T 1477 (OTTO) Tetramethylammonium hydroxide 1M solution in water Cas 75-59-2 - used as anisotropic etching of silicon, as a basic solvent in the development of acidic photo resist in the photolithography process, and is highly effective in stripping photo resist, and is used as a surfactant in the synthesis of ferrofluid, to inhibit nanoparticle aggregation.