Crystallization Behavior of Hf-rich Aluminates and Influence on Film Dielectric Properties

2004 ◽  
Vol 811 ◽  
Author(s):  
M. Climent ◽  
B. Crivelli ◽  
G. Righini ◽  
S. Alberici ◽  
M. Alessandri ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Thermal Evolution ◽  
Orthorhombic Phase ◽  
Interface Layer ◽  
Thermal Treatments ◽  
Prolonged Annealing ◽  
Increasing Trend ◽  
Sequential Mode ◽  
Film Dielectric ◽  
Post Deposition

ABSTRACTIn this study, the investigation of crystallization behaviour of Hf-rich aluminate is presented. Different alloys were deposited by ALCVD™ with composition ranging between 16 and 47 Al2O3 mol%. Post-deposition annealings were carried out in single or sequential mode using purified N2 at atmospheric pressure. Process temperature and time were varied from 700°C to 900°C and from 1' to 30' respectively. Upon these conditions, film thermal evolution was observed without any relevant increasing of in interface layer and any change in material composition. Measurements on 20 Al2O3 mol% films evidenced that thermal treatments up to 800°C promoted initial shrinking in thickness and material densification. Above 900°C, all considered aluminates were found to crystallize in orthorhombic phase maintaining original alloy composition. The higher the alumina content, the lower the grain size, the higher the crystallites density. Stability of orthorhombic crystalline structure was demonstrated upon single prolonged annealing up to 30' and upon sequential processes. In correspondence with film crystallization, enhancement of dielectric constant was detected with an increasing trend upon hafnia content. For 20 Al2O3 mol% aluminate, change in k form 19 to 40-45 was observed together with limited degradation in conduction and breakdown characteristics.

Physical-Chemical Evolution of Hf-aluminates upon Thermal Treatments

2003 ◽  
Vol 765 ◽  
Author(s):  
B. Crivelli ◽  
M. Alessandri ◽  
S. Alberici ◽  
D. Brazzelli ◽  
A. C. Elbaz ◽  
...  
Keyword(s):  
Orthorhombic Phase ◽  
Interface Layer ◽  
Film Structure ◽  
Thermal Treatments ◽  
Tem Analysis ◽  
K Value ◽  
Physical Chemical ◽  
High K ◽  
Post Deposition ◽  
Limited Oxygen

AbstractThis study presents an investigation on physical-chemical stability of (HfO2)x(Al2O3 )1-x alloys upon prolonged post-deposition annealings. Two different Hf-aluminates were deposited by ALCVDTM, containing 34% and 74% Al2O3 mol% respectively. Post-deposition annealings (PDA) were carried out in O2 or N2 atmosphere, at 850°C and 900°C for 30 minutes. Interfacial layer (IL) increase after PDA was detected on all the samples, but with small differences between N2 and O2 treatments. Stack composition was characterized by means of XRR, XRF, RBS and TOF-SIMS. Growth of interface layer was justified by limited oxygen incorporation from external ambient. Silicon diffusion from the substrate into high-k material and aluminum/hafnium redistribution were observed and associated to annealing temperature. XRD and planar TEM analysis evidenced first grain formation and then, in the case of Hf-rich samples, almost complete crystallization. Overall, Hf-aluminates were found to remain XRD amorphous during high temperature prolonged treatments up to 900°C for 74% and 850°C for 34% alloys respectively. Differently from HfO2, (HfO2)0.66(Al2O3 )0.34 alloy was observed to crystallized in orthorhombic phase. Hf-aluminates were also electrically characterized by means of C(V) and I(V) measurements on basic capacitors. Variations in material electrical properties were found consistent with change in physical-chemical film structure. Increase in k value up to 30 was observed on Hf-rich samples crystallized in orthorhombic phase.

