A method of forming a semiconductor structure includes forming a photoresist layer over a substrate. When the ultraviolet drying device is turned on and the photoelectric sensor detects that a contamination-preventive member is mounted on the outer surface of the transport cylinder, the driving of a printing press stops. The foot pedals and handles are positioned forward the operator to allow easy ingress and egress. A high-resistivity encapsulant greater than 1. Moreover, a prescribed conditional formula is fulfilled. The combination optical film can prevent light leakage without degrading appearance.