Effect of oxygen plasma etching on graphene studied with raman spectroscopy and electronic transport isaac childres1,2, luis a. We developed a method of identifying the structural defects in graphitic materials by an anisotropic etching technique. I would like to know the thermal etching conditions and if there is any chemical etchant for graphite. In this study, with the aid of a custommade plasmaenhanced hydrogen etching pehe system, a detailed graphene etching process by remote. The etching process can be used to nanostructure and electrically. Because plasma strength at the ground electrode is lower than that at the powered electrode, the sse by oxygen plasma can potentially introduce a rel. Panel e shows raman spectra acquired on bulk graphene, again before yellow, after 3h blue and after 5h red of h plasma etching. Etching of graphene devices with a helium ion beam acs nano. In all cases, afm reveals that etching residues persist beyond the point where optical microscopy and raman suggest complete graphene removal. Etching experiments of four different chips in four independent runs under the same plasma conditions found etching rates of 0. The surfaces of highly oriented pyrolytic graphite hopg samples were treated using two different methods, exposure to an energetic oxygen ion beam and immersion in an oxygen ion plasma, and the. Experiment study on etching process of graphite electrode. Patterning of highly oriented pyrolytic graphite by oxygen plasma.
We studied, by scanning tunneling microscopy, the morphology of nanopits of monolayer depth created at graphite surfaces by hydrogenplasma etching under various conditions such as h2 pressure. We report on the etching of graphene devices with a helium ion beam, including in situ electrical measurement during lithography. In this manner, we show that afm allows accurate determination of etching conditions that minimize graphene dry etch residues. Introduction to plasma etching university of texas at austin. Anisotropic etching of graphite and graphene in a remote. We did not observe a dpeak in the bulk of the graphene akes. Anisotropic hplasma etching of graphite and graphene on hbn. Study on the etching characteristics of amorphous carbon layer in oxygen plasma with carbonyl sulfide jong kyu kim memory division semiconductor business, samsung electronics, san no. Singular sheet etching of graphene with oxygen plasma.
Plasma etching, as the name implies, is a technique of etching in which plasma is used as an etchant instead of strong acids. It has been shown that exposure of graphite to hplasma creates hexagonal etch. Intrinsic and oxygen or argon plasma induced artificial defects density and. Anisotropic etching of graphite and graphene in a remote hydrogen. Synthesis of fewlayered graphene by h2o2 plasma etching. It involves a highspeed stream of glow discharge of an appropriate gas mixture being shot in pulses at a sample. Chen1,2,3 1 department of physics, purdue university, west lafayette, in, 47907, usa 2 birck nanotechnology center, purdue university, west lafayette, in, 47907, usa 3 school of electrical and computer engineering, purdue university.
The durations of oxygen plasma etching were selected as 10 seconds, 30 seconds, 60. Optimization of graphene dry etching conditions via. Nanotechnology tailoring graphite with the goal of. The etching either directly from chemical vapor deposition growth process or plasma technology process has been emerging as attracting research topic in achieving the thinner graphene layer and. Research highlights diamond films were deposited on graphite by microwave cvd with ch 4 h 2 ar mixtures.
Plasma etching techniques including rie, pe, icp, and drie. Transfer patterning of largearea graphene nanomesh via. Reactive ion etching is a simple operation, and an economical solution for general plasma etching. Periodic arrays of islands, or holes of several microns on an edge, were obtained on freshly cleaved hopg surfaces which had been prepared with sio2 mask stops and then oxygen plasma etched. Hexagonal nanopits with the zigzag edge state on graphite. Effects of sputtering and plasma etching on the surface. Formation of graphite nanocones using metal nanoparticles. Pdf the c layers have been patterned by dry etching. Patterning of highly oriented pyrolytic graphite hopg.
Selective plasma etching of polymeric substrates for advanced. Patterning of highly oriented pyrolytic graphite by oxygen. Singular sheet etching of graphene with oxygen plasma pdf. Pdf formation mechanism of graphite hexagonal pyramids. Hydrogen plasma etching resulted in preferential etching of nondiamond carbon. We investigate the etching of a pure hydrogen plasma on graphite samples and graphene flakes on sio 2 and hbn substrates. Some manufacturers introduce a quartz, graphite or silicon carbide plates to avoid sputtering and re. In all cases, afm reveals that etching residues persist beyond the point where optical microscopy and raman suggest complete graphene. Pdf dry etching of carbon layers in various etch gases. Study on the etching characteristics of amorphous carbon. Selective etching of graphene edges by hydrogen plasma. As it turned out gold nanoparticles, which were deposited by immersing hopg. The surface topography of highly oriented pyrolytic graphite hopg after exposure to a radiofrequency rf oxygen plasma has been studied.
Etching of graphite with hydrogen plasma gives rise to two distinct etching regimes, governed by the degree of direct plasma exposure. Arrays of graphite nanocones were fabricated by oxygenplasma etching of highly oriented pyrolytic graphite hopg. Anisotropic reactive ion etching in silicon, using a graphite electrode. We investigate the etching of a pure hydrogen plasma on graphite samples and graphene flakes on sio2 and hexagonal boronnitride hbn substrates. Paper open access related content effect of oxygen. Tailoring gas chemistry for selectivity vs anisotropy. Formation mechanism of graphite hexagonal pyramids by argon plasma etching of graphite substrates article pdf available in journal of physics d applied physics 4849.
The arc, positive photoresist, and graphene are all etched through in a single o 2 plasma etching step. Periodic arrays of islands, or holes of several microns on an. Effect of oxygen plasma etching on graphene studied with. Dc direct current graphite electrodes were used to investigate the hydrogen plasma etching characteristics. Chemical etchant or thermal etching condition for graphite. The surface topography of highly oriented pyrolytic graphite hopg after exposure to a radiofrequency rf oxygen plasma has been studied using scanning tunnelling microscopy stm in ambient air. Pdf singular sheet etching of graphene with oxygen plasma. Radiofrequency rf plasma etching of graphite with oxygen. Results show that the intermittent spark is marked by physical etching, whereas glow. Scalable preparation of broadband ultrablack graphite. Plasma etching is a form of plasma processing used to fabricate integrated circuits.
Precise control of graphene etch ing by remote hydrogen plasma. Sem images of graphite islands created by oxygen plasma etching on an hopg substrate. The xps analysis suggested that h 2 o 2 plasma etching of graphite could oxidize graphene and generated c oh and c o groups on the graphene surfaces. The pressure and distance dependence of the graphite. However, the etching process is still poorly understood. Plasma is the fourth state of matter, formed by ionizing gas particles, through. Plasma etching and the benefits over liquid etching. We investigate the etching of a pure hydrogen plasma on graphite samples and graphene flakes on sio2 and hexagonal boron.
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