Stress and Deformation of Pzt Thin Film on Silicon Wafer Due to Thermal Expansion

1999 ◽  
Vol 574 ◽  
Author(s):  
Ming Zang ◽  
Dennis L. Polla ◽  
Shayne M. Zurn ◽  
Tianhong Cui
Keyword(s):  
Thin Films ◽  
Thermal Stress ◽  
Silicon Nitride ◽  
Tensile Stress ◽  
Silicon Dioxide ◽  
Silicon Wafer ◽  
Thermal Stresses ◽  
Pzt Thin Films ◽  
Pzt Film ◽  
Stress And Deformation

AbstractStress and deformation of PZT thin films deposited on silicon wafers due to thermal expansion during the annealing process are modeled using a 3-D shell element of ANSYS. Two different designs of PZT thin films on the wafer are modeled. The first design is a PZT/Pt/Ti/silicon dioxide/silicon wafer, which is used for making acoustic emission sensors. The second design is a PZT/Pt/Ti/silicon dioxide/silicon nitride/silicon dioxide/silicon wafer, commonly used in fabrication of cantilever beams. For the design without the silicon nitride layer, the thermal stress of the PZT film is 298MPa, Pt 1280MPa, Ti 647MPa, the silicon dioxide layer is 228MPa, and the silicon wafer is 0.41–1.67MPa. For the design with silicon nitride, the thermal stresses are: PZT 301MPa, Pt 1280MPa, Ti 651MPa, silicon dioxide 226MPa, silicon nitride 416MPa, silicon dioxide 226MPa, and silicon wafer 1.05–4.23MPa. The residual stress of the PZT film is measured at 200–25OMPa for the design without silicon nitride, and 336MPa for the design with silicon nitride. Comparisons of the thermal stress with the tensile or proof stress of material for each layer indicate that thermal stress of the PZT film is slightly greater than its bulk tensile stress, that of Pt film is five times greater than its bulk tensile stress, and that of Ti film is approximately equal to its bulk tensile stress. The thermal stresses of silicon dioxide, silicon nitride, and silicon wafer layers are far smaller than their proof stresses.

Effect on Crystal Orientation on Residual Stress and Electrical Properties of a PZT Thin Film Deposited on Buffered-Si Substrate

2006 ◽  
Vol 320 ◽  
pp. 65-68
Author(s):  
Keisuke Fujito ◽  
Naoki Wakiya ◽  
Takanori Kiguchi ◽  
Nobuyasu Mizutani ◽  
Kazuo Shinozaki
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Electrical Properties ◽  
Tensile Stress ◽  
Remanent Polarization ◽  
Residual Tensile Stress ◽  
Si Substrate ◽  
Pzt Thin Films ◽  
Pzt Film ◽  
Pzt Thin Film

Changes of residual stress and electrical properties were examined in (001)-oriented and (111)-oriented Pb(Zr0.5Ti0.5)O3 (PZT) thin films deposited on a buffered-Si substrate with a buffer and bottom electrode layer of a (La,Sr)CoO3(LSCO). A (001)-epitaxial PZT film was prepared on LSCO/CeO2 /Zr0.85Y0.15O1.93(YSZ)/Si. In addition, a (111)-oriented PZT film was prepared on LSCO/SrTiO3(ST) /Mn0.24Zn0.09Fe2.67O4(MZF)/YSZ/Si. The residual tensile stress in (001)-PZT thin films decreased from 2.92 to 1.98 GPa and the remanent polarization increased from 7.5 to 41.7 @C/cm2 as the LSCO thickness increased. In (111)-PZT, the residual tensile stress decreased from 1.72 to 0.95 GPa and remanent polarization increased from 9.5 to 26.7 @C/cm2. The residual tensile stress of (111)-PZT was less than that of (001)-PZT. The remanent polarization in the 80 nm (111)-PZT was greater than that of the 60 nm (001)-PZT. In the 700-nm-thick PZT, the remanent polarization in (001)-PZT was greater than that in (111)-PZT.

Thermal Stress Analysis of Silver Welding Spot on Solar Cell of Space Solar Array

2013 ◽  
Vol 278-280 ◽  
pp. 500-504
Author(s):  
Shu Jie Zhang ◽  
Yu Han Zhang
Keyword(s):  
Thermal Stress ◽  
Solar Cell ◽  
Thermal Deformation ◽  
Thermal Stresses ◽  
Solar Array ◽  
Thermal Vacuum ◽  
Welding Spot ◽  
Stress And Deformation ◽  
Cyclic Changes ◽  
Design And Manufacture

Cyclic changes of temperature in space may cause thermal deformation and thermal stresses at the silver welding spots on solar cells, which result in the solar array work abnormally. According to the temperature conditions in the thermal vacuum, the thermal stress and deformation at silver welding spot that between solar cell and inter-link chip were analyzed. The result shows that thermal cycling can make the sliver welding spot separated or contacted, which cause the solar array work wrong. The phenomenon of thermal vacuum reliability test was corresponding with these results. This paper could offer some references for the design and manufacture of solar array in the future.

