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Despite the unique advantages of the memristive switching devices based on two-dimensional (2D) transition metal dichalcogenides, scalable growth technologies of such 2D materials and wafer-level fabrication remain challenging. In this work, we present the gold-assisted large-area physical vapor deposition (PVD) growth of Bi2Se3 features for the scalable fabrication of 2D-material-based crossbar arrays of memristor devices. This work indicates that gold layers, prepatterned by photolithography processes, can catalyze PVD growth of few-layer Bi2Se3 with 100-folds larger crystal grain size in comparison with that grown on bare Si/SiO2 substrates. We also present a fluid-guided growth strategy to improve growth selectivity of Bi2Se3 on Au layers. Through the experimental and computational analyses, we identify two key processing parameters, i.e., the distance between Bi2Se3 powder and the target substrate and the distance between the leading edges of the substrate and the substrate holder with a hollow interior, which plays a critical role in realizing large-scale growth. By optimizing these growth parameters, we have successfully demonstrated cm-scale highly-selective Bi2Se3 growth on crossbar-arrayed structures with an in-lab yield of 86%. The whole process is etch- and plasma-free, substantially minimizing the damage to the crystal structure and also preventing the formation of rough 2D-material surfaces. Furthermore, we also preliminarily demonstrated memristive devices, which exhibit reproducible resistance switching characteristics (over 50 cycles) and a retention time of up to 106 s. This work provides a useful guideline for the scalable fabrication of vertically arranged crossbar arrays of 2D-material-based memristive devices, which is critical to the implementation of such devices for practical neuromorphic applications.
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Rubbing-induced site-selective deposition of 2D material patterns on nanomembranes
2D-layered materials (e.g., graphene and transition metal dichalcogenides) have attracted huge attention due to their unique mechanical and electrical properties. Emerging research efforts, which seek to combine device characterization and high-resolution electron micrography analysis for 2D-layered device features, demand nano/microlithographic techniques capable of producing ordered 2D material patterns on ultrathin membranes with nanoscale thicknesses. However, such membranes are so fragile that most conventional lithographic techniques can be hardly performed on them to generate 2D material patterns. Our previous works have demonstrated that the rubbing-induced site-selective (RISS) deposition method can produce arbitrary 2D semiconductor (e.g., MoS2 and Bi2Se3) patterns on regular device substrates. This fabrication route prevents the vulnerable 2D-layered structures from the detrimental damage introduced by plasma etching and resist-based lithography processes. In this work, we explore the applicability of RISS for directly producing 2D material patterns on nanomembranes. Specifically, this work shows that a polymeric interfacing layer on the rubbing template features, which can effectively prevent stress concentration during the rubbing process, is crucial to successful implementation of RISS processes on nanomembranes. Furthermore, we carried out the mechanics simulation of the Von Mises stress and pressure distribution on the RISS-processed membrane to identify the optimal rubbing load, which can generate sufficient triboelectric charge for material deposition but no damage to the membrane. Using this approach, we have successfully demonstrated the deposition of Bi2Se3 patterns on 25 nm SiOx nanomembranes and high-resolution transmission electron micrography characterization of the crystallographic structures.
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- Award ID(s):
- 2001036
- PAR ID:
- 10552261
- Publisher / Repository:
- AIP Publishing
- Date Published:
- Journal Name:
- Journal of Vacuum Science & Technology B
- Volume:
- 42
- Issue:
- 6
- ISSN:
- 2166-2746
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1116/6.0003961
