| 摘要 |
Described herein is an improved target for use in a pulsed induced plasma X-ray lithography system. The target is formed as a disk shaped base having a series of concentric grooves formed on the side thereof incident to the focused laser beam. A plurality of small holes are fabricated through the base to the facing wall of the groove against which the laser beam is focused and a film, of a polyimide or silicon nitride material, covers the hole. A thin layer of metal target material is then placed on the film aligned with each hole. The thickness of the metal is selected to be sufficient to allow the complete ablation of the material during the existence of the X-ray emitting plasma. In this manner, a minimal amount of debris, either in the form of molten droplets or evaporated metal material, will be generated. The angle of the incident, or facing, side of the grooves is selected to be at an angle so that both the laser beam optical elements and the X-ray mask are positioned in an area where few, if any, molten droplets of debris are emitted. Such an angle may be 45 DEG with respect to the plane in which the target substrate is moved while placing different target areas in incident with the laser beam. Such a target also allows the angle at which the laser beam is focused at the target to be approximately 65 DEG from the alignment of the focal spot on the target and the vertical line to the mask. This angle, in turn, allows a slower lens and less optical coating to be used on the optical elements beyond the lens. pg,8
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