Thermal expansion coefficient of polycrystalline silicon and silicon dioxide thin films at high temperatures

Tada, Haruna; Kumpel, Amy E.; Lathrop, Richard E.; Slanina, John B.; Nieva, P.; Zavracky, P.M.; Miaoulis, Ioannis N.; Wong, Peter Y.

doi:10.1063/1.373050

Cited by 201 publications

(93 citation statements)

References 16 publications

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“…The number of graphene layers are identified using This G band upshift is consistent with our previous work on suspended graphene, which showed a 25 cm -1 upshift in the supported region, while the suspended region remained constant after thermal cycling [30]. In this previous work, ripple formation in the suspended region of the graphene indicated that the G band upshift originated from the compression of the graphene lattice created by the mismatch of thermal expansion coefficients between the graphene and the underlying Si/SiO 2 substrate [18,19,31,32] 0.034 cm -1 /K. However, the Raman spectra observed before and after thermal cycling exhibit irreversible upshifts of the G band after the thermal cycle is complete, which must be taken into consideration when estimating the temperature coefficients of graphene.…”

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confidence: 78%

“…In this previous work, ripple formation in the suspended region of the graphene indicated that the G band upshift originated from the compression of the graphene lattice created by the mismatch of thermal expansion coefficients between the graphene and the underlying Si/SiO 2 substrate [18,19,31,32]. In addition to compression, doping effects can also cause the G and 2D bands upshifts.…”

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confidence: 99%

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Raman spectroscopy of substrate-induced compression and substrate doping in thermally cycled graphene

et al. 2012

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By thermally cycling single layer graphene in air, we observe irreversible upshifts of the Raman G and 2D bands of 24 cm -1 and 23 cm -1 , respectively. These upshifts are attributed to an in-plane compression of the graphene induced by the mismatch of thermal expansion coefficients between the graphene and the underlying Si/SiO 2 substrate, as well as doping effects from the trapped surface charge in the underlying substrate. Since the G and the 2D band frequencies have different responses to doping, we can separate the effects of compression and doping associated with thermal cycling.By performing the thermal cycling in an argon gas environment and by comparing suspended and on-substrate regions of the graphene, we can separate the effects of gas doping and doping from the underlying substrate. Variations in the ratio of the 2D to G band Raman intensities provide an independent measure of the doping in graphene that occurs during thermal cycling. During subsequent thermal cycles, both the G and 2Dbands downshift linearly with increasing temperature, and then upshift reversibly to their original frequencies after cooling. This indicates that no further compression or doping is 2 induced after the first thermal cycle. The observation of ripple formation in suspended graphene after thermal cycling confirms the induction of in-plane compression. The amplitude and wavelength of these ripples remain unchanged after subsequent thermal cycling, corroborating that no further compression is induced after the first thermal cycle. 3In the study of graphene, Raman spectroscopy is used widely for identifying the thickness, carrier concentration, temperature, and strain [1][2][3][4]. The sensitivity of the Raman G and 2D bands to both anharmonic coupling of phonon modes and carboncarbon length make Raman spectroscopy a useful tool for studying the temperature and strain dependence of graphene [5][6][7][8] that the effects of strain and doping cannot be neglected when calibrating the temperature coefficient of the Raman modes of graphene. In this work, we measure the Raman spectra of both suspended and supported graphene before, during, and after thermal cycling from 300K to 700K. Both the Raman G and 2D bands are studied systematically. Atomic force microscopy (AFM) is used to determine the suspended graphene profile variation before and after thermal cycling. Thermal cycling in air and Ar gas environments enables us to indentify changes associated with gas doping. In doing so, we are able to separate the effects of doping, compression, and temperature in graphene through the interpretation of the resulting Raman spectra.In this work, graphene flakes are deposited on Si/SiO 2 substrates using mechanical exfoliation [22,23]. The number of graphene layers are identified using This G band upshift is consistent with our previous work on suspended graphene, which showed a 25 cm -1 upshift in the supported region, while the suspended region remained constant after thermal cycling [30]. In this previous work, ripple formati...

