Cavity formation within and under semiconductor devices

A structure comprising:

• a first semiconductor layer;
• a device structure arranged at least in part in the first semiconductor layer;
• a handle wafer;
• a second semiconductor layer arranged between the handle wafer and the first semiconductor layer;
• a dielectric layer including a section arranged between the handle wafer and the second semiconductor layer;
• a bonding layer configured to attach the handle wafer to the section of the dielectric layer;
• a first cavity arranged between the handle wafer and the first semiconductor layer, the first cavity extending completely through the second semiconductor layer and the section of the dielectric layer, and the first cavity having an arrangement in the second semiconductor layer beneath the device structure;
• and
• a third semiconductor layer arranged between the first semiconductor layer and the second semiconductor layer,
• wherein the first cavity extends from the handle wafer to the third semiconductor layer.

A structure comprising:

• a first semiconductor layer;
• a device structure arranged at least in part in the first semiconductor layer;
• a handle wafer;
• a second semiconductor layer arranged between the handle wafer and the first semiconductor layer;
• a dielectric layer including a section arranged between the handle wafer and the second semiconductor layer;
• a bonding layer configured to attach the handle wafer to the section of the dielectric layer;
• a first cavity arranged between the handle wafer and the first semiconductor layer, the first cavity extending completely through the second semiconductor layer and the section of the dielectric layer, and the first cavity having an arrangement in the second semiconductor layer beneath the device structure;
• and
• a third semiconductor layer arranged between the first semiconductor layer and the handle wafer,
• wherein the first semiconductor layer is comprised of a first semiconductor material, and the third semiconductor layer is comprised of a second semiconductor material that is capable of being etched and removed selective to the first semiconductor material.