Why do semiconductor fabs use isopropanol instead of ethanol for wafer cleaning?

Why do semiconductor fabs use isopropanol instead of ethanol for wafer cleaning?
Wafer fabs prohibit ethanol as a primary cleaning agent for several reasons. Electronic-grade IPA reaches SEMI G5 purity of 99.9999% or higher, while ethanol cannot be easily dehydrated from its azeotrope and typically remains at reagent grade. IPA's moderate evaporation rate allows uniform drying without water marks, and it forms an azeotrope with deionized water suitable for Marangoni drying. Its slightly lower polarity than ethanol gives better compatibility with organic solvents like NMP and acetone, improving photoresist residue removal. IPA also has lower surface tension, leaving fewer spots after evaporation, making it the standard choice across wafer cleaning, etching, and equipment maintenance processes.