The characteristics of Zn diffusion in patterned InP substrates was investigated and compared with that of Zn diffusion in InP planar substrates. The activation energy for diffusion was equal to 1.3 to 1.4eV for both patterned and planar diffusion; thus indicating that there was no difference in the diffusion mechanism, and that 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 used. As the encapsulation layer thickness was increased, the diffusion coefficient decreased in both planar and patterned substrates. However, the diffusion coefficient exhibited little dependence upon the thickness of a SiO2 encapsulation layer on patterned or planar substrates.

Characteristics of Zn Diffusion in Planar and Patterned InP Substrate using Zn3P2 Film and Rapid Thermal Annealing. S.Y.Yang, J.B.Yoo: Surface Coating Technology, 2000, 131[1-3], 66-9