Dipoles in semiconductor devices

A semiconductor device, comprising:

• a semiconductor substrate;
• a first transistor having a first threshold voltage, the first transistor comprising:
• a first interfacial layer formed on the semiconductor substrate;
• a first high-k dielectric layer formed on the first interfacial layer;
• and
• a first conductive gate electrode layer formed on the first high-k dielectric layer;
• and
• a second transistor having a second threshold voltage, the second transistor comprising:
• a second interfacial layer formed on the semiconductor substrate;
• a second high-k dielectric layer formed on the second interfacial layer;
• and
• a second conductive gate electrode layer formed on the second high-k dielectric layer,
• wherein at least one of the first high-k dielectric layer and the first interfacial layer, and at least one of the second high-k dielectric layer and the second interfacial layer are doped with:
• a first dopant species,
• a second dopant species, and
• a third dopant species,
• wherein at least one of the first dopant species and the second dopant species forms a first dipole element having a first polarity,
• wherein the third dopant species forms a second dipole element having a second polarity,
• wherein the first and second polarities are opposite,
• wherein the first and second threshold voltages are different,
• wherein the first transistor has a first concentration of the first dopant species at a first particular location in the at least one of the first high-k dielectric layer and the first interfacial layer and has a second concentration of the second dopant species at the first particular location in the at least one of the first high-k dielectric layer and the first interfacial layer,
• wherein the second transistor has a third concentration of the first dopant species in a second particular location of at least one of the second high-k dielectric layer and the second interfacial layer and has a fourth concentration of the second dopant species in the second particular location of the at least one of the second high-k dielectric layer and the second interfacial layer, wherein the second particular location of the second transistor corresponds with the first particular location of the first transistor, and
• wherein a first ratio of the first concentration to the second concentration is substantially equal to a second ratio of the third concentration to the fourth concentration, and wherein the first and second transistors have different conductivity types.

A method of forming a semiconductor device, the method comprising:

• forming a first interfacial layer on a semiconductor substrate;
• forming a first high-k dielectric layer on the first interfacial layer;
• and
• forming a first conductive gate electrode layer on the first high-k dielectric layer, doping at least one of the first high-k dielectric layer and the first interfacial layer with:
• a first dopant species,
• a second dopant species, and
• a third dopant species,
• wherein at least one of the first dopant species and the second dopant species forms a first dipole element having a first polarity,
• wherein the third dopant species forms a second dipole element having a second polarity,
• wherein the first and second polarities are opposite, and
• wherein doping the at least one of the first high-k dielectric layer and the first interfacial layer with the first and second dopant species comprises:
• depositing a first dopant layer comprising the first dopant species and a second dopant layer comprising the second species;
• and
• depositing a third dopant layer comprising the third dopant species.