Photronics, Inc., a worldwide supplier of innovative imaging technology solutions for the global electronics industry, opened a semiconductor photomask manufacturing facility in Shanghai, said the company in a statement.   Located in the Zhangjiang Semiconductor Industrial Park, the facility is the first merchant photomask fabrication facility to be brought on-line in the Shanghai region for more than a decade. Production at the facility will be initiated in the fourth quarter of this year.   "Our new Shanghai facility represents the completion of another strategic action by positioning Photronics to serve one of the fastest growing semiconductor design and manufacturing regions in the world," stated Michael J. Luttati, Chief Executive Officer of Photronics.   Dr. Soo Hong Jeong, Chief Operating Officer and President of Photronics Asia added that the move is to serve the growing customer demands in China and Asia-Pacific.