Semiconductor structure with device including at least one in-well porous region

A structure comprising:

• a semiconductor layer having a first surface and a second surface opposite the first surface, wherein the semiconductor layer comprises silicon;
• and
• a device including:
• an active device region in the semiconductor layer;
• a well region in the active device region, wherein the well region extends into the semiconductor layer from the second surface to a first depth;
• at least one porous region of the semiconductor layer, wherein the at least one porous region comprises porous silicon and extends partially through the well region from the second surface to a second depth shallower than the first depth;
• at opposing ends of the active device region, a source region and a drain region, wherein the drain region is immediately adjacent to the well region and parallel to the at least one porous region;
• a drain region immediately adjacent to the well region;
• and
• a gate on the second surface partially overlaying the well region and completely horizontally offset from the at least one porous region, wherein at least a portion of the second surface from below the gate across the at least one porous region to the drain region is substantially planar and wherein the at least one porous region is laterally between and separated from the drain region and the gate.

A method comprising:

• providing a semiconductor layer having a first surface and a second surface opposite the first surface;
• and
• forming a device including:
• a well region within the semiconductor layer, wherein the well region extends into the semiconductor layer from the second surface to a first depth;
• at least one porous region of the semiconductor layer, wherein the at least one porous region extends through the well region from the second surface to a second depth shallower;
• and a gate on the second surface partially overlaying the well region and completely horizontally offset from the at least one porous region, wherein at least a portion of the second surface from below the gate across the at least one porous region to the drain region is substantially planar and wherein the at least one porous region is laterally between and separated from the drain region and the gate.