Abstract: A phase shift mask comprises a transparent substrate having a patterned opaque material layer formed thereupon to form a non-transmissive region of the transparent substrate and an adjoining transmissive region of the transparent substrate. A pit is formed within the transmissive region of the transparent substrate. The pit has a stepped sidewall such as to provide the phase shift mask with enhanced optical performance. The phase shift mask may be fabricated employing a self aligned method.

Abstract: Single spot laser focusing systems are widely used by photolithographic stepping systems. The stage is moved until a spot, located in the immediate area in which the image is to be projected, achieves minimum size. This system is sensitive to the local topography within the area of the image and this can lead to less than optimum results. The present invention overcomes this problem by a process in which the spot is always directed to fall within an alignment mark field (as opposed to within the integrated circuit field). Several ways for accomplishing this are described.