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Bell Labs Researchers Demonstrate Projection Electron Beam Lithography
Researchers at Bell Laboratories, the research and development arm of Lucent Technologies, used their SCALPEL™ system, a development effort supported in part by the Defense Advanced Research Project Agency (DARPA) and SEMATECH, in the first demonstration of step-and-scan lithography using electron beams. The demonstration involved a pattern mask that was scanned to print a stripe of features on a semiconductor wafer. The mask and wafer then were shifted and another stripe was printed next to and aligned with the first. The printing of four adjacent stacks of 100 stripes produced a 1 cm square of semiconductor features.
The SCALPEL effort is one of a number of techniques being investigated by the semiconductor industry as an inevitable replacement for today's optical lithography process, which produces features as small as 0.25 mm. The process is expected to support another one or two generations of miniaturization with 0.18 and 0.13 mm features. However, techniques using shorter wavelength radiation sources will be needed to continue doubling the number of components on a chip through the next decade.
SCALPEL printed the first 0.08 mm features in June 1996. The recent demonstration produced stripes aligned with each other to an accuracy of at least 0.05 mm. As envisaged currently, the goal is to achieve 0.01 mm alignment, and increase the size of the usable field and process throughput speed.
New Uses Being Examined for Miniature Decoy
As reported in Defense weekly, Teledyne Ryan and Northrop Grumman are exploring expanded uses for the miniature air-launched decoy (MALD), which successfully completed its advanced concept technology demonstration (ACTD) recently. Potential applications include the use of the MALD unit for lethal suppression of enemy air defenses, as a low cost cruise missile defense, as an autonomous attack system, as an electronic warfare/communications jammer, as a low cost system for delivery of acoustic or seismic sensors, or for intelligence gathering.
As designed currently, the MALD unit is used to distract enemy fighters or ground-based air defense systems prior to the firing of high speed anti-radiation missiles. The MALD ACTD, supported jointly by the DARPA and the Air Force, has received $24.4 M in funding and has been in operation for a little less than a year.
The decoy measures 7.5 feet long and less than 6 inches in diameter, weighs less than 90 lb and has a design shelf life of 15 years within which time it will operate without maintenance. The unit has a range of 20 miles at 30,000 feet and high subsonic speed, and will simulate the F-16 fighter for approximately 20 minutes. An onboard Global Positioning Satellite-guided navigation system will fly the unit through as many as eight separate waypoints. The F-16 is the first aircraft expected to carry the MALD unit but future versions of the decoy will be compatible with the F-15, F/A-18 and the B-1.
Teledyne Ryan is scheduled to deliver 32 MALD units by April. Based on a production run of 3000 units, the company is committed to deliver future units at an average flyaway price of $30,000 each.
DoD's Long-term Aircraft Acquisition Strategy Questioned
In its report "Aircraft Acquisition, Affordability of DoD's Investment Strategy," (GAO/NSIAD-97-88) the General Accounting Office (GAO) examines the affordability of the Department of Defense's (DoD) aircraft investment strategy and discusses the factors that are likely to adversely affect the success of the effort. The GAO finds that the DoD currently is in the process of buying or funding significant modification of at least 8499 aircraft in 17 programs at a total cost of $334.8 B (FY 97 dollars). To provide sufficient funds for this work on its present schedule, the DoD is relying on two major assumptions: that overall defense spending will begin to increase in real terms starting in 2002; and that large savings derived from downsizing defense infrastructure and a reformed acquisition process will become available to apply to the programs.
The GAO points out that, contrary to the first assumption, both DoD and congressional projections forecast stable defense budgets for the foreseeable future. Except for in one year, the DoD's planned spending on the aircraft programs between FY 2000 and FY 2015 also exceeds the long-term average percentage of the DoD budget devoted to aircraft purchases and, for several of the years, approaches the percentages reached during the peak Cold War era. In addition, the DoD's cost projections do not allow for cost growth, which, historically, has averaged at least 20 percent. The projections also do not allow for other procurements, although replacements are being considered for a number of other aircraft not covered by existing plans. The GAO also fails to find compelling evidence that savings from infrastructure reduction and acquisition reform will contribute significantly to the aircraft programs.
The report characterizes the DoD's aircraft investment strategy as a business-as-usual approach that adds billions of dollars to defense acquisition costs and delays delivery of systems to operational forces. The report points out that the DoD historically has made long-term commitments to weapons system acquisition based on optimistic procurement profiles and has frequently altered the profiles due to funding problems.
The GAO recommends that the DoD recognize the defense budget limitations on its aircraft investment strategy. The report states that the strategy must be based on a realistic rather than optimistic view of the procurement levels that can be supported. The report also suggests that the DoD provide more assurance that its aircraft procurement plans have full military justification and are fully affordable throughout the aircrafts' lives. The GAO recognizes that while there may be general agreement on the need to reduce the planned spending on aircraft programs, there will be serious problems identifying and terminating specific programs to reduce that spending.
Electronically Scanned Array Radar to Serve Ground Vehicle Applications
Northrop Grumman's Land Combat Systems division has announced the development of a low cost, lightweight, electronically scanned array (ESA) radar suitable for ground vehicle surveillance and helicopter target acquisition applications. The model ESA XXI system is based on the company's Longbow radar. The ESA XXI system will provide tactical ground vehicles (such as the Future Scout Calvary System/Tracer) with the all-weather performance and wide area situational awareness enjoyed by tactical aircraft, including low altitude helicopters and fixed-wing aircraft. The system relies heavily on the technology developed for Longbow that detects and classifies stationery targets as well as on Longbow's low probability-of-intercept waveforms, which protect the system from countermeasure threats. However, major reductions in cost and packaging were needed before those technologies were suitable for ground vehicle application. These improvements were achieved with a four-year, $5 M internal development.
The ESA XXI system is a lightweight, Ka-band radar with a modular configuration suitable for integration with most combat or utility vehicles. The system occupies 2 cubic feet of internal space and 4 cubic feet externally; operates in adverse weather or obscurant situations; detects moving targets to 20 km and classifies targets within 10 km; detects and classifies stationery targets to 3 km; provides monopulse ground mapping; and operates with a FLIR system. The system's electronically scanned antenna supports both azimuth and elevation monopulse channels, and has full polarization diversity capability.
A prototype antenna system currently is undergoing system-level testing. System-level testing of the antenna with low cost modular radar electronics was scheduled for the end of 1997.
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