PZT Thin Films Deposited by RF Magnetron Sputtering

2013 ◽  
Vol 302 ◽  
pp. 8-13
Author(s):  
Shun Fa Hwang ◽  
Wen Bin Li
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Annealing Temperature ◽  
Bottom Electrode ◽  
Rf Sputtering ◽  
Rf Magnetron Sputtering ◽  
Pzt Thin Films ◽  
Pzt Film ◽  
Pzt Thin Film

PZT thin film was fabricated by using RF-sputtering process, and platinum was used as bottom electrodes. The sputtering gases were Ar：O2＝25：0 sccm, Ar：O2＝20：5 sccm, or Ar：O2＝15：10 sccm. After sputtering, the PZT film was annealed for 5 minutes under O2 gas environment and at the temperature of 600 0C, 650 0C, 700 0C or 750 0C. To judge the quality of the deposited PZT film, its physical properties and electric properties were evaluated. The results indicate that the best crystallization temperature of PZT thin film is about 700 0C. Also, the roughness of the PZT thin film becomes larger with the increasing of annealing temperature. By adding more oxygen in the sputtering gas, one could have better crystallization of the PZT film. As for the electrical properties, the leakage current of PZT thin film increases with the increasing of annealing temperature. Furthermore, the ferroelectric property is affected by the crystallization amount of perovskite, the thickness of PZT thin film, and the diffusion situation between the bottom electrode and the PZT film.

THERMAL STRESS BEHAVIOR IN NANO-SIZE THIN ALUMINUM FILMS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4691-4696 ◽  
Author(s):  
TAKAO HANABUSA ◽  
KAZUYA KUSAKA ◽  
SHOSO SHINGUBARA ◽  
OSAMI SAKATA
Keyword(s):  
Thin Films ◽  
Thermal Stress ◽  
Synchrotron Radiation ◽  
Thermal Stresses ◽  
In Situ Observation ◽  
Aluminum Films ◽  
Stress Behavior ◽  
Thin Aluminum ◽  
20 Nm ◽  
Nano Size

In-situ observation of thermal stresses in thin films deposited on a silicon substrate was made by synchrotron radiation. Specimens prepared in this experiment were nano-size thin aluminum films with SiO 2 passivation. The thickness of the films was 10 nm, 20 nm and 50 nm. Synchrotron radiation revealed the diffraction intensities for these thin films and make possible to measure stresses in nano-size thin films. Residual stresses in the as-deposited state were tensile. Compressive stresses were developed in a heating cycle up to 300°C and tensile stresses were developed in a cooling cycle. The thermal stresses in the 50 nm film showed linear behavior in the first heating stage from room temperature to 250°C followed by no change in the stress at 300°C, however, linearly behaved in the second cycle. On the other hand, the thermal stresses in 20 nm and 10 nm films almost linearly behaved without any hysteresis in increasing and decreasing temperature cycles. The mechanism of thermal stress behavior in thin films can be explained by strengthening of the nano-size thin films due to inhibition of dislocation source and dislocation motion.

Tuning of nanogap size in high tensile stress silicon nitride thin films

2012 ◽  
Vol 83 (5) ◽  
pp. 055003 ◽  
Author(s):  
Anıl Günay-Demirkol ◽  
İsmet İ. Kaya
Keyword(s):  
Thin Films ◽  
Silicon Nitride ◽  
Tensile Stress

Electrode Contacts on PZT Thin Films and Their Influence on Fatigue Properties

1994 ◽  
Vol 361 ◽  
Author(s):  
J.J. Lee ◽  
C.L. Thio ◽  
M. Bhattacharya ◽  
S.B. Desu
Keyword(s):  
Thin Films ◽  
Dielectric Permittivity ◽  
Lead Zirconate Titanate ◽  
Interfacial Layer ◽  
Ruthenium Oxide ◽  
Lead Zirconate ◽  
Fatigue Properties ◽  
Pzt Thin Films ◽  
Pzt Film ◽  
Metal Organic

ABSTRACTThe degradation (fatigue) of dielectric properties of ferroelectric PZT (Lead Zirconate Titanate) thin films during cycling was investigated. PZT thin films were fabricated by metal-organic decomposition (MOD). Samples with electrodes of platinum (Pt) and ruthenium oxide (RuO2) were studied. The interfacial capacitance (if any) at the Pt/PZT and RuO2/PZT interfaces was determined from the thickness dependence of low-field dielectric permittivity (εr) measurements. It was observed that a low εrlayer existed at the Pt/PZT interface but not at the RuO2/PZT interface. The dielectric permittivity of this interfacial layer degrades with increasing fatigue while the εrof the bulk PZT film remains constant. This indicates that fatigue increases the interfacial layer thickness but does not change the bulk properties. For the capacitors with RuO2/PZT/RuO2 structure, however, the εdoes not change with thickness and fatigue cycling. This implies no interfacial layer exists between RuO2/PZT and, therefore, no fatigue was observed. Additionally, an impedance spectroscopie technique has been proposed for possible use in analyzing the nature of the interfacial layer during the fatigue process.

Thermal Stresses, Interfacial Reactions and Microstructures of Al/Ti and Al/TiN Thin Films Encapsulated by SiOF

1997 ◽  
Vol 476 ◽  
Author(s):  
Wei-Tsu Tseng ◽  
Li-Wen Chen ◽  
G.-C. Tu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Plastic Deformation ◽  
Grain Size ◽  
Stress Relaxation ◽  
Silicon Dioxide ◽  
Thermal Stresses ◽  
Plastic Behavior ◽  
Tin Thin Films ◽  
Metal Layers

AbstractVariations in stress and grain size of Ti- and TiN- capped Al thin films passivated by fluorinated silicon dioxide (SiOF) during repetitive thermal cycling are investigated. The amount of stress relaxation, elastic and plastic behavior of these thin film structures are compared. Ti and TiN cap layers strengthen the single Al film significantly while the presence of SiOF induces plastic deformation of metal layers. Less grain growth is associated with a dielectric passivated Al film. The penetration of fluorine into Al upon annealing can be reduced by a TiN barrier layer.

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