Abstract
The main of this thesis is the method and the characteristics of Ge diffusion in GaAs/AlxGa1-xAs, and furthermore, its applications for quantum well intermixing. First, the diffusion source is made by annealing GeAs (99.999%) powder along with GaAs substrates in quartz ampoules, which may produce Ge-Ga-As ternary compounds on the surface of GaAs substrates. Then, the diffusion source is used to perform the experiment of Ge diffusion in GaAs/AlxGa1-xAs samples from vapor phase by ampoule sealing. Besides, the excess As is also added into the ampoule to make sure that the ampoule is under the ambience of As overpressure. After annealing 2.5 hours at 810℃, the diffusion depth in p-GaAs is generally 1μm, while after 25 hours, quantum well intermixing can take place in 808nm laser structures. Ge diffusion in GaAs/AlxGa1-xAs is characterized by using photoluminescence(PL), which verifying the form of Ge diffusion in GaAs substrates is Ge_Ga-V_Ga complex, Hall measurement and electrochemical capacitor-voltage(ECV),which reconfirming Ge diffusion in GaAs/AlxGa1-xAs is n-type.