《Wafer cleaning》.pdf

Cleaning 75% of Yield loss due to particles 3-pronged appraoch: 1.Clean Factories 2. Wafer Cleaning 3. Gettering From Intel Cleaning Prof. Milo Koretsky Chemical Engineering Dept . 1. Clean Factories Class of the clean room Laminar Flow From Middleman Cleaning Prof. Milo Koretsky Chemical Engineering Dept . 2. Wafer Cleaning • It is important to have clean wafers at all stages of fabrication. • Cleaning is especially important before any high temperature process. • Improper cleaning can result in yield loss and process variability • Cleaning comprises roughly 1/4 of the IC process steps Wafers Cleaning solution Cleaning Prof. Milo Koretsky Chemical Engineering Dept . Typical Chemicals Involved Chemical Name H O (DI) De-Ionized water 2 H SO Sulfuric Acid 2 4 H O Hydrogen Peroxide 2 2 H O Water 2 HF Hydrofluoric Acid NH OH Ammonium Hydroxide 4 HCl Hydrochloric Acid IPA Isopropyl alcohol