Spatial Confinement Approach Using Ni to Modulate Local Carbon Supply for the Growth of Uniform Transfer-Free Graphene Monolayers

Abstract

Direct growth of high-quality graphene on dielectric substrates without a sophisticated transfer process is one of the key challenges to effectively integrate graphene synthesis with the existing semiconductor manufacturing process. In this study, we take advantages offered by a customized reactor to realize the synthesis of uniform transfer-free graphene monolayers on SiO2/Si substrates via the metal-catalytic chemical vapor deposition method. The optimal reactor is designed to be a Ni-covered quartz slit with a confined reaction space (length × width × height = 85 × 13 × 0.55 mm3). The slit structure of this reactor offers a spatially confined environment for effectively suppressing Cu evaporation and modulating the growth kinetics of graphene. In addition, the Ni cover serves as a carbon absorbent for regulating the local concentration of carbon species within the slit reactor, which increases the monolayer content of the produced graphene. With the optimal synthesis protocol, transfer-free graphene with low defects and high monolayer content (>90%) was prepared directly on SiO2/Si substrates as continuous large-area films (1 × 1 cm2) or microscale patterns with sheet resistance and field-effect mobility of 334 Ω/sq and 962 cm2/(V s), respectively.

Quasistatic Equilibrium Chemical Vapor Deposition of Graphene

“…Henceforth, graphene with high structural integrity and mostly covered with single layer is evidenced (Figure 11b–d). [ 37 ] Undesirably, small nucleation number lead to large crystal growth but it also drop the growth rate which takes growth period elongation. The synthesis of large‐domain graphene requires a low nucleation density, which inevitably reduces the growth rate.…”

“…Adapted with permission. [ 37 ] Copyright 2020, American Chemical Society. e) Cu foil mounted on quartz slide with channel configuration.…”

Cobalt-Activated Transfer-Free Synthesis of the Graphene on Si(100) by Anode Layer Ion Source

“…The flat surface area seen in the SEM image is planar graphene (Figures 5 and 9). It should be mentioned that the graphene detachment during the chemical etching of the sacrificial catalytic film was already reported in [56]. In a high-magnification SEM image, one can see the planar graphene at the bottom, some graphene flakes of the 20-40 nm size, and larger rolled graphene flakes (Figure S10).…”

“…The inhomogeneous surface was observed by SEM similarly to Figures 9 and 11[9,10,19,54]. In[9,56], for some graphene samples, smooth surface areas with darker gray islands were seen by SEM similarly to the graphene on Si(100) areas free of the detached graphene seen in Figure11. AFM images of the graphene synthesized using catalyst-assisted direct synthesis in[40] revealed a granular structure similar to our study results (Figures9 and 10).…”

Evolution of Graphene Patterning: From Dimension Regulation to Molecular Engineering

“…The growth of GNRs can also be achieved by rapid annealing of nickel‐carbon nanowires prepared by electrodeposition. [ 118 ] These nickel‐carbon nanowires were prepared by using alumina membranes as templates and graphene quantum dots as carbon sources in the process of nickel electroplating. Specifically, alumina membranes coated with a gallium/indium alloy and Watts nickel platting solution mixed with GQD were used as a cathode and an electrolyte, respectively.…”