Growth of low doped monolayer graphene on SiC(0001) via sublimation at low argon pressure

Abstract

Silicon carbide (SiC) sublimation is the most promising option to achieve transfer-free graphene at the wafer-scale. We investigated the initial growth stages from the buffer layer to monolayer graphene on SiC(0001) as a function of annealing temperature at low argon pressure (10 mbar). A buffer layer, fully covering the SiC substrate, forms when the substrate is annealed at 1600 °C. Graphene formation starts from the step edges of the SiC substrate at higher temperature (1700 °C). The spatial homogeneity of the monolayer graphene was observed at 1750 °C, as characterized by Raman spectroscopy and magneto-transport. Raman spectroscopy mapping indicated an A/A ratio of around 3.3%, which is very close to the experimental value reported for a graphene monolayer. Transport measurements from room temperature down to 1.7 K indicated slightly p-doped samples (p ≃ 10 cm) and confirmed both continuity and thickness of the monolayer graphene film. Successive growth processes have confirmed the reproducibility and homogeneity of these monolayer films.

Nanostructured Bi Grown on Epitaxial Graphene/SiC

“…The growth of Bi thin films and nanoislands on Si(111), Ag(111), Bi 2 Te 3 , HOPG, , and so on was extensively studied. However, only a little research has been done on the growth of Bi on epitaxial graphene (EG), although EG is considered as a promising material for high-performance devices. − Furthermore, EG prepared through thermal decomposition of SiC usually coexists with SiC buffer layer (BL). Thus it provides us a good platform to study the substrate effect on the growth of Bi nanostructures as well as on the electronic states .…”

2D Oxides Realized via Confinement Heteroepitaxy

“…[40] Additionally, the ordered EG buffer Raman signal intensity is ≈10× less than the disordered EG buffer, preventing the identifica tion of EG buffer peaks without SiC background signal subtraction (Figure S1a,b, Supporting Information). [33] EG buffer layer peaks are denoted as 1 -8 (Figure S2a,b, Supporting Information), similar to [41,42] . The dispersion relation as a function of excitation laser wavelength of the Raman features (Figure S2c,d, Supporting Information) indicates a linear excitation energy dependence of the disordered EG buffer peaks (44.6 cm −1 /eV for 6 , 32.6 cm −1 /eV for 7 , and 17.2 cm −1 /eV for 8 ), and little wavelength dependence for ordered EG buffer.…”

“…[26][27][28][29] When EG buffer layers are used for metal intercalation, the metal can remain stabilized as metallic [28,29] or transform into a disordered oxide [27,30] based on the structural properties (level of disorder) of the starting EG buffer layer. [31][32][33][34][35] Hence, controlled synthesis of ordered and disordered EG buffers, and its impact on the intercalated 2D layers should be understood such that the interface can be engineered for next-generation applications.…”

Toward the Reproducible Growth of Graphene on Wide SiC Steps: A Study of the Geometric Properties of 4H-SiC (0001) Substrates

“…During thermal annealing, around 1300°C in our experimental conditions, 4H-SiC(0001) will starts to undergo a surface reconstruction [4,5]. At this stage, new steps with a certain shape, height and width begin to form.…”