High-Sensitivity and High-Resolution Contact Hole Patterning by Enhanced-Wettability Developer

We have determined that high-sensitivity and high-resolution contact hole photoresist patterning can be achieved using an optimized combination of developer, added surfactant and ammonium chloride salt. The addition of surfactant improves the wettability of the developer to promote resist dissolution. The presence of ammonium chloride salt protects the sidewall of the contact hole resist pattern to achieve good pattern profile. The optimal developer can form contact hole patterns smaller than the illumination wavelength of the stepper without the use of phase shifting technology.