Research On Key Technology Of Ge-based Infrared Quantum Well Laser

The high-efficiency light source for Si-based optical interconnects is generally the III-V laser,but the poor compatibility of the process with Si-CMOS has hindered its development.The Ge material of the same group IV can solve this problem,so the Ge-based laser has become a hot spot in semiconductor laser research in recent years.GeSn lasers have great potential in Ge-based lasers,because GeSn materials are converted into direct bandgap materials by high-Sn components,which improves its laser luminescence efficiency.The active region material?GeSn,SiGeSn?and structure of GeSn laser is the main factor affecting its performance,and it is also the research focus of this paper.Based on the study of the relationship between the energy band,lattice constant and the composition of each element of GeSn and SiGeSn materials,the quantum well structure of Si_0.17Ge_0.66Sn_0.17/Ge_0.9Sn_0.1.1 was designed.The characteristics of the active region of the quantum well laser are analyzed by the working mechanism of the semiconductor laser,and the influence of its structure on the photoelectric performance of the laser is revealed.On this basis,the PiN laser(Ge_0.9Sn_0.1.1 in the i-zone),the single quantum well laser(Si_0.17Ge_0.66Sn_0.17/Ge_0.9Sn_0.1.1 in the well layer),and the multiple quantum well laser(Si_0.17Ge_0.66Sn_0.17/Ge_0.9Sn_0.1.1 in the well layer)were designed.The influence of the geometric parameters and physical parameters of these three lasers on the photoelectric characteristics of these three lasers is analyzed,and the optimized structural and physical parameters are obtained:For the PiN laser,the device performance is optimal when the i region is 100 nm thick and the P region is doped at 1×10¹⁹/cm³.For single quantum well lasers The device performance is optimal when the well layer has a thickness of 100 nm and the P region has a doping concentration of 1×10¹⁹/cm³.For a multiple quantum well laser,the well layer has a thickness of 10 nm and a barrier layer thickness of 10 nm.The device performance is optimal when the logarithm is 3 pairs and the P-doping concentration is 1×10¹⁹/cm³.The optimized threshold current density of each laser is 3.42kA/cm²,2.21 kA/cm²,1.9 kA/cm²,and the output power is 4.8 mW,6.3 mW,8.5 mW,and the illuminance slope efficiency is 16 mW/A,21 mW/A,28.3 mW/A,the emission wavelength is between 2440²460 nm.On this basis,the characteristic temperature models of PiN laser,single quantum well laser and multi-quantum well laser are established.The simulation results show that the characteristic temperatures of the three lasers are 47.6 K,71.2 K and 104 K.In summary,the multi-quantum well structure laser is superior to other lasers.Through the research of the above lasers,it provides a theoretical basis for the development of GeSn quantum well lasers.For the Ge_0.9Sn_0.1/Si_0.17Ge_0.66Sn_0.17.17 multiple quantum well laser,the influence of the characteristic parameters of the cavity mask material on its photoelectric properties was analyzed.The relationship between the reflectivity and the output power of the AR coating and the high reflective film was studied.The optimized antireflection coating and high reflective film were obtained.The antireflective coating material is selected as SiO₂,the film thickness is designed to be 414 nm,the surface reflectance is 10.3%,and the high reflective film is Si/SiO₂ composite film,the thickness of which is 178 nm and 414 nm,respectively,and is added before the combined film.The 378 nm Al₂O₃ film increases its adhesion,and when the combined film is 3 pairs,its reflectance exceeds 95%.Finally,the preparation process of Ge_0.9Sn_0.1/Si_0.17Ge_0.66Sn_0.17.17 multiple quantum well laser was proposed.The above studies provide theoretical basis for the development of GeSn/SiGeSn quantum well lasers,which provides an important reference for the development of Si-based photonics.