Influence of Impurities and Microstructure on the Resistivity of LPCVD Titanium Nitride Films

1989 ◽  
Vol 168 ◽  
Author(s):  
M. J. Buiting ◽  
A. H. Reader

AbstractThe electrical resistivity of LPCVD TiN films deposited at temperatures between 450 and 700°C has been found to vary from about 900 to 150 μ Ωcm. The elemental composition (Ti:N), impurity content and the microstructure of the films have been investigated in order to explain the resistivity variation. It appears that this variation is directly related to the chlorine (impurity) content of the films. Films deposited at 700°C have both the lowest chlorine content and the lowest value of resistivity. Additionally the difference between the resistivity of this latter film and the (lower) value for bulk TiN is discussed.

1996 ◽  
Vol 11 (2) ◽  
pp. 399-411 ◽  
Author(s):  
T. Zheleva ◽  
S. Oktyabrsky ◽  
K. Jagannadham ◽  
R. D. Vispute ◽  
J. Narayan

The characteristics of epitaxial growth of titanium nitride films on Ge/Si(001) have been studied. The growth of titanium nitride and germanium films on (001)Si was carried out in situ in a high vacuum chamber (<10−7 Torr) using a multitarget stage in a pulsed laser deposition system. Electrical resistivity, stoichiometry, crystallinity, and epitaxial relationships as a function of deposition temperature have been studied. Electrical resistivity of the titanium nitride films grown at deposition temperatures in the range of 450 °C–750 °C was measured using a four-point probe. The stoichiometry of these films was investigated using Auger electron spectroscopy and Raman spectroscopy. The crystalline quality and epitaxial nature of TiN films grown at different substrate temperatures were characterized using x-ray diffraction and transmission electron microscopy. Highly oriented titanium nitride films with (110) orientation were obtained on Ge(001) film when the substrate temperature was maintained between 550 °C and 650 °C. The epitaxial growth of the titanium nitride films was found to be a function of two-dimensional or three-dimensional growth mode of germanium film on silicon (001) substrate. Titanium nitride films grown at a substrate temperature of 650 °C exhibited the lowest room temperature resistivity (26 μΩ-cm), highest nitrogen content (close to stoichiometry), and the best epitaxiality with the Ge(001) films on Si(001). The epitaxial relationships for the TiN/Ge/Si(001) heterostructure are found to be [001]TiN‖ [110]Ge‖ [110]Si and [110]TiN‖ [110] Ge‖ [110]Si. To explain the epitaxial growth in a large mismatch system (∼28%) such as TiN/Ge(001), the domain matching mechanism is proposed. Domains of size four (001)TiN by seventeen (220)TiN in the titanium nitride film match closely with domains of size three (220)Ge by sixteen (220)Ge in the germanium film, respectively. The lattice matching epitaxy involving a 4% mismatch between Ge and Si provides a mechanism for epitaxial growth of Ge on Si(001).


2021 ◽  
Vol 11 (6) ◽  
pp. 2448
Author(s):  
Alex Sendrós ◽  
Aritz Urruela ◽  
Mahjoub Himi ◽  
Carlos Alonso ◽  
Raúl Lovera ◽  
...  

Water percolation through infiltration ponds is creating significant synergies for the broad adoption of water reuse as an additional non-conventional water supply. Despite the apparent simplicity of the soil aquifer treatment (SAT) approaches, the complexity of site-specific hydrogeological conditions and the processes occurring at various scales require an exhaustive understanding of the system’s response. The non-saturated zone and underlying aquifers cannot be considered as a black box, nor accept its characterization from few boreholes not well distributed over the area to be investigated. Electrical resistivity tomography (ERT) is a non-invasive technology, highly responsive to geological heterogeneities that has demonstrated useful to provide the detailed subsurface information required for groundwater modeling. The relationships between the electrical resistivity of the alluvial sediments and the bedrock and the difference in salinity of groundwater highlight the potential of geophysical methods over other more costly subsurface exploration techniques. The results of our research show that ERT coupled with implicit modeling tools provides information that can significantly help to identify aquifer geometry and characterize the saltwater intrusion of shallow alluvial aquifers. The proposed approaches could improve the reliability of groundwater models and the commitment of stakeholders to the benefits of SAT procedures.


