Seal ring with continuous ring shape features for semiconductor device with gate-all-around transistors

Abstract

A semiconductor structure includes a substrate, a circuit region, and a seal ring surrounding the circuit region. The circuit region includes two first source/drains, first semiconductor layers connecting the two first source/drains, and a first gate disposed between the two first source/drains and wrapping around each of the first semiconductor layers. The seal ring includes two epitaxially grown semiconductor structures, second semiconductor layers, third semiconductor layers, and a second gate. The second and the third semiconductor layers are alternately stacked one over another to form a stack of layers. A topmost layer of the stack is one of the third semiconductor layers. The second gate is disposed between the two epitaxially grown semiconductor structures and above the topmost layer of the stack. The first and the third semiconductor layers include a first semiconductor material. The second semiconductor layers include a second semiconductor material different from the first semiconductor material.