Patent ID: 9028620
Filing Date: 2015-05-12
Classification: H01L

Abstract:
1. A method for selectively removing metallic contaminants from a substrate surface, comprising: exposing a substrate to a peroxide clean solution subsequent an epitaxial lift off (ELO) process, wherein the substrate comprises gallium arsenide material, and disposing a copper contaminant on the substrate at a first copper contaminant concentration of at least 1×10 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 at a rate of about 100 times or greater than the gallium arsenide material and the first copper contaminant concentration is lowered to a second copper contaminant concentration of about 1×10