In this paper we propose a method for growing fast Germanium pin photodetectors in pre-patterned areas on a Silicon-on-insulator substrate. The layers are deposited by means of molecular beam epitaxy and structured by chemical mechanical polishing. A comparison of the electrical and optical characteristics between a photodetector grown with the proposed method and a reference detector grown on a planar Silicon substrate is made indicating only minor differences. (C) 2011 Elsevier Ltd. All rights reserved.