An Empirical Formula for the Estimation of the Residual Stress in Boron-Doped Silicon Films

2003 ◽  
Author(s):  
Ok Chan Jeong ◽  
Sang Sik Yang
Keyword(s):  
Residual Stress ◽  
Correlation Coefficient ◽  
Concentration Profile ◽  
Empirical Formula ◽  
Boron Concentration ◽  
Silicon Film ◽  
Stress Profile ◽  
Residual Stress Profile ◽  
Boron Doped ◽  
Doped Silicon

In this paper, a novel empirical formula is proposed to estimate the residual stress profile as a function of the boron-doped silicon film depth. The residual stress profile is derived from the proposed boron concentration profile, which is a second order function of the film depth, the boron diffusion length, and the correlation coefficient between the residual stress and the boron concentration. The proposed empirical formula is verified by the comparison of the previous results such as the residual stress profiles determined by the quantitative analysis method and the boron concentration profile measured by SIMS and spreading resistance. If the correlation coefficient increases, the residual average and maximum stresses are exponentially reduced. If the drive-in process time or the temperature increase, the compressive stress develops on the surface of the boron-doped silicon film due to the thermal oxidation process.

The Effects of Drive-In Process Parameters on the Residual Stress Profile of the Boron-Doped Silicon Layer

2002 ◽  
Author(s):  
Ok Chan Jeong ◽  
Sang Sik Yang
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Process Parameters ◽  
Boron Concentration ◽  
Silicon Film ◽  
Correlation Coefficients ◽  
Stress Profile ◽  
Residual Tensile Stress ◽  
Residual Stress Profile ◽  
Stress Profiles

The paper represents the effects of the drive-in process parameters on the residual stress profile of the p+ silicon film quantitatively. Since the residual stress profile is not uniform along the direction normal to the surface, the residual stress is assumed to be a polynomial function of the depth. All of the coefficients of the polynomial are determined from the deflections of cantilevers and the displacement of a rotating beam structure, which are measured with a surface profiler meter and a microscope. As the drive-in temperature or the drive-in time increases, the boron concentration decreases and the magnitude of the average residual tensile stress decreases. Also, near the surface of the p+ film the residual tensile stress is transformed into the residual compressive stress and its magnitude increases. The correlation coefficients between the residual stress profiles and the simulated boron concentration are calculated. As the drive-in time and temperature increase, all correlation coefficients become close to 1, and the boron concentration profiles after the drive-in process are similar to the stress profiles. Also, the lattice contractions of test wafers are measured by HRXRD (High Resolution X-Ray Diffractometry).

scholarly journals Influence of residual stress profile and surface microstructure on fatigue life of a 15-5PH

2018 ◽  
Vol 213 ◽  
pp. 623-629 ◽  
Author(s):  
F. Valiorgue ◽  
V. Zmelty ◽  
M. Dumas ◽  
V. Chomienne ◽  
C. Verdu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Surface Microstructure ◽  
Stress Profile ◽  
Residual Stress Profile

scholarly journals Cross-Sectional Mapping of Residual Stresses by Measuring the Surface Contour After a Cut

2000 ◽  
Vol 123 (2) ◽  
pp. 162-168 ◽  
Author(s):  
M. B. Prime
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Superposition Principle ◽  
New Method ◽  
Contour Method ◽  
Stress Profile ◽  
Relaxation Methods ◽  
Cross Sectional ◽  
Residual Stress Profile

A powerful new method for residual stress measurement is presented. A part is cut in two, and the contour, or profile, of the resulting new surface is measured to determine the displacements caused by release of the residual stresses. Analytically, for example using a finite element model, the opposite of the measured contour is applied to the surface as a displacement boundary condition. By Bueckner’s superposition principle, this calculation gives the original residual stresses normal to the plane of the cut. This “contour method” is more powerful than other relaxation methods because it can determine an arbitrary cross-sectional area map of residual stress, yet more simple because the stresses can be determined directly from the data without a tedious inversion technique. The new method is verified with a numerical simulation, then experimentally validated on a steel beam with a known residual stress profile.

