Crystallization of Silicon Ion Implanted LPCVD Amorphous Silicon Films for High Performance Poly-TFT

1990 ◽  
Vol 182 ◽  
Author(s):  
I-W. Wu ◽  
A. Chiang ◽  
M. Fuse ◽  
L. Öveqoglut ◽  
T. Y. Huang

AbstractThe mechanism of silicon ion implantation on the crystallization kinetics and the resulting grain sizes of LPCVD α-Si films have been studied by x-ray diffraction and transmission electron microscopy. The solid-phase crystallization was proceeded by random nucleation and growth from the Si/SiO2 interface. The most effective grain size enhancement was found by targeting the peak concentration of implanted siliconbeyond the Si/SiO2 interface, such that the maximum kinetic energy transfer occurred at that interface. The average grain size increases from ∼0.16 μm to ∼2.0 μm by a Si + implantation at 92KeV and a dose of 2X1015 cm-2 for 0.1 μm silicon film. X-ray diffraction intensities were analyzed to optimize implanting dose, beam current and energy for different film thickness. Grain size enhancement was achieved by retarding the random nucleation and increasing the nucleation activation barrier from ∼3.9eV to ∼4.9 eV for the implanted sample. The amorphous to crystalline growth activation barrier of ∼3.2 eV was not altered by Si+ implantation. The observed nucleation and growth kinetics change may be due to the chemical effect of the recoiled oxygen atoms from the substrate. The field-effect mobilities for both n- and p-channel TFTs increase by a factor of two with deep silicon implant.

2010 ◽  
Vol 44-47 ◽  
pp. 4151-4153 ◽  
Author(s):  
Rui Min Jin ◽  
Ding Zhen Li ◽  
Lan Li Chen ◽  
Xiang Ju Han ◽  
Jing Xiao Lu

Amorphous silicon films prepared by PECVD on glass substrate has been crystallized by rapid thermal annealing (RTA) at the same temperature for different time. From X-ray diffraction (XRD) and scanning electronic microscope (SEM), it is found that the grain size is biggest crystallized at 720°C for 8 min, an average grain size of 28nm or so is obtained. The thin film is smoothly and perfect structure.


1989 ◽  
Vol 164 ◽  
Author(s):  
M.A. Hachicha ◽  
Etienne Bustarret

AbstractUndoped 500 nm-thick silicon layers with a crystalline fraction around 95% and an average grain size of 20 nm have been deposited at 350°C by 50 kHz triode PECVD in a H2/SiH4 mixture, in the presence of a magnetic field. Their room temperature (rt) dc conductivity μrt is 0.03 Δ−1cm−1 for a Hall mobility of 0.8 cm 2V−1s−1.The study by SIMS, infrared absorption, grazing angle x-ray diffraction and Raman scattering spectroscopies of the doped samples shows how the crystalline fraction and the grain size drop as the B2H6/SiH4 and PH3/SiH4 volumic ratios increase from 10 ppm to 1%.The rt dc conductivity reaches 2 Δ−1 cm−1 (Hall mobility: 15 cm2V−ls−1) for a solid phase density of 1019 cm−3 boron atoms, and 30 Δ−1cm−1 (Hall mobility: 55 cm2V−ls−1) at the maximum P incorporation of 8 × 1020cm−3.


2007 ◽  
Vol 26-28 ◽  
pp. 243-246
Author(s):  
Xing Hua Yang ◽  
Jin Liang Huang ◽  
Xiao Wang ◽  
Chun Wei Cui

BaBi4-xLaxTi4O15 (BBLT) ceramics were prepared by conventional solid phase sintering ceramics processing technology. The crystal structure and the microstructure were detected by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analyses show that La3+ ions doping did not change the crystal structure of BBT ceramics. The sintering temperature increased from 1120°C to 1150°C with increasing Lanthanum content from 0 to 0.5, but it widened the sintering temperature range from 20°C to 50°C and refined the grain size of the BBT ceramic. Additionally, polarization treatment was performed and finally piezoelectric property was measured. As a result, the piezoelectric constant d33 of the 0.1at.% doped BBLT ceramics reached its highest value about 22pc/N at polarizing electric field of 8kV/mm and polarizing temperature of 120°C for 30min.


