Micromechanical Characterization of Dielectric Thin Films

1993 ◽  
Vol 308 ◽  
Author(s):  
James M. Grow

ABSTRACTA nanoindenter has been used to obtain Young's modulus and hardness data for a variety of dielectric thin films including silicon carbide, boron nitride, silicon carbonitride, and silicon oxide. These films, were synthesized by low pressure and plasma enhanced chemical vapor deposition, and had a thickness from 0.25 to a few microns. For the BN films, the modulus and hardness of the films decreased significantly as the deposition temperature increased while the reverse was true for the SiC films. In both cases, these changes were related to variations in the compositions of the deposits due to the onset of different reactions as the temperature is increased. Silicon carbonitride films oxidized slowly when synthesized at temperatures below 200º C and the Young's modulus of these films increased at higher deposition temperatures. For silicon dioxide, there was little change in the composition of the films over the deposition temperature range investigated (375–475º C), thus correspondingly, small variations in the micromechanical properties of the material. However, moisture and hydrogen removal caused by an anneal at 800º C resulted in an significant increase in the modulus and hardness of these films.

1999 ◽  
Vol 594 ◽  
Author(s):  
T. Y. Zhang ◽  
Y. J. Su ◽  
C. F. Qian ◽  
M. H. Zhao ◽  
L. Q. Chen

AbstractThe present work proposes a novel microbridge testing method to simultaneously evaluate the Young's modulus, residual stress of thin films under small deformation. Theoretic analysis and finite element calculation are conducted on microbridge deformation to provide a closed formula of deflection versus load, considering both substrate deformation and residual stress in the film. Silicon nitride films fabricated by low pressure chemical vapor deposition on silicon substrates are tested to demonstrate the proposed method. The results show that the Young's modulus and residual stress for the annealed silicon nitride film are respectively 202 GPa and 334.9 MPa.


1998 ◽  
Vol 555 ◽  
Author(s):  
A. E. Alexiou ◽  
M. R. Hendrick ◽  
J. M. Hampikian

AbstractChromia thin films were deposited onto substrates of Ni and Ni-20Cr by gaseous fuel combustion chemical vapor deposition. The chemical precursor utilized to achieve chromia films was aqueous 0.27M chromium nitrate, and the depositions took place within the flame at temperatures between 200 and 550°C. Amorphous coatings were deposited between 200 and 375°C, whereas crystalline coatings of chromia (eskolaite) were deposited between 400 and 550°C. The eskolaite deposition rate was approximately five times faster than the amorphous chromia. Chromia coatings containing 2 wt% yttria were also formed. The deposition temperature necessary to form crystalline chromia/yttria coatings was slightly higher (∼50°C) than those containing chromia only. The ability of the various coatings to provide oxidation protection was characterized using thermogravimetric analysis (TGA). The eskolaite coatings that are at least 1 im thick reduce the oxidation mass gain/area of Ni-20Cr by nearly a factor of ten and the parabolic constant by an order of magnitude, whereas the amorphous chromia coatings that are 0.6 μm thick do not demonstrate such an improvement. Yttria-doped chromia coatings further reduce the parabolic constant by two orders of magnitude, consistent with expectation. Characterization of the coatings was accomplished using a variety of techniques, including SEM, TEM, EDS, and XRD.


2012 ◽  
Vol 198-199 ◽  
pp. 28-31
Author(s):  
Chun Ya Li ◽  
Xi Feng Li ◽  
Long Long Chen ◽  
Ji Feng Shi ◽  
Jian Hua Zhang

Under different growth conditions, silicon Oxide (SiOx) thin films were deposited successfully on Si (100) substrates and glass substrates by plasma enhanced chemical vapor deposition (PECVD). The thickness, refractive index and growth rate of the thin films were tested by ellipsometer. The effects of deposition temperature on the structure and properties of SiOx films were studied using X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS) and UV-Visible spectroscopy. The results show that the SiOx films were amorphous at different deposition temperature. The peaks of Si2p and O1s shifted to higher binding energy with temperature increasing. The SiOx films had high transmissivity at the range of 400-900nm. By analyzing the observation and data, the influence of deposition parameters on the electrical properties and interface characteristics of SiOx thin film prepared by PECVD is systematically discussed. At last, SiOx thin film with excellent electrical properties and good interface characteristic is prepared under the relatively optimum parameters.