Study of Effect of Repetition Rate on Laser Shock Peening Using Finite Element Modeling

2020 ◽  
Author(s):  
Sai Kosaraju ◽  
Xin Zhao
Keyword(s):  
Shock Wave ◽  
Residual Stress ◽  
Finite Element ◽  
Shock Waves ◽  
Repetition Rate ◽  
High Repetition Rate ◽  
Stress Profile ◽  
Surface Residual Stress ◽  
Residual Stress Profile ◽  
High Repetition

Abstract A two-dimensional finite element model is developed to simulate the interaction between metal samples and laser-induced shock waves. Multiple laser impacts are applied at each location to increase plastically affected depth and compressive stress. The in-depth and surface residual stress profiles are analyzed at various repetition rates and spot sizes. It is found that the residual stress is not sensitive to repetition rate until it reaches a very high level. At extremely high repetition rate (100 MHz), the delay between two shock waves is even shorter than their duration, and there will be shock wave superposition. It is revealed that the interaction of metal with shock wave is significantly different, leading to a different residual stress profile. Stronger residual stress with deeper distribution will be obtained comparing with lower repetition rate cases. The effect of repetition rate at different spot sizes is also studied. It is found that with larger laser spot, the peak compressive residual stress decreases but the distribution is deeper at extremely high repetition rates.

scholarly journals Impact of grinding wheel specification on surface integrity and residual stress when grinding Inconel 718

2020 ◽  
pp. 095440542096120
Author(s):  
David Curtis ◽  
Holger Krain ◽  
Andrew Winder ◽  
Donka Novovic
Keyword(s):  
Residual Stress ◽  
Inconel 718 ◽  
Cubic Boron Nitride ◽  
Grinding Wheel ◽  
Stress Profile ◽  
Standard Equipment ◽  
Residual Stress Profile ◽  
Grinding Parameters ◽  
Stress Formation

The grinding process is often maligned by grinding burn; which refers to many unwanted effects, including residual stress formation. This paper presents an overview of the role of grinding wheel technologies in the surface response and residual stress formation of thin section Inconel 718. Using production standard equipment, conventional abrasive vitrified, and super abrasive electroplated wheel technologies were evaluated in initial comparative trials. Results revealed the dominant residual stress profiles, which manifested as measurable distortion and the thermo-mechanical impact of grinding, such as softening. Following this, a parametric study was carried out using cubic boron nitride super abrasive electroplated wheels to investigate the interaction of grinding parameters on the generated output. It was shown that at increased grinding aggressions, tensile stress regimes increased resulting in increased distortion magnitudes. The study highlights the importance of assessing residual stress formation when manipulating both wheel technologies and grinding parameters. It is envisaged that with additional assessment, a route to an engineered residual stress profile might be achieved.

scholarly journals Parametric Study of Fixtured Vibropeening

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 910 ◽  
Author(s):  
Chan ◽  
Ahluwalia ◽  
Gopinath
Keyword(s):  
Residual Stress ◽  
Process Parameters ◽  
Continuous Treatment ◽  
Optimal Time ◽  
Process Time ◽  
Time Range ◽  
Work Piece ◽  
Stress Profile ◽  
Process Step ◽  
Residual Stress Profile

Vibropeening is a surface treatment process, which combines the peening effect of introducing residual stress with the polishing effect of reducing surface roughness in one single process step. Vibropeening equipment induces vibrations into the media to impart residual compressive stresses in sub-surface layers, as well as polishing on the surface of the work piece. In addition to process parameters, such as vibration frequency, amplitude, and media mass, which are well known in literature, this paper will focus on the study of two additional parameters: immersion depth and process time. It was found that the lower-middle section of the vibratory trough produced the highest Almen deflection. Different continuous treatment times were also studied to explore the maximum introducible residual compressive stress state, and it was concluded that an optimal time range is required to achieve the best residual stress profile. The study demonstrates that different process parameters can influence the effectiveness of the vibropeening process, and that these can be potentially optimized for higher treatment capability.

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