Experimental verification of the stress model for the wrinkling of ion-implanted layers

Experiments were conducted to verify the stress model for the wrinkling of ion-implanted layers [C. Hajdu et al., preceding paper, Phys. Rev. B 41, 3920 (1990)]. The model is based on the elastic instability of the implanted layer, and in its simplified form it predicts a wavelength of wrinkling (λ) equal to 4.3 times the thickness (Γ) of the implanted-atom distribution. This is in reasonable agreement with earlier experiments performed with various parameters. A more realistic evaluation of the model using a fitting parameter (which carries the material dependence) predicts λ=c${\mathrm{\Gamma }}^{3/4}$. As further proof of the model, experiments were performed with all parameters kept the same as in control samples except for a larger ion distribution width using our quasisimultaneous multiple-energy-implantation method. The results are in full accord with the predictions of the model; i.e., a sixfold increase in wavelength is observed, and the material dependence is pointed out.