Author(s):  
Zhiqiang Cao ◽  
Tong-Yi Zhang ◽  
Xin Zhang

Plasma-enhanced chemical vapor deposited (PECVD) silane-based oxides (SiOx) have been widely used in both microelectronics and MEMS (MicroElectroMechanical Systems) to form electrical and/or mechanical components. In this paper, a novel nanoindentation-based microbridge testing method is developed to measure both the residual stresses and Young’s modulus of PECVD SiOx films on silicon wafers. Theoretically, we considered both the substrate deformation and residual stress in the thin film and derived a closed formula of deflection versus load. The formula fitted the experimental curves almost perfectly, from which the residual stresses and Young’s modulus of the film were determined. Experimentally, freestanding microbridges made of PECVD SiOx films were fabricated using the silicon undercut bulk micromachining technique. The results showed that the as-deposited PECVD SiOx films had a residual stress of −155±17 MPa and a Young’s modulus of 74.8±3.3 GPa.


2012 ◽  
Author(s):  
Sean King ◽  
George A. Antonelli ◽  
Gheorghe Stan ◽  
Robert F. Cook ◽  
R. Sooryakumar

Author(s):  
E. Bassiachvili ◽  
P. Nieva ◽  
A. Khajepour

Information on material properties of structural thin films for MEMS fabrication is very limited. The small information available in the literature suggests that the Young’s modulus of structural thin films such as polysilicon can change up to 30% with heavy doping at room temperature. Accurate knowledge of these variations is critical for proper design as well as operation of MEMS devices, especially for applications that require them to be exposed to harsh environmental conditions. In this paper, devices for the on-chip characterization of the Young’s modulus of polysilicon as a function of the doping concentration conditions are presented. Analytical modeling has been performed to predict the change in the devices’ pull-in voltage as a function of doping concentration. The devices were fabricated using the PolyMUMPs process on two different polysilicon layers on the same chip separated by a layer of oxide. The top layer devices are heavily doped while the bottom layer devices are left lightly doped. The lightly doped devices serve as a reference, allowing some account for fabrication uncertainties in order to ensure consistent results. Devices for measuring in-plane stresses, out-of-plane stress gradients and specially designed resistor structures that account for the effect of contact resistance have also been fabricated to monitor these quantities while testing. The devices will be tested using a customized vacuum chamber to study the effect of phosphorus concentration on these structures.


2013 ◽  
Vol 7 (1) ◽  
pp. 073094 ◽  
Author(s):  
Brian C. Daly ◽  
Sheldon T. Bailey ◽  
Ratnasingham Sooryakumar ◽  
Sean W. King

1994 ◽  
Vol 9 (1) ◽  
pp. 96-103 ◽  
Author(s):  
M.A. El Khakani ◽  
M. Chaker ◽  
A. Jean ◽  
S. Boily ◽  
J.C. Kieffer ◽  
...  

Due to its interesting mechanical properties, silicon carbide is an excellent material for many applications. In this paper, we report on the mechanical properties of amorphous hydrogenated or hydrogen-free silicon carbide thin films deposited by using different deposition techniques, namely plasma enhanced chemical vapor deposition (PECVD), laser ablation deposition (LAD), and triode sputtering deposition (TSD). a-SixC1−x: H PECVD, a-SiC LAD, and a-SiC TSD thin films and corresponding free-standing membranes were mechanically investigated by using nanoindentation and bulge techniques, respectively. Hardness (H), Young's modulus (E), and Poisson's ratio (v) of the studied silicon carbide thin films were determined. It is shown that for hydrogenated a-SixC1−x: H PECVD films, both hardness and Young's modulus are dependent on the film composition. The nearly stoichiometric a-SiC: H films present higher H and E values than the Si-rich a-SixC1−x: H films. For hydrogen-free a-SiC films, the hardness and Young's modulus were as high as about 30 GPa and 240 GPa, respectively. Hydrogen-free a-SiC films present both hardness and Young's modulus values higher by about 50% than those of hydrogenated a-SiC: H PECVD films. By using the FTIR absorption spectroscopy, we estimated the Si-C bond densities (NSiC) from the Si-C stretching absorption band (centered around 780 cm−1), and were thus able to correlate the observed mechanical behavior of a-SiC films to their microstructure. We indeed point out a constant-plus-linear variation of the hardness and Young's modulus upon the Si-C bond density, over the NSiC investigated range [(4–18) × 1022 bond · cm−3], regardless of the film composition or the deposition technique.


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