scholarly journals Brittle-to-ductile transition in ultrathin Ta/Cu film systems

2009 ◽  
Vol 24 (6) ◽  
pp. 1906-1918 ◽  
Author(s):  
Patric A. Gruber ◽  
Eduard Arzt ◽  
Ralph Spolenak
Keyword(s):  
Integrated Circuits ◽  
Film Thickness ◽  
Tensile Tests ◽  
Testing Technique ◽  
Cracking Behavior ◽  
Cu Films ◽  
Brittle To Ductile Transition ◽  
Compliant Substrates ◽  
Cu Film

Current semiconductor technology demands the use of compliant substrates for flexible integrated circuits. However, the maximum total strain of such devices is often limited by the extensibility of the metallic components. Although cracking in thin films is extensively studied theoretically, little experimental work has been carried out thus far. Here, we present a systematic study of the cracking behavior of 34- to 506-nm-thick Cu films on polyamide with 3.5-to 19-nm-thick Ta interlayers. The film systems have been investigated by a synchrotron-based tensile testing technique and in situ tensile tests in a scanning electron microscope. By relating the energy release during cracking obtained from the stress-strain curves to the crack area, the fracture toughness of the Cu films can be obtained. It increases with Cu film thickness and decreases with increasing Ta film thickness. Films thinner than 70 nm exhibit brittle fracture, indicating an increasing inherent brittleness of the Cu films.

Research on Internal Stress in Electroplated Cu Films and Ni Films on Ag Substrates

2011 ◽  
Vol 287-290 ◽  
pp. 3085-3088
Author(s):  
Yao Min Zhu ◽  
Shan Shan Wang ◽  
Feng Zhang Ren
Keyword(s):  
Film Thickness ◽  
Internal Stress ◽  
Calculation Model ◽  
Internal Stresses ◽  
Film Material ◽  
Beam Test ◽  
Cu Films ◽  
Cu Film ◽  
Reduced Gradient

Electroplating was employed to prepare Cu films and Ni films on Ag substrates. The average internal stresses in Cu film and Ni film were measured in situ by cantilever beam test. The values of experimental internal stresses were compared with theoretical internal stresses. The results showed that the internal stresses of Cu film and Ni film decreased with the increase of the film thickness. The reduced gradient was faster. The values of experimental and theoretical internal stresses had the same variation trend with film thickness and the same characteristics (tensile stress). Theoretical calculation model of internal stress was of accuracy. The internal stress for the same substrate was in relation to the film material.

scholarly journals Effect of De-Twinning on Tensile Strength of Nano-Twinned Cu Films

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1630
Author(s):  
Chia-Hung Lee ◽  
Erh-Ju Lin ◽  
Jyun-Yang Wang ◽  
Yi-Xuan Lin ◽  
Chen-Yu Wu ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Twin Boundary ◽  
Fracture Strength ◽  
Ion Beam ◽  
Tensile Tests ◽  
Sulfate Electrolyte ◽  
Twin Boundaries ◽  
Cu Films ◽  
Boundary Density ◽  
Cu Film

Tensile tests were carried on the electroplated Cu films with various densities of twin grain boundary. With TEM images and a selected area diffraction pattern, nano-twinned structure can be observed and defined in the electroplated Cu films. The density of the nano-twin grain structure can be manipulated with the concentration of gelatin in the Cu-sulfate electrolyte solution. We found that the strength of the Cu films is highly related to the twin-boundary density. The Cu film with a greater twin-boundary density has a larger fracture strength than the Cu film with a lesser twin-boundary density. After tensile tests, necking phenomenon (about 20 μm) occurred in the fractured Cu films. Moreover, by focused ion beam (FIB) cross-sectional analysis, the de-twinning can be observed in the region where necking begins. Thus, we believe that the de-twinning of the nano-twinned structure initiates the plastic deformation of the nano-twinned Cu films. Furthermore, with the analysis of the TEM images on the nano-twinned structure in the necking region of the fractured Cu films, the de-twinning mechanism attributes to two processes: (1) the ledge formation by the engagement of the dislocations with the twin boundaries and (2) the collapse of the ledges with the opposite twin-boundaries. In conclusion, the plastic deformation of nano-twinned Cu films is governed by the de-twinning of the nano-twinned structure. Moreover, the fracture strength of the nano-twinned Cu films is proportional to the twin-boundaries density.

In situ tensile tests in SEM of sputtered CNx films deposited on Ti6Al4V substrate: effect of film thickness and plasma surface pretreatment

2005 ◽  
Vol 482 (1-2) ◽  
pp. 324-329 ◽  
Author(s):  
P. Villechaise ◽  
X. Milhet ◽  
B. Angleraud ◽  
V. Fouquet ◽  
L. Pichon ◽  
...  
Keyword(s):  
Film Thickness ◽  
Tensile Tests ◽  
Substrate Effect ◽  
Surface Pretreatment ◽  
Plasma Surface ◽  
Ti6al4v Substrate ◽  
Cnx Films

AN INVESTIGATION OF SMOOTH NANOSIZED COPPER FILMS ON GLASS SUBSTRATE BY IMPROVED ELECTROLESS PLATING

2006 ◽  
Vol 13 (04) ◽  
pp. 471-478 ◽  
Author(s):  
HUIPING ZHANG ◽  
ZHONGHAO JIANG ◽  
XIANLI LIU ◽  
JIANSHE LIAN
Keyword(s):  
Grain Size ◽  
Film Thickness ◽  
Electroless Plating ◽  
Glass Substrate ◽  
Deposition Time ◽  
Copper Films ◽  
Diffraction Intensity ◽  
Cu Films ◽  
Fine Grain ◽  
Cu Film

Thin nanocrystalline Cu films (< 1 μm) are deposited on a glass substrate using an improved electroless plating technique. The deposition course of the Cu film is illustrated by the variation of surface morphology with different deposition time. The results show that a more uniform and continuous nanocrystalline Cu film with very small nodules can be formed on a glass substrate at the deposition time over 1 min. The roles of SDBS as an additive in the bath are also discussed. According to the relation of the film thickness and the deposition time, it is obvious that the film thickness nearly linearly varies with the deposition time in the present work. An enhanced (111) texture with the diffraction intensity ratio (I(111)/I(200)) of about 4.0 and the very fine grain size of 15–28 nm determined by X-ray results has been observed. The variations of the resistivity show that it is strongly affected by the film thickness and grain size.

Effect of Film Thickness on the Annealing Texture in Sputtered and Electroplated Cu Films

2006 ◽  
Vol 15-17 ◽  
pp. 982-988
Author(s):  
Sang Hoon Lee ◽  
No Jin Park ◽  
David P. Field ◽  
Paul R. Besser
Keyword(s):  
Film Thickness ◽  
Grain Growth ◽  
Processing Conditions ◽  
X Ray ◽  
Cu Films ◽  
Annealing Texture ◽  
Cu Film ◽  
The Relationship ◽  
Si Wafer

For optimum fabrication and usage of Cu films, an understanding of the relationship between processing and microstructure is required. The existence of twins is another significant factor for texture development in Cu films. Texture character and strength in the Cu film is dependent on the twin boundary development that is a function of processing conditions and film thickness. In this study, determination of grain growth and texture in the sputtered and electroplated Cu films during annealing was performed for films of 100, 480 and 850 nm in thickness deposited on a Ta(25 nm)/Si wafer. The texture was measured by X-ray pole figure. The effect of film thickness on the annealing texture in the sputtered and electroplated Cu films is examined and discussed.

In-situ measurement of Cu film thickness during the CMP process by using eddy current method alone

2013 ◽  
Vol 108 ◽  
pp. 66-70 ◽  
Author(s):  
Zilian Qu ◽  
Qian Zhao ◽  
Yonggang Meng ◽  
Tongqing Wang ◽  
Dewen Zhao ◽  
...  
Keyword(s):  
Film Thickness ◽  
Eddy Current ◽  
Current Method ◽  
In Situ Measurement ◽  
Eddy Current Method ◽  
Cu Film

Influence of Film Thickness and Capping Layer on the Mechanical Properties of Copper Films

1995 ◽  
Vol 391 ◽  
Author(s):  
R.-M. Keller ◽  
W.-M. Kuschke ◽  
A. Kretschmann ◽  
S. Bader ◽  
R.P. Vinci ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Dislocation Density ◽  
Film Thickness ◽  
Copper Films ◽  
Peak Width ◽  
Capping Layer ◽  
X Ray ◽  
Cu Films ◽  
Cu Film

AbstractSubstrate curvature and X-ray technique were used to study the mechanical properties of Cu films. Stress-temperature curves were measured using both methods. An additional analysis of the X-ray peak width allows us to estimate grain size and dislocation density as a function of temperature. It can be shown that a capping layer changes the mechanical properties of a Cu film strongly and that in capped films dislocation processes seem to be more important than diffusion at high temperatures.

Preparation of integrated circuits for TEM electromigration in situ studies

1986 ◽  
Vol 44 ◽  
pp. 882-883
Author(s):  
J. V. Maskowitz ◽  
W. E. Rhoden ◽  
D. R. Kitchen ◽  
R. E. Omlor ◽  
P. F. Lloyd
Keyword(s):  
Integrated Circuits ◽  
Crystallographic Orientation ◽  
Silicon Wafers ◽  
Minimum Size ◽  
Test Vehicle ◽  
In Situ Studies ◽  
Boron Doped ◽  
Doped Silicon ◽  
Drill Holes

The fabrication of the aluminum bridge test vehicle for use in the crystallographic studies of electromigration involves several photolithographic processes, some common, while others quite unique. It is most important to start with a clean wafer of known orientation. The wafers used are 7 mil thick boron doped silicon. The diameter of the wafer is 1.5 inches with a resistivity of 10-20 ohm-cm. The crystallographic orientation is (111).Initial attempts were made to both drill and laser holes in the silicon wafers then back fill with photoresist or mounting wax. A diamond tipped dentist burr was used to successfully drill holes in the wafer. This proved unacceptable in that the perimeter of the hole was cracked and chipped. Additionally, the minimum size hole realizable was > 300 μm. The drilled holes could not be arrayed on the wafer to any extent because the wafer would not stand up to the stress of multiple drilling.

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

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.

scholarly journals Optimization of spaceflight millimeter-wave impedance matching networks using laser trimming

2021 ◽  
pp. 1-7
Author(s):  
K. Parow-Souchon ◽  
D. Cuadrado-Calle ◽  
S. Rea ◽  
M. Henry ◽  
M. Merritt ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Millimeter Wave ◽  
Impedance Matching ◽  
Wave Impedance ◽  
Low Noise ◽  
Device Performance ◽  
Interface Circuits ◽  
Interface Circuit ◽  
Noise Amplifier

Abstract Realizing packaged state-of-the-art performance of monolithic microwave integrated circuits (MMICs) operating at millimeter wavelengths presents significant challenges in terms of electrical interface circuitry and physical construction. For instance, even with the aid of modern electromagnetic simulation tools, modeling the interaction between the MMIC and its package embedding circuit can lack the necessary precision to achieve optimum device performance. Physical implementation also introduces inaccuracies and requires iterative interface component substitution that can produce variable results, is invasive and risks damaging the MMIC. This paper describes a novel method for in situ optimization of packaged millimeter-wave devices using a pulsed ultraviolet laser to remove pre-selected areas of interface circuit metallization. The method was successfully demonstrated through the optimization of a 183 GHz low noise amplifier destined for use on the MetOp-SG meteorological satellite series. An improvement in amplifier output return loss from an average of 12.9 dB to 22.7 dB was achieved across an operational frequency range of 175–191 GHz and the improved circuit reproduced. We believe that our in situ tuning technique can be applied more widely to planar millimeter-wave interface circuits that are critical in achieving optimum device performance.

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