Characteristics of Zn diffusion in planar and patterned InP substrate using Zn3P2 film and rapid thermal annealing process

Characteristics of Zn diffusion in patterned InP substrates was investigated and compared with that of Zn diffusion in InP planar substrates. The activation energy of diffusion coefficient was 1.3∼1.4 eV in both patterned and planar diffusion, which indicates that there is no difference in the diffusion mechanism and that the diffusion was controlled by an interstitial-substitutional mechanism. The diffusion coefficient in patterned substrates was smaller than that in planar substrates when a Si3N4 encapsulation layer was employed. As the Si3N4 encapsulation layer thickness increased, the diffusion coefficient decreased in both planar and patterned substrates. But, the diffusion coefficient showed little dependence on the thickness of the SiO2 encapsulation layer in both patterned and planar substrates.