Mechanical characteristics of hydrogen-implanted crystalline silicon after post-implantation annealing

Knowing the mechanical properties of single crystal silicon after implantation with hydrogen and annealing are important for “smart cut” process and in improving ultra-precision cutting of silicon. There is limited information on hardness and modulus of such silicon. In this article, the effect of hydrogen implantation dose and post-implantation annealing on silicon hardness and modulus were investigated. Continuous implanted silicon layers, from the surface to the depth of ∼500 nm, were produced. Samples with three different implantation doses and with post-implantation annealing at 350 °C and 400 °C were prepared. Hardness and modulus were obtained through dynamic nanoindentation, while structural properties were evaluated by Rutherford backscattering spectroscopy and high resolution x-ray diffraction. Hardness and modulus were significantly reduced after annealing for the highest implantation dose. With the annealing, the implantation-induced strain had the least relaxation for the lowest implantation dose. The obtained results could be useful for understanding the role of hydrogen in nano-cutting of hydrogen-implanted silicon.