Effect of Nitrogen Diffusion in Ti and TiTiN Films for Future DRAM Bit Line Interconnects and Plugs

1996 ◽  
Vol 429 ◽  
Author(s):  
John M. Drynan ◽  
Kuniaki Koyama
Keyword(s):  
Solid Solution ◽  
Gas Phase ◽  
Sheet Resistance ◽  
Solid Phase ◽  
Deposition Process ◽  
Thermal Treatments ◽  
Nitrogen Diffusion ◽  
Materials Properties ◽  
Post Deposition

AbstractThe effects of nitrogen diffusion from both N2 gas phase and TiN solid phase sources on the characteristics of Ti/TiN bilayer and TiN/Ti/TiN trilayer films have been investigated in terms of both materials properties such as resistance, coloration, composition, and crystallinity, and prospective applications such as for DRAM bit line interconnections and contact-hole plugs. Using blank films it has been found, in coincidence with other work, that at the onset of N diffusion and hence low N concentrations within a Ti film, the sheet resistance increases and the Ti layer becomes a solid solution of N in hexagonal Ti. As the concentration increases, the sheet resistance reaches a maximum, after which it decreases abruptly and the structure becomes primarily tetragonal Ti2N phase. At higher concentrations the resistance stabilizes or increases slightly and the structure becomes more cubic TiN phase. Sheet resistances calculated from resistance measurements of Ti and TiN mono- and multilayer conductor lines with and without RTN and RTAr thermal treatments have shown that the conductor lines exhibit similar behavior to the blank films. In comparison with the mon-olayer lines, the multilayer ones are generally lower in resistance and more stable over a wider range of post-deposition process temperatures.

Low-temperature luminescence in organic-inorganic lead iodide perovskite single crystals

2021 ◽  
Author(s):  
Irina Vladimirovna Zhevstovskikh ◽  
Nikita Averkiev ◽  
Maksim Sarychev ◽  
Olga Semenova ◽  
Oleg Tereshchenko
Keyword(s):  
Single Crystals ◽  
Thermal Evolution ◽  
Free Exciton ◽  
Orthorhombic Phase ◽  
Lead Iodide ◽  
Acceptor Pair ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Pl Emission ◽  
Methylammonium Lead Iodide

Abstract We present temperature and laser-power dependent photoluminescence (PL) study of methylammonium lead iodide (CH3NH3PbI3) single crystals in the orthorhombic phase. At temperatures below 140 K, we revealed the multi-component PL emission. In addition to a free exciton with an energy of 1.65 eV, we found emission bands with peaks approximately equal to 1.6 eV, 1.52 eV, and 1.48 eV. Analysis of the thermal evolution of the intensities, peak positions, and linewidths of all the PL bands allowed one to determine their origin. We attributed the PL peak with the energy of 1.6 eV to a bound exciton, while the free exciton-bound exciton splitting energy is 50-60 meV. The PL emission with an energy of 1.52 eV can be explained by the donor-acceptor pair (DAP) recombination, where donor and acceptor defects have a depth of about 12 meV and 120 meV, respectively. MA (CH3NH3) interstitials (MA+i ) and lead vacancies (V2-Pb) are the most suitable for the DAP transition to occur in CH3NH3PbI3 crystals. The 1.48 eV PL emission is consistent with the recombination of self-trapped excitons, and interstitial iodine is likely to be an active trap source. We found the variation of the self-trapped depth from 15 meV (at T<80 K) to 53 meV (at T>80 K) with increasing the temperature. Although the multi-component PL emission in CH3NH3PbI3 single crystals appears at low temperatures, defects and excitonic traps that cause this emission can affect the photophysics of hybrid perovskites at higher temperatures.

