US 2026/0304926 A1 · FIELD EFFECT TRANSISTOR THRESHOLD VOLTAGE TUNING THROUGH FLUORINE DOPING OF GATE STACK

Abstract

Integrated circuitry comprising transistors having different transistor threshold voltages (Vt). In some examples, a gate electrode of the transistors with different Vt may include only one workfunction metal. Another metal, such as a fill metal, may be deposited over the workfunction metal and provide a solid-state source of fluorine that will subsequently diffuse toward the channel region(s), entering the workfunction metal. As diffused, different concentrations of fluorine may remain with workfunction metals of different transistors, thereby altering their threshold voltages. Different amounts of fluorine may be allowed to diffuse into different transistor structures to provide a range of Vt suitable for integrated circuit topologies of different performance/power metrics.

Claims20

Dependent claims

An integrated circuit (IC) structure, comprising:

a first transistor, comprising:
a first channel region, wherein the first channel region comprise at least one of Si or Ge;
a first gate insulator layer over the first channel region;
and
a first gate electrode over the first gate insulator layer, wherein the first gate electrode has a first fluorine concentration;
and
a second transistor comprising:
a second channel region, wherein the second channel region comprise at least one of Si or Ge;
a second gate insulator layer over the second channel region;
and
a second gate electrode over the second gate insulator layer, wherein the second gate electrode has a second, different, fluorine concentration.

8 more elements

A transistor stack structure, comprising:

a first channel region over a second channel region, wherein each of the first channel region and the second channel region comprises at least one of Si or Ge;
a gate electrode around the first channel region, and around the second channel region, wherein a first concentration of fluorine within a first portion of the gate electrode around the first channel is different from a second concentration of fluorine within a second portion of the gate electrode around the second channel;
and
a gate insulator material between the gate electrode and each of the first channel region and the second channel region, wherein the gate insulator material comprises oxygen and a first metal.

1 more element

Dependencies are inferred from the claim text.

Field effect transistor threshold voltage tuning through fluorine doping of gate stack

Life of this patent

Field effect transistor threshold voltage tuning through fluorine doping of gate stack

Life of this patent

Abstract

Claims20