Analysis of the structural properties of polycrystalline silicon germanium films

In this work, poly SiGe is proposed as a suitable material for surface micromachining applications that require a low thermal budget. The effect of the deposition conditions and layer thickness on the structural and mechanical properties of poly SiGe is analyzed by means of transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD). It is demonstrated that using as-grown poly SiGe (deposited at 625/spl deg/C), a low tensile stress (+60 MPa) and a negligible stress gradient can be achieved.