Abstract:
An illumination method and system use a light source and illumination optics to illuminate a pattern generator. The illumination optics can include at least two devices. For example, if first and second diffractive and/or refractive devices are used, one can be a pupil defining element (PDE) and one can be a field defining element (FDE). In another example, a third diffractive or refractive element can be used to make light entering the illumination system uniform. When only two are used, the PDE forms one or more light beams having a defined profile. The FDE directs the one or more light beams having the defined profile, such that each directed beam substantially corresponds in size and shape to a desired illumination area(s) on the pattern generator. The directed beams are directed to impinge substantially only on the desired illumination area(s). Thus, using the PDE and the FDE increases optical efficiency of light impinging on the pattern generator and substantially reduces or eliminates stray light caused by light impinging on undesired areas of the pattern generator.
Abstract:
A system and method are used for pulse to pulse dose control in an illumination system, used, for example, in a lithography or a maskless lithography machine. The system and method can be used to decrease effective laser pulse-to-pulse variability in lithographic lasers, allowing adequate dose control using a minimum number of pulses (e.g. as little as one pulse).
Abstract:
A maskless lithography system that writes patterns on an object. The system can include an illumination system, the object, spatial light modulators (SLMs), and a controller. The SLMs can pattern light from the illumination system before the object receives the light. The SLMs can include a leading set and a trailing set of the SLMs. The SLMs in the leading and trailing sets change based on a scanning direction of the object. The controller can transmit control signals to the SLMs based on at least one of light pulse period information, physical layout information about the SLMs, and scanning speed of the object. The system can also correct for dose non-uniformity using various methods.
Abstract:
A maskless lithography system and method produces gray scale patterns on objects. The system includes an illumination source (e.g., either pulsed or effectively continuous), an object including an array of exposure areas, an array of spatial light modulators (e.g., either digital, binary, or analog), and a controller. The array of spatial light modulators pattern and direct light from the illumination source to the object. Each of the spatial light modulators have active areas that respectively correspond with one of the exposure areas on the object. The controller controls the array of spatial light modulators, such that the pattern of the light has spatially varying intensities.