Stress Relaxation During Diffusional Phase Transformation Under Induced Thermal Stress

1993 ◽  
Vol 308 ◽  
Author(s):  
E C Zingu ◽  
B T Mofokeng
Keyword(s):  
Thin Film ◽  
Growth Rate ◽  
Phase Transformation ◽  
Thermal Stress ◽  
Molar Fraction ◽  
Si Substrates ◽  
Expansion Coefficients ◽  
The Difference ◽  
Stress States ◽  
Si Thin Film

ABSTRACTThermal mismatch between the expansion coefficients of a substrate and deposited thin film gives rise to extrinsic stress in the film. Different stress states are induced into the Co/Si thin film combination by depositing the multi-layers on Al and Si substrates respectively. Interdiffusion at 360°C is found to be influenced by the extrinsic stress in the films. The difference in Co2Si growth rate on different substrates is ascribed to the difference in composition (Co molar fraction) at the Co/Co2Si and Co2Si/Si interfaces due to different stress states.

Measurements of Residual Stress in the Layers of Thin Film Micro-Gas Sensors

2000 ◽  
Vol 657 ◽  
Author(s):  
Youngman Kim ◽  
Sung-Ho Choo
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Residual Stress ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Micro Gas Sensor ◽  
Thin Film Layer ◽  
Film Layer ◽  
The Difference ◽  
Stress States

ABSTRACTThe mechanical properties of thin film materials are known to be different from those of bulk materials, which are generally overlooked in practice. The difference in mechanical properties can be misleading in the estimation of residual stress states in micro-gas sensors with multi-layer structures during manufacturing and in service.In this study the residual stress of each film layer in a micro-gas sensor was measured according to the five difference sets of film stacking structure used for the sensor. The Pt thin film layer was found to have the highest tensile residual stress, which may affect the reliability of the micro-gas sensor. For the Pt layer the changes in residual stress were measured as a function of processing variables and thermal cycling.

Selective Deposition of N+ Doped MC-SI:H:F by Rf Plasma Cvd on Si and S1O2 Substrates

1989 ◽  
Vol 164 ◽  
Author(s):  
K. Baert ◽  
P. Deschepper ◽  
H. Pattyn ◽  
J. Nijs ◽  
R. Mertens
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Growth Process ◽  
Selective Growth ◽  
Rf Plasma ◽  
Plasma Cvd ◽  
Selective Deposition ◽  
Si Substrates ◽  
Si Thin Film

Abstractμc-Si:H:F can be deposited by if plasma-CVD of fluorinated gas sources like SiF4 and SiH2F2, mixed with H2 and/or SiH4. However, this growth process is usually not selective: the layers are deposited on SiO2 as well as on Si substrates. In this paper, selective growth from SiF4 + SiH4 is reported. N+ Si layers were deposited on <100> Si and poly-Si with a conductivity up to 300 resp. 100 S/cm. The selective growth process was applied for Source and Drain regions of poly-Si thin film transistors on insulating substrate.

scholarly journals Study of Crystallization and Phase Transformation in Amorphous Co-Si Thin Film by X-ray Diffraction

2004 ◽  
Vol 45 (7) ◽  
pp. 2471-2473 ◽  
Author(s):  
Fanxiong Cheng ◽  
Chuanhai Jiang ◽  
Jiansheng Wu
Keyword(s):  
Thin Film ◽  
Phase Transformation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Thin Film

AN ANALYSIS OF MODE I FATIGUE CRACK GROWTH UNDER BIAXIAL STRESS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3824-3829
Author(s):  
M. ENDO ◽  
H. SAKAI ◽  
A. J. MCEVILY
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth ◽  
Biaxial Stress ◽  
Mode I ◽  
Plastic Behavior ◽  
Elastic Plastic ◽  
Linear Elastic ◽  
The Difference ◽  
Stress States

A modified linear-elastic method of analysis was proposed for the estimation of fatigue lifetimes of biaxially loaded components containing cracks. A constitutive relation of the crack growth rate, d a/ d N, was used as a basis for the analysis. The modifications included a correction for elastic-plastic behavior, consideration of Kitagawa effect, and consideration of the development of crack closure in the wake of a newly formed crack. A unified evaluation for the d a/ d N data measured by Brown and Miller in different biaxial stress states was made by use of the proposed method. It was found that the difference in elastic-plastic behavior accounted for the effect of biaxial stress on d a/ d N.