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Raman spectroscopy of substrate-induced compression and substrate doping in thermally cycled graphene

et al. 2012

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“…At RT, SiO2 TEC is ~0.5 × 10 -6 K -1 , much smaller than that of monolayer MoS2 ~7 × 10 -6 K -1 , and increases with increasing temperature at a much smaller rate than MoS2. 38,39 Therefore, the strain in MoS2 film tends to accumulate with increasing temperature, and eventually goes beyond the confinement force of van der Waals bonding between the film and substrate, resulting in the change of the film morphology. Similar result has also been observed in graphene and WS2.…”

Section: Resultsmentioning

confidence: 99%

In Situ Monitoring of the Thermal-Annealing Effect in a Monolayer of MoS2

Cao

et al. 2017

Phys. Rev. Applied

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We perform in-situ two-cycle thermal cycling and annealing studies for a transferred CVDgrown monolayer MoS2 on a SiO2/Si substrate, using spatially resolved micro-Raman and PL spectroscopy. After the thermal cycling and being annealed at 305 °C twice, the film morphology and film-substrate bonding are significantly modified, which together with the removal of polymer residues cause major changes in the strain and doping distribution over the film, and thus the optical properties. Before annealing, the strain associated with ripples in the transferred film dominates the spatial distributions of the PL peak position and intensity over the film; after annealing, the variation in film-substrate bonding, affecting both strain and doping, becomes the leading factor. This work reveals that the film-substrate bonding, and thus the strain and doping, is unstable under thermal stress, which is important for understanding the substrate effects on the optical and transport properties of the 2D material and their impact on device applications.

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“…In contrast, with reducing temperatures, the intensity of the two-phonon mode (E 1g ) expands. This feature can be interpreted as when reducing the background signal from the two phonon procedure that increases the visibility of this peak and also the strain-instigated effects due to dissimilarity in thermal expansion coefficients of thinner films and substrate [84,85]. The frequency changes of two-phonon modes for monolayer, bilayers and bulk samples are plotted as a function of temperature ( Figure 7D), showing frequency jumps at 120 K, which also indicates the existence of the IC-CDW state in the thinner crystals of 2H-TaSe 2 .…”

Section: Temperature-dependent Resistivity and Magnetic Susceptibilitymentioning

confidence: 99%

Recent Advances in Two-Dimensional Materials with Charge Density Waves: Synthesis, Characterization and Applications

et al. 2017

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Abstract:Recently, two-dimensional (2D) charge density wave (CDW) materials have attracted extensive interest due to potential applications as high performance functional nanomaterials. As other 2D materials, 2D CDW materials are layered materials with strong in-plane bonding and weak out-of-plane interactions enabling exfoliation into layers of single unit cell thickness. Although bulk CDW materials have been studied for decades, recent developments in nanoscale characterization and device fabrication have opened up new opportunities allowing applications such as oscillators, electrodes in supercapacitors, energy storage and conversion, sensors and spinelectronic devices. In this review, we first outline the synthesis techniques of 2D CDW materials including mechanical exfoliation, liquid exfoliation, chemical vapor transport (CVT), chemical vapor deposition (CVD), molecular beam epitaxy (MBE) and electrochemical exfoliation. Then, the characterization procedure of the 2D CDW materials such as temperature-dependent Raman spectroscopy, temperature-dependent resistivity, magnetic susceptibility and scanning tunneling microscopy (STM) are reviewed. Finally, applications of 2D CDW materials are reviewed.

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Thermal expansion coefficient of polycrystalline silicon and silicon dioxide thin films at high temperatures

Cited by 201 publications

References 16 publications

Raman spectroscopy of substrate-induced compression and substrate doping in thermally cycled graphene

Raman spectroscopy of substrate-induced compression and substrate doping in thermally cycled graphene

In Situ Monitoring of the Thermal-Annealing Effect in a Monolayer of MoS2

Recent Advances in Two-Dimensional Materials with Charge Density Waves: Synthesis, Characterization and Applications

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