Abstract: A method includes providing a substrate, forming a patterned hard mask layer over the substrate, etching the patterned hard mask layer to form a hole that penetrates the patterned hard mask layer, forming a barrier portion in the hole, removing the patterned hard mask layer, and forming a gate structure over the substrate. Formation of the gate structure includes forming a dielectric body portion on the substrate. The barrier portion that is thicker than the dielectric body portion adjoins one end of the dielectric body portion. The dielectric body portion and the barrier portion are collectively referred to as a gate dielectric layer. Formation of the gate structure further includes forming a gate electrode on the gate dielectric layer and forming gate spacers on opposite sidewalls of the gate electrode. During formation of the gate spacers, a portion of the barrier portion is removed to form a recessed corner.

Abstract: A method for forming a semiconductor structure includes: forming a first gate structure in a predetermined low-potential region of a substrate and a second gate structure in a predetermined high-potential region of the substrate; sequentially forming a first dielectric layer and a second dielectric layer covering the first gate structure and the second gate structure; forming a portion of a third dielectric layer along sidewalls of the second gate structure and on the second dielectric layer; and etching the first dielectric layer and the second dielectric layer with the portion of the third dielectric layer as an etching hard mask to form a first composite spacer covering sidewalls of the first gate structure, and a second composite spacer covering the sidewalls of the second gate structure, wherein a width of the first composite spacer is less than a width of the second composite spacer.

Abstract: A method for forming a semiconductor structure includes: forming a first gate structure in a predetermined low-potential region of a substrate and a second gate structure in a predetermined high-potential region of the substrate; sequentially forming a first dielectric layer and a second dielectric layer covering the first gate structure and the second gate structure; forming a portion of a third dielectric layer along sidewalls of the second gate structure and on the second dielectric layer; and etching the first dielectric layer and the second dielectric layer with the portion of the third dielectric layer as an etching hard mask to form a first composite spacer covering sidewalls of the first gate structure, and a second composite spacer covering the sidewalls of the second gate structure, wherein a width of the first composite spacer is less than a width of the second composite spacer.

Abstract: A semiconductor device is provided. The semiconductor device includes a substrate including a first conductive type well region; a gate structure; a lightly-doped drain region and a lightly-doped source region disposed at two opposite sides of the gate structure; a second conductive type first doped region disposed in the lightly-doped drain region, wherein the doping concentration of the second conductive type first doped region is less than the doping concentration of the lightly-doped drain region; a heavily-doped source region disposed in the lightly-doped source region; and a heavily-doped drain region disposed in the second conductive type first doped region. The present disclosure also provides a method for manufacturing the semiconductor device.

Abstract: A semiconductor device is provided. The semiconductor device includes a substrate including a first conductive type well region; a gate structure; a lightly-doped drain region and a lightly-doped source region disposed at two opposite sides of the gate structure; a second conductive type first doped region disposed in the lightly-doped drain region, wherein the doping concentration of the second conductive type first doped region is less than the doping concentration of the lightly-doped drain region; a heavily-doped source region disposed in the lightly-doped source region; and a heavily-doped drain region disposed in the second conductive type first doped region. The present disclosure also provides a method for manufacturing the semiconductor device.