Related Experiment Video
Updated: Dec 3, 2025
14:01
Making Record-efficiency SnS Solar Cells by Thermal Evaporation and Atomic Layer Deposition
Published on: May 22, 2015
43.2K
Area-Selective Atomic Layer Deposition of TiN Using Trimethoxy(octadecyl)silane as a Passivation Layer
Li Zheng1,2, Wei He2, Valentina Spampinato1
1Interuniversity Microelectronics Centre, Kapeldreef 75, B-3001 Leuven, Belgium.
Langmuir : the ACS Journal of Surfaces and Colloids
|October 26, 2020
Summary
Area-selective deposition (ASD) uses self-assembled monolayers (SAMs) to block atomic layer deposition (ALD) on specific areas. Optimized SAMs, like TMODS, enhance selectivity for advanced 3D feature fabrication in semiconductor manufacturing.
Area of Science:
- Materials Science
- Nanotechnology
- Chemical Engineering
Background:
- Area-selective deposition (ASD) is crucial for advanced semiconductor manufacturing, enabling bottom-up additive fabrication of 3D features.
- Conventional patterning methods face limitations, driving interest in ASD among IC manufacturers and suppliers.
- ASD typically combines self-assembled monolayers (SAMs) for surface passivation with atomic layer deposition (ALD) for controlled growth.
Purpose of the Study:
- To screen self-assembled monolayer (SAM) precursors for optimal passivation performance on SiO2 substrates.
- To investigate the surface dependence and growth inhibition of TiN ALD on various SAM terminations.
- To identify SAM characteristics that broaden the ALD selectivity window for improved area-selective deposition.
Main Methods:
- Screening of various siloxane SAM precursors with different terminal groups and alkyl chain lengths.
- Investigation of TiN ALD growth inhibition on SAMs with -NH2, -CF3, and -CH3 terminations.
- Characterization of SAM film properties including surface coverage, thermal stability, and deposition methods (liquid phase).
Main Results:
- Methyl termination (-CH3) on SAM precursors, particularly with a C18 alkyl chain, significantly broadens the ALD selectivity window by suppressing precursor adsorption.
- An optimized trimethoxy(octadecyl)silane (TMODS) SAM film achieved a selectivity higher than 0.99 for up to 20 nm of ALD film on hydroxyl-terminated Si oxide.
- The TMODS film demonstrated high surface coverage and excellent thermal stability, crucial for robust passivation.
Conclusions:
- The study demonstrates that specific SAM structures, like methyl-terminated long alkyl chains (TMODS), are effective in enabling high-selectivity area-selective deposition.
- This approach extends the process window for ASD, making it more viable for a wider range of semiconductor applications.
- Optimized SAMs are key to advancing bottom-up additive manufacturing techniques for complex 3D structures.
