Iron detection in crystalline silicon by carrier lifetime measurements for arbitrary injection and doping

An existing technique for accurate measurement of iron in silicon, which was previously restricted to low injection and a narrow doping range, has been extended to arbitrary injection and doping levels. This allows contactless lifetime measurement techniques to be used for very sensitive and rapid iron detection under a wide range of conditions. In addition, an easily measured and unambiguous “fingerprint” of iron in silicon has been identified. It is based on the invariant nature of the excess carrier density at which the injection-dependent lifetime curves, measured before and after iron–boron pair dissociation, cross over. This characteristic crossover point lies in the narrow range of 1.4 to 2.0×10¹⁴ cm⁻³, provided only that the boron concentration is below 5×10¹⁶ cm⁻³. To demonstrate the value of these techniques, they have been applied to photovoltaic-grade cast multicrystalline silicon wafers.This work has been supported by NOVEM (The Netherlands Agency for Energy and the Environment) under contract no. 2020.01.13.11.2002

DISPLAY THE DISEASE PLACE FOR NON LINEAR MODEL WITH “ ANOVA” TECHNIQUE

ABSTRACTIn this paper, we transform a nonlinear model to a linear one by using numerical analysis with ‘‘Runger-Kutta4(RK4)’’. Whichis a mathematical technique to approximate solution of ordinary differential equations; this method is most popular where thestep size H is working to increase the lighting of the image compared with the original picture. The new data (normal &pathological images) obtained from this method is used in the statistical study of simple regression and “ANOVA” techniqueto detect the tumor of MRI images. After that, we study the linear regression and “ANOVA” technique by using ANOVAstatistical test (equation of ANOVA: fcal) and compare it with ANOVA table(ftab) for probability p-value =0.01 (here forarea 200x200, ftab=1) and see all pixels inferior to‘’1’’ that means the hypothesis ho is accepted. All these detail is to extractthe place of the lesion on MRI ,(which contain matrix data of normal image and pathological ones), the extract the acceptedho pixels directly on the pathological image. The simulation program applied here is Matlab.KEYWORDS: Runge kutta ,linear regression, Anova

Gettering of interstitial iron in silicon by plasma enhanced chemical vapour deposited silicon nitride films

It is known that the interstitial iron concentration in silicon is reduced after annealing silicon wafers coated with plasma-enhanced chemical vapour deposited (PECVD) silicon nitride films. The underlying mechanism for the significant iron reduction has remained unclear and is investigated in this work. Secondary ion mass spectrometry (SIMS) depth profiling of iron is performed on annealed iron- contaminated single-crystalline silicon wafers passivated with PECVD silicon nitride films. SIMS measurements reveal a high concentration of iron uniformly distributed in the annealed silicon nitride films. This accumulation of iron in the silicon nitride film matches the interstitial iron loss in the silicon bulk. This finding conclusively shows that the interstitial iron is gettered by the silicon nitride films during annealing over a wide temperature range from 250o C to 900o C, via a segregation gettering effect. Further experimental evidence is presented to support this finding. Deep-level transient spectroscopy (DLTS) analysis shows that no new electrically active defects are formed in the silicon bulk after annealing iron-containing silicon with silicon nitride films, confirming that the interstitial iron loss is not due to a change of the chemical structure of iron related defects in the silicon bulk. In addition, once the annealed silicon nitride films are removed, subsequent high temperature processes do not result in any reappearance of iron. Finally, the experimentally measured iron decay kinetics are shown to agree with a model of iron diffusion to the surface gettering sites, indicating a diffusion-limited iron gettering process for temperatures below 700o C. The gettering process is found to become reaction-limited at higher temperatures

Optimization parameters for circumferentