Abstract: Semiconductor devices and methods of forming the same are provided. An exemplary semiconductor device according to the present disclosure includes a first gate structure disposed over a first backside dielectric feature, a second gate structure disposed over a second backside dielectric feature, and a gate cut feature extending continuously from laterally between the first gate structure and the second gate structure to laterally between the first backside dielectric feature and the second backside dielectric feature. The gate cut feature includes an air gap laterally between the first gate structure and the second gate structure.

Abstract: Semiconductor devices and methods of forming the same are provided. A method according to the present disclosure includes providing a workpiece including a frontside and a backside. The workpiece includes a substrate, a first plurality of channel members over a first portion of the substrate, a second plurality of channel members over a second portion of the substrate, an isolation feature sandwiched between the first and second portions of the substrate. The method also includes forming a joint gate structure to wrap around each of the first and second pluralities of channel members, forming a pilot opening in the isolation feature, extending the pilot opening through the join gate structure to form a gate cut opening that separates the joint gate structure into a first gate structure and a second gate structure, and depositing a dielectric material into the gate cut opening to form a gate cut feature.