Graphene grown on Ge(0 0 1) from atomic source

Abstract

Among the many anticipated applications of graphene, some -such as transistors for Si microelectronics -would greatly benefit from the possibility to deposit graphene directly on a semiconductor grown on a Si wafer. We report that Ge(001) layers on Si(001) wafers can be uniformly covered with graphene at temperatures between 800 • C and the melting temperature of Ge. The graphene is closed, with sheet resistivity strongly decreasing with growth temperature, weakly decreasing with the amount of deposited C, and reaching down to 2 kΩ/2. Activation energy of surface roughness is low (about 0.66 eV) and constant throughout the range of temperatures in which graphene is formed. Density functional theory calculations indicate that the major physical processes affecting the growth are: (1) substitution of Ge in surface dimers by C, (2) interaction between C clusters and Ge monomers, and (3) formation of chemical bonds between graphene edge and Ge(001), and that the processes 1 and 2 are surpassed by CH 2 surface diffusion when the C atoms are delivered from CH 4 . The results of this study indicate that graphene can be produced directly at the active region of the transistor in a process compatible with the Si technology.

Chemical vapor deposited graphene: From synthesis to applications

“…However, graphene transfer from Ge substrate to desired substrates led to wrinkled and folded regions. Lippert et al have also reported direct uniform deposition of graphene on Ge (001) layers on Si (001) wafers. Their results indicate that graphene can be directly deposited at the active regions of Si transistors with a process compatible with Si technology.…”

Decoupling of graphene from Ni(111) via formation of an interfacial NiO layer

“…For example, implementation of graphene in the present-day scalable semiconducting technology requires its synthesis on insulating or semiconducting substrates. Presently this is only possible on h-BN [7][8][9][10] and Ge [11][12][13][14][15] substrates at the conditions which cannot be easily adapted.…”

On the rotational alignment of graphene domains grown on Ge(110) andGe(111)

“…[6] Recently, germanium, a group IV semiconductor, has emerged as a viable substrate for graphene epitaxy. [7][8][9] High quality epitaxial growth on semiconductor wafers is very attractive because it presents a path toward production by existing very large scale integration processes. Graphene growth on Ge(110) by chemical vapor deposition (CVD) has been shown to exhibit considerably improved rotational alignment compared with growth on Ge(111).…”