AVS 49th International Symposium
    Manufacturing Science and Technology Monday Sessions
       Session MS-MoA

Paper MS-MoA9
Improved Tool Utilization and Process Capability Through Improved Flow Verficiation Technique

Monday, November 4, 2002, 4:40 pm, Room C-109

Session: Control Issues in Electronics Manufacturing
Presenter: S.A. Tison, Mykrolis Corporation
Authors: S.A. Tison, Mykrolis Corporation
S. Lu, Mykrolis Corporation
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Critical processes require accurate and reproduceable chemical delivery to acheive the necessary process capabilities. Continues reductions is device scaling requires improved process capabilities for high aspect ratios.@footnote 1@. Many dry etching processes require highly accurate and reproduceable delivery for flows below 10 sccm.@footnote 2@ Historically, gas delivery reproduceability was acheived using rate-of-rise chamber verification techniques. Two of the most common techniques are refered to as "Flow Verification" and "Flow Cal". These techniques use the chamber as an accumulation tank and measure the pressure rise with time. Through the use of the gas equation of state they derive the average delivered gas flow. With the introduction of 300 mm processes the chamber volumes have increased and some critical gas flows have decreased. These effects have resulted in long times to complete the rate-of-rise measurements with the subsequent reduction in tool availability. Data is presented which shows that improved high resolution capacitance diaphragm gages can be used to make the necessary measurements with lower accumulation pressures and improve equipment availability. For a typical etch system the "Flow Verification" sequence can be reduce by one hour per chamber. These process improvements are enabled by reducing uncertainies associated with parasitic effects such as thermal transpiration@footnote 3@ and other gage nonlinearities. @FootnoteText@ @footnote 1@ J. Givens et al., J. Vac. Sci. Technol. B12, 427 (1994) @footnote 2@ M. Matsui et al., J. Vac. Sci. Technol. A20, 117 (2002) @footnote 3@ K. Poulter et al., Vacuum, 33, 311 (1983).