An aspect of the invention is directed to a silicon-on-insulator device including a silicon layer on an insulating layer on a substrate; a raised source and a raised drain on the silicon layer; a gate between the raised source and the raised drain; a first spacer separating the gate from the raised source and substantially covering a first sidewall of the gate; a second spacer separating the gate from the raised drain and substantially covering a second sidewall of the gate; and a low-k layer over the raised source, the raised drain, the gate and each of the first spacer and the second spacer; and a dielectric layer over the low-k layer.