Hexagon Flower Quantum Dot-like Cu Pattern Formation during Low-Pressure Chemical Vapor Deposited Graphene Growth on a Liquid Cu/W Substrate

Abstract

The H 2 -induced etching of low-dimensional materials is of significant interest for controlled architecture design of crystalline materials at the micro- and nanoscale. This principle is applied to the thinnest crystalline etchant, graphene. In this study, by using a high H 2 concentration, the etched hexagonal holes of copper quantum dots (Cu QDs) were formed and embedded into the large-scale graphene region by low-pressure chemical vapor deposition on a liquid Cu/W surface. With this procedure, the hexagon flower-etched Cu patterns were formed in a H 2 environment at a higher melting temperature of Cu foil (1090 °C). The etching into the large-scale graphene was confirmed by optical microscopy, atomic force microscopy, scanning electron microscopy, and Raman analysis. This first observation could be an intriguing case for the fundamental study of low-dimensional material etching during chemical vapor deposition growth; moreover, it may supply a simple approach for the controlled etching/growth. In addition, it could be significant in the fabrication of controllable etched structures based on Cu QD patterns for nanoelectronic devices as well as in-plane heterostructures on other low-dimensional materials in the near future.

Carbon Nanotubes: Synthesis, Properties and Applications

“…Reactor: It contains a quartz chamber which is connected to vacuum pump and a diffusion pump to inert gas supply. Initially the chamber is made vacuum by the vacuum pump and then the chamber is filled with helium gas by the diffusion pump [24].…”

The New Etching Technologies of Graphene Surfaces

“…In addition, there are still strategies for graphene surface etching such as Ar/H 2 mixture in reactive ion etching (RIE) (Figure 4a) [29], H 2 etching during CVD graphene growth (Figure 4b-e) [30], CH 4 /H 2 etching during CVD graphene growth (Figure 4f) [31] or thermally activated Fe nanoparticles (NPs) (Figure 4g, h) [32]. However, the demonstrated results showed high defects through very high D-peak intensity in Raman spectra [29] or the random and nonuniform nanoribbon-etched graphene [28] and nanotrench-etched graphene based on Fe NPs [32].…”

“…Recently, etching technologies are emerging as one of the best efficient tools to tune a device's performance, thereby extending to many different fields in broadband [20][21][22][23][24][25][26][27][28][29][30]. The new approaches include the following: (i) inductively coupled plasma (ICP), neutral beam-based atomic layer etching (ALE), ion beam and reactive ion etching (RIE) [22][23][24][25][26][27][28][29], (ii) chemical vapor deposition (CVD) [30,31] and (iii) thermally activated nanoparticles [32]. Plasma has used Si-integrated circuits for etching [22].…”

Growth Kinetics of Thin Film Epitaxy

“…Epitaxial thin films and artificial multilayers are grown on solid single-crystal surfaces with atomic monolayer thickness control either by chemical vapor deposition (CVD) [1,2] or by molecular beam epitaxy (MBE). In CVD, precursor molecules are thermally decomposed in a continuous flow oven in a background atmosphere of clean inert gas, whereas in MBE the surface is held in ultrahigh vacuum (UHV, 10 À8 Pa).…”