Effects of Supercritical Carbon Dioxide on Adhesive Strength between Micro-sized Photoresist Patterns and Silicon Substrates

Abstract

AbstractAdhesive bend testing for micro-sized photoresist components has been performed to clarify the effects of supercritical CO2 (ScCO2) treatment. Multiple microsized cylindrical specimens were fabricated on a silicon substrate using epoxy-type photoresist. The specimens were ScCO2 treated at a temperature of 323K at a pressure of 15MPa for 30 min, and then, decompressed to atmospheric pressure at two different rates. Double refraction appeared in the SU-8 specimens near by the interface between the SU-8 specimens and a substrate after ScCO2 treatment. Adhesive bend strength of ScCO2 treated specimen with slow decompression process is approximately 60% higher than that of non- ScCO2 treated specimens, however, the strength of the microsized photoresist was slightly degraded by ScCO2 treatment with quick decompression process. All the results suggest that ScCO2 treatment improves the adhesive strength between microsized photoresist components and a silicon substrate by control of the decompression process.