Polycrystalline silicon germanium (Si1-xGex) films deposited by the rf sputtering technique were characterized using a combination of transmission electron microscopy (TEM), atomic force microscopy (AFM), x-ray diffraction (XRD), and Raman spectroscopy techniques. The TEM results showed small grains (10–20 nm) with microtwins, and AFM showed islands of 100–200 nm in the films. The XRD results show that our films consist of Si1-xGex alloy with no cluster of Ge or a Ge-rich material embedded in a Si matrix. The smaller grains in our films could be a result of an abundance of nucleating sites or impurities in the films. Raman spectroscopy results indicate that our films were strain free. © 2002 American Institute of Physics.