The Effects of Processing on the Microstructure of Copper Thin Films on Tantalum Barrier Layers

1995 ◽  
Vol 391 ◽  
Author(s):  
E.M. Zielinski ◽  
R.P. Vinci ◽  
J.C. Bravman

abstractPreferred crystallographic orientation and grain size distribution were characterized as a function of processing for sputtered Cu films on Ta underlayers. The Ta barrier layer was deposited at two temperatures, 30 and 100 °C. Cu was deposited at 30, 150 and 250 °C on the 30 °C Ta, and at 100, 150, 200 and 250 °C on the 100 °C Ta. In the first set of samples, with increasing deposition temperature, the Cu (111) fiber texture grew weaker and the volume fraction of randomly oriented grains increased from 0.23 to 0.74. In contrast, for the films deposited on the 100 °C Ta, with increasing deposition temperature, Cu (111) fiber texture strengthened and the fractions of randomly oriented and twinned grains decreased. Grain size was lognormally distributed in all samples and varied approximately parabolically with deposition temperature. At a given deposition temperature, median grain size in the Cu was larger in the films deposited on the 100 °C Ta. These results will be related to the microstructure of the Ta underlayers. Cu microstructure on the 100 °C Ta is shown to be influenced by textural inheritance from the Ta underlayer. Microstructure of the Cu on 30 °C Ta is discussed in terms of trace contaminants.

1999 ◽  
Vol 594 ◽  
Author(s):  
R. Spolenak ◽  
C. A. Volkert ◽  
K. Takahashi ◽  
S. Fiorillo ◽  
J. Miner ◽  
...  

AbstractIt is well known that the mechanical properties of thin films depend critically on film thickness However, the contributions from film thickness and grain size are difficult to separate, because they typically scale with each other. In one study by Venkatraman and Bravman, Al films, which were thinned using anodic oxidation to reduce film thickness without changing grain size, showed a clear increase in yield stress with decreasing film thickness.We have performed a similar study on both electroplated and sputtered Cu films by using chemical-mechanical polishing (CMP) to reduce the film thickness without changing the grain size. Stress-temperature curves were measured for both the electroplated and sputtered Cu films with thicknesses between 0.1 and 1.8 microns using a laser scanning wafer curvature technique. The yield stress at room temperature was found to increase with decreasing film thickness for both sets of samples. The sputtered films, however, showed higher yield stresses in comparison to the electroplated films. Most of these differences can be attributed to the different microstructures of the films, which were determined by focused ion beam (FIB) microscopy and x-ray diffraction.


2015 ◽  
Vol 1115 ◽  
pp. 422-425
Author(s):  
Souad A.M. Al-Bat’hi ◽  
Maizatulnisa Othman

This investigation deals with the effect of temperature on the optical and morphological properties of Zinc Oxide thin films prepared by radio-Frequency (RF) magnetron sputtering technique. In the present work, zinc oxide (ZnO) thin films have been deposited on glass substrates from 50°C to 300°C by radio frequency magnetron sputtering. The effects of deposition temperature on the crystallization behaviour and optical properties of the films have been studied. The thin films were characterized using Ultraviolet Visible Spectroscopy (UV-VIS), Field Emission Scanning Electron Microscopy (FESEM) and X-ray Diffraction Analysis (XRD). From the UV-VIS testing, the average transmission percentage of the films is between 80-95% for all deposition temperatures meanwhile the energy gap of ZnO thin films varies from 3.26 eV to 3.35 eV which is not much different from the theoretical value. Also, the grain size is getting smaller from 3.886nm, 3.216nm, 3.119nm and 3.079nm with respect to the increasing deposition temperature 50°C, 100°C, 200°C and 300°C respectively whereas the average grain size per intercept value is increasing. The patterns of the peak were about the same for all deposition temperature where the thin films have polycrystalline hexagonal wurtzite structure with the orientation perpendicular (002) to the substrate surface (c-axis orientation) at 34.5(2θ).


1995 ◽  
Vol 403 ◽  
Author(s):  
Krishna Rajan ◽  
Ronald Petkie

AbstractThe concept of fcc fiber texture is examined in the context of Rodrigues-Frank (R-F) representations. Using fiber texture in thin films as the basis of our analysis, it is shown that this approach when combined with grain specific determination of crystallographic orientation provides a useful means of detecting a number of texture components with relatively small grain sampling densities. The application of R-F representations is also shown to be a useful methodology to couple grain boundary structure information with microtexture data.


2000 ◽  
Vol 614 ◽  
Author(s):  
Anil Mane ◽  
K. Shalini ◽  
Anjana Devi ◽  
R. Lakshmi ◽  
M.S. Dharmaprakash ◽  
...  

ABSTRACTWe have investigated the growth of thin films of Cu and Co by CVD using the β-diketonate complexes of the metals, viz., the respective acetylacetonates, dipivaloylmethanates, and ketocarboxylates. Film growth rate was measured as a function of CVD parameters such as substrate temperature and reactor pressure. Film microstructure was examined by optical microscopy, XRD, SEM, and STM. Electrical resistivity was measured as a function of temperature and film thickness. It was found that film microstructure is a function of the molecular structure of the precursor and of the other growth parameters. For example, Cu films from Cu(II) ethylacetoacetate comprise uniform, fine grains which result in bulk electrical conductivity at a thickness as small as 75nm. Though grown under nearly the same conditions, Cu films from Cu(II) dipivaloylmethanate are porous, with faceted, large crystallites. Cobalt films from Co(II) acetylacetonate are x-ray amorphous even at a deposition temperature of 450°C. It is possible, by choosing CVD parameters, to obtain metal films with microstructures appropriate to devices and to structures of very small dimensions.


