The invention provides a semiconductor device, a semiconductor device manufacturing method and an electronic device, and relates to the technical field of semiconductors. The semiconductor device comprises a semiconductor substrate, a grid electrode, a source electrode and a drain electrode, wherein the grid electrode, the source electrode and the drain electrode are located on the semiconductor substrate. The semiconductor device further comprises a trench which is located in the semiconductor substrate and below the grid electrode, a stress adjusting layer located at the lower part of the inner side of the trench and a channel area located at the upper part of the inner side of the trench, wherein the upper part of the cross section of the trench is wide, and the lower part of the cross section of the trench is narrow. According to the semiconductor device, the stress adjusting layer is located below the channel area and in such a shape that the upper part is wide and the lower part is narrow, so that the surface stress of the channel area can be enhanced, and a short-channel effect is suppressed; and trench bottom high in-situ doping diffusion suppression and surface low doping are adopted so as to be able to effectively reduce channel impurity scattering, thereby improving the channel mobility of the semiconductor device and other operating characteristics. Devices manufactured according to the semiconductor device manufacturing method also have the above advantages. The electronic device provided by the invention comprises the semiconductor device, thereby also having the above advantages.