SAW in phosphorus-implanted Si coupled with theinterdigital and wedge transducers

Abstract

The phase velocity and attenuation of SAW in phosphorus-implanted Si coupled with the interdigital transducer has been derived theoretically considering both the mechanical and electrical perturbations and compared with experimental results. The dose of phousphorus implanted in the boron doped Si varied from $1\times10"$ to $5\times10^{14}cm^{-2}$ at 80 KeV and the diffusion of phosphorus derived by the Gaussian profile showed the damage enhanced diffusion due to the induced damage by the implantation. The mechanical perturbation contributed significantly to the phase velocity change in both as-implanted and annealed Si, as a result the overall velocity increased by the stiffening effect. The velocity in annealed Si decreased due to the dielectric relaxation. The attenuation in as-implanted Si increased slowly with the dose due to the damage. On the other hand, the phase velocities measured by the wedge transducer decreased due to the induced damage in the as-implanted Si, and due to the carrier concentration effect in the elastic constant. The decreases of velocity showed the same behaviors with the modified perturbation equations.