Femtosecond Laser Fabrication And Characterization Of Point Defects In Wide Band Gap Semiconductor

With the development of mode-locking and chirped-pulse amplification technology,femtosecond laser has begun to enter the human society.The application of femtosecond laser has carved out a new way to explore the natural laws and develop human technological civilization.The use of the interaction between light and matter has become an important means to explore the structure and motion laws of micro substance.At present,femtosecond laser fabrication and spectral detection technology are being used in the processing and characterization of new wide band gap semiconductor materials,especially in the preparation and characterization of solidstate spin quantum dots based on the third generation of wide band gap semiconductor materials such as diamond and silicon carbide.In this paper,based on the application in quantum information technology,super resolution imaging and high sensitivity detection of nitrogen vacancy(NV)color center defect in diamond,the femtosecond laser fabrication technology of NV color center in diamond was explored based on the principle of laser processing and detection technology,and the NV color center was characterized and analyzed through two-photon photoluminescence imaging and photoluminescence spectrum.Finally,based on the principle of photoluminescence characterization,the luminescent defects in 4H SiC were studied.This paper includes the following aspects:First of all,based on the application of NV color center in diamond in quantum information technology,this paper introduced the diamond as the new semiconductor material and the NV color center in diamond,and also investigated the preparation methods of NV color center and the research status of its photoluminescence characteristics.The features of femtosecond laser and its processing mechanism of semiconductor materials was studied,as well as the key optical parameters affecting the processing.According to the principle of NV color center photoluminescence and two-photon excitation,the two-photon photoluminescence imaging characterization technology was analyzed.Secondly,the exploratory experimental research on the preparation of NV color center of diamond by femtosecond laser was carried out.Several key optical parameters were regulated in the femtosecond laser processing and different types of diamond processing were realized.As a result,the preparation of NV color center was realized by combinating acid pickling and annealing treatment.Based on different characterization and testing methods,especially the two-photon photoluminescence imaging and spectral detection,the formation and distribution of NV color center in the samples before and after each process were studied and analyzed,and the feasibility of preparing NV color center in diamond by femtosecond laser nanofabrication was demonstrated.Finally,based on the research of NV color center photoluminescence characterization,the performance of UVPL tool in Fraunhofer IISB was evaluated according to different optical parameters,and the photoluminescence spectrum of 4HSiC substrates and the home-growning epitaxial layers by CVD were characterized;the photoluminescence characterization results of different implanted conditions and processing were analyzed as the basis of SiC device processing control.