Abstract: A method is provided for fabricating a phase-shift mask (10, 30). A mask plate (11, 31) is provided. A semitransparent layer (12, 32) is deposited onto the mask plate (11,31). The semitransparent layer (12, 32) is then patterned into a predetermined geometric pattern. The patterning of the semitransparent layer (12, 32) is then continued into the mask plate (11, 31) for a predetermined distance (38), thus providing a phase-shift mask (10, 30).

Abstract: A method is provided for forming a right angle (30) on a chromeless phase-shift mask (31). A first phase-shift element (32) and a second phase-shift element (33) are positioned at a ninety degree angle, on the chromeless phase-shift mask (31), wherein there is a predetermined space (34) between the first and second phase-shift elements (32,33). The space between the phase-shift elements eliminates hot spot formation that causes unintentional exposure of the semiconductor substrate.

Abstract: A method for fabricating a sub-micron geometry semiconductor device using a chromeless mask. An optical exposure system (22) directs light through a chromeless mask (21). The chromeless mask (21) uses destructive interference of light to pattern a light sensitive material (32) on a semiconductor wafer (28). Phase differences in light passing thru chromeless mask (21) creates dark regions which form a non-exposed area of light sensitive material (37). The exposed light sensitive material is removed. The non-exposed area of light sensitive material (37) which remains, protects the gate material underneath it, as all other gate material is removed from the wafer. The non-exposed area of light sensitive material (37) is removed leaving a sub-micron gate (39). A drain and source is then formed to complete the device.