Description: The Diffusion Wet Bench is used for cleaning 3" and 4" silicon wafers prior to processing in diffusion furnaces, LPCVD furnaces or before metal deposition. To be processed at this station, wafers may not contain or have ever contained any metals, nor been exposed to equipment which may pose this contamination risk. This station contains two hot pots and two Teflon tanks in addition to dump rinse and spin-rinse-dry modules. The available chemical baths are:

• 4:1 Sulfuric Acid:Hydrogen Peroxide for removal of trace organics
• 5:1:1 H2O:H2O2:HCl for removal of trace metal ions
• 50:1 HF, for oxide etching
• 6:1 BOE for oxide etching