Semiconductor device

A semiconductor device includes a source/drain feature over a semiconductor substrate; a channel layer 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, and an air gap between the inner spacer and the source/drain feature. 一种半导体裝置，包括源极/漏极部件，位于半导体基板之上；通道层，位于半导体基板之上，且连接至源极/漏极部件；栅极部分，位于垂直邻近通道层之间；以及内间隔物，位于源极/漏极部件与栅极部分之间，以及邻近通道层之间，以及空气间隙，位于内间隔物及源极/漏极部件之间。