Zero Hysteresis in Shape-Memory TI-NI-X Films (X = CU, PD) Under Constraint

1999 ◽  
Vol 604 ◽  
Author(s):  
B. Winzek ◽  
E. Quandt
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Shape Memory ◽  
Dc Magnetron Sputtering ◽  
Hysteresis Width ◽  
Metallic Substrates ◽  
Shape Memory Actuators ◽  
Expansion Coefficients ◽  
The Difference ◽  
Hysteresis Properties

AbstractThe hysteresis of thin film shape memory actuators affects the frequency of actuators switching between martensite and austenite. Therefore the hysteresis properties of thin films of TiNi, Ti(Ni,Cu) and Ti(NiPd) deposited onto metallic substrates by DC-Magnetron sputtering have been investigated. The substrates have different expansion coefficients to establish biaxial tensile and compressive film stresses, respectively. The results show, that the hysteresis width is significantly affected by the stress state of the shape memory film and in principal depends on the temperature range of measurement. In contrast, the difference Af-Mf remains unchanged. In some alloys zero hysteresis width could be obtained.

High-Throughput Evaluation of Crystallization Temperature of Pd-Cu-Si System Using Integrated Thin Film Samples

2010 ◽  
Vol 654-656 ◽  
pp. 2426-2429 ◽  
Author(s):  
Yuko Aono ◽  
Junpei Sakurai ◽  
Akira Shimokohbe ◽  
Seiichi Hata
Keyword(s):  
Thin Film ◽  
Phase Diagram ◽  
Amorphous Alloy ◽  
High Throughput ◽  
Crystallization Temperature ◽  
Evaluation Method ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
The Difference ◽  
Si Thin Film

In this paper, a new high-throughput evaluation method for crystallization temperature (Tx) of thin film amorphous alloy is introduced. For measurement of Tx on integrated thin film samples, thermography is used. The order of one hundred Pd-Cu-Si thin film amorphous samples with different composition are integrated on one chip and measured their Tx at once. The validity of measured Tx are examined by comparing with results of differential scanning calorimeter that is a conventional method for Tx measurement, and equilibrium phase diagram of Pd-Si. As results, the difference of two methods is within 10 K and the trend of Tx map has strong correlation with the phase diagram, respectively.

Defect Reduction by Thermal Cyclic Growth in GaAs Grown on Si by Movpe

1993 ◽  
Vol 325 ◽  
Author(s):  
W. KÜrner ◽  
R. Dieter ◽  
K. Zieger ◽  
F. Goroncy ◽  
A. DÖrnen ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
Dislocation Density ◽  
Lattice Mismatch ◽  
Gaas Layer ◽  
Defect Reduction ◽  
Thermal Expansion Coefficients ◽  
Related Defect ◽  
Expansion Coefficients ◽  
The Difference

AbstractThe growth of GaAs epilayers on Si should combine the advantages of both materials. The lattice mismatch and the difference in thermal expansion coefficients, however, result in the yet unsolved problems of high dislocation density and thermal stress in the GaAs layer. Recently, considerable improvements have been achieved by a ‘thermal cyclic growth’ (TCG) process. In this study we focus on the reduction of high defect concentration and dislocation density. The improvement of the epilayer quality is verified by DLTS, PL and DCXD. Results of TEM and DLTS measurements lead to the identification of a dislocation related defect.

Diffusional Phase Transformation under Induced Thermal Stress

1991 ◽  
Vol 230 ◽  
Author(s):  
E C Zingu ◽  
B T Mofokeng
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Elevated Temperatures ◽  
Film Structure ◽  
Intrinsic Stress ◽  
Silicide Formation ◽  
Si Substrates ◽  
Silicide Growth ◽  
Expansion Coefficients ◽  
Large Tensile Stress

AbstractWhen thin films are deposited on substrates or when compound films are formed through interdiffusion of multi-film structures, intrinsic stress develops in the various films. Thermal mismatch between the expansion coefficients of the substrate and films in multi-film structures gives rise to extrinsic stress at elevated temperaturesBy using Si<100> and rolled Al foil substrates supporting the same multi-film structure SiO2/Si/Co, the effect of extrinsic stress on interdiffusion of thin films is isolated.Silicide growth is found to be inhibited (delayed) when formed on Al substrates compared to that formed on Si substrates. The delay in silicide growth is ascribed to delamination caused by large tensile stress prior to silicide formation. The growth rate of Co2Si is found to be similar on both Al and Si substrates

Defects in β-SiC thin films grown on α-SiC substrates

1988 ◽  
Vol 46 ◽  
pp. 568-569
Author(s):  
Karren L. More
Keyword(s):  
Thin Films ◽  
Semiconductor Device ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Substrate Material ◽  
Growth Interface ◽  
Si Substrates ◽  
Thermal Expansion Coefficients ◽  
Device Applications ◽  
Expansion Coefficients

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.

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