As total elimination of contaminants is not possible, methods of semiconductor surface cleaning are employed throughout the device manufacturing sequence. The cleaning can be achieved by a chemical reaction with a reactant and contaminant on the surface, by the physical interaction between cleaning ambient and the surface, the momentum transfer between high kinetic energy particles directed toward the contaminant etc. In Wet Cleaning, contaminant is removed via selective chemical reaction in the liquid-phase by its dissolution in the solvent, or its conversion into the soluble compound. Typically, reaction process is enhanced by ultrasonic agitation. In Dry Cleaning, contaminant is removed via chemical reaction in the gas phase converting it into a volatile compound. Wet cleaning is the dominant cleaning technology in semiconductor device manufacturing. Wet cleans use combinations of acids and solvents, oxidize, etch, and scrub contaminants from the wafer surface. An integral part of every wet cleaning scheme is rinses in ultra-pure deionized (DI) water which stops chemical reaction on the wafer surface and washes off reactants and reaction products. Wet cleaning is always completed with a wafer drying process.

RCA clean Wet cleaning recipes first proposed over 30 years ago presents a complete cleaning process to remove from the surface heavy organics, particles, and metallic contaminants as well as native/chemical oxide. Typically the first step is to remove organic contamination remaining on the surface. The H₂SO₄ :H₂O₂ solution at 100°C-130°C, also known as SPM (Sulfuric Peroxide Mixture), or "piranha" clean. NH₄OH : H₂O₂ : H₂O mixture 1:1:50, at temperature ~ 70°C with ultrasonic agitation is used to remove particles.