Optimization of Chromeless Phase Mask by Comparing Scattering Bars with Zebra Patterns
- Title
- Optimization of Chromeless Phase Mask by Comparing Scattering Bars with Zebra Patterns
- Author
- 정희준
- Keywords
- Chromeless Phase Shift Mask; Optical Proximity Correction (OPC); Phase; Scattering Bars; Transmission; Zebra Patterns
- Issue Date
- 2006-04
- Publisher
- SPIE-The International Society for Optical Engineering
- Citation
- Proceedings of SPIE - The International Society for Optical Engineering, SPIE 31st International Symposium on Advanced Lithography, v. 6154, Article no. 615429
- Abstract
- Resolution enhancement technology (RET) refer to techniques that extend the usable resolution of an imaging system
without decreasing the wavelength of light or increasing the numerical aperture (NA) of the imaging tool. Off-axis
illumination (OAI) and phase shift mask (PSM) are essentially accompanied with optical proximity correction (OPC) for
most devices nowadays. In general, these three techniques do not work in isolation and the most aggressive mainstream
lithography approaches use combinations of all RETs. In fact, OAI and PSM are essentially useless for typical
chip-manufacturing applications unless accompanied by OPC.
For low k1 imaging, strong OAI such as Quasar or dipole illumination types is the best. We used dipole illumination in
this study. By using strong OAI, the amplitude of the 0th order is decreased and the amplitude of the 1st order is
increased.
Chromeless phase lithography (CPL) is one of PSM technologies and CPL mask is the possible solution for small
geometry with low mask error enhancement factor (MEEF). CPL uses only 180 degrees phase-shifter on transparent
glass without chromium film to define light-shielding region, destructive interference between light transmitted through
the 0 degree and 180 degrees regions produces dark images. To obtain the best resolution, proper OPC is required with
CPL. While the most common and straightforward application of OPC is to simply move absorber edges on the mask by
giving simple mask bias, the interesting and important additional technique is the use of scattering bars. Also, we can use
zebra patterns for the transmission control. Mask intensity transmission changes can impact the image quality. Zebra
patterns are formed by adding chromium transverse features. The transmission will be controlled by the zebra pattern
density. Technology node with ArF source is studied and the mask optimization is found to be a critical. And the
linewidth of scattering bars, transmission (using zebra feature) are varied at line and space (L/S) patterns. We used 65
nm node 5 L/S and 45 nm node isolated line pattern. In order to optimize the zebra pattern density, we need to control
the line width and pitch of the zebra patterns. For dense line and isolated line, the use of scattering bars and zebra
patterns affected target critical dimension. We found out the better process window at dense 65 nm node by comparing
the use of scattering bars with zebra patterns. Likewise, we optimized the isolated 45 nm node.
- URI
- https://www.spiedigitallibrary.org/conference-proceedings-of-spie/6154/615429/Optimization-of-chromeless-phase-mask-by-comparing-scattering-bars-with/10.1117/12.656145.full?SSO=1https://repository.hanyang.ac.kr/handle/20.500.11754/107892
- ISSN
- 0277-786X
- DOI
- 10.1117/12.656145
- Appears in Collections:
- COLLEGE OF SCIENCE AND CONVERGENCE TECHNOLOGY[E](과학기술융합대학) > APPLIED PHYSICS(응용물리학과) > Articles
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