A Comparison of Electromigration in Bulk and Thin - Film Aluminum

1995 ◽  
Vol 391 ◽  
Author(s):  
Anthony S. Oates

AbstractThe dominant mode of electromigration in polycrystalline Al thin - film conductors is along grain boundaries when the conductor width is significantly larger than the grain size. Integrated circuit feature sizes, however, have now decreased to the point where microstructures are no longer polycrystalline, but are near - bamboo. Electromigration must operate along pathways other than grain boundaries in the bamboo segments. Here drift velocity data is presented for bamboo microstructures with widths down to 0.6 μm and compared with drift data available in the literature for thin films with a variety of microstructures and bulk Al. Bamboo films show lower drift velocities and higher activation energies for drift than polycrystalline films. The data for bamboo microstructures is consistent with drift measurements performed on bulk Al indicating that the transport mechanism in bamboo films is identical to that in bulk Al.

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Shanyue Zhao ◽  
Yinqun Hua ◽  
Ruifang Chen ◽  
Jian Zhang ◽  
Ping Ji

The effects of laser irradiation on the structural and electrical properties of ZnO-based thin films were investigated. The XRD pattern shows that the thin films were highly textured along thec-axis and perpendicular to the surface of the substrate. Raman spectra reveal that Bi2O3segregates mainly at ZnO-ZnO grain boundaries. After laser irradiation processing, the grain size of the film was reduced significantly, and the intrinsic atomic defects of grain boundaries and Bi element segregated at the grain boundary were interacted frequently and formed the composite defects of acceptor state. The nonlinear coefficient increased to 24.31 and the breakdown voltage reduced to 5.34 V.


RSC Advances ◽  
2017 ◽  
Vol 7 (86) ◽  
pp. 54911-54919 ◽  
Author(s):  
Varsha Rani ◽  
Akanksha Sharma ◽  
Pramod Kumar ◽  
Budhi Singh ◽  
Subhasis Ghosh

We investigate the charge transport mechanism in copper phthalocyanine thin films with and without traps. We find that the density of interface states at the grain boundaries can decide the mechanism of charge transport in organic thin films.


1999 ◽  
Vol 574 ◽  
Author(s):  
Norifumi Fujimura ◽  
Tamaki Shimura ◽  
Toshifumi Wakano ◽  
Atsushi Ashida ◽  
Taichiro Ito

AbstractWe propose the application of ZnO:X (X = Li, Mg, N, In, Al, Mn, Gd, Yb etc.) films for a monolithic Optical Integrated Circuit (OIC). Since ZnO exhibits excellent piezoelectric effect and has also electro-optic and nonlinear optic effects and the thin films are easily obtained, it has been studied as one of the important thin film wave guide materials especially for an acoustooptic device[1]. In terms of electro-optic and nonlinear optic effects, however, LiNbO3 or LiTaO3 is superior to ZnO. The most important issue of thin film waveguide using such ferroelectrics is optical losses at the film/substrate interface and the film surface, because the process window to control the surface morphology is very narrow due to their high deposition temperature. Since ZnO can be grown at extremely low temperature, the roughness at the surface and the interface is expected to be minimized. This is the absolute requirement especially for waveguide using a blue or ultraviolet laser. Recently, lasing at the wavelength of ultraviolet, ferroelectric and antiferromagnetic behaviors of ZnO doped with various exotic elements (exotic doping) have been reported. This paper discusses the OIC application of ZnO thin films doped with exotic elements.


Author(s):  
Pornvitoo Rittinon ◽  
Ken Suzuki ◽  
Hideo Miura

Copper thin films are indispensable for the interconnections in the advanced electronic products, such as TSV (Trough Silicon Via), fine bumps, and thin-film interconnections in various devices and interposers. However, it has been reported that both electrical and mechanical properties of the films vary drastically comparing with those of conventional bulk copper. The main reason for the variation can be attributed to the fluctuation of the crystallinity of grain boundaries in the films. Porous or sparse grain boundaries show very high resistivity and brittle fracture characteristic in the films. Thus, the thermal conductivity of the electroplated copper thin films should be varied drastically depending on their micro texture based on the Wiedemann-Franz’s law. Since the copper interconnections are used not only for the electrical conduction but also for the thermal conduction, it is very important to quantitatively evaluate the crystallinity of the polycrystalline thin-film materials and clarify the relationship between the crystallinity and thermal properties of the films. The crystallinity of the interconnections were quantitatively evaluated using an electron back-scatter diffraction method. It was found that the porous grain boundaries which contain a significant amount of vacancies increase the local electrical resistance in the interconnections, and thus, cause the local high Joule heating. Such porous grain boundaries can be eliminated by control the crystallinity of the seed layer material on which the electroplated copper thin film is electroplated.


