Electromagnet pulsing effect on PVD step coverage
Methods and apparatus for processing a substrate are provided herein. For example, a physical vapor deposition processing chamber comprises a chamber body defining a processing volume, a substrate support disposed within the processing volume and comprising a substrate support surface configured to support a substrate, a power supply configured to energize a target for sputtering material toward the substrate, an electromagnet operably coupled to the chamber body and positioned to form electromagnetic filed lines through a sheath above the substrate during sputtering for directing sputtered material toward the substrate, and a controller operably coupled to the physical vapor deposition processing chamber for controlling the electromagnet based on a recipe comprising a pulsing schedule for pulsing the electromagnet during operation to control directionality of ions relative to a feature on the substrate.
1. A physical vapor deposition processing chamber, comprising:
a chamber body defining a processing volume;
a substrate support disposed within the processing volume and comprising a substrate support surface configured to support a substrate, wherein an RF power source is configured to provide an AC bias power of greater than zero up to about 1000 W to the substrate support;
a power supply configured to energize a target when disposed in the processing volume for sputtering material toward the substrate;
a collimator;
a first electromagnet disposed above the collimator;
a second electromagnet that is disposed below the first electromagnet;
a third electromagnet between the first electromagnet and the second electromagnet;
the second electromagnet and third electromagnet operably coupled to the chamber body and positioned to form electromagnetic field lines through a sheath above the substrate during sputtering for directing sputtered material toward the substrate; and
a controller operably coupled to the physical vapor deposition processing chamber and programmed to control the second electromagnet and the third electromagnet based on a recipe comprising a pulsing schedule to the second electromagnet and the third electromagnet to supply a current to the third electromagnet different from a current to the second electromagnet, wherein the current to the second electromagnet is about −25 A to about 25 A with a frequency of a pulse being about 0 Hz to about 2000 Hz, and the current to the third electromagnet being about −25 A to about 25 A with a frequency of a pulse being about 0 Hz to about 2000 Hz, resulting in agitation of ions at a surface of the substrate to widen angular distribution of incident ions as ions approach the sheath and to control the ions relative to a feature on the substrate to improve overhang and increase coverage of sputtered material from the target on a sidewall of the feature relative to a bottom of the feature, wherein a ratio of sputtered material deposited on the sidewall of the feature and the bottom of the feature without the AC bias power is greater than a ratio of sputtered material deposited on the sidewall and the bottom of the feature on the substrate with the AC bias power.
2. The physical vapor deposition processing chamber of claim 1 , wherein the controller is further programmed to control the second electromagnet and the third electromagnet so that the ratio of sputtered material deposited on the sidewall of the feature and the bottom of the feature without the AC bias power is about 0.65 to about 0.67 and the ratio of sputtered material deposited on the sidewall and the bottom of the feature on the substrate with the AC bias power is about 0.36 to about 0.38.
3. The physical vapor deposition processing chamber of claim 1 , wherein the power supply is a DC power source configured to provide about zero to about 100 kW during sputtering.
4. The physical vapor deposition processing chamber of claim 1 , wherein the pulsing schedule comprises a plurality of pulses to be transmitted to the electromagnet in one of a sinusoidal wave, a non-sinusoidal wave, or a square wave.
5. The physical vapor deposition processing chamber of claim 1 , wherein the current to the second electromagnet is about −8.75 A to about −0.75 A and the current to the third electromagnet is about 5.6 A to about 23.6 A.