A 193 nm Deep-UV Lithography System Using a Line-Narrowed ArF Excimer Laser

A small field refractive projection system for operation at the 193.3 nm wavelength of a spectrally narrowed ArF excimer laser is being constructed. The 1 mm field, 20X system operates with a variable objective lens numerical aperture from 0.30 to 0.60, variable partial coherence, and control over illumination fill and mask tilt. A 30 W maximum power ArF excimer laser has been spectrally line-narrowed through incorporation of tilted Fabry-Perot etalons into the laser cavity, allowing linewidths on the order of7 cm\u27 (26 pm) with one etalon and 0.5 cm1 (2pm) with two etalons. This work reports laser line narrowing and lens performance results. Simulations of aerial image intensity distributions from lens aberration data will be presented for 0.25 and 0.20 micron geometry

Comparison of Scalar and Vector Diffraction Modelling for Deep-UV Lithography

As deep-UV projection system complexity increases to pursue 0.25 micron resolution, the adequacy of diffraction theory using scalar models is of concern. Approximations that are suitable for low NA reduction systems do not hold true for higher NAs. Furthermore, scalar models treat all illumination as polarized perpendicular to the plane of incidence. Feature interaction effects from the polarized radiation of an excimer laser both in a projection system and within a photoresist film cannot be accounted for. Vector diffraction theory has been utilized more appropriately for modelling in these situations, but deviations of scalar predictions from those made with vector models do not warrant abandonment. This paper will describe investigations into scalar and vector diffraction modelling for 248 nm lithography. An experimental design approach was used to study the effects and interactions of coherence, polarization, and numerical aperture on a resist feature response. An exposure latitude response to achieve 1 0% linewidth control with +1- 0.3 micron of defocus was utilized. Both vector and scalar diffraction models were used to simulate process runs. Experimental comparisons were made using a variable NA, variable coherence deep-UV projection system, adapted for control of polarization at the aperture of the mask. Exposure latitude response surfaces are presented, along with details on isolated process runs

FAPRI 2000 U.S. Agricultural Outlook

Crop Production/Industries, Livestock Production/Industries,

FAPRI 2000 World Agricultural Outlook

The Food and Agricultural Policy Research Institute (FAPRI) prepares a preliminary agricultural outlook on world agricultural production, consumption, and trade every fall. This is followed by an outside review, re-evaluation of projections, and completion of the final baseline in January. The FAPRI 2000 World Agricultural Outlook presents these final projections for world agricultural markets. A companion volume, the FAPRI 2000 U.S. Agricultural Outlook, presents the U.S. component of the baseline. FAPRI projections assume average weather patterns worldwide, existing policy, and policy commitments under current trade agreements. FAPRI projections do not include conjectures on potential policy changes, such as those resulting from the likely eastward enlargement of the European Union (EU). The baseline predicts recovery of world agricultural production, consumption, and trade, but with remaining price weakness for crops. Stock-to-use ratios in world crop markets remain high despite the strong recovery of Asian and Latin American economies. Above-average yields kept world production high relative to demand in 1999. In contrast, pork and beef prices are increasing significantly above their 1999 level. The physical volume of U.S. agricultural exports is projected to reverse the downward trend of fiscal year (FY) 1999, whereas the value of agricultural exports continue to decline for one more year before recovering because of low crop prices in 2000/01. World crop trade is projected to increase by 55 million metric tons (mmt) in the coming decade, with the United States capturing 49 percent of the expanded market, but still unable to increase its market share by a large percentage. Following this expansion of the market, grain prices increase by 35 percent in the projection period, but still stay well below the peak of 1995/96. The increase in world crop trade reflects the increasing specialization occurring in world agriculture. Increased market access and land scarcity in many Asian economies induce them to import grains and oilseeds to meet their feed demand. Developing Asia remains the fastest growing market for corn in the next decade. With implementation of Agenda 2000 reforms, the EU will reduce its wheat domestic price relative to the world price and will export wheat without subsidies after 2004, constraining gains in market shares for the United States. EU barley exports will expand significantly in the coming years but are likely to be constrained by General Agreement on Tariffs and Trade (GATT) commitments on export subsidies after 2004. World meat trade will increase by 31 percent over the next decade. The United States has become a competitive producer and exporter of meat products. In the coming decade, the United States will experience the largest meat export growth rates among major exporters of beef, pork, and broilers. U.S. exporters capture more than 70 percent of the growth in trade, increasing their share of the combined meat markets from 23 percent in 1999 to 37 percent in 2009. Meat imports are recovering and expanding rapidly in Japan, South Korea, and Taiwan. In Japan, the share of imports in consumption increases from 38 percent in the 1990s to 49 percent at the end of the next decade. Taiwan meat imports will triple from 1990-1999 levels to 2000-2009 levels, driven by imports of beef, non muscle pork products, and the opening of the poultry market. Recovery of Asian food demand will prompt dairy prices to grow by about 1 percent per year over the next decade. Total milk production is projected to increase, with particularly strong growth in the United States, Mexico, Argentina, and Brazil. Most of the growth occurs through yield increases. Per capita cheese consumption is expected to grow by 1 to 2 percent a year in most countries.Crop Production/Industries, Livestock Production/Industries,

FAPRI 2001 U.S. and World Agricultural Outlook

Crop Production/Industries, Livestock Production/Industries,

FAPRI 2002 World Agricultural Outlook

Crop Production/Industries, Livestock Production/Industries,

FAPRI 1999 U.S. Agricultural Outlook

Crop Production/Industries, Livestock Production/Industries,