RESIDUAL-SURFACTANT-FREE PHOTORESIST DEVELOPMENT PROCESS

The addition of small amounts of surfactant and hydrogen peroxide (H2O2) to the developer is shown to improve the performance of the photoresist development process. Exposed photoresist areas are dissolved more uniformly, the smoothness of Si surface is maintained, and carbon contamination during the development process is prevented. Ozone (O3) treated ultrapure water rinsing at room temperature is an efficient way to remove the surfactant adsorbed on Si surface. A surfactant-added developer improves wettability on the photoresist surface, which leads to more uniform developing. The dissolution rate in the exposed photoresist is promoted and the etching rate of Si substrate is suppressed due to the effect of the additional surfactant. The only major disadvantage, due to the reaction of the surfactant in the strong alkali solution, is that the surfactant remains adsorbed on Si surface. H2O2 additions to the developer or ozone treated rinse water can remove the surfactant residues.