Removal of nitride bump in opening replacement gate structure

A method comprising:

• providing a polysilicon gate with a nitride cap on a top surface thereof;
• defining PFET and NFET regions of the polysilicon gate, creating a nitride bump on a top surface of the nitride cap;
• covering the nitride cap to a top of the nitride bump with a pre-metal dielectric (PMD);
• recessing the PMD to expose the nitride cap;
• covering the nitride cap and the nitride bump with a nitride fill, forming a planar nitride surface;
• and
• removing the nitride fill, nitride bump, and nitride cap down to the polysilicon gate.

A method comprising:

• providing a polysilicon gate with a silicon nitride (SiN) cap on a top surface thereof;
• defining PFET and NFET regions of the polysilicon gate, creating a nitride bump on a top surface of the SiN cap;
• covering the SiN cap to a top of the nitride bump with an oxide pre-metal dielectric (PMD);
• performing a 1:1 dry etch of the oxide PMD and the nitride bump by a SiCoNi etch, a remote plasma dry etch, or a reactive ion etch (RIE), at an etch rate of 30 to 150 nanometers (nm)/minute to a depth of 30 to 50 nm;
• performing a second dry etch, selective to the oxide PMD, at an etch rate of 30 to 150 nm/minute, to remove any remaining PMD;
• and
• performing a third dry etch, selective to the SiN cap, by a nitride RIE or a remote plasma dry etch, at an etch rate of 30 to 150 nm/minute, down to the top surface of the polysilicon gate.