Backside contact formation

A semiconductor structure comprising:

• a first nanosheet transistor and a second nanosheet transistor on a substrate;
• a source/drain region shared by the first and second nanosheet transistors;
• and
• a backside source/drain contact underneath the source/drain region, wherein a central portion of the backside source/drain contact extends upwardly further, than a side portion of the backside source/drain contact, into the source/drain region.

A method comprising:

• forming a dummy contact structure in a substrate, the dummy contact structure having a central portion and a side portion, the central portion being higher than the side portion to have a height above the substrate;
• forming a source/drain region of a first transistor and a second transistor above the dummy contact structure, the first and second transistors being above the substrate;
• removing the dummy contact structure from a backside of the substrate to create a backside contact opening;
• and
• forming a backside source/drain contact by filling the backside contact opening with a conductive material.