Batch-Fabricated α-Si Assisted Nanogap Tunneling Junctions

Nanomaterials

Ryan Looper¹  Samuel Broadbent¹  Aishwaryadev Banerjee²  CarlosH. Mastrangelo²  Shakir-UlHaque Khan²  Rugved Likhite²  Hanseup Kim² 

[1] Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA;Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84112, USA;

关键词: nanogap electrodes;    gold adhesion;    IOT;    batch fabrication;    bio-sensing;    molecular junctions;    α-Si;    quantum tunneling;    protein detection;   

DOI  :  10.3390/nano9050727

来源: DOAJ

【 摘 要 】

This paper details the design, fabrication, and characterization of highly uniform batch-fabricated sidewall etched vertical nanogap tunneling junctions for bio-sensing applications. The device consists of two vertically stacked gold electrodes separated by a partially etched sacrificial spacer layer of sputtered α-Si and Atomic Layer Deposited (ALD) SiO₂. A ~10 nm wide air-gap is formed along the sidewall by a controlled dry etch of the spacer. The thickness of the spacer layer can be tuned by adjusting the number of ALD cycles. The rigorous statistical characterization of the ultra-thin spacer films has also been performed. We fabricated nanogap electrodes under two design layouts with different overlap areas and spacer gaps, from ~4.0 nm to ~9.0 nm. Optical measurements reported an average non-uniformity of 0.46 nm (~8%) and 0.56 nm (~30%) in SiO₂ and α-Si film thickness respectively. Direct tunneling and Fowler–Nordheim tunneling measurements were done and the barrier potential of the spacer stack was determined to be ~3.5 eV. I–V measurements showed a maximum resistance of 46 × 10³ GΩ and the average dielectric breakdown field of the spacer stack was experimentally determined to be ~11 MV/cm.

【 授权许可】

Unknown