Silicon nitride dry trim without top pulldown

摘要

A method for forming devices with silicon gates over a substrate is provided. Silicon nitride spacers are formed on sides of the silicon gates. An ion implant is provided using the silicon nitride spacers as masks to form ion implant regions. A nonconformal layer is selectively deposited over the spacers and gates that selectively deposits a thicker layer on tops of the gates and spacers and between spacers than on sidewalls of the silicon nitride spacers. Sidewalls of the nonconformal layer are etched away on sidewalls of the silicon nitride spacers. The silicon nitride spacers are trimmed.