Experimental setup

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Experimental setup
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Sample holders / clamping
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Video setup / wiring
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Electrowetting / basics

• Important properies
• low leakage current
• high ?r
• high contact angle
• charge trapping behaviour ?

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Tested film combinations
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PECVD teflon-like coating13.56MHz
parallel-plate RIE, CHF3 / CF4 plasma
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Electrowetting experiment / DI-waterSi substrate
/ 250nm PECVD SixNy / 20nm PECVD SixOy / 10nm FC
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Electrowetting experiment / NaCl water sol.Si
substrate / 250nm PECVD SixNy / 20nm PECVD SixOy
/ 10nm FC
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Electrowetting experiment / charge trappingSi
substrate / 150nm LPCVD SixOy / 350nm LPCVD SixNy
/ 10nm FC
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Electrowetting experiment / 2-waferBottom Si
substrate / 10nm FCTop Si substrate / 250nm
PECVD SixNy / 20nm PECVD SixOy / 10nm FC
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Electrowetting experiment / breakthroughTiny
defect great troubles
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Conclusions

• Video setup was upgraded extended
• Best film combination so far SixNy/SixOy/CF
• Both single wafer and 2-wafer configuration
  succesfully tested
• Charge trapping effect ( bipolar behaviour)
  observed
• Behaviour depends on ion concentration
• Detailed analysis of the trapping effect needed
  (transient current characteristics with and w/o
  liquid, XPS, AFM )
• Control electronics has to be integrated into the
  setup, on-screen status display needed
• Patterned structures ? nitride step coverage