Abstract: The present disclosure relates to semiconductor devices, manufacturing methods, and electronic devices. One example semiconductor device manufacturing method includes forming a semiconductor laminated structure on a substrate. The semiconductor laminated structure includes channel layers and sacrificial layers that are alternately stacked. At least part of the sacrificial layers are removed. Dummy gate layers are manufactured at positions at which the sacrificial layers are removed and on a surface of the channel layer at a top layer to form a fin structure. A same process step is used to simultaneously form spacers at two ends of the dummy gate layers.

Abstract: A method includes providing a substrate; forming, on the substrate, an overlapping layer in which first materials and second materials are sequentially stacked; forming a first mask layer on the overlapping layer; forming a first trench in the first mask layer; forming a second trench in the first trench by forming a second mask layer in the first mask layer and the first trench; etching, through anisotropic etching, the second mask layer along a direction perpendicular to the substrate, until the second mask layer that is located between sides of the second trench and on a lower surface of the first trench is removed to form a third trench based on the second trench; etching downwards from a lower surface of the third trench to form a fourth trench that penetrates the overlapping layer; and forming a sidewall in the fourth trench.