Study on proton implantation isolation of GaAs-based devices

Proton injection parameters have a great influence on the position of current confinement aperture and the effect of current isolation of the implantation vertical cavity surface emitting laser (VCSEL). From the influence rule and mechanism of the energy and dose of proton implantation and their interaction on the current confinement aperture of VCSEL, this paper analyzes the influence of implantation parameters on the proton distribution and the resistance value of the implanted region by theoretical simulation firstly. And then proton implantation experimental research were carried out using VCSEL epitaxial wafers on this basis. Both the experimental results and theoretical analysis show that the current isolation effect and proton distribution in the injection region are controlled by injection energy and dose. When the implantation parameters are 320 keV and 8×10¹⁴ cm⁻², after annealing at 430 ℃ for 30 s, a proton implantation region can be obtained with a junction depth of about 0.7 μm, an average range of about 1.3 μm from the active region and a resistance value of 4.6×10⁷ Ω∙cm². The VCSEL device was fabricated by using this parameter, and better laser excitation was achieved. It is proved that the proton distribution can not only avoid the damage of VCSEL active region, but also achieve a excellent current isolation effect, meeting the fabrication requirements of the VCSEL current confinement aperture. The results of this study have important guiding significance for the chip structure and process optimization of proton-injected VCSELs.