To optimize the doping process and enhance the performance of 980 nm wavelength GaAs-based semiconductor laser, this paper explores the Zn diffusion technology using solid Zn compound thin films as the diffusion source. The ZnO diffusion source and SiO₂ capping layer are fabricated through vacuum coating and plasma-enhanced chemical vapor deposition（PECVD）techniques. Different annealing conditions are combined to regulate the diffusion behavior of Zn in GaAs and InGaAs/GaAs/GaAsP heterostructures. Multiple testing methods are employed to analyze the diffusion rules and their impact on device perfor-mance.The research indicates that the diffusion depth of Zn increases with the rise of annealing temperature and time. The impurity concentration reaches the order of approximately 10²⁰cm^-3, and the ratio of the longitudinal diffusion depth to the lateral diffusion depth is 1∶1. Moreover, the diffusion behavior of Zn impurities in the multi-layer heterostructure significantly affects the photoluminescence characteristics of the laser and the integrity of the active region.