An exemplary wafer structure comprises a source wafer having a patterned sacrificial layer defining anchor portions separating sacrificial portions. A patterned device layer is disposed on or over the patterned sacrificial layer, forming a device anchor on each of the anchor portions. One or more devices are disposed in the patterned device layer, each device disposed entirely over a corresponding one of the one or more sacrificial portions and spatially separated from the one or more device anchors. A tether structure connects each device to a device anchor. The tether structure comprises a tether device portion disposed on or over the device, a tether anchor portion disposed on or over the device anchor, and a tether connecting the tether device portion to the tether anchor portion. The tether is disposed at least partly in the patterned device layer between the device and the device anchor.