Patent attributes
Semiconductor devices and fabrication methods are provided. An exemplary fabrication method includes providing a semiconductor substrate; forming a first well region and a second well region in the semiconductor substrate; and forming a first gate structure on a surface of the second well region and a portion of a surface of the first well region and a second gate structure on a portion of the first well region. A first opening is formed between the first gate structure and the second gate structure. The method also include forming a sidewall spacer layer covering sidewall and bottom surfaces of the first opening in the first opening; forming a dielectric layer on the semiconductor substrate to cover the first gate structure, the second gate structure and the sidewall spacer layer; and forming a floating plug in the dielectric layer and on the sidewall spacer layer.