Won-Jun Lee's Group
Semiconductor Materials Lab
Sejong University, Seoul, Korea
Atomic Layer Deposition (ALD)
ALD is based on two half-reactions that occur on the substrate surface when alternately exposed to different precursors.
These reactions are self-saturated, ensuring excellent conformality of the deposited film on high aspect ratio structures.
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The ALD process requires precursors and co-reactants with excellent reactivity, thermal stability, and volatility.
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We perform deposition, film characterization, in-situ analysis, and DFT calculations to study the ALD process.
Atomic Layer Etching (ALE)
ALE is based on two self-limiting reactions, the formation and removal of the modified layer.
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In the first half-reaction, the film surface is treated to form a stable modified layer.
In the second half-reaction, the modified layer is removed as volatile etch products.
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Thermal ALE processes can achieve isotropic etching for three-dimensional device fabrication.
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We perform experiments, in-situ analysis, and DFT/MD simulations to study the ALE process.
Hybrid bonding
Hybrid bonding technology consists of two steps, room-temperature bonding and post-bonding annealing.
At room temperature, the two wafers are aligned, and the dielectric layers are bonded. During the post-bonding annealing, Cu-to-Cu bonding can be achieved due to the thermal expansion of the Cu pads.
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Cu/SiCN hybrid bonding technology can achieve high interconnect density by enabling bonding at a sub-micron pitch.
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We perform FEM simulations to study the hybrid bonding process.
