Megasonic free single wafer cleaning using ozone jet without pattern damage and with minimum substrate etching

A newly developed single wafer cleaning process using gaseous ozone and very dilute chemistries at room temperatures shows high particle removal performance without the use of megasonics. The process utilizes the strong oxidative properties of ozone with the oxide etching property of HF and zeta potential advantages of NH₄OH for particle removal. Alumina, silica, ceria, and nitride particles on silicon wafers were removed with 95% or greater particle removal efficiency with about 0.2 Å of oxide and 0.4 Å silicon loss. The physical force of the ozone gas stream effectively reduces the boundary layer thickness enhancing particle removal with very dilute chemistries and without damaging patterns. Therefore, improved particle removal efficiencies can be achieved with significant cost advantages when compared with a batch type cleaning process. The process can be applied to FEOL and BEOL cleans.