2001 ◽  
Vol 703 ◽  
Author(s):  
L. Bessais ◽  
C. Djéga-Mariadassou ◽  
J. Zhang ◽  
V. Lalanne ◽  
A. Percheron-Guégan

ABSTRACTThe evolution of both micro structural and magnetic properties of the Sm[BE]Co[BD][BJ] Cu powder, is studied as a function of soft co-milling time. The average grain size in the range 20 - 50 nm was determined by transmission electron microscopy coupled with x-ray diffraction using the Rietveld method. The particle shape and chemical distribution were investigated by elemental mapping, using wavelength dispersive x-ray analysis with electron microprobe analysis. The coercivity evolution shows that an optimum value of 6 kOe is obtained after 5 h co-milling. The microstructure analysis indicates that both materials are well mixed in nanometer scale. This technique appears as a potential route to synthesize nanocrystalline Sm[BE]Co[BD][BJ] isolated by non-magnetic metal Cu.


2013 ◽  
Vol 747-748 ◽  
pp. 613-618
Author(s):  
Qiao Zhang ◽  
Shu Hua Liang ◽  
Chen Zhang ◽  
Jun Tao Zou

The as-cast Ni-W alloys with 15wt%W, 25wt%W and 30wt%W were annealed in hydrogen at 1100. The effect of the annealing time on the microstructure of Ni-W alloys was studied, and the phase constituents and microstructure of annealed Ni-W alloys were characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that no any phase changed for Ni-15%W, Ni-25%W and Ni-30%W alloys annealed for 60 min, 90 min and 150 min, which were still consisted of single-phase Ni (W) solid solution. However, microstructure had a significant change after annealing. With increase of annealing time, the microstructure of Ni-15%W alloy became more uniform after annealing for 90 min, and the average grain size was 95μm, whereas the grain size of Ni-15%W alloy increased significantly after annealing for 150 min. For Ni-25%W and Ni-30%W, there was no obvious change on the grain size with increase of annealing time, and the amount of oxides at grain boundaries gradually reduced. After annealing for 150 min, the impurities at grain boundaries almost disappeared. Subsequently, the annealing at 1100 for 150 min was beneficial for the desired microstructure of Ni-25%W and Ni-30%W alloys.


2001 ◽  
Vol 672 ◽  
Author(s):  
Kathleen A. Dunn ◽  
Katharine Dovidenko ◽  
Anna W. Topol ◽  
Serge R. Oktyabrsky ◽  
Alain E. Kaloyeros

ABSTRACTZinc sulfide doped with manganese is extensively used for thin film electroluminescent device applications. In order to assess the key material and process challenges, ZnS:Mn layers were fabricated by metalorganic chemical vapor deposition in the 250°-500°C range on an AlTiO/InSnO/glass stack. The microstructure of the ZnS:Mn films was examined by Transmission Electron Microscopy (TEM) as part of a larger study which fully characterizes these films by a variety of structural and chemical characterization techniques, including Rutherford Backscattering, Secondary Ion Mass Spectroscopy, Atomic Force Microscopy, Scanning Electron Microscopy and X-ray Diffraction. For all the growth conditions, the films were found to be polycrystalline having predominantly 2H hexagonal ZnS structure. The ZnS grains are found to grow columnar as the film thickness increases, also widening in the direction parallel to the substrate surface and reaching the 100 - 200 nm average lateral size at the 650 nm film thickness. The presence of the 8H ZnS polytype was detected in the low-temperature ZnS:Mn films by TEM selected area electron diffraction and confirmed by X-ray diffraction analysis. Dark field TEM imaging correlated this 8H ring with very small (∼2.5 nm) grains present throughout the low temperature film with a slightly higher density at the film/substrate interface. The 700°C post-deposition annealing was found to initiate a solid state transformation to the cubic (3C) ZnS crystal structure, and resulted in an average grain size of ∼250 nm at the surface of the annealed film.


