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Published on: August 22, 2017
Characterization of crystallographic properties of SMC poly Si using electron backscattered diffraction
1School of Materials Science & Engineering, Seoul National University ENG445, San 56-1, Shilim-dong, Kwanak-ku, Seoul 151-744, Korea. dkim@imm.rwth-aachen.de
Journal of Microscopy
|August 19, 2004
Summary
Silicide mediated crystallization (SMC) produces large-grain polycrystalline silicon (poly Si) with low-angle boundaries, while excimer laser annealing (ELA) yields small-grain poly Si with high-angle boundaries. Long-range crystallinity, not short-range, impacts thin-film transistor performance.
Area of Science:
- Materials Science
- Semiconductor Physics
- Crystallography
Background:
- Polycrystalline silicon (poly Si) is crucial for thin-film transistors (TFTs).
- Crystallographic properties significantly influence poly Si performance in electronic devices.
- Controlling grain size and boundary characteristics is key for advanced TFT fabrication.
Purpose of the Study:
- To compare the crystallographic properties of poly Si produced by silicide mediated crystallization (SMC) and excimer laser annealing (ELA).
- To investigate the correlation between these crystallographic properties and the performance of thin-film transistors (TFTs).
- To determine which aspects of crystallinity (short-range vs. long-range) are more critical for TFT device characteristics.
Main Methods:
- Electron backscattered diffraction (EBSD) was employed to analyze the crystallographic structures.
- Characterization of grain size, grain boundary types (low-angle vs. high-angle), and misorientation distributions.
- Fabrication and testing of thin-film transistors (TFTs) using poly Si films from both SMC and ELA processes.
Main Results:
- SMC resulted in large-grain poly Si with a high fraction of low-angle grain boundaries.
- ELA produced small-grain poly Si characterized by a prevalence of high-angle grain boundaries, particularly around 60 degrees.
- Short-range crystallinity (pattern quality) showed minimal impact on TFT device characteristics.
- Long-range crystallinity, specifically the distribution of misorientation and the presence of low-energy special boundaries, demonstrated a stronger correlation with TFT performance.
Conclusions:
- The crystallographic characteristics imparted by SMC and ELA significantly differ.
- Long-range crystallinity, influenced by grain boundary energy, is a more critical factor for optimizing poly Si TFT device performance than short-range crystallinity.
- Understanding and controlling grain boundary characteristics is essential for developing high-performance poly Si-based TFTs.
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