Low-temperature rapid thermal CVD of nanocrystalline graphene on Cu thin films

AbstractLow-temperature growth of polycrystalline Silicon thin films has been investigated to fabricate thin film transistors by a new thermal CVD with the reactive source gases, Si2H6 and F2, resulting in the film growth at a low-temperature less than 500°C. In order to establish the optimal condition, gas pressure, total gas flow rate of Si2H6+F2 and He as a carrier gas, and residence time, τ, were tuned. Deposition rates and film crystallinity were influenced by the gas flow rations. The growth rate was 3.2-4.2[nm/min] and film uniformity was within ±6.5% over 4cm2 area. High crystallinity films showed a sharp peak at 520[cm-1] in Raman spectra whose full width at half maximum was 6-8[cm-1]. The high crystallinity even at the early stage of film growth was confirmed by transmission electron microscopy. The conductivity and activation energy is on the order of 10-5-10-6 [S/cm] and 0.53[eV], respectively, after hydrogenation. We fabricated poly-Si bottom-gate TFT that have field effect mobility as high as 32.3cm2/Vs and on/off current ratio of 104.

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High-quality Ge-rich SiGe thin films epitaxially grown on Si at low temperature by a two-step approach

CrystEngComm ◽

10.1039/c9ce00948e ◽

2019 ◽

Vol 21 (43) ◽

pp. 6623-6629

Author(s):

Ke Tao ◽

Jin Wang ◽

Shuai Jiang ◽

Rui Jia ◽

Zhi Jin ◽

...

Keyword(s):

Thin Films ◽

Low Temperature ◽

Seed Layer ◽

Si Substrate ◽

High Quality ◽

Bulk Layer ◽

Thermal Cvd ◽

Post Annealing ◽

Step Growth ◽

Growth Approach

A two-step growth approach including seed layer epitaxy, post-annealing, and bulk layer epitaxy was proposed to deposit high quality Ge-rich Si1−xGex epilayer directly on Si substrate by reactive thermal CVD (RTCVD) at low temperature (350 °C).

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Deposition of Si Thin Films by Reactive CVD

MRS Proceedings ◽

10.1557/proc-377-105 ◽

1995 ◽

Vol 377 ◽

Cited By ~ 11

Author(s):

Jun-Ichi Hanna

Keyword(s):

Thin Films ◽

Low Temperature ◽

Gas Phase ◽

Film Growth ◽

Chemical Deposition ◽

Gas Phase Reactions ◽

Temperature Growth ◽

Low Temperature Growth ◽

Thermal Cvd

ABSTRACTA new concept of Reactive CVD is proposed for the low-temperature growth of thin films by CVD and discussed in terms of general features of such film growth. One demonstrated example of the reactive CVD, called Spontaneous Chemical Deposition, features gas phase reactions of silane with fluorine is outlined in terms of the general characteristics of the film growth and properties.In addition, a second example of reactive CVD, called Reactive Thermal CVD and involving thermal CVD of poly-SiGe from germanium fluoride and disilane, is discussed and low-temperature growth using this method is reviewed.

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Low-temperature Growth of Poly-Si and SiGe Thin Films by Reactive Thermal CVD and Fabrication of High Mobility TFTs over 50 cm2/Vs

MRS Proceedings ◽

10.1557/proc-762-a20.1 ◽

2003 ◽

Vol 762 ◽

Cited By ~ 1

Author(s):

Jun-Ichi Hanna ◽

Kousaku Shimizu

Keyword(s):

Thin Films ◽

Low Temperature ◽

Silicon Germanium ◽

Film Growth ◽

Early Stage ◽

Substrate Surface ◽

Large Area ◽

Glass Substrates ◽

Thermal Cvd ◽

Technical Requirements

AbstractWe have established a new thermal CVD technique, Reactive Thermal CVD, for polycrystalline silicon (poly-Si) and silicon germanium (poly-SiGe) thin films aiming at thin film transistors (TFTs) applications, in which a low substrate temperature of 450°C enables us to use glass substrates. This technique achieved high crystallinity at very early stage of the film growth, resulting no amorphous incubation layer on the substrate surface. We fabricated bottom and top gate n-and p-channel TFTs with these of 200 nm thick films on SiO2/Si wafers and glass substrates, respectively: the high field effect mobilities as high as 55 cm2/Vs and 25 cm2/Vs were achieved in the bottom-gate and top-gate TFTs, respectively. Here, we discuss the technical requirements in the low-temperature CVD technique for the large-area poly-Si thin films and how they can be achieved in the reactive thermal CVD.

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Observation by HVEM of the martensite transformation and the superconducting transition in Nb3Sn

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106004 ◽

1988 ◽

Vol 46 ◽

pp. 788-789

Author(s):

M. A. Kirk ◽

M. C. Baker ◽

B. J. Kestel ◽

H. W. Weber

Keyword(s):

Thin Films ◽

Low Temperature ◽

Superconducting State ◽

Martensite Transformation ◽

Sputter Deposition ◽

Diffusion Reaction ◽

Solute Diffusion ◽

Superconducting Transition ◽

Twin Boundaries ◽

Martensite Structure

It is well known that a number of compound superconductors with the A15 structure undergo a martensite transformation when cooled to the superconducting state. Nb3Sn is one of those compounds that transforms, at least partially, from a cubic to tetragonal structure near 43 K. To our knowledge this transformation in Nb3Sn has not been studied by TEM. In fact, the only low temperature TEM study of an A15 material, V3Si, was performed by Goringe and Valdre over 20 years ago. They found the martensite structure in some foil areas at temperatures between 11 and 29 K, accompanied by faults that consisted of coherent twin boundaries on {110} planes. In pursuing our studies of irradiation defects in superconductors, we are the first to observe by TEM a similar martensite structure in Nb3Sn.Samples of Nb3Sn suitable for TEM studies have been produced by both a liquid solute diffusion reaction and by sputter deposition of thin films.

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