| AVS 56th International Symposium & Exhibition | |
| Graphene Topical Conference | Wednesday Sessions |
| Session GR+AS-WeA |
| Session: | Graphene: Surface Characterization |
| Presenter: | A. Pirkle, University of Texas at Dallas |
| Authors: | A. Pirkle, University of Texas at Dallas L. Colombo, Texas Instruments Incorporated R.M. Wallace, University of Texas at Dallas |
| Correspondent: | Click to Email |
We present a study of dielectric deposition on graphene and bulk graphite for nanoelectronic device applications. Recent studies have demonstrated that the chemically inert nature of the graphene surface presents challenges to uniform deposition of high quality dielectrics by conventional deposition techniques including ALD. These issues are compounded by the ultrathin nature of graphene, as any covalent bonding that disturbs the underlying graphene lattice is likely to induce scattering and degrade mobility.
In this study, Al, Hf and Si are deposited by electron beam evaporation and subsequently oxidized. We also examine deposition of dielectrics by reactive electron beam evaporation in the presence of a partial pressure of oxygen in the vacuum chamber. Chemical interactions with the substrate are analyzed by means of in-situ x-ray photoelectron spectroscopy (XPS) before and after oxidation. Any presence of carbide bonding (AlC, HfC, SiC) is likely to degrade mobility, and we examine the conditions under which carbide bonds are formed. The oxidized films are also characterized by ex-situ Raman spectroscopy, particularly with regard to the formation of D-band states that are indicative of damage to the graphene lattice during deposition or oxidation. Surface morphology of the deposited films is studied using atomic force microscopy (AFM), particularly with regard to uniformity as pertinent to thickness scaling.
This work is sponsored by the NRI SWAN center.