US20080076216A1

Method to fabricate high-k/metal gate transistors using a double capping layer process

Claim Score by NHIP

Read claim 1, the broadest

Abstract

Semiconductor devices and methods to fabricate thereof are described. For an embodiment, a semiconductor device features a double capping layer. The double capping layer may include a first-capping layer and a second-capping layer. The first-capping layer protects a high-k gate dielectric film during a replacement gate process and the second-capping layer protects the first-capping layer during metal deposition. For other embodiments, the first-capping layer prevents the interaction between a polysilicon layer and a high-k gate dielectric film to prevent Vt-pinning of fabricated transistors.

US20080076216A1, drawing sheet 1
Sheet 1 of 9

Term

Projected expiry 25 September 2026.

  1. Priority and filed
  2. Published
  3. Today
  4. Projected expiry

22 claims: 3 independent, 19 dependent

  1. 1
    Broadest claimClaim Score 62, broad(NHIP)A device, comprising:a substrate;an interlayer dielectric disposed on a top surface of said substrate, wherein said interlayer dielectric comprises a first portion and a second portion;a gate dielectric layer disposed between said first and second portions of said interlayer dielectric and over said substrate;a first-capping layer disposed between said first and second portions of said interlayer dielectric and on said gate dielectric layer;a second-capping layer disposed between said first and second portions of said interlayer dielectric and on said first-capping layer;and a metal gate electrode disposed between said first and second portions of interlayer dielectric and on said second-capping layer;
  2. 9
    A semiconductor device, comprising:a semiconductor substrate;an interlayer dielectric disposed on a top surface of said substrate, wherein said interlayer dielectric comprises a first portion and a second portion;a high-k gate dielectric layer disposed between said first and second portions of said interlayer dielectric and over said substrate;a first-capping layer disposed between said first and second portions of interlayer dielectric and on said high-k gate dielectric layer;an atomic deposition layer disposed between said first and second portions of said interlayer dielectric and on said first-capping layer;a metal gate electrode disposed between said first and second portions of said interlayer dielectric and over said atomic deposition layer;a source and drain region disposed within said substrate and adjacent to said interlayer dielectric and said set of spacers;a channel region disposed within said substrate and adjacent to said high-k gate dielectric layer and said source and drain regions;and a set of spacers adjacent to said high-k gate dielectric layer, first-capping layer, second-capping layer, and said metal gate electrode.
  3. 16
    A method, comprising depositing a high-k gate dielectric layer on a semiconductor substrate, depositing a first-capping layer on said high-k gate dielectric layer;forming a sacrificial gate electrode material on said first-capping layer;etching said high-k gate dielectric layer, first-capping layer, and said sacrificial gate electrode material to define a sacrificial gate stack;depositing a set of spacers adjacent to said sacrificial gate stack;implanting dopants in said semiconductor substrate to define a source and drain region;depositing an interlayer dielectric on said semiconductor substrate and adjacent to said set of spacers;etching said sacrificial gate electrode material to expose said first-capping layer and to define a trench;and forming a second-capping layer within said trench and on said first-capping layer by an atomic layer deposition process. filling said trench with a metal gate material to form a metal gate electrode.