Multi-layer structures and process for fabricating semiconductor devices

A method for the manufacture of a multilayer semiconductor structure comprising multiple semiconductor and oxide layers of different thicknesses, which comprises the following steps:

• providing a Silicon-On-Insulator (SOI) stack comprising a substrate layer, a first oxide layer on the substrate layer and a silicon layer on the first oxide layer (BOX layer);
• providing at least one first region of the SOI stack wherein the silicon layer is thinned by thermally oxidizing part of the silicon layer;
• and
• providing at least one second region of the SOI stack wherein the first oxide layer (BOX layer) is thinned by annealing to thus provide a multilayer semiconductor structure having semiconductor and oxide layers of different thicknesses on different regions of the substrate to facilitate the addition of electronic devices by providing more headroom for the formation of such devices on the SOI stack.