2013 ◽  
Vol 802 ◽  
pp. 47-52
Author(s):  
Chuleerat Ibuki ◽  
Rachasak Sakdanuphab

In this work the effects of amorphous (glass) and crystalline (Si) substrates on the structural, morphological and adhesion properties of CoFeB thin film deposited by DC Magnetron sputtering were investigated. It was found that the structure of a substrate affects to crystal formation, surface morphology and adhesion of CoFeB thin films. The X-Ray diffraction patterns reveal that as-deposited CoFeB thin film at low sputtering power was amorphous and would become crystal when the power increased. The increase in crystalline structure of CoFeB thin film is attributed to the crystalline substrate and the increase of kinetic energy of sputtering atoms. Atomic Force Microscopy images of CoFeB thin film clearly show that the roughness, grain size, and uniformity correlate to the sputtering power and the structure of substrate. The CoFeB thin film on glass substrate shows a smooth surface and a small grain size whereas the CoFeB thin film on Si substrate shows a rough surface and a slightly increases of grain size. Sticky Tape Test on CoFeB thin film deposited on glass substrate indicates the adhesion failure with a high sputtering power. The results suggest that the crystalline structure of substrate affects to the atomic bonding and the sputtering power affects to intrinsic stress of CoFeB thin film.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 252 ◽  
Author(s):  
A. M. Alsaad ◽  
A. A. Ahmad ◽  
I. A. Qattan ◽  
Qais M. Al-Bataineh ◽  
Zaid Albataineh

Undoped ZnO and group III (B, Al, Ga, and In)-doped ZnO thin films at 3% doping concentration level are dip-coated on glass substrates using a sol-gel technique. The optical properties of the as-prepared thin films are investigated using UV–Vis spectrophotometer measurements. Transmittance of all investigated thin films is found to attain high values of ≥80% in the visible region. We found that the index of refraction of undoped ZnO films exhibits values ranging between 1.6 and 2.2 and approximately match that of bulk ZnO. Furthermore, we measure and interpret nonlinear optical parameters and the electrical and optical conductivities of the investigated thin films to obtain a deeper insight from fundamental and practical points of view. In addition, the structural properties of all studied thin film samples are investigated using the XRD technique. In particular, undoped ZnO thin film is found to exhibit a hexagonal structure. Due to the large difference in size of boron and indium compared with that of zinc, doping ZnO thin films with these two elements is expected to cause a phase transition. However, Al-doped ZnO and Ga-doped ZnO thin films preserve the hexagonal phase. Moreover, as boron and indium are introduced in ZnO thin films, the grain size increases. On the other hand, grain size is found to decrease upon doping ZnO with aluminum and gallium. The drastic enhancement of optical properties of annealed dip-synthesized undoped ZnO thin films upon doping with group III metals paves the way to tune these properties in a skillful manner, in order to be used as key candidate materials in the fabrication of modern optoelectronic devices.


2009 ◽  
Vol 17 (3) ◽  
pp. 50-53
Author(s):  
Ron Anderson

It has been in the back of my mind to write this up for MT since I retired from a certain large computer company. Inasmuch as Paul's article above is a perfect lead-in, there is no time like the present. Our lab supported a semiconductor integrated circuit and a ceramic substrate manufacturing facility. We were continually required to measure circuit line widths on plan-view specimens and layer thicknesses on cross-section specimens for both semiconductor and ceramic substrate specimens and we were often asked to determine thin film grain size and ceramic raw material particle size data. A large number of measurements were required for each specimen to guarantee statistically sound data. We had image analysis software available that we used whenever we could, but often found that measuring things on a system using grey-level image analysis as input simply did not work. This is especially true for thin film grain size determination when using diffraction contrast TEM images for input.


Solar Energy ◽  
2005 ◽  
Author(s):  
Gye-Choon Park ◽  
Woon-Jo Jeong ◽  
Hyeon-Hun Yang ◽  
Hae-Duck Jung ◽  
Jin Lee ◽  
...  

CuInS2 thin films were fabricated by sulphurization of S/In/Cu Stacked elemental layers (SEL) on slide glass substrates by annealing in vacuum of 10−3 Torr at temperature of 50 °C ∼ 350 °C. Some S/In/Cu SEL were vacuum annealed under a sulfur atmosphere. The thin films thus annealed were analyzed by measuring structural, electrical and optical properties. When CuInS2 thin films were made under a sulfur atmosphere, lattice constant of a and grain size of the thin film were a little larger than those in only vacuum annealing. The largest lattice constant of a and grain size was 5.63 Å and 1.2 μm respectively. Also, when the thin films were made under a sulfur atmosphere, conduction types were all p-type with resistivities of around 10−1 Ωcm and optical energy band gaps of the films were a little larger than those in only vacuum and the largest optical energy band gap of CuInS2 thin film was 1.53 eV.


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