Abstract: A method for forming a photomask is provided. The method includes: providing a photomask pattern for a target pattern; obtaining a first light intensity curve according to the photomask pattern by simulation; subjecting the first light intensity curve to a check on light intensities at pattern edges of the target pattern to define a light intensity error; retargeting the photomask pattern to reduce the light intensity error; identifying a lithography weak region in the target pattern; obtaining a second light intensity curve of the lithography weak region by simulation; subjecting the second light intensity curve to a check on a peak light intensity to define a peak intensity error; retargeting the target pattern to reduce the peak intensity error; and retargeting the photomask pattern again based on the modified target pattern.

Abstract: A method of making mask patterns includes the following steps. A first octagon feature is created, wherein the first octagon feature includes first sides, second sides orthogonal to the first sides, and third sides, wherein each of the third sides connects the corresponding first side to the corresponding second side. An optical proximity correction (OPC) process is applied by using a computer to parallel shift the first sides, the second sides and the third sides of the first octagon feature respectively, and thus to create a second octagon feature. The second octagon feature is applied to make a pattern of a photomask. A method of forming a pattern in a layer is also provided, which includes printing a circular pattern on a surface of a layer by using an octagon pattern of a photomask.

Abstract: A fiber laser system includes a fiber laser, a laser light detecting apparatus, and a control apparatus. The fiber laser outputs a laser light, including a noise-like pulse laser light, a mode-locked pulse laser light, or a continuous-wave laser light. The laser light detecting apparatus consists of a lens and a photodiode. The photodiode absorbs the laser light outputted from the fiber laser and generates an output signal in terms of a two-photon absorption effect. The control apparatus reads the output signal of the photodiode and automatically adjusts the fiber laser, according to a preset value, to obtain the noise-like pulse laser light or the mode-locked pulse laser light.