Patent ID: 10090402

Abstract:
The method includes steps for improving gate cut isolation region critical dimension (CD) control. Prior to replacement metal gate (RMG) formation, a first sacrificial gate adjacent to first and second channel regions and made of a first sacrificial material (e.g., polysilicon or amorphous silicon) is replaced with a second sacrificial gate made of a second sacrificial material (e.g., amorphous carbon) that is more selectively and anisotropically etchable. A cut is made, dividing the second sacrificial gate into first and second sections, and the cut is then filled with a dielectric to form the gate cut isolation region. The second sacrificial material ensures that, when an opening in a mask pattern used to form the cut extends over a gate sidewall spacer and interlayer dielectric (ILD) material, recesses are not form within the spacer or ILD. Thus, the CD of the isolation region can be controlled.