Influence of plasma treatment on SiO2/Si and Si3N4/Si substrates for large-scale transfer of graphene

Abstract

One of the limiting factors of graphene integration into electronic, photonic, or sensing devices is the unavailability of large-scale graphene directly grown on the isolators. Therefore, it is necessary to transfer graphene from the donor growth wafers onto the isolating target wafers. In the present research, graphene was transferred from the chemical vapor deposited 200 mm Germanium/Silicon (Ge/Si) wafers onto isolating (SiO2/Si and Si3N4/Si) wafers by electrochemical delamination procedure, employing poly(methylmethacrylate) as an intermediate support layer. In order to influence the adhesion properties of graphene, the wettability properties of the target substrates were investigated in this study. To increase the adhesion of the graphene on the isolating surfaces, they were pre-treated with oxygen plasma prior the transfer process of graphene. The wetting contact angle measurements revealed the increase of the hydrophilicity after surface interaction with oxygen plasma, leading to improved adhesion of the graphene on 200 mm target wafers and possible proof-of-concept development of graphene-based devices in standard Si technologies.

Highly enhanced visible light photodetection properties of a ZnO phototransistor via an additional solution processed thin Al2O3 layer

“…From the O 1s spectra of Al 2 O 3 , the peak centered at a lower binding energy of B531.2 eV was slightly observed, indicating the oxygen binding with Al, while the large peak centered at the higher binding energy of B532.83 eV indicates the oxygen binding with silicon (Si) as SiO 2 form. 21,22 The reason for the slight peak of O-Al binding is due to the B1 nm thickness of Al 2 O 3 , which was thin enough for X-rays to penetrate the Al 2 O 3 layer and reach the substrate. To demonstrate the penetration, the XPS spectrum of Si 2p of Al 2 O 3 is shown in Fig.…”

Laminar Flow-Assisted Metal Etching for the Preparation of High-Quality Transfer-Free Graphene

“…In O 2 plasma cleaning, organic contaminants are effectively removed through chemical reactions with highly reactive oxygen radicals and ablation with energetic oxygen ions. The surfaces of the SiO 2 /Si substrates subjected to O 2 plasma cleaning were activated by the formation of Si–OH and dangling silicon bonds because of the breakage of the Si–O–Si bond in the SiO 2 layer, − resulting in significantly enhanced surface hydrophilicity and a water contact angle of 11.18°, which corresponds to a high surface energy of 71.43 mJ m –2 (Figure c). Furthermore, long-term recordings of the water contact angle indicated that gaseous hydrocarbons in ambient air gradually adsorbed and contaminated all three types of treated surfaces, resulting in gradual increases in the water contact angle and reductions in the surface hydrophilicity (Figure S7).…”

Substrate Engineering-Tailored Fabrication of Aligned Graphene Nanoribbon Arrays: Implications for Graphene Electronic Devices

“…One can readily use CVD to fabricate graphene of the same quality as that acquired by mechanical exfoliation. Inevitably, wrinkles of graphene form not only during growth because of the difference in the coefficient of thermal expansion between the Cu foil and graphene − but also when the liquid between the graphene and substrate evaporates after graphene transfer to the target substrate. , Some reports indicate that the nature of the target substrate affects the quantity of graphene wrinkles; an effective method to reduce the quantity of graphene wrinkles is to render the SiO 2 /Si target substrate hydrophilic by reactive ion etching (RIE) or hydrofluoric acid treatment. , …”

“…35,36 Some reports indicate that the nature of the target substrate affects the quantity of graphene wrinkles; an effective method to reduce the quantity of graphene wrinkles is to render the SiO 2 /Si target substrate hydrophilic by reactive ion etching (RIE) or hydrofluoric acid treatment. 36,37 In this work, we introduced an aligned wrinkle array by using a substrate with an optimized nanostructure which can perfectly control the density, length, and direction of wrinkles. Making full use of the features of the graphene wrinkles, we turned these wrinkles into GNRs.…”