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 rehabilitation assistant system for a patient with depression is provided, comprising a support unit, an audio stimulation unit, an acupoint stimulation unit, an electronic stimulation unit, a display and optical frequency-flashed stimulation and an exercise unit. The audio stimulation unit comprises two speakers configured for broadcasting a binaural beats with frequency following response which has an audio frequency difference to two ears of the user. The acupoint stimulation unit comprises acupoint agents, and at least a part of the acupoint agents are arranged on the support unit. The electronic stimulation unit comprises two electrical stimulation agents arranged on the support unit, and the display and optical frequency-flashed stimulation is arranged on the support unit and is switchable between a display mode and an optical frequency-flashed stimulation mode so that multiple stimulations are performed simultaneously in a single treatment course.