Method and apparatus for plasma nitridation of gate dielectrics using amplitude modulated radio-frequency energy

A method of plasma nitridation of a gate dielectric, comprising:

• placing a substrate comprising a gate dielectric film in an inductively coupled plasma chamber;
• and
• exposing the substrate to a nitrogen-containing plasma, ionized by a smooth-varying modulated power source, to form a nitrided gate dielectric on the substrate, wherein the smooth-varying modulated power source varies a duty cycle of pulses between about 5% and about 90% at a frequency between about 1 kHz to about 100 kHz, and varies an ionizing power between about 0% and about 100% of the peak power, and a process gas for the nitrogen-containing plasma comprises at least one of nitrogen (N2) and ammonia (NH3) gases at a flow rate between about 50 sccm to about 20 slm.

A method of plasma nitridation of a gate dielectric, comprising:

• placing a substrate comprising a gate dielectric film in a plasma chamber;
• and
• exposing the substrate to a nitrogen-containing plasma, ionized by a modulated power source that lacks discontinuities in the time-derivative of the magnitude of the power, to form a nitrided gate dielectric on the substrate.

A method of plasma nitridation of a gate dielectric, comprising:

• placing a substrate comprising a gate dielectric film in an inductively coupled plasma chamber;
• and
• exposing the substrate to a nitrogen-containing plasma, ionized by a modulated power source that lacks discontinuities in the time-derivative of the magnitude of the power, to form a nitrided gate dielectric on the substrate, wherein the modulated power source varies a duty cycle of pulses between about 5% and about 90% at a frequency between about 1 kHz to about 100 kHz, and varies an ionizing power between about 0% and about 100% of peak power, and a process gas for the nitrogen-containing plasma comprises at least one of nitrogen (N2) and ammonia (NH3) gases at a flow rate between about 50 sccm to about 20 slm.

A method of plasma nitridation of a gate dielectric, comprising:

• placing a substrate comprising a gate dielectric film in a plasma chamber;
• and
• exposing the substrate to a nitrogen-containing plasma, ionized by a square-wave modulated RF waveform that is filtered by a resistor-capacitor to become a smooth-varying modulated RF waveform power source, to form a nitrided gate dielectric on the substrate.

A method of plasma nitridation of a gate dielectric, comprising:

• placing a substrate comprising a gate dielectric film in an inductively coupled plasma chamber;
• and
• exposing the substrate to a nitrogen-containing plasma, ionized by a square-wave modulated RF waveform that is filtered by a resistor-capacitor to become a smooth-varying modulated RF waveform power source, to form a nitrided gate dielectric on the substrate, wherein the power source varies a duty cycle of pulses between about 5% and about 90% at a frequency between about 1 kHz to about 100 kHz, and varies an ionizing power between about 0% and about 100% of peak power, and a process gas for the nitrogen-containing plasma comprises at least one of nitrogen (N2) and ammonia (NH3) gases at a flow rate between about 50 sccm to about 20 slm.