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.degree. 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.degree. 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.
The present invention refers to a refractive arrangement for X-rays, and specially to a lens comprising: a member of low-Z material, said member of low-Z material having a first end adapted to receive x-rays emitted from an x-ray source and a second end from which emerge said x-rays received at said first end. It further comprises a plurality of substantially saw-tooth formed grooves disposed between said first and second ends, said plurality of grooves oriented such that said x-rays which are received at said first end, pass through said member of low-Z material and said plurality of grooves, and emerge from said second end, are refracted to a focal point.
A method of generating EUV radiation is described, comprising the steps of: transporting a solid medium (33) through a source space (34) connected to a vacuum pump (35), and irradiating a portion (37) of the medium with an intense, pulsed, laser beam (41) focused on said portion of the medium, thus creating a plasma (47) which emits EUV radiation. To increase the intensity of the EUV radiation and improve the possibility to collect particles (51, 52, 53) released from the medium, at least the medium portions (37) to be irradiated have a concave shape. The method can be improved by embedding the medium in a flow of rare gas. Also described are a EUV radiation source unit for realizing the method and the application of the method in the manufacture of devices such as IC devices, and in a lithographic projection apparatus.
Capillary discharge extreme ultraviolet lamp sources for EUV microlithography and other applications. The invention covers operating conditions for a pulsed capillary discharge lamp for EUVL and other applications such as resist exposure tools, microscopy, interferometry, metrology, biology and pathology. Techniques and processes are described to mitigate against capillary bore erosion, pressure pulse generation, and debris formation in capillary discharge-powered lamps operating in the EUV. Additional materials are described for constructing capillary discharge devices fore EUVL and related applications. Further, lamp designs and configurations are described for lamps using gasses and metal vapors as the radiating species.
Methods for making pulsed and continuous discharge plasma light sources for extreme ultraviolet(EUV) projection lithography and soft-x-ray microscopy as well as other applications are disclosed. A first light source of doubly ionized lithium ions emits over a narrow bandwidth of approximately 13.5 nm. A second light source of beryllium ions radiates at approximately 7.60 nm. A third light source of boron ions radiates at approximately 4.86 nm, and a fourth light source of carbon ions radiates at approximately 3.38 nm. Preferred embodiments of apparatus for generating pulsed and continuous discharge sources are disclosed.
This invention relates to Lithium Plasma discharge sources, and in particular to methods of making and producing pulsed and continuous discharge sources for plasma soft-x-ray or EUV projection lithography. Specifically, novel configurations, metal and ceramic material combinations and efficient wavelengths over and including 11.4 nm are disclosed for EUV lithium plasma discharge lamps.
