CAREER: Scalable Manufacturing of Two-dimensional Atomic Layer Materials for Energy-efficient Electronic Devices via Selective-area Atomic Layer Deposition

This Faculty Early Career Development Program (CAREER) grant supports research in the scalable manufacturing of atomically-thin semiconducting materials for high performance, energy-efficient electronic devices. The project studies selective-area or seeded atomic layer deposition, a manufacturing technique used to deposit materials with high precision and uniformity. This award establishes a new mode of manufacturing for low temperature fabrication of high quality two-dimensional nanomaterials, which allows early adoption of these new materials into the semiconductor industry and supports continued improvements in electronic device performance, including information storage capacity and computational power, all while lowering the energy demands of these devices. These materials are also promising components of quantum information processing devices, thus aligning well with NSF's Quantum Leap effort. The results of this research benefits society and the national economy through the advancement of innovative solutions to the nation's increasing energy and computational demands. Additionally, this research advances engineering knowledge and trains the next generation of scientists and engineers in advanced manufacturing and prepare them for careers in industry. Through partnership with Boise State's Science, Technology, Engineering, and Mathematics (STEM) Diversity and Inclusion Initiative, the research and outreach activities of this award expands participation for underrepresented groups, directly supporting the aims of the NSF INCLUDES program.

Semiconducting two-dimensional (2D) atomic layer materials, such as transition metal dichalcogenides, offer large direct band gaps, high on-off ratios, and high room temperature mobilities. The key challenge to deploying these materials in memory and logic devices is the ability to synthesize them in their 2D form at device compatible temperatures with minimal substrate interaction, control over the number of layers, and control over the chemical composition for heterostructure formation and doping. Selective-area atomic layer deposition (ALD), in a unique van der Waals growth mode, can overcome the current limitations for synthesis of the 2D nanomaterials. Typically, 2D materials are grown by chemical vapor deposition at high temperatures, which is not suitable for high aspect-ratio structures. Low temperature ALD produces amorphous films, which requires high temperature annealing to generate the desired microstructure, which is not suitable for some semiconductor devices. This research is to provide the knowledge necessary to synthesize crystalline 2D atomic layer materials at backend-compatible low temperatures through selective-area or seeded ALD with van der Waals bonding to the underlying substrate. The research team employs in situ and ex situ experimentation combined with first-principles computation to understand the chemical reactions critical to both promoting and inhibiting the nucleation and growth of 2D materials on engineered surfaces for high volume semiconductor device manufacturing.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.