Method for the preparation of a pattern overlay accuracy-measuring mark

摘要

A method for the preparation of a pattern overlay accuracy-measuring mark, consisting of an inner box and an outer box. The method creates a groove along the inside boundary line of the outer box so as to form an enlarged step. The enlarged step prevents inaccuracy in defining the boundary line of the outer box whose inaccuracy is mainly attributed to reflow which occurs at the boundary line as a metal layer is later coated over the outer box. The method can easily define the boundary line and thus more define the overlay accuracy.