Changing effective work function using ion implantation during dual work function metal gate integration

Patent metadata

Field	Value
Publication number	US-9564505-B2
Application number	US-201414254939-A
Country	US
Kind code	B2
Filing date	Apr 17, 2014
Priority date	Aug 12, 2008
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

Ion implantation to change an effective work function for dual work function metal gate integration is presented. One method may include forming a high dielectric constant (high-k) layer over a first-type field effect transistor (FET) region and a second-type FET region; forming a metal layer having a first effective work function compatible for a first-type FET over the first-type FET region and the second-type FET region; and changing the first effective work function to a second, different effective work function over the second-type FET region by implanting a species into the metal layer over the second-type FET region.

First claim

What is claimed is:

1. A structure comprising:
a first-type field effect transistor (FET) including a gate having a high dielectric constant (high-k) layer and a single metal layer over a first type FET region and the high-k layer, the single metal layer having a first effective work function; and
a second-type FET including the high-k layer and the single metal layer over a second type FET region and the high-k layer, the high-k layer further including an implanted aluminum (Al) species, the single metal layer further including the implanted aluminum (Al) species that changes the first effective work function to a different second effective work function resulting in a greater than 50 millivolt threshold voltage shift for the second type FET region when compared to the first type FET region, wherein the single metal layer is selected from the group consisting of: tungsten (W), tantalum (Ta), aluminum (Al), ruthenium (Ru), platinum (Pt), titanium nitride (TiN), tantalum nitride (TaN), titanium carbide (TiC), tantalum carbide (TaC), tantalum carbide oxynitride (TaCNO), ruthenium oxide (RuO 2 ), and mixtures and multi-layers thereof.

2. The structure of claim 1 , further comprising a polysilicon layer over the metal layer in each of the first-type and second-type FETs.

3. The structure of claim 1 , wherein the threshold voltage shift is approximately 600 milli-Volts.

4. The structure of claim 1 , wherein the first-type FET includes an n-type FET (NFET), and the second-type FET includes a p-type FET (PFET), and a threshold voltage shift between the NFET and the PFET approaches a band edge threshold voltage shift of the PFET.

5. A structure comprising:
a first-type field effect transistor (FET) including a gate having a high dielectric constant (high-k) layer and a single metal layer over a first type FET region and the high-k layer, the single metal layer having a first effective work function; and
a second-type FET including the high-k layer and the single metal layer over a second type FET region and the high-k layer, the single metal layer and the high-k layer each further including an implanted aluminum (Al) species that changes the first effective work function to a different second effective work function wherein a threshold voltage shift for the second-type FET is greater than 50 milli-Volt compared to the first-type FET, wherein the single metal layer is selected from the group consisting of: tungsten (W), tantalum (Ta), aluminum (Al), ruthenium (Ru), platinum (Pt), titanium nitride (TIN), tantalum nitride (TAN), titanium carbide (TIC), tantalum carbide (TaC), tantalum carbide oxynitride (TaCNO), ruthenium oxide (RuO2), and mixtures and multi-layers thereof, the structure further comprising a polysilicon layer over the metal layer in each of the first-type and second type FETs, and wherein the threshold voltage shift is approximately 600 milli-Volts.

6. The structure of claim 5 , wherein the first-type FET includes an n-type FET (NFET), and the second-type FET includes a p-type FET (PFET), and a threshold voltage shift between the NFET and the PFET approaches a band edge threshold voltage shift of the PFET.

Assignees

• Globalfoundries Inc

Inventors

• Chudzik Michael P
• Frank Martin M
• Ho Herbert L
• Hurley Mark J
• Jha Rashmi
• Moumen Naim
• Narayanan Vijay
• Park Dae-Gyu
• Paruchuri Vamsi K

Classifications

• H10D64/01318

  the conductor comprising a layer of alloy material, compound material or organic material contacting the insulator, e.g. TiN (comprising a layer of alloys of Si, Ge or C H10D64/01314) · CPC title

• H10D64/01316 Primary

  the conductor comprising a layer of elemental metal contacting the insulator, e.g. Ta, W, Mo or Al · CPC title

• H10D84/85

  Complementary IGFETs, e.g. CMOS · CPC title

• H10D84/83135

  the IGFETs characterised by having different gate conductor materials or different gate conductor implants · CPC title

• H01L29/4958

  Electricity · mapped topic