Eliminating solvents in resist removal processes using low-cost detergents

Cleaning processes may account for up to 25% of all steps in the manufacture of a microelectronic device. According to the 2009 ITRS, ESH strategies include the reduction of chemical exposure, usage, and waste, and soon may consider building certification. One simple way to move towards these objectives and save over 50% in costs is by replacing organic solvents with aqueous detergents to strip photoresist (PR). Positive-tone and negative-tone acrylic resins may be removed in seconds or minutes with aqueous detergents meeting performance and selectivity needs of the process. Aggressive systems of high alkaline strength (i.e. pH=14) can be built to perform as needed while metals and substrates are protected. Successful aqueous chemistries provide good penetration, particle removal, and sheet rinsing while foaming is held in check. Detergents used at 3-10% by weight in water can offer superior performance, eliminate solvents, lower costs, and reduce waste.