Improved conductivity of ZnO thin films by exposure to an atmospheric hydrogen plasma

2012 ◽  
Vol 1447 ◽  
Author(s):  
A. Illiberi ◽  
B. Kniknie ◽  
J. van Deelen ◽  
H.L.A.H. Steijvers ◽  
D. Habets ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Metalorganic Chemical Vapor Deposition ◽  
Hydrogen Plasma ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Atmospheric Plasma ◽  
Crystalline Quality ◽  
Plasma Exposure ◽  
Aluminum Doped Zinc Oxide ◽  
Post Deposition

ABSTRACTAluminum-doped zinc oxide (ZnOx:Al) films have been deposited on a moving glass substrate by a high throughput metalorganic chemical vapor deposition process at atmospheric pressure. Thin (< 250 nm) ZnOx:Al films have a poor crystalline quality, due to a small grain size and the presence of different crystallographic orientations. The crystalline quality improves with increasing film thickness (from 50 nm to 1000 nm), resulting in a lower value of resistivity (from 100 Ohm cm to 1·10-3 Ohm cm, respectively). We have investigated the variation in the films’ conductivity and transparency induced by a post-deposition exposure to a He/H2 atmospheric plasma. The resistivity of thin (< 250 nm) films is found to decreased sharply from 100 Ohm cm to about 4·10-3 Ohm cm by a short (∼ seconds) plasma exposure, while the resistivity of thicker films remains unaffected.

scholarly journals Influence of Post-Deposition Heat Treatments on the Microstructure and Tensile Properties of Ti-6Al-4V Parts Manufactured by CMT-WAAM

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1161
Author(s):  
Lexuri Vazquez ◽  
Maria Nieves Rodriguez ◽  
Iker Rodriguez ◽  
Pedro Alvarez
Keyword(s):  
Mechanical Properties ◽  
State Of The Art ◽  
Microstructural Analysis ◽  
Thermal Treatments ◽  
Cold Metal Transfer ◽  
Α Phase ◽  
Different Temperatures ◽  
Cold Metal ◽  
Post Deposition ◽  
Strength And Ductility

Cold metal transfer (CMT)-based wire and arc additive manufacturing (WAAM) of Ti-6Al-4V alloy has been investigated to manufacture walls with two different building strategies. This study focuses on the influence of the application of thermal treatments on the resulting microstructure and mechanical properties. Deep microstructural analysis revealed different grades of growth of lamellae α phase after several thermal treatments at different temperatures, which lead to different tensile mechanical properties and better strength and ductility balance compared to the as-built condition. Results are compared with equivalent forged and casting standards and the state of the art for WAAM of Ti-6Al-4V alloy. At temperatures of 920 °C, anisotropy was maintained and elongation increased by 70% while yield strength and UTS was slightly decreased by 8%.

scholarly journals Properties of RF Magnetron-Sputtered Copper Gallium Oxide (CuGa2O4) Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 921
Author(s):  
Ashwin Kumar Saikumar ◽  
Sreeram Sundaresh ◽  
Shraddha Dhanraj Nehate ◽  
Kalpathy B. Sundaram
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Wavelength Region ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Morphological Studies ◽  
Increasing Trend ◽  
First Time ◽  
Post Deposition

Thin films of CuGa2O4 were deposited using an RF magnetron-sputtering technique for the first time. The sputtered CuGa2O4 thin films were post-deposition annealed at temperatures varying from 100 to 900 °C in a constant O2 ambience for 1.5 h. Structural and morphological studies were performed on the films using X-ray diffraction analysis (XRD) and a Field Emission Scanning Electron Microscope (FESEM). The presence of CuGa2O4 phases along with the CuO phases was confirmed from the XRD analysis. The minimum critical temperature required to promote the crystal growth in the films was identified to be 500 °C using XRD analysis. The FESEM images showed an increase in the grain size with an increase in the annealing temperature. The resistivity values of the films were calculated to range between 6.47 × 103 and 2.5 × 108 Ωcm. Optical studies were performed on all of the films using a UV-Vis spectrophotometer. The optical transmission in the 200–800 nm wavelength region was noted to decrease with an increase in the annealing temperature. The optical bandgap value was recorded to range between 3.59 and 4.5 eV and showed an increasing trend with an increase in the annealing temperature.

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