Abstract: A semiconductor device includes a source/drain feature over a semiconductor substrate, channel layers over the semiconductor substrate and connected to the source/drain feature, a gate portion between vertically adjacent channel layers, and an inner spacer between the source/drain feature and the gate portion and between adjacent channel layers. The semiconductor device further includes an air gap between the inner spacer and the source/drain feature.

Abstract: A structure of a four-legged mounting peg for connection of boards comprising a loose-proof ring, a T-shaped four-legged mounting peg mounting body having a top plate with a center screw hole, and a plurality of pointed discs, vertically extended from the top plate, characterized in that at least an upwardly protruded securing disc is provided on the top plate, closely adjacent to the screw hole to enclose the loose-proof ring, the protruded securing disc being bent inwardly towards the center screw hole and integrally formed as a unit with the peg body, thereby the mounting peg secures firmly onto the boards to mount the boards together without dislocation.