Photomask (mask) with patterns for the reduction of the performance of a stepper

摘要

A photomask is described which has patterns for the reduction of the performance of a stepper. The energy-saving photomask comprises: at least one first pattern area in which light can pass the photomask without diffraction; and a second pattern area in which a plurality of fine patterns are constructed in such a way that they serve as slots through which the light is diffracted in order to increase the light energy of the light which is radiated onto the first pattern area, and is diffracted to such an extent that it has an energy which is not sufficient to expose the entire light-sensitive film, apart from the area below the first pattern area. Due to the auxiliary pattern the energy of the light impinging on the light-sensitive film can be high in desired sections since, as a result of the auxiliary pattern, the diffraction of the light contributes to the intensity of the light in the desired sections without influencing other sections to any considerable extent. The photomask results in a reduction in the treatment time, extends the service life of a light lamp in the stepper and results in the possibility of using a stepper with reduced performance.