Residual Stress Measurement of Porous Silicon Thin Film by Substrate Curvature Method

2006 ◽  
Vol 326-328 ◽  
pp. 223-226
Author(s):  
Yu Xian Di ◽  
Xin Hua Ji ◽  
Ming Hu ◽  
Yu Wen Qin ◽  
Jin Long Chen
Keyword(s):  
Residual Stress ◽  
Porous Silicon ◽  
Stress Measurement ◽  
Electrochemical Etching ◽  
Intrinsic Stress ◽  
Residual Tensile Stress ◽  
Porous Films ◽  
Silicon Thin Film ◽  
Before And After ◽  
Substrate Curvature

Extensive research has been done on porous silicon (PS) and its applications in optoelectronics since the discovery of its light emitting properties. Porous silicon technology is also used for silicon micro machining. However, porous films can be seriously strained and this often causes mechanical curling, fracture and device failures. In the present study an optical apparatus based on substrate curvature method was developed for intrinsic stress measurement of thin films, which offered a lot of advantages as overall field, non-contact, high precision, nondestructive, easy operation and quick response. Using the apparatus, the residual stress in porous silicon layers prepared by electrochemical etching was obtained. The residual stresses in the films were determined by measuring the curvature of the Si substrate before and after etching. It is found that the residual tensile stress tends to increase with the porosity increasing and the doping concentration of the silicon wafer increasing. The results show that there is a deep connection between the microstructure PS and the residual stress distribution.

scholarly journals Residual stress measurement of porous silicon thin film by substrate curvature method

2006 ◽  
Vol 55 (10) ◽  
pp. 5451
Author(s):  
Di Yu-Xian ◽  
Ji Xin-Hua ◽  
Hu Ming ◽  
Qin Yu-Wen ◽  
Chen Jin-Long
Keyword(s):  
Thin Film ◽  
Residual Stress ◽  
Porous Silicon ◽  
Stress Measurement ◽  
Residual Stress Measurement ◽  
Silicon Thin Film ◽  
Substrate Curvature

scholarly journals Semi-Empirical Prediction of Residual Stress Distributions Introduced by Turning Inconel 718 Alloy Based on Lorentz Function

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4341
Author(s):  
Huachen Peng ◽  
Penghao Dong ◽  
Xianqiang Cheng ◽  
Chen Zhang ◽  
Wencheng Tang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Compressive Stress ◽  
Inconel 718 ◽  
Stress Measurement ◽  
Residual Stress Distribution ◽  
Residual Compressive Stress ◽  
Residual Tensile Stress ◽  
Semi Empirical ◽  
Prediction Approach

The residual stress of machined surface has a crucial influence on the performance of parts. It results in large deviations in terms of the position accuracy, dimension accuracy and service life. The purpose of the present study is to provide a novel semi-empirical residual stress prediction approach for turning Inconel 718. In the method, the bimodal Lorentz function was originally applied to express the residual stress distribution. A statistical model between the coefficients of the bimodal Lorentz function and cutting parameters was established by the random forest regression, in order to predict the residual stress distribution along the depth direction. Finally, the turning experiments, electrolytic corrosion peeling, residual stress measurement and correlation analysis were carried out to verify the accuracy of predicted residual stress. The results show that the bimodal Lorentz function has a great fitting accuracy. The adjusted R2 (Ad-R2) are ranging from 95.4% to 99.4% and 94.7% to 99.6% in circumferential and axial directions, respectively. The maximum and minimum errors of the surface residual tensile stress (SRTS) are 124.564 MPa and 18.082 MPa, those of the peak residual compressive stress (PRCS) are 84.649 MPa and 3.009 MPa and those of the depth of the peak residual compressive stress (DPRCS) are 0.00875 mm and 0.00155 mm, comparing three key feature indicators of predicted and simulated residual stress. The predicted residual stress is highly correlated with the measured residual stress, with correlation coefficients greater than 0.8. In the range of experimental measurement error, the research in the present work provides a quite accurate method for predicting the residual stress in turning Inconel 718, and plays a vital role in controlling the machining deformation of parts.

Etching Silicon Through an Effective Nanomask: An Electrochemical Way to Nanomachining

2005 ◽  
Vol 872 ◽  
Author(s):  
Stefano Borini ◽  
Andrea M. Rossi ◽  
Luca Boarino ◽  
Giampiero Amato
Keyword(s):  
Porous Silicon ◽  
Electrochemical Etching ◽  
Bulk Material ◽  
Strong Electric Field ◽  
Electrochemical Process ◽  
Process Time ◽  
High Dose ◽  
Silicon Thin Film ◽  
Time Duration ◽  
Novel Approach

