Stability of Photo Resist Coating Performance of Small Dispense Nozzle Size in Photolithographic Spin Coating Process

摘要

Reduction of photoresist consumption to reduce costs while maintaining resist coating quality is becoming a major challenge for process and equipment engineers in the semiconductor industry. This challenge can be met by reducing dispense nozzle diameter to maintain a constant dispense rate at a reduced dispense volume. In this study, two small dispense nozzle sizes (0.5 and 0.6 mm in diameter) and two resist dispense volumes (0.4 and 0.5cc per coating) were evaluated during the resist spin coating process. Stability tests of five resist thickness means and ranges of three photo resists types with various resist viscosities were performed using small dispense nozzles and small resist dispense volumes. Each stability test consisted of both 25 wafer continuous resist coats and one wafer per coating for 15 days. Coat defects from the coat process using a small dispense nozzle and small resist dispense volume were analyzed on the layers of Island, Poly, Metal and Contact in a manufacturing fab. The effect of the resist coat process using a small dispense nozzle and a small resist dispense volume on critical dimension (CD) performance of Island, Poly, Metal and Contact layers before and after etch was reported. Resist thickness uniformity data , coating defect data and CD data from the small dispense nozzle size and reduced resist dispense volume coating process were also compared with a normal resist coating process with dispense nozzle size of 1.5mm and resist dispense volume of 0.6 to 0.75cc per coating.