2015 ◽  
Vol 15 (8) ◽  
pp. 4145-4159 ◽  
Author(s):  
A. P. Praplan ◽  
S. Schobesberger ◽  
F. Bianchi ◽  
M. P. Rissanen ◽  
M. Ehn ◽  
...  

Abstract. This study presents the difference between oxidised organic compounds formed by α-pinene oxidation under various conditions in the CLOUD environmental chamber: (1) pure ozonolysis (in the presence of hydrogen as hydroxyl radical (OH) scavenger) and (2) OH oxidation (initiated by nitrous acid (HONO) photolysis by ultraviolet light) in the absence of ozone. We discuss results from three Atmospheric Pressure interface Time-of-Flight (APi-TOF) mass spectrometers measuring simultaneously the composition of naturally charged as well as neutral species (via chemical ionisation with nitrate). Natural chemical ionisation takes place in the CLOUD chamber and organic oxidised compounds form clusters with nitrate, bisulfate, bisulfate/sulfuric acid clusters, ammonium, and dimethylaminium, or get protonated. The results from this study show that this process is selective for various oxidised organic compounds with low molar mass and ions, so that in order to obtain a comprehensive picture of the elemental composition of oxidation products and their clustering behaviour, several instruments must be used. We compare oxidation products containing 10 and 20 carbon atoms and show that highly oxidised organic compounds are formed in the early stages of the oxidation.


2018 ◽  
Vol 52 (27) ◽  
pp. 3745-3758 ◽  
Author(s):  
Amin Bahrami ◽  
Niloofar Soltani ◽  
Martin I Pech-Canul ◽  
Shaghayegh Soltani ◽  
Luis A González ◽  
...  

In this study, wettability behavior of B4C substrate as well as B4C/crystalline rice husk ash and B4C/amorphous rice husk ash substrates with two aluminum alloys were studied. The electrical resistivity, thermal expansion coefficients, and thermal diffusivity of bilayer Al/B4C/rice husk ash composite fabricated by one-step pressureless infiltration were measured and the obtained data were systemically analyzed using the Taguchi method and analysis of variance. Boron carbide substrates after addition of amorphous or crystalline rice husk ash display good wettability with molten aluminum alloys. The results show that, electrical resistivity of Al/B4C/rice husk ash composites is mainly influenced by initial preform porosity, while the coefficient of thermal expansion of composites is determined by the chemical composition of infiltrated alloys. The measured values for coefficient of thermal expansion (10.5 × 10−6/℃) and electrical resistivity (0.60 × 10−5 Ω.m) of Al/B4C/rice husk ash composites, fabricated according to analysis of variance's optimal conditions are in good agreement with those of the projected values (11.02 × 10−6/℃ and 0.65 × 10−5 Ω.m, respectively). The difference between the corresponding values obtained from verification tests and projected values, for electrical resistivity and coefficient of thermal expansion are less than 5%. Finally, as a material selection approach, the strengths and weaknesses of the composites have been graphed in the form of radar diagrams.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chun-Chieh Chang ◽  
John Nogan ◽  
Zu-Po Yang ◽  
Wilton J. M. Kort-Kamp ◽  
Willard Ross ◽  
...  

Abstract Titanium nitride (TiN) has recently emerged as an attractive alternative material for plasmonics. However, the typical high-temperature deposition of plasmonic TiN using either sputtering or atomic layer deposition has greatly limited its potential applications and prevented its integration into existing CMOS device architectures. Here, we demonstrate highly plasmonic TiN thin films and nanostructures by a room-temperature, low-power, and bias-free reactive sputtering process. We investigate the optical properties of the TiN films and their dependence on the sputtering conditions and substrate materials. We find that our TiN possesses one of the largest negative values of the real part of the dielectric function as compared to all other plasmonic TiN films reported to date. Two-dimensional periodic arrays of TiN nanodisks are then fabricated, from which we validate that strong plasmonic resonances are supported. Our room-temperature deposition process can allow for fabricating complex plasmonic TiN nanostructures and be integrated into the fabrication of existing CMOS-based photonic devices to enhance their performance and functionalities.


