Conducting force microscopy and hole charging in Ge islands grown by RF sputtering

We have grown self assembled nearly monomodal Ge islands on Si(100) using RF magnetron sputtering at a much higher pressure compared to molecular beam epitaxy. Raman spectra of the grown sample exhibits the formation of strained Ge islands intermixed with Si. Both the Both the conducting atomic force microscopy image and I-V characteristics of individual Ge islands exhibit hole charging in isolated form.