The aim of this paper is to develop accurate models to take into account the effects of the fabrication temperatures on the elastic constants of Silicon, germanium, and Silicon-Germanium thin  films used as performance boosters in the new generation of nano pMOS and nMOS transistors and  solar cells.

We are calculating the elastic constants of  Silicon-Germanium (Si(1-x)Ge(x)) using a linear extrapolation based on the Germanium mole fractions x and the elastic constants of Silicon and Germanium materials. And, to calculate accurately the temperature dependent elastic constants of Silicon and Germanium, we are using Taylor’s expansion around room temperature with polynomials of degree two.

We found an excellent agreement between the calculated temperature dependent elastic constants  and  the experimental data. The values of the calculated elastic constants of Si(1-x)Ge(x)) films have been used to calculate accurately the resulting intrinsic and extrinsic stresses in 14 nm nano pMOS transistors developed by Intel in 2014. We found out that the values obtained for theses intrinsic and extrinsic stresses are in excellent agreement with the experimental data found in literature.  The obtained simulation results in three dimensions will be presented and analyzed  for various temperatures.