METHODS OF FORMING SEMICONDUCTOR DEVICE STRUCTURES

Methods of forming a semiconductor device structure are described. In some embodiments, the method includes forming a contact opening in an interlayer dielectric (ILD) layer disposed over an epitaxy source/drain region and forming a metal layer in the contact opening. The metal layer includes top portions, side portions, and a bottom portion, and a space is defined between the top portions of the metal layer. The method further includes performing a gradient metal removal process on the metal layer to enlarge the space, forming a sacrificial layer in the contact opening, recessing the sacrificial layer in the contact opening to expose a portion of the sidewall portions, removing the top portions and the exposed portion of the sidewall portions, removing the sacrificial layer, and forming a bulk metal layer on the bottom portion of the metal layer.