Air gaps formed by porous silicon removal
AssigneeGlobalfoundries Inc.
InventorsRichard A. Phelps, James A. Slinkman
Life of this patent
Estimating the term…
Abstract
Semiconductor structures formed using a substrate that has a porous semiconductor layer and a device layer on the porous semiconductor layer. One or more trench isolation regions are formed in the device layer that surround an active device region. An opening is formed that extends through the one or more trench isolation regions to the porous semiconductor layer. A removal agent is directed through the opening to remove the porous semiconductor layer from a volume beneath the active device region and thereby form an air gap vertically beneath the active device region.
Claims11
A semiconductor structure formed using a substrate that has a porous semiconductor layer and a device layer on the porous semiconductor layer, the semiconductor structure comprising:
- a first trench isolation region and a second trench isolation region in the device layer;
- an active device region including a bridge located laterally between the first trench isolation region and the second trench isolation region, the bridge having a first side edge adjacent to the first trench isolation region;
- an air gap in the porous semiconductor layer, the air gap vertically located beneath the bridge and laterally located between a first section of the porous semiconductor layer and a second section of the porous semiconductor layer;
- and
- a first opening in the device layer laterally located directly between the first side edge of the bridge and the first trench isolation region such that the bridge is not supported at the first side edge, the first opening providing an open path communicating with the air gap,
- wherein the first section of the porous semiconductor layer and the second section of the porous semiconductor layer are located beneath the active device region and support the active device region.
Dependencies are inferred from the claim text.