Part 5 – Shape PEC – “ODUS” Contrast Enhancement
Speaker:
Doc Daugherty, Nezih Ünal - GenISys GmbH
Takeaways:
- 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