Abstract: A zero power identical pair of oppositely-oriented meniscus lens elements mounted in the projection light path, serves as curved mask support while compensating for optical anomalies such as beam shift and beam deviations produced by other transparent supports for the curved mask. The zero-power meniscus lens pair, without affecting the transmission beam characteristics, lets the beam diffract as efficiently as does a regular planar mask, thus preserving the partial coherence effects and resolution concepts of projection lithography. This simple but novel optics device is not only expected to clear several barriers for curved mask projection lithography but also find place in other applications where collimated or converging light beams have to travel extra paths without significant aberration.

Abstract: A turbulence-controlled vacuum debris removal subsystem safely exhausts particles ejected during photoablation. Nested interconnected chambers provide diminishing sweeping gas partial pressure and diminishing turbulence, ejecting particles from the ablation beam path between pulses, without compromising continuing particle conductance. Removal rate (debris generation rate) depends on conductance and particle sizes. The chambers interconnect through metering holes which enable optimization of partial pressure differentials. Controlled flow accomplishes debris removal, reducing turbulence of the mixture of debris and sweeping gases. A preferred embodiment uses a nest of concentric chambers, providing a clear light path. Another preferred embodiment uses orifices on chamber faces for removal and forming an envelope of gas around the processing region for dynamically containing the ejected particulate matter from the ablation site to the exhaust.

Abstract: An optimized illumination system that efficiently produces uniform illumination for exposure, photoablation, and laser crystallization systems. The illumination system includes a homogenizer that uniformizes and shapes a light beam, which is directed onto a mask by condenser optics. The illumination system recycles radiation by directing light reflected by the mask back into the illumination system, where an apertured mirror situated at the input end re-directs it back toward the mask. The relative areas of the mirror and aperture affect recycling efficiency and system throughput, so the system features a larger-diameter recycling segment enabling greater mirror-to-aperture area ratios. An added segment at the output end of the homogenizer matches the homogenizer diameter to the projection imaging system object field size. This standardizes the homogenizer and condenser lens integration, reducing the need for customized parts and thus reducing manufacturing time and expense.

Abstract: A zero power identical pair of oppositely-oriented meniscus lens elements mounted in the projection light path, serves as curved mask support while compensating for optical anomalies such as beam shift and beam deviations produced by other transparent supports for the curved mask. The zero-power meniscus lens pair, without affecting the transmission beam characteristics, lets the beam diffract as efficiently as does a regular planar mask, thus preserving the partial coherence effects and resolution concepts of projection lithography. This simple but novel optics device is not only expected to clear several barriers for curved mask projection lithography but also find place in other applications where collimated or converging light beams have to travel extra paths without significant aberration.

Abstract: Single-stage projection systems typically have a twice-folded optical path, with mask leg, crossover, 1:1 projection lens system, and substrate leg. They offer seamless patterning of large microlithographic substrates by overlapping complementary small-field scanning. A reverser maintains mask/substrate pattern congruence despite optical reversal, but presents the requirement of large working distance to permit access to the scanning stage. The required working distance demands large-diameter lens elements which are expensive in materials, grinding and assembly. A high-resolution 1:1 projection lens, for high-fluence laser light, adds extreme expense. Dividing the projection lens into two distributed-part-lenses, in mask and substrate legs, maintains satisfactory working distance, minimizes lens diameter requirements, and thus cuts cost. The aperture stop is positioned at the midpoint of the optical path, preferably at the time of manufacture, by an auxiliary stage.

Abstract: Single-stage projection systems typically have a twice-folded optical path, with mask leg, crossover, 1:1 projection lens system, and substrate leg. They offer seamless patterning of large microlithographic substrates by overlapping complementary small-field scanning. A reverser maintains mask/substrate pattern congruence despite optical reversal, but presents the requirement of large working distance to permit access to the scanning stage. The required working distance demands large-diameter lens elements which are expensive in materials, grinding and assembly. A high-resolution 1:1 projection lens, for high-fluence laser light, adds extreme expense. Dividing the projection lens into two distributed-part-lenses, in mask and substrate legs, maintains satisfactory working distance, minimizes lens diameter requirements, and thus cuts cost. The aperture stop is positioned at the midpoint of the optical path, preferably at the time of manufacture, by an auxiliary stage.