Process for integrated circuit fabrication including a uniform depth tungsten recess technique

摘要

Dummy gates are removed from a pre-metal layer to produce a first opening (with a first length) and a second opening (with a second length longer than the first length). Work function metal for a metal gate electrode is provided in the first and second openings. Tungsten is deposited to fill the first opening and conformally line the second opening, thus leaving a third opening. The thickness of the tungsten layer substantially equals the length of the first opening. The third opening is filled with an insulating material. The tungsten is then recessed in both the first and second openings using a dry etch to substantially a same depth from a top surface of the pre-metal layer to complete the metal gate electrode. Openings left following the recess operation are then filled with a dielectric material forming a cap on the gate stack which includes the metal gate electrode.

主权项

1. A process, comprising:
removing dummy gates from a pre-metal layer formed over a substrate to produce a first opening having a first length over a first channel region and produce a second opening having a second length longer than the first length over a second channel region; depositing work function metal at a bottom of each of the first and second openings; depositing an overlying metal layer on said pre-metal layer that fills the first opening and lines the second opening leaving a third opening; depositing an insulating material in the third opening; removing a portion of the overlying metal layer in said first opening to a first recessed depth from a top surface of said pre-metal layer; and removing first and second portions of the overlying metal layer in said second opening on either side of the deposited insulating material to a second recessed depth from the top surface of said pre-metal layer; wherein the first and second recesses depths are uniform.