Part 5 – Shape PEC – “ODUS” Contrast Enhancement


Doc Daugherty, Nezih Ünal - GenISys GmbH


  • Shape modulation strength and weaknesses
  • Shape PEC with and without over-dose
  • Contrast enhancement by overdosing
  • Impact of overdose to process window
  • Application for resolution enhancement and lift-off process

Summary of the Webinar:

  • Long Range (back-scatter) effects is always done with dose
  • Short- and mid-range effects may be compensated by dose or shape
    • Dose - Pro: Higher Contrast and more stable for complex shapes
    • Dose – Con: Symmetric correction, not optimal for non-symetric scenario (e.g. line end, different distance at edges)
    • Shape – Pro: Enables non-symmetric correction, allows ODUS (s. below)
    • Shape – Con: Lower contrast (without ODUS), limitation for complex curved shapes
  • Shape with ODUS
    • Enabling to push image contrast (litho quality) beyond Dose PEC
    • Higher edge quality, steeper resist profile
    • More stable process (larger process window)
    • Overdose factor (typically 2-4) and effective SR-blur define how much undersize
  • Application example
    • Single layer resist lift-off process by achieving negative resist profile
    • Resolving features & gaps in the order of the blur
    • Contrast enhancement for negative resist mr-EBL 6000
  • Warning:
    • Dose PEC is method of choice (effective and stable) for most application
    • ODUS offers advanced solution for some application, but needs special attention on complex (curved )layouts