A four-bounce two-element projection system designed to achieve 0.14 {mu}m resolution over a 1.2 {times} 5 mm{sup 2} ring field has been fabricated. The radiation transport properties of both the individual multilayer-coated optics and the assembled system has been measured. The individual mirror measurements demonstrated that the coatings were within 0.03 nm of d-spacing specifications; however, the mirrors exhibited significant scatter which reduced reflectance below the design specification of 60%. The peak radiation transport efficiency of the assembled projector was 7% at 13.2 nm. To the best of the authors` knowledge, this represented the first measurement of the radiation transport efficiency of a multi-element optical system for EUV lithography. Experiments performed at LLNL`s front-end test bed facility were consistent with the measured transport efficiency.

Any potential lithography must demonstrate an industrially-compatable reticle pattern repair process before the lithographic process can be seriously considered for production. Repair of clear defects on ELTV reticles (i.e., regions on the mask which are reflective and should be non-reflective) requires the deposition of a thin layer of absorbing material. This process has been demonstrated in commercially available tools which were originally developed to repair proximity-print x-ray lithography masks. However, the repair of opaque defects (i.e., the recovery of reflectivity from regions on the reticle covered with an absorber) is more difficult. Opaque defect repair requires the removal of the absorber layer without damaging the underlying multilayer, a process which could degrade the mirror reflectivity. While opaque defect repair processes have been demonstrated in a research environment these processes may not be commercially suitable. We are developing reticle repair processes that will be consistent with a commercially available repair tool. In this paper, we report on our first results.

We have demonstrated the operation of a high average power, all solid state laser and target system for EUV lithography. The laser operates at 1.06 {mu}m with a pulse repetition rate of 200 Hz. Each pulse contains up to 400 mJ of energy and is less than 10 ns in duration. The ELTV conversion efficiency measured with the laser is independent of the laser repetition rate. Operating at 200 Hz, the laser has been used for lithography using a 3 bounce Kohler illuminator.

The US Department of Energy (DOE) is preparing to request the US Environmental Protection Agency to certify compliance with the radioactive waste disposal standards found in 40 CFR Part 191 for the Waste Isolation Pilot Plant (WIPP). The DOE will also need to demonstrate compliance with a number of other State and Federal standards and, in particular, the Land Disposal Restrictions of the Resource Conservation and Recovery Act (RCRA), 40 CFR Part 268. Demonstrating compliance with these regulations requires an assessment of the long-term performance of the WIPP disposal system. Re-evaluation and extension of past scenario development for the WIPP forms an integral part of the ongoing performance assessment (PA) process.

The cost of fabricating state-of-the-art integrated circuits (ICs) has been increasing and it will likely be economic rather than technical factors that ultimately limit the progress of ICs toward smaller devices. It is estimated that lithography currently accounts for approximately one-third the total cost of fabricating modem ICs({sup 1}). It is expected that this factor will be fairly stable for the forseeable future, and as a result, any lithographic process must be cost-effective before it can be considered for production. Additionally, the capital equipment cost for a new fabrication facility is growing at an exponential rate (2); it will soon require a multibillion dollar investment in capital equipment alone to build a manufacturing facility. In this regard, it is vital that any advanced lithography candidate justify itself on the basis of cost effectiveness. EUV lithography is no exception and close attention to issues of wafer fabrication costs have been a hallmark of its early history. To date, two prior cost analyses have been conducted for EUV lithography (formerly called {open_quotes}Soft X-ray Projection Lithography{close_quotes}). The analysis by Ceglio, et. al., provided a preliminary system design, set performance specifications and identified critical technical issues for cost control. A follow-on analysis by Early, …

Laser-produced plasmas are source candidates for EUV lithography. The radiation angular distribution for several target materials is investigated and source debris is characterized.

Good illumination uniformity at the mask and wafer planes, and high wafer thoroughput in the EUVL front-end test bed facility at LLNL require graded period multilayer (ML) coatings on several of the optics. The ML deposition was accomplished using a newly developed deposition technique which avoids the use of {open_quotes}uniformity masks{close_quotes} to define the spatial dependence of the ML period variation. The capabilities of the process in providing the specified ML coatings are discussed for both EUVL condenser and imaging systems.

Mo/Si multilayers, were removed from superpolished zerodur and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates.

The US Department of Energy (DOE) has more than 2.5 million tons of radioactive scrap metal (RSM) that is either in inventory or expected to be generated over the next 25 years as major facilities within the weapons complex are decommissioned. Since much of this metal cannot be decontaminated easily, past practice has been to either retain this material in inventory or ship it to DOE disposal sites for burial. In an attempt to conserve natural resources and to avoid burial of this material at DOE disposal sites, options are now being explored to ``beneficially reuse`` this material. Under the beneficial reuse concept, RSM that cannot be decontaminated and free released is used in applications where the inherent contamination is not a detriment to its end use. This paper describes initiatives currently in progress in the United States that support the DOE beneficial reuse concept.