Phase shifting masks and methods of manufacture

摘要

A phase shifting mask comprises a transparent region (20) which is transparent to exposure light and a light shielding region (10) for shielding the exposure light. The transparent region (20) has a light transmitting segment (12) for directly transmitting the exposure light therethrough and a phase shifting segment (11; 11a, 11b) for transmitting the exposure light therethrough with a phase difference from the light passed through the transmitting segment (12). In this structure, the light shielding region (10) is formed adjacent at least the phase shifting segment (11; 11a 11b) or the light transmitting segment (12), and the phase shifting segment and the light transmitting segment are formed adjacent each other. A method of manufacturing such a phase shifting mask comprises the steps of: forming a light shielding layer (10') on a substrate (1); forming a photoresist (2') on the light shielding layer (10'); patterning the photoresist (2') to form a first resist pattern (2); forming an opening (20) in the light shielding layer (10') by the use of the first resist pattern (2) as a mask so as to form a light shielding pattern (10); removing the first resist pattern (2); forming a photoresist (3') on the light shielding pattern (10) and opening (20); removing the photoresist (3') partially from the opening (20) to form a second resist pattern (3); anisotropically etching the substrate (1) in a partial area (31) of the opening (20) to form a light transmitting region (12); and removing the second resist pattern (3) so as to leave a phase shifting region (11a, 11b) adjacent the light transmitting region (12). <IMAGE>