AbstractWe present a novel approach to silicon nanomachining, based on the electrochemical etching of the material through a nanopatterned mask.Combining a porous silicon (PS) buffer layer with cross-linked poly(methyl methacrylate) (PMMA) we have obtained masks which show high resistance to the electrochemical etching. PMMA is normally dissolved in a HF/EtOH mixture, but it becomes resistant to such a solution after cross-linking of the polymer. This can be achieved by high-dose electron irradiation in a Scanning Electron Microscope (SEM), obtaining a mask for the subsequent etching. Anyway, due to the strong electric field across the masking layer during the electrochemical process, time duration of such a mask is limited. We demonstrate that the presence of a highly porous silicon thin film lying under the resist leads to an evident improvement of the masking power. A final PS removal leads to the formation of silicon micro- and nanostructures in relief, such as microtips and nanomolds. Thus, we have at hand a simple silicon nanomachining process, where the nanofeatures written by the electron beam in the SEM are transferred to the bulk material through a short anodization step in acid solution. This may be a useful alternative method for fabricating nanodevice elements, such as nanofluidic channels or field emitter arrays.

scholarly journals In Situ Growth of ZnO inside a Porous Silicon Matrix Obtained by Electrochemical Etching with a Hydrofluoric Acid-Formaldehyde Solution

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
R. Juárez-Nahuatlato ◽  
G. García ◽  
M. Pacio ◽  
Roberto Portillo ◽  
N. Perez-Amaro ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Hydrofluoric Acid ◽  
Electrochemical Etching ◽  
Nitrogen Adsorption ◽  
Ultraviolet Region ◽  
Ultraviolet Emission ◽  
Silicon Matrix ◽  
Electrolytic Process ◽  
Band Emission ◽  
Before And After

We present zinc oxide (ZnO) particles obtained inside a porous silicon matrix in the same electrolytic process using a p-type silicon wafer in a hydrofluoric acid (HF) solution containing formaldehyde (CH2O) and hydrated zinc sulfate as additives. The X-ray diffraction pattern of the sample confirmed the presence of ZnO with a hexagonal-type wurtzite structure. Photoluminescence (PL) spectra of the samples, before and after the functionalization process, were measured to observe the effect of ZnO inside the porous silicon. The PL measurements of porous silicon functionalized with ZnO (ZnO/PS) revealed infrared, red, blue, and ultraviolet emission bands. The ultraviolet region corresponds to the band-band emission of ZnO, and the visible emission is attributed to defects. The results of the nitrogen adsorption/desorption isotherms of the PS and ZnO/PS samples revealed larger BET surface areas and pore diameters for the ZnO/PS sample. We conclude that ZnO/PS can be obtained in a one-step electrolytic process. These types of samples can be used in gas sensors and photocatalysis.

Estimation of Residual Stress Change due to Cyclic Loading by Classical Elastoplasticity Model and Subloading Surface Model

2016 ◽  
Vol 725 ◽  
pp. 281-286 ◽  
Author(s):  
Ryota Higuchi ◽  
Kazuo Okamura
Keyword(s):  
Residual Stress ◽  
Cyclic Loading ◽  
Stress Measurement ◽  
Kinematic Hardening ◽  
Bending Test ◽  
Surface Model ◽  
Material Function ◽  
X Ray ◽  
Before And After ◽  
Good Agreement

The subloading surface model has been formulated and applied to the prediction of cyclic loading behavior. The material function prescribing elastic-plastic transition in the original subloading surface model has been extended so as to describe the inverse and reloading behavior and the strain accumulation in cyclic loading more accurately for steel. In the present paper, the extended subloading surface model was applied to the prediction of the change of the residual stress due to cyclic loading. The four-point cyclic bending test was performed for the specimen that had initial residual stress. The distributions of the residual stress before and after cyclic loading were measured by the X-ray stress measurement method. The simulation to the experiment was performed by the extended subloading surface model. The stress distribution after cyclic loading simulated by the extended subloading surface model was in good agreement with measured one, and was more accurate than that by the nonlinear isotropic/kinematic hardening model.

Mechanical Stress-Induced Damage on Breakdown Characteristic of Dielectric Thin Films in MOS Transistors

2003 ◽  
Author(s):  
Hideo Miura ◽  
Hiroshi Moriya
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Mechanical Stress ◽  
Stress Measurement ◽  
Surface Oxidation ◽  
Intrinsic Stress ◽  
First Principles Calculation ◽  
Mos Transistors ◽  
Mos Transistor

Mechanical Stress-induced deterioration of the breakdown characteristic of SiO2 films was discussed analytically and experimentally. The decrease in the band gap of the oxide due to the crystal deformation is the main reason for the deterioration. The change rate was analyzed by the first principles calculation. The mechanism of the stress development in a MOS transistor structure was clarified by stress measurement of thin films. The intrinsic stress of the thin films used for the gate electrode of the transistor is the important factor for determining the residual stress in the oxide under the electrode. The residual stress in the silicon substrate before the oxide (SiO2) formation (surface oxidation of the substrate) is another important factor which affects the quality of the oxide film. In particular, the density of the unstable atomic bonding of silicon near the Si/SiO2 interface varies depending on the stress in the substrate.

Sign in / Sign up

Export Citation Format

Share Document