Origin and FEM-assisted evaluation of residual stress in thermally oxidized porous silicon

The origin of residual strain is investigated in thermally oxidized porous silicon structures by computer supported finite element modeling. Based on theoretical approaches, unit cell series were developed to simulate the porous matter and its oxidation process. It is found that the residual strain is caused by both thermal and intrinsic stress components. The results show strain values between 1.69 × 10−3 and 2.26 × 10−3 according to the different oxidation extent, which is in good agreement with the experimental strain data obtained by XRD.