Abstract: A photomask including first opaque patterns and second opaque patterns is provided. The first opaque patterns are distributed in a first plane defined in the photomask, while the second opaque patterns are disposed above the first opaque patterns and spaced apart from the first opaque patterns. In other words, the first opaque pattern and second opaque pattern are not distributed in the same plane.

Abstract: A calculation method for generating a layout pattern in a photomask includes at least the following steps. A two-dimensional design layout including several geometric patterns distributed in a plane is provided to a computer system. The computer system is used to mark portions of the geometric patterns and generate at least one marked geometric pattern and at least one non-marked geometric pattern. The marked geometric pattern is then simulated and corrected by the computer system so as to generate a 3-D design layout. Through the simulation and correction, the marked geometric pattern and the non-marked geometric pattern are arranged alternately along an axis orthogonal to the plane. The 3-D design layout is outputted to a mask-making system afterwards.

Abstract: A method of forming assist feature patterns includes providing an original layout pattern having at least a first region defined therein, the first region having a first light transmission rate larger than 0%; performing a search step to the original layout pattern to define at least a second region having a second light transmission rate equal to 0% in the original layout pattern; forming a plurality of assist features in the second region to increase the second light transmission rate to larger than 0%; and outputting the original layout pattern and the assist features to a reticle blank.

Abstract: A method of forming assist feature patterns includes providing an original layout pattern having at least a first region defined therein, the first region having a first light transmission rate larger than 0%; performing a search step to the original layout pattern to define at least a second region having a second light transmission rate equal to 0% in the original layout pattern; forming a plurality of assist features in the second region to increase the second light transmission rate to larger than 0%; and outputting the original layout pattern and the assist features to a reticle blank.

Abstract: A semiconductor exposure method that uses a semiconductor exposure apparatus to expose a wafer is described. The semiconductor exposure apparatus comprises at least an exposure lens, a platform for supporting the wafer and a liquid-circulating device. The liquid-circulating device supplies a liquid to the space between the wafer and the exposure lens during exposure. One major feature of the present invention is that at least one aligning light source is used to perform an alignment operation for aligning the supporting platform before the actual exposure, wherein the aligning light source has a particular wavelength in which the effect on the aligning light source due to the evaporation of the liquid is minimized to prevent the liquid from affecting the alignment operation.