Characteristics of film peel-off in STP technology

STP (Spin-coating film Transfer and hot-Pressing) technology is a new film-formation technique that transfers a dielectric on a base film onto a wafer by hot pressing. The base film is then peeled off at the interface between the base film and the dielectric. It is examined to control the peel force by a surface treatment of the base film of fluoropolymer and process conditions during the hot-pressing step. An apparatus to measure peel force during peel-off was also devised. The measured results clarified the dependence of the peel force on the intensity of the surface treatment, temperature, and process time. The x-ray photoelectron spectroscopy spectrum of the surface of the base film after peel-off indicated that the peel-off was carried out at the interface. Therefore, it is confirmed that the technique enables control of the characteristics of peel-off and contributes to the establishment of STP technology.