Selective High-K formation in gate-last process

A method comprising:

• removing a dummy gate stack to form an opening between gate spacers, wherein a surface of a semiconductor region is exposed to the opening as an exposed top surface of the semiconductor region;
• forming an inhibitor film contacting sidewalls and top surfaces of the gate spacers;
• after the inhibitor film is formed, forming a dielectric interfacial layer in the opening and contacting the exposed top surface of the semiconductor region;
• in a deposition process, selectively depositing a high-k dielectric layer over and contacting the dielectric interfacial layer, wherein the selective depositing the high-k dielectric layer is performed using a hafnium-containing process gas, wherein the high-k dielectric layer, as deposited, is free from portions on the sidewalls of the gate spacers, and is free from portions over the gate spacers;
• after the high-k dielectric layer is deposited, removing an upper portion of the inhibitor film, wherein a bottom portion of the inhibitor film remains after the removing;
• and
• forming a replacement gate electrode in a remaining portion of the opening that remains after the deposition process.

A method comprising:

• removing a dummy gate stack to form an opening between gate spacers, wherein a surface of a semiconductor region is exposed to the opening as an exposed top surface of the semiconductor region;
• selectively forming an inhibitor film on exposed dielectric features, wherein the semiconductor region prohibits the inhibitor film to form thereon;
• forming a dielectric interfacial layer in the opening and contacting the exposed top surface of the semiconductor region;
• in a deposition process, selectively depositing a high-k dielectric layer over and contacting the dielectric interfacial layer, wherein the high-k dielectric layer is selectively deposited by using the inhibitor film to prevent the high-k dielectric layer from grown on the gate spacers, and wherein the high-k dielectric layer, as deposited, is free from portions on sidewalls of the gate spacers, and is free from portions over the gate spacers;
• removing the inhibitor film, wherein after the removing, a residue portion of the inhibitor film remains;
• and
• forming a replacement gate electrode in a remaining portion of the opening that remains after the deposition process, wherein the replacement gate electrode contacts the gate spacers to form vertical interfaces.