2020 ◽  
Vol 10 (24) ◽  
pp. 8993
Author(s):  
Ilhwan You ◽  
Seung-Jung Lee ◽  
Goangseup Zi ◽  
Daehyun Lim

This study investigated the effects of carbon fiber (CF) length, electrode spacing, and probe configuration on the electrical conductivity of cement composites. Accordingly, 57 different types of samples were prepared, considering three different CF lengths, five different CF contents, three different electrode spacings, and two different probe configurations. This research found that the influence of CF length on the electrical resistivity of cement composite depends electrode spacing. For the cement composite with wide electrode spacing of 40 mm, its resistivity decreased as increasing CF length as in the previous study. However, when the electrode spacing is 10 mm, which is narrow (10 mm), the resistivity of the cement composite rather increased with increasing CF length. The results implied that when an electrode is designed for the cement composite incorporating CF, the CF length should be short compared to the electrode spacing. The percolation threshold of CF measured by the two-probe configuration was 2% or more. This is higher than that measured by the four-probe configuration (1%). At a lower CF content than 2%, the two-probe configuration gave higher resistivity of the cement composite than the four-probe configuration. However, the difference coming from the different probe configurations was marginal as increasing the CF content.


2020 ◽  
Vol 13 (20) ◽  
Author(s):  
Xiangchun Li ◽  
Qi Zhang ◽  
Zhenxing An ◽  
Xiaolong Chen ◽  
Fan Zhang

1988 ◽  
Vol 254 (5) ◽  
pp. C614-C620 ◽  
Author(s):  
R. G. Eckenhoff ◽  
A. P. Somlyo

We determined the in situ elemental composition of alveolar type II cells (ATII) and lamellar bodies (LB) with electronprobe microanalysis (EPMA) of freeze-dried unstained cryosections (100-200 nm) obtained from lungs frozen in anesthetized rats. Twenty-nine ATII from seven rats were subjected to EPMA. Cytoplasmic (Cyto) composition was the following (in mmol/kg dry wt, mean +/- SE, n = 30): 136 +/- 14.1 Na, 60 +/- 2.8 Mg, 549 +/- 34.8 P, 278 +/- 10.5 S, 158 +/- 7.3 Cl, 525 +/- 26.4 K, and 6.6 +/- 0.9 Ca. LB composition was the following (n = 66): 44 +/- 4.0 Na, 7.9 +/- 0.8 Mg, 1,060 +/- 25.0 P, 79 +/- 4.8 S, 64 +/- 3.6 Cl, 114 +/- 4.1 K, and 30 +/- 0.9 Ca. P and S concentrations were consistent with previous biochemical determinations of phospholipid and protein content of isolated LBs. LBs contain significantly more Ca and less Mg than Cyto. Ca correlated significantly with LB P but not S concentration, and the reported low Ca binding affinity of similar phospholipid mixtures implies a high LB free Ca concentration. Ca was significantly higher in apical and exocytotic LBs compared with those in the perinuclear region. Differences between LB and Cyto monovalent ion concentrations are not entirely due to the difference in hydration revealed by significantly lower K-Cl ratios in LBs. The relative excess of Cl and Ca in LB suggests that these ions may be distributed by active transport systems known to be present in the Golgi apparatus and in Golgi-derived organelles of other cell types.


1998 ◽  
Vol 555 ◽  
Author(s):  
Xinye Liu ◽  
Yuan Z. LU ◽  
Roy G. Gordon

AbstractWe demonstrate a novel approach to improving the step coverage of thin films made by chemical vapor deposition (CVD). Titanium nitride (TiN) films were deposited by atmospheric pressure CVD using tetrakis(diethylamido)titanium vapor (TDEAT) and ammonia gas (NH3) carried in nitrogen gas. Trimethylamine (NMe3) gas was added during some of the depositions. The substrates were patterned silicon wafers having holes with aspect ratio of 3.5 through a silicon dioxide layer. We discovered that the step coverage was significantly increased for TiN films made with NMe3. At 320 °C, the step coverage was increased from 70% to nearly 100%. Within the range of deposition temperatures used in our study, 320 °C to 370 °C, the amount of improvement increased as the deposition temperature decreased. The trimethylamine did not increase the resistivity or the impurity levels in the films, but it did reduce the growth rate slightly. We suggest that the trimethylamine adsorbs onto the surface, temporarily blocking some of the sites on which growth could take place. Thus the effective sticking coefficients for the precursors are decreased, and the step coverage is increased.


2014 ◽  
Vol 8 (4) ◽  
pp. 1869-1880 ◽  
Author(s):  
Qiang Sun ◽  
Shuyun Zhu ◽  
Lei Xue

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