Spin coating properties of SU-8 thick-layer photoresist

In this paper the coating properties including film thickness, thickness uniformity and variation of viscosity of SU8 photoresist were investigated by using a spin coater and rheometer. Experimental results indicate that the coating qualities of SU8 are affected by several factors including the spinning speed, the photoresist viscosity, the initial acceleration and the duration. Some recommendations are presented for increasing the quality of SU8 spin coating in thick-film processing.