Copper electroplating bath composition and a method of copper electroplating to improve gapfill

A method of electroplating comprising:

• providing an aqueous electroplating composition, comprising:
• copper,
• at least one acid,
• at least one halogen ion,
• an additive including an accelerating agent, a suppressing agent, and a suppressing-accelerating agent, and
• the solution and mixture products thereof;
• contacting a substrate with the electroplating composition;
• and
• impressing a multi-step waveform potential upon the substrate, wherein the multi-step waveform potential includes an entry step, wherein the entry step includes a first sub-step applying a first current and a second sub-step applying second current, the second current being greater than the first current.

A method of electroplating including:

• providing an aqueous electroplating composition, including:
• copper,
• at least one acid,
• at least one halogen ion,
• an accelerating agent, wherein concentration of the accelerating agent is greater than 1.5 ml/liter,
• a suppressing agent, wherein concentration of the suppressing agent is greater than 15 ml/liter,
• an accelerating-suppressing agent, wherein concentration of the accelerating-suppressing agent is greater than 10 ml/liter, and
• the solution and mixture products thereof;
• contacting a substrate with the aqueous electroplating composition;
• and
• impressing a multi-step waveform potential upon the substrate, wherein the multi-step waveform potential includes an entry step, wherein the entry step includes a first sub-step applying a first current and a second sub-step applying second current, the second current being greater than the first current.