A method of sequentially forming a silicide layer and a contact barrier in a semiconductor device is provided. A first dielectric layer with a first conductor line along a first direction is disposed on a semiconductor substrate, wherein the top surface of the first conductor line is lower than the top surface of the first dielectric layer. The invention also provides a method for producing the metabolically enhanced cyanobacterium, a method for producing ethanol with the metabolically enhanced cyanobacterium, and a method for screening of alcohol dehydrogenase enzyme expressing cyanobacterial strains for the presence of NADPH-dependent native alcohol dehydrogenase enzymes. The control unit compares one or more representations corresponding to one or more edges in the first stationary image with one or more representations corresponding to one or more edges in the second stationary image to determine whether an object has been deposited or removed during the event.