The present disclosure relates to a radio frequency (RF) device and a process for making the same. According to the process, a precursor wafer, which includes device regions, individual interfacial layers, individual p-type doped layers, and a silicon handle substrate, is firstly provided. Each individual interfacial layer is over an active layer of a corresponding device region, each individual p-type doped layer is over a corresponding individual interfacial layer, and the silicon handle substrate is over each individual p-type doped layer. Herein, each individual interfacial layer is formed of SiGe, and each individual p-type doped layer is a silicon layer doped with a p-type material that has a doped concentration greater than 1E18cm-3. Next, the silicon handle substrate is completely removed to provide an etched wafer, and each individual p-type doped layer is completely removed from the etched wafer.