Microstructure and strain distribution in freestanding Si membrane strained by Si_xN_y deposition

Strain in a bridge-shaped freestanding Si membrane (FSSM) induced by depositing an amorphous Si_xN_y layer was measured by convergent-beam electron diffraction (CBED). CBED results show that the strain magnitude depends negatively on the FSSM thickness. FEM is a supplement of the result of CBED due to the relaxation of TEM samples during fabricating. The FEM analysis results ascertain the strain property in three dimensions, and show that the strain magnitude depends negatively on the length of FSSM, and the magnitude of the compressive strain in FSSM increases as the position is closer to the upper Si/Si_xN_y interface.