Patent ID: 8974987
Filing Date: 2015-03-10
Classification: G03F

Abstract:
1. A halftone phase shifting mask using an ArF excimer laser as an exposing source, being used for a projection exposure by an off axis illumination, and comprising on a principal plane of a transparent substrate a main pattern transferred to a transfer-target surface by the projection exposure and an assist pattern formed nearby the main pattern, where the assist pattern is not transferred to the transfer-target surface and a minimum pattern pitch of the main pattern on the transfer-target surface is a pitch of 120 nm or less; wherein the main pattern and the assist pattern are each constituted from a semi-transparent film made of a same material; and a first retardation of 180° is generated between a first light transmitting through the main pattern and a second light transmitting through a transparent region of the transparent substrate, and a predetermined second retardation within a scope of 70° to 115° is generated between a third light transmitting through the assist pattern and the second light transmitting through the transparent region of the transparent substrate.