Patent ID: 7332255

Claim:
A method for measuring the line shortening of a photolithographic image on a substrate, the substrate having been coated with a photo resist, the method comprising: developing the photo resist and forming a composite image on the substrate, the composite image comprising a first pattern of spaced lines and rectangles, the spaced lines and rectangles each having an inner edge and an outer edge, the first pattern surrounding a second pattern of concentric boxes, the concentric boxes including an inside box and an outside box, the inside box having a first edge and a second edge opposite the first edge, the outside box having a first edge and a second edge opposite the first edge; determining misalignment (MA) as a function of measurements relative to the edges of the inside box and to the edges of the outside box; determining total line shortening (TLS) as a function of measurements relative to the inner edge of the spaced lines and one of the edges of the outside box, and to another edge of the outside box and the rectangle inner edge; determining equipment line shortening (ELS) as a function of measurements relative to the outer edge of the spaced lines, the edges of the outside box, and the outer edge of the rectangle; and determining process line shortening (PLS) as a function of TLS and ELS.