Pre-oxidation cleaning is a process used in semiconductor manufacturing to clean the surface of a silicon wafer before it undergoes an oxidation process. The goal of this cleaning step is to remove any contaminants, such as organic compounds or metal particles, from the surface of the wafer that could interfere with the oxidation process or introduce defects into the final device.

The pre-oxidation cleaning process typically involves using a combination of chemical solutions and mechanical scrubbing to remove contaminants from the surface of the wafer. Common cleaning solutions used in this step include hydrofluoric acid (HF), ammonium hydroxide (NH4OH), and hydrogen peroxide (H2O2). The wafer is typically immersed in one of these solutions for a period of time, followed by a rinse with deionized water and drying.

After the pre-oxidation cleaning step, the wafer is ready to undergo the oxidation process, which forms a thin layer of silicon dioxide on the surface of the wafer. This oxide layer serves as a barrier between the silicon substrate and other materials that will be deposited on top of it during subsequent processing steps.