Tetramethylammonium hydroxide solution (25 wt. % solution in water) may be used as a base for pH adjustment to obtain hexagonal mesoporous aluminophosphate (TAP). Tetramethylammonium hydroxide is a quaternary ammonium salt generally used as an anisotropic etchant for silicon due to its high silicon etching rate.
TMAH solution is widely used in the electronics industry as a developer or cleaner. TMAH is typically one of several ingredients in etching / stripping mixtures, although it may also be used as a pure chemical. It is often used in solution in water, and less frequently, in methanol.
KOH and TMAH are anisotropic silicon etches, used to make V-grooves, membranes, and holes through wafers, as well as other devices. ... KOH is simply the hydroxide of potassium. TMAH is a organic hydroxide and stands for Tetramethyl ammonium hydroxide.
One of the industrial uses of TMAH is for the anisotropic etching of silicon. It is used as a basic solvent in the development of acidic photoresist in the photolithography process, and is highly effective in stripping photoresist.
