Substrate clean solution for copper contamination removal

A method for selectively removing metallic contaminants from a substrate surface, comprising:

• exposing a substrate to a peroxide clean solution, wherein the substrate comprises gallium arsenide material, and disposing a copper contaminant on the substrate at a first copper contaminant concentration of at least 1×1015 copper atoms/cm2;
• exposing the substrate to a hydroxide clean solution;
• and
• exposing the substrate to a selective etch solution comprising potassium iodide, iodine, sulfuric acid, and water during a selective etch process, wherein the copper contaminant is selectively etched faster than the gallium arsenide material and the first copper contaminant concentration is lowered to a second copper contaminant concentration of about 1×1014 copper atoms/cm2 or less.

A method for selectively removing metallic contaminants from a substrate surface, comprising:

• exposing a substrate comprising a gallium arsenide material to an ELO etch solution comprising a complexing inhibitor compound during an epitaxial lift off process, wherein a sacrificial layer is disposed on the substrate and an epitaxial film is disposed on the sacrificial layer;
• etching the sacrificial layer while peeling the substrate from the wafer;
• forming the copper contaminant on the substrate;
• and
• separating the epitaxial film from the substrate containing the copper contaminant;
• rinsing the substrate to remove residues of the ELO etch solution;
• exposing the substrate to a peroxide clean solution comprising hydrogen peroxide;
• rinsing the substrate to remove residues of the peroxide clean solution;
• exposing the substrate to a hydroxide clean solution;
• rinsing the substrate to remove residues of the hydroxide clean solution;
• and
• exposing the substrate to a selective etch solution comprising potassium iodide, iodine, sulfuric acid, and water during a selective etch process.