38 which may provide electrical isolation from the underlying substrate 24 to reduce the coupling of noise for example in some embodiments a variety of radio frequency mems components may be formed inside the same system 10 a switch 34 is an example of a mems device with a mechanically moving part that needs a solid substrate the fbar is an example of a membrane device located over an area where the silicon needs to be etched away the devices 32 and 34 may be provided in a common cavity 44 it is also possible that multiple devices are located in the cavity 44 or that multiple devices are maintained in separate cavities by using a surface mountable wall 18 and moderate temperatures the entire structure may be formed without interfering with delicate mems systems since the entire structure may be formed on a wafer at the wafer level it is not necessary to deal with individual silicon dice in some embodiments at the same time electrical inputs and outputs may be readily realized using interconnects that run through the semiconductor structure 12 in one embodiment semiconductor material underneath the transmission lines 30 may be etched away to reduce substrate losses and semiconductor material under the resonator 32 may be removed to form a membrane even if the resulting lower structure 12 is weakened the overall system 10 may have sufficient strength due to the operation of the upper semiconductor structure 14 in some embodiments surface mounting techniques may be.