Elbow contact for field-effect transistor and manufacture thereof
A field-effect transistor (FET) and method of manufacture thereof include a gate, a doped semiconductor structure formed on top of the planar source and drain regions, and a sheath of conducting materials flanking the formed doped semiconductor structure, where the sheath is perpendicular to a surface of the planar source and drain regions.
1. A field-effect transistor (FET) including planar source and drain regions, the FET comprising:
a gate;
a doped semiconductor structure formed on top of the planar source and drain regions; and
a sheath of conducting materials flanking the doped semiconductor structure,
wherein the sheath is perpendicular to a surface of the planar source and drain regions,
wherein the sheath is bent up, out of plane alongside the gate, to thereby increase a contact area,
wherein more than one sheath are present per contact of the doped semiconductor structure,
wherein the planar source and drain regions include a trench,
wherein the trench includes an elongated pillar extending in a direction of growth through the trench,
wherein a core of the trench is removed and replaced with a metal, and
wherein an outside of the elongated pillar includes a metal coating.
2. The FET of claim 1 , wherein the sheath is alongside the gate, and
wherein the sheath is vertical.
3. The FET of claim 1 , wherein the doped semiconductor structure is formed by one of:
epitaxial growth;
etching a highly doped Si region; and
recrystallizing a highly doped amorphous semiconductor region.
4. The FET of claim 1 , wherein the sheath increases the contact area between the doped semiconductor structure and an upper metallization thereby lowering a contact resistance.
5. The FET of claim 1 , wherein the sheath has a non-uniform thickness.
6. The FET of claim 1 , wherein the sheath flanks both sides of the doped semiconductor structure.