Structures including a field-effect transistor and methods of forming a structure including a field-effect transistor. The structure comprises a trench isolation region in a substrate, and a body contact region that extends through the trench isolation region to the substrate. The structure further comprises a field-effect transistor including a gate connector, a first gate finger that extends from the gate connector, a second gate finger that extends from the gate connector, and a source/drain region disposed between the first gate finger and the second gate finger. The gate connector is positioned over the trench isolation region. The structure further comprises a gate contact coupled to the gate connector, and a body contact that penetrates through a portion of the gate connector to the body contact region.