Leveler compounds

A composition comprising a source of copper ions, an electrolyte, and a leveling agent, wherein the leveling agent is capable of providing a first copper deposit in <130 nm apertures of a substrate and a second copper deposit in >130 nm apertures, where the first copper deposit has <20 ppm of total impurities and the second copper deposit has >50 ppm of total impurities wherein the leveling agent is a polymeric leveling agent comprising as polymerized units 1-70 wt % of an ethylenically unsaturated cross-linking agent, 5-80% of an ethylenically unsaturated nitrogen-containing heterocyclic monomer, and 5-80 wt % of a (meth)acrylate monomer.

A method of depositing copper on a substrate comprising the steps of:

• contacting a substrate having <130 nm apertures and >130 nm apertures with a plating bath comprising a source of copper ions, an electrolyte and a leveling agent;
• and applying a potential to the substrate using direct current to deposit a copper layer of a desired thickness, wherein copper deposited in the <130 nm apertures has <20 ppm of total impurities and the copper deposited in the >130 nm apertures has >50 ppm of total impurities wherein the leveling agent is a polymeric leveling agent comprising as polymerized units 1-70 wt % of an ethylenically unsaturated cross-linking agent, 5-80% of an ethylenically unsaturated nitrogen-containing heterocyclic monomer, and 5-80 wt % of a (meth)acrylate monomer.