2002 ◽  
Vol 721 ◽  
Author(s):  
A. Gungor ◽  
K. Barmak ◽  
A. D. Rollett ◽  
C. Cabral ◽  
J. M. E. Harper

AbstractAnnealing Cu and dilute Cu(Ti), Cu(Sn) and Cu(Al) alloy films resulted in the strengthening of film texture, with the strongest <111> fiber texture being found for Cu(Ti). Annealing also resulted in a decrease of electrical resistivity and the growth of grains, with the largest grain size and lowest resistivity being seen for pure Cu itself. Among the alloy films, the lowest resistivity was found for Cu(Ti) and the largest grain size for Cu(Al). Electron beam evaporated films with compositions in the range of 2.0-3.0 at% and thicknesses in the range of 420-540 nm were annealed at 400°C for 5 hours. Four point probe resistance measurement, xray diffraction and transmission electron microscopy were used to follow the changes in film resistivity, texture and grain size.


2000 ◽  
Vol 612 ◽  
Author(s):  
Yuxiao Zeng ◽  
Linghui Chen ◽  
T. L. Alford

AbstractHSQ (hydrogen silsesquioxane) is one of the promising low-k materials used in VLSI technology as an intra-metal dielectric to reduce capacitance-related issues. Like any other dielectrics, the integration of HSQ in multilevel interconnect schemes has been of considerable importance. In this study, the compatibility of HSQ with different nitride barrier layers, such as PVD and CVD TiN, PVD TaN, and CVD W2N, has been investigated by using a variety of techniques. The refractory metal barriers, Ti and Ta, are also included for a comparison. The degradation of HSQ films indicates a strong underlying barrier layer dependence. With CVD nitrides or refractory metals as barrier, HSQ exhibits a better structural and property stability than that with PVD nitrides. The possible mechanisms have been discussed to account for these observations.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Shiwen Du ◽  
Yongtang Li

Cu thin films were deposited on Si substrates using direct current (DC) magnetron sputtering. Microstructure evolution and mechanical properties of Cu thin films with different annealing temperatures were investigated by atomic force microscopy (AFM), X-ray diffraction (XRD), and nanoindentation. The surface morphology, roughness, and grain size of the Cu films were characterized by AFM. The minimization of energy including surface energy, interface energy, and strain energy (elastic strain energy and plastic strain energy) controlled the microstructural evolution. A classical Hall-Petch relationship was exhibited between the yield stress and grain size. The residual stress depended on crystal orientation. The residual stress as-deposited was of tension and decreased with decreasing of (111) orientation. The ratio of texture coefficient of (111)/(220) can be used as a merit for the state of residual stress.


2014 ◽  
Vol 492 ◽  
pp. 235-238
Author(s):  
Xiao Jing Wang

μc-Si:H thin films have been deposited on the 7059 glass substrate by RF-PECVD. Effects of film thickness on structure and properties of Si thin films were investigated by XRDRamanUV-Vis and precision multimeter. Experimental results indicated that uniform dense microcrystalline silicon thin films can be prepared by rf-PECVD, silicon thin films transferred from a-Si:H to μc-Si:H along with film thickness increased. For μc-Si:H, XRD spectrum occurred (111)(220) and (331) peak, grain size and crystalline volume fraction increased with thickness enhanced, arrived at 82%; optical band gap of μc-Si:H is 2.0~2.36eV and decreased when thickness increased, the transmittance was added firstly and then reduced with film thickness increased, the transmittance curve occurred redshift;the photosensitivity of the thin films was improved firstly and then decreased with thickness increased, which was highest at 104 quantity in the transition zone from a-Si:H to μc-Si:H.


2001 ◽  
Vol 664 ◽  
Author(s):  
J. J. Gutierrez ◽  
C. E. Inglefield ◽  
C. P. An ◽  
M. C. DeLong ◽  
P. C. Taylor ◽  
...  

ABSTRACTIn this paper, we present a comprehensive study of microcrystalline silicon thin film samples deposited by a novel growth process intended to maximize their grain size and crystal volume fraction. Using Atomic Force Microscopy, Raman spectroscopy, and x ray diffraction the structural properties of these samples were characterized qualitatively and quantitatively. Samples were grown using a Hot-Wire Chemical Vapor Deposition process with or without a post-growth hot-wire annealing treatment. During Hot-Wire Chemical Vapor Deposition, SiF4 is used along with SiH4 and H2 to grow the thin films. After growth, some samples received an annealing treatment with only SiF4 and H2 present. These samples were compared to each other in order to determine the deposition conditions that maximize grain size. Large microcrystalline grains were found to be aggregates of much smaller crystallites whose size is nearly independent of deposition type and post-annealing treatment. Thin films deposited using the deposition process with SiF4 partial flow rate of 2 sccm and post-growth annealing treatment had the largest aggregate grains ∼.5 µm and relatively high crystal volume fraction.


2002 ◽  
Vol 721 ◽  
Author(s):  
Oleg V. Kononenko ◽  
Victor N. Matveev ◽  
Andrei G. Vasiliev ◽  
Ivan Khorin ◽  
Tejodher Muppidi ◽  
...  

AbstractCu may diffuse into the active areas of semiconductors resulting in degradation of the devices. Therefore Cu is isolated from silicon wafers by barrier layers. In this study, copper films were deposited onto silicon substrates coated using polycrystalline Ta3N5 and amorphous α-C:H barrier by the partially ionized beam deposition technique at 6 kV bias, to investigate an influence of barrier layer structure on texture and microstructure of Cu films. After deposition, films were annealed under vacuum. Texture of the films was studied by X-ray diffraction and further microstructural analysis of the copper films was performed by orientation imaging microscopy. Results of the structural analysis reveal large (100) grains in films deposited on α-C:H barrier layer and a bi-modal texture in films on Ta3N5.


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