Advanced development process for ultrafine photoresist patterns

Addition of appropriate surfactant to developer will improve wettability of the developer, thus promoting uniformity of dissolution of exposed photoresist. Surface smoothness of the Si substrate is also improved when developer contains surfactant. The only disadvantage is that surfactant is adsorbed onto the wafer surface; however, it can be removed by a Pt-H/sub 2/O/sub 2/ treatment without degrading the photoresist pattern. The optimal tetramethylammonium hydroxide (TMAH) concentration in the developer was investigated by measuring the developing selectivity of the photoresist against various TMAH concentration levels. The developing selectivity is considered to directly affect the photoresist profile and resolution in the development process.<
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