CVD assisted fabrication of graphene layers for field effect device fabrication

Journal of Vacuum Science &Amp; Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phen

et al. 2012

Self Cite

We invented a method to fabricate graphene transistors on oxidized silicon wafers without the need to transfer graphene layers. To stimulate the growth of graphene layers on oxidized silicon a catalyst system of nanometer thin aluminum/nickel double layer is used. This catalyst system is structured via liftoff before the wafer enters the catalytic chemical vapor deposition (CCVD) chamber. In the subsequent methane based growth process monolayer graphene field-effect transistors (MoLGFETs) and bilayer graphene transistors (BiLGFETs) are realized directly on oxidized silicon substrate, whereby the number of stacked graphene layers is determined by the selected CCVD process parameters, e.g. temperature and gas mixture. Subsequently, Raman spectroscopy is performed within the channel region in between the catalytic areas and the Raman spectra of fivelayer, bilayer and monolayer graphene confirm the existence of graphene grown by this silicon-compatible, transfer-free and in-situ fabrication approach. These graphene FETs will allow a simple and low-cost integration of graphene devices for nanoelectronic applications in a hybrid silicon CMOS environment.2

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confidence: 72%

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confidence: 99%

Transfer-free fabrication of graphene transistors

Journal of Vacuum Science &Amp; Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phen

et al. 2012

Self Cite

“…During growth the graphene layer extends a few microns from the catalyst onto the oxidized wafer surface which is sufficient for device fabrication. The results of a Fourieranalysis of transmission electron microscopy (TEM) data of a fewlayer graphene sample revealed the crystalline properties of the graphene multilayer more in detail as published in [11]. In Fig.…”

Section: Introductionmentioning

confidence: 91%

“…In-situ means, that graphene films are grown directly on the oxidized wafer at its final position, so that subsequent transfer and alignments are obsolete. Using a metallic catalyst seed, mono-, bi-and fewlayer graphene films are growing directly on SiO 2 covered Si wafers at moderate growth temperatures of 800 -900°C by means of catalytic chemical vapor deposition (CCVD) from a methane feedstock [11]. During growth the graphene layer extends a few microns from the catalyst onto the oxidized wafer surface which is sufficient for device fabrication.…”

Section: Introductionmentioning

confidence: 99%

On/off-current ratios of transfer-free bilayer graphene FETs as a function of temperature

7th International Conference on Design &Amp; Technology of Integrated Systems in Nanoscale Era

et al. 2012

In this paper we report on a novel method to fabricate graphene transistors directly on oxidized silicon wafers without the need to transfer graphene. By means of catalytic chemical vapor deposition (CCVD) the in-situ grown bilayer graphene transistors (BiLGFETs) are realized directly on oxidized silicon substrate. These BiLGFETs possess unipolar p-type device characteristics with an extremely high on/off-current ratio between 1×10 6 and 1×10 7 at room temperature [1, 2], exceeding previously reported values by several orders of magnitude. Furthermore, when increasing the ambient temperature to 200°C, the on/off-current ratio only degrades by one order of magnitude for BiLGFETs. Besides the excellent device characteristics, the complete CCVD fabrication process is silicon CMOS compatible. This will allow a simple and low-cost integration of graphene devices for nanoelectronic applications in a hybrid silicon CMOS environment

“…14,15 The results of a Fourieranalysis of transmission electron microscopy (TEM) data of a fewlayer graphene sample revealed the crystalline properties of the graphene multilayer more in detail as published in April 2011. 16 In fact, the observed interplanar spacing of 3.5Å is an additional strong evidence for the existence of fewlayer graphene grown by means of CCVD. When using a suitable device layout, the in situ grown graphene film can be used as back-gated field effect device material contacted directly via the catalytic source/drain (S/D) areas (cf.…”

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confidence: 99%

Hysteresis of In Situ CCVD Grown Graphene Transistors

Electrochem. Solid-State Lett.

et al. 2012

In this paper we report on a novel method to fabricate graphene transistors directly on oxidized silicon wafers without the need to transfer graphene. By means of catalytic chemical vapor deposition (CCVD) the in situ grown monolayer graphene field-effect transistors (MoLGFETs) and bilayer graphene field-effect transistors (BiLGFETs) are realized directly on oxidized silicon substrate. In situ CCVD grown BiLGFETs possess unipolar p-type device characteristics with an extremely high on/off-current ratio up to 1 × 10 7 . With this novel fabrication method hundreds of large scale in situ CCVD grown graphene FETs are realized simultaneously on one 2'' wafer in a silicon CMOS compatible process.