant for national defense.Domestic research on BIB detector is still in its infancy, which limits the development of China's astronomical industry. Therefore, the systemic investigate of BIB detector is significant for our country.The main aim of our research is to optimize the design of BIB detector. We discussed the working principle, photoresponse characteristics and influence of SPP on BIB detector by both experimental and simulation methods. The investigation in this work provides theoretical support for the development of different material based BIB detectors,including Si-based BIB detector. The innovative research results are as follows:1. A 100?200nm thick Si:As layer with good electrical properties and crystal quality that is suitable as epitaxial substrate is achieved through ion implantation followed by rapid thermal annealing ?RTA?. Compared with the well-known EOR defects,the evolution of PR defects induced by ion implantation is comprehensively investigated. EDX characterization proves PR defects are related to doping atoms precipitations. The sizes of PR defects enlarge at the expense of small ones with the elevation of annealing temperature. The characterizations of electrochemical capacitance-voltage and EDX conclude that the SiO₂/Si interface is playing an indispensable role in the deactivation of dopant atoms during the annealing process.2. Comparison of photoresponse of the detectors under alternate operating mode?AOM? and conventional operation modes ?COM? is made. We demonstrate that the detectors can achieve high responsivity under AOM when operating bias is below 2.0V. For example, the relative responsivity at 0.6V under AOM is 2.3 times of that under COM. Moreover, the response of the detectors terminates at wavelength of 35?m ?8.57THz? under AOM while it is cut off at 31?m ?9.68 THz?under COM. By analyzing the origination of the dark current under the AOM,a method to improve the performance of BIB detectors under AOM is proposed.3. To explore plasmonic effect on the THz detection, both a backside-illuminated and a topside-illuminated blocking impurity band ?BIB? THz detectors are developed and significant influence of plasmonic effect on the performance of BIB THz detectors is observed. The plasmonic effect in the heavily doped semiconductor layer of BIB THz detectors causes high reflectance of THz radiation which curtails the detection frequencies of the backside-illuminated BIB detectors. This discovery is important for the development of backside-illuminated BIB detectors.4. We integrate 2DHA-a plasmonic structure into epitaxial Si-based BIB THz detectors. The photoresponse of the reference device without 2DHA covers a broad spectral scope from 35?m ?8.57 THz? to 15?m ?20 THz?. When integrated with 2DHA, the spectrum of the detector is apparently modulated. The intensity of the photoresponse away from the resonance wavelength is prominently suppressed. Our work plays a vital role in realization of multi-spectral BIB detectors.5. We integrate 2DHA into ion-implantation Si-based BIB THz detectors. The photoresponse of the reference device without 2DHA covers a broad spectral scope from 31?m ?9.68 THz? to 15?m ?20 THz?. Though 80 percent of active region is covered with a metal film in the surface plasmon ?SP?-enhanced device,its absolute photoresponse is still of 25?35 percent higher than that of the reference device at the resonance wavelength. We further find that the SP-enhanced device presents about 8-fold enhancement in comparison with the reference device at ?=30.7?m?9.77 THz? that is beyond the SP resonance wavelength. By an energy band model and electromagnetic field simulation,we uncovered the photoresponse enhancement at the non-resonance wavelength originates from Franz-Keldysh effect induced by a strong confined electromagnetic field at the interface between 2DHA and active region.