Elastic and anelastic properties of Fe-doped InP films on silicon cantilevers

Abstract

The effect of Fe doping on the elastic and anelastic properties of heteroepitaxial InP films on microfabricated silicon cantilevers has been investigated by the vibrating-reed technique (typical frequencies 100 Hz to 10 kHz) with strain amplitudes in the range of 10−6 to 10−3 and in the temperature interval from 113 to 508 K. A matter of particular interest has been the effect of iron doping on the motion and multiplication of dislocations which are known to restrict the application of the material for instance in optoelectronic devices. For this purpose, the amplitude dependence of damping as well as internal friction as a function of temperature, thermal treatment, and frequency have been investigated and are discussed in terms of the present knowledge about twins and dislocations in InP. In addition, Young’s modulus as well as film stress have been measured as a function of temperature, which permits an estimate of the thermal expansion coefficient.