Author(s):  
Narender Budhiraja ◽  
Ashwani Sharma ◽  
Sanjay Kumar ◽  
Anupreet Kaur ◽  
N.V. Unikrishnan

In the present paper, main emphasis is given to synthesize the Stannous-Cerium oxide nanocomposites in nanofilms, nanodots and nanorods by Chemical bath method, Chemical drop method and Chemical rolling Method. These nanocomposite materials are synthesized on a glass substrate at 100 °C temperature. Crystallography investigation of these materials is done by X-ray diffraction (XRD) which reveals that average grain size is 58.9 nm and 62.3 nm for nanofilms and nanodots on glass substrate respectively whereas XRD diffraction for nanorod on glass substrate reveals that material is amorphous in nature.


2022 ◽  
Vol 961 (1) ◽  
pp. 012018
Author(s):  
Sukaina Iskandar Yusuf ◽  
Mohammed Muhana Meteab ◽  
Abdulkader Ahmed Annaz

Abstract Due to the importance of these alloys in the manufacture of aircraft, coatings, radiation shields, and electronic circuits, the study’s objectives include investigating previously unstudied structural properties of some aluminum alloys, alloy A (Al-Zn-Mg-Ti) and alloy B (Al-Zn-Mg-Mn) were prepared using the casting method, and their structural properties were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques (granular size and theoretical density). The results of analyzing the X-ray diffraction data and determining the phases formed on the two alloys after matching them with the international standard cards (JCPDS) revealed that it is polycrystalline, with structures (cubic and hexagonal) on alloy A and structures (cube, hexagonal, and anorthic) on alloy B. The results revealed that the average grain size estimated by the Debye-Scherer method is less than that estimated by the Williamson-Hall method, and that the grain size of alloy A is less than that of alloy B due to the presence of titanium in alloy A’s composition, which works to reduce particle size. The theoretical density of Alloy A and B that was used in X-ray diffraction was calculated. SEM analysis of the spherical shape of the grains on the surfaces of alloys A and B revealed that the average grain size on the surface of alloy A is smaller than on the surface of alloy B, which is consistent with the results of XRD analyses.


2005 ◽  
Vol 20 (10) ◽  
pp. 2676-2681 ◽  
Author(s):  
Maolin Pang ◽  
Xiaoming Liu ◽  
Jun Lin

R2MoO6:Eu3+ (R = Gd, Y, La) phosphors were prepared by the Pechini sol-gel process. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), reflectance spectra, photoluminescence (PL) spectra, and lifetimes were used to characterize the resulting phosphors. The results of XRD indicate that all of the R1.96Eu0.04MoO6 (R = Gd, Y, La) phosphors crystallized completely at 800 °C. Y1.96Eu0.04MoO6 and Gd1.96Eu0.04MoO6 are of isomorphous monoclinic (α) structure, while La1.96Eu0.04MoO6 preferentially adopts the tetragonal (γ) form. FE-SEM study reveals that the samples mainly consist of aggregated particles with an average grain size ranging from 100 to 250 nm. The luminescent properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors are largely dependent on their structure, grain size, and powder morphology. The isomorphous Y2MoO6:Eu3+ and Gd2MoO6:Eu3+ phosphors show very similar luminescence properties, which differ greatly from that of the La2MoO6:Eu3+ phosphor.


2007 ◽  
Vol 23 ◽  
pp. 63-66
Author(s):  
Virgiliu Călin Prică ◽  
George Arghir

Fe-Cu system is a binary alloys system, nevertheless very difficult. This paper presented the milling duration influence on ball-milled Fe30Cu70 alloys. After 16 hour of milling it has been concluded that true alloying at atomic level occurs during milling. The average grain size depends by milling time. Varying the milling time changes the powder morphology, their size and structure. We found that the complete fcc Fe –Cu solid solution is formed when the grain size of Fe-bcc reach a value about 10 nm, because at this value of crystallite the free energy for interface become less than interfaces energy. The milling duration have a strongly influence on solid solubility and phases form in Fe-Cu system. The phase formation for Fe30Cu70 (mass %) has been investigated by X-ray diffraction (XRD). The mixing enthalpy (positive in this system) also depends on alloy composition.


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