Renesas Electronics Corporation

Manabu Ishibashi

Akemi Moniwa

Ayumi Minamide

Junjiro Sakai

Mitsuru Okuno

A photomask is provided which can have a large depth of focus even if four main features are annularly arranged at random. The photomask has four annularly arranged main features based on design information of a circuit feature to be formed on a wafer, and a sub-feature is laid at an intersection point of two diagonal lines of a quadrangle formed by four vertices inside the four main features in order to increase a depth of focus of an exposure feature. Therefore, the depth of focus can be increased even if the main features are not arranged at a constant pitch.

Photomask, manufacturing apparatus and method of semiconductor device using the same, and photomask feature layout method

A photomask is disclosed which can suppress deterioration of the depth of focus even in the case where main features are arranged randomly. Sub-features are replaced by a quadrangular sub-feature located inside an external quadrangle which includes as part of its outer periphery the outermost portions of the original sub-features. The sub-feature after the replacement is preferably in a square shape and the length of one side thereof is determined in accordance with the length of the associated external quadrangle. A central position of the sub-feature after the replacement is preferably coincident with the center of the external quadrangle or the center of gravity of the region which includes the original sub-features.

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Itami, Japan

Manabu Ishibashi