A New Type of Dislocation Mechanism in Ultrathin Copper Films

2001 ◽  
Vol 695 ◽  
Author(s):  
T. John Balk ◽  
Gerhard Dehm ◽  
Eduard Arzt

ABSTRACTIn this study of thin film plasticity, the relationship between thermomechanical behavior and dislocation motion has been investigated in copper constrained by a silicon substrate. The stress-temperature behavior as determined from wafer curvature experiments has been directly compared to deformation microstructures observed during in situ thermal cycling of plan-view specimens in the transmission electron microscope. The flow stress of copper films with thicknesses ranging from 100 nm to 400 nm was found to be constant, indicating that strengthening mechanisms may be saturated in this thickness regime. Moreover, unexpected dislocation glide on a plane parallel to the film surface, which should experience no resolved shear stress, provides potential evidence for the occurrence of constrained diffusional creep in a 270 nm film.

1996 ◽  
Vol 436 ◽  
Author(s):  
R.-M. Keller ◽  
W. Sigle ◽  
S. P. Baker ◽  
O. Kraft ◽  
E. Arzt

AbstractIn-situ transmission electron microscopy (TEM) was performed to study grain growth and dislocation motion during temperature cycles of Cu films with and without a cap layer. In addition, the substrate curvature method was employed to determine the corresponding stresstemperature curves from room temperature up to 600°C. The results of the in-situ TEM investigations provide insight into the microstructural evolution which occurs during the stress measurements. Grain growth occurred continuously throughout the first heating cycle in both cases. The evolution of dislocation structure observed in TEM supports an explanation of the stress evolution in both capped and uncapped films in terms of dislocation effects.


2001 ◽  
Vol 673 ◽  
Author(s):  
T. John Balk ◽  
Gerhard Dehm ◽  
Eduard Arzt

ABSTRACTIn situ transmission electron microscopy has been utilized to study dislocation plasticity in a 200 nm thick copper film. The behavior of dislocations in a [111]-oriented grain was recorded during a thermal cycle. During cooling, it was observed that dislocations were emitted from a grain boundary triple junction in regular intervals of 30°C to 40°C. Subsequent glide occurred on a (111) plane parallel to the film surface, despite the expectation of zero resolved shear stress on such planes. The initial emitted dislocations remained close to the triple junction, avoiding contact with another [111] grain rotated by 17°. Glide into the opposite end of the grain was initiated only after the injection of several additional dislocations, which induced strong curvature in all dislocations near the active triple junction. Post mortem examination of dislocation curvature revealed that an inhomogeneous stress state existed within the grain.


Author(s):  
T. Marieb ◽  
J. C. Bravman ◽  
P. Flinn ◽  
D. Gardner ◽  
M. Madden

Electromigration and stress voiding have been active areas of research in the microelectronics industry for many years. While accelerated testing of these phenomena has been performed for the last 25 years[1-2], only recently has the introduction of high voltage scanning electron microscopy (HVSEM) made possible in situ testing of realistic, passivated, full thickness samples at high resolution.With a combination of in situ HVSEM and post-testing transmission electron microscopy (TEM) , electromigration void nucleation sites in both normal polycrystalline and near-bamboo pure Al were investigated. The effect of the microstructure of the lines on the void motion was also studied.The HVSEM used was a slightly modified JEOL 1200 EX II scanning TEM with a backscatter electron detector placed above the sample[3]. To observe electromigration in situ the sample was heated and the line had current supplied to it to accelerate the voiding process. After testing lines were prepared for TEM by employing the plan-view wedge technique [6].


Author(s):  
Hyoung H. Kang ◽  
Michael A. Gribelyuk ◽  
Oliver D. Patterson ◽  
Steven B. Herschbein ◽  
Corey Senowitz

Abstract Cross-sectional style transmission electron microscopy (TEM) sample preparation techniques by DualBeam (SEM/FIB) systems are widely used in both laboratory and manufacturing lines with either in-situ or ex-situ lift out methods. By contrast, however, the plan view TEM sample has only been prepared in the laboratory environment, and only after breaking the wafer. This paper introduces a novel methodology for in-line, plan view TEM sample preparation at the 300mm wafer level that does not require breaking the wafer. It also presents the benefit of the technique on electrically short defects. The methodology of thin lamella TEM sample preparation for plan view work in two different tool configurations is also presented. The detailed procedure of thin lamella sample preparation is also described. In-line, full wafer plan view (S)TEM provides a quick turn around solution for defect analysis in the manufacturing line.


2004 ◽  
Vol 10 (1) ◽  
pp. 134-138 ◽  
Author(s):  
Masaki Takeguchi ◽  
Kazutaka Mitsuishi ◽  
Miyoko Tanaka ◽  
Kazuo Furuya

About 1 monolayer of palladium was deposited onto a silicon (111) 7 × 7 surface at a temperature of about 550 K inside an ultrahigh vacuum transmission electron microscope, resulting in formation of Pd2Si nanoislands and a 1 × 1 surface layer. Pd clusters created from an excess of Pd atoms on the 1 × 1 surface layer were directly observed byin situplan view high-resolution transmission electron microscopy. When an objective aperture was introduced so that electron diffractions less than 0.20 nm were filtered out, the lattice structure of the 1 × 1 surface with 0.33 nm spacing and the Pd clusters with a trimer shape were visualized. It was found that image contrast of the 1 × 1 lattice on the specific height terraces disappeared, and thereby an atomic structure of the Pd clusters was clearly observed. The appearance and disappearance of the 1 × 1 lattice was explained by the effect of the kinematical diffraction. It was identified that a Pd cluster was composed of three Pd atoms without a centered Si atom, which is consistent with the model proposed previously. The feature of the Pd clusters stuck at the surface step was also described.


1994 ◽  
Vol 364 ◽  
Author(s):  
A. Korner

AbstractThe domain structure and the evolution of antiphase boundaries (APBs) have been investigated in Fe-Al by means of “in-situ” transmission electron microscopy (TEM) heating experiments. Single crystals with composition Fe22.1at%Al and Fe25.6at%Al have been used.The grown-in structure of the Fe22.1at%al single crystal is composed of DO3 ordered particles embedded in the disorderd ±-matrix. A bimodal distribution of the particles was found. Small ordered particles are in between the large precipitates which are surrounded by particle-free zones. Numerous of this large ordered precipitates contain APBs. Crossing the transition temperature to the disordered phase, the small particles dissolve into the ±-matrix and the large particles start to shrink by dissolving.The single crystal with composition Fe25.6at%Al was found to be completely DO3 ordered. The grown-in domains are separated by APBs of type a′0/2〈100〉. At temperatures far below the transition temperature to the B2 phase no significant change in the APB and domain structure has been detected. In contrast, a remarkable evolution in the APB structure has been observed approaching the transition temperature. Coarsening of the domains has been found. Furthermore, APBs of B2-type (a′0/4〈lll〉 shear) are dragged out by dislocation motion. B2- and DC3-type APBs react and junctions are formed. With increasing annealing time, the density of B2-type boundaries increases. The TEM image is dominated by B2-type boundaries linked by the D03-type boundaries. The DO3 superlattice spots are clearly excited approaching the transition temperature to B2. Above the transition temperature, the DO3 spots disappear completely and the diffraction pattern reveals B2 long range order.


1994 ◽  
Vol 356 ◽  
Author(s):  
S. Bader ◽  
E. M. Kalaugher ◽  
E. Arzt

AbstractThe microstructure and mechanical properties of hot (h) and cold (c) sputtered Al-lwt%Si and Al-lwt%Si-0.5wt%Cu films were studied using transmission electron microscopy and wafer curvature stress measurements.Stress/temperature curves of all films showed only slight differences in compression on healing once a stable grain size was established. However, on cooling several remarkable differences were observed. These observations cannot be explained by assuming dislocation glide/climb as the dominant relaxation mechanism. The results will be discussed in terms of grain boundary diffusional relaxation (Coble creep), which occurs in addition to dislocation glide.


1994 ◽  
Vol 341 ◽  
Author(s):  
Jinshan Li ◽  
Robert Sinclair ◽  
Stephen S. Rosenblum ◽  
Hidetaka Hayashi

AbstractUsing facing target sputtering, randomly oriented crystalline barium ferrite(BaFe12O19, BaM) has been deposited onto a Ultra Densified Amorphous Carbon® (UDAC) substrate, producing high quality films in-situ at a substrate temperature of 6400°C without any post-deposition annealing. Cross section transmission electron microscopy (TEM) reveals that the films have columnar structure. A ˜100Å thick interdiffusion layer between BaM and silicon nitride underlayer was observed. Films grown at low oxygen partial pressure have lower saturation magnetization (Ms), that may be caused by the formation of some amorphous phase at the grain boundaries as noticed by plan-view TEM. The existence of the Fe2O3 phase in the BaM was also revealed by electron diffraction.


1992 ◽  
Vol 280 ◽  
Author(s):  
I. Hashim ◽  
B. Park ◽  
H. A. Atwater

ABSTRACTEpitaxial Cu thin films have been grown on H-terminated Si(OOl) substrates at room temperature by D.C. ion-beam sputter deposition in ultrahigh vacuum. The development of orientation and microstructure during epitaxial growth from the initial stages of Cu growth up to Cu thicknesses of few hundred nm has been investigated. Analysis by in-situ reflection high energy electron diffraction, thin film x-ray diffraction, and plan-view and cross-sectional transmission electron microscopy indicates that the films are well textured with Cu(001)∥ Si(001) and Cu[100]∥ Si[110]. Interestingly, it is found that a distribution of orientations occurs at the early stages of Cu epitaxy on Si(001) surface, and that a (001) texture emerges gradually with increasing Cu thickness. The effect of silicide formation and deposition conditions on the crystalline quality of Cu epitaxy is also discussed.


1987 ◽  
Vol 2 (4) ◽  
pp. 436-440 ◽  
Author(s):  
G. M. Bond ◽  
I. M. Robertson ◽  
H. K. Birnbaum

The effect of boron on the mechanism of strain transfer across grain boundaries in Ni3Al has been investigated by dynamic recording of events occurring during in-situ straining in the transmission electron microscope. Boundaries in both doped and undoped material can act as effective barriers to dislocation motion, large numbers of dislocations being incorporated into the boundary without any plastic strain occurring in the adjacent grain. In the undoped material, the grain-boundary strain is relieved by the sudden failure of the grain boundary. In the doped material the strain is relieved by the sudden generation and emission of large numbers of dislocations from the grain boundary. This effect may be understood by boron either increasing the grain-boundary cohesion or reducing the stress required to operate grain-boundary dislocation sources, rather than easing the passage of slip dislocations through the grain boundary.


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