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353UV, AOP algorithm, 0.18 µm
351, APA algorithm, 0.25 µm
Figure 2. The 353UV significantly improves defect sensitivity over previous inspection systems.
tures, as well as identify OPC defects. Recently, DPI evaluated and characterized KLA-Tencor’s new Ultraviolet UV inspection system, the 353UV. During the evaluation, DPI engineers used both standard test plates and specially designed OPC reticles to characterize the new 0.18 nm pixel inspection, AOP algorithm, and defect highlighting tools.
System evaluation The 353UV demonstrated improved defect sensitivity on OPC features as a result of: 1) shorter wavelength, 2)
smaller pixel size, and 3) improved detection algorithms. Defects among serifs, hammerheads and assist lines were detected in isolated and dense geometries. Additionally, the 353UV system also showed improved sensitivity on UV-opaque defects and better resolution on DUV EA phase shift masks (figure 2). DPI engineers also realized that improved review tools are required to accurately classify the smaller defects. New review features such as edge sharpening and pixel displacement helped to classify 50 nm localized gate CD errors and process defects.
Inspection issues are closely linked to a photomask producer’s ability to generate features with sufficient clarity. The better a feature image is resolved on a photomask, the easier it becomes to do pattern inspections, saving valuable cycle time. The interdependent nature of production and inspection technology ensures that the development process will be ongoing, with advancements in production capabilities necessitating new developments in inspection technology.
KLA-Tencor Fall-Winter ’98 Trade Show Calendar
36
October 19-21
ITC – International Test Conference, Washington, DC, USA
November 4-6
SEMICON Taiwan, Taipei, Taiwan
November 16-17
VDE/VDI Conference, Munich, Germany
December 1-3
Fall MRS, Boston, MA, USA
December 2-4
SEMICON Japan, Makuhari, Japan
Autumn 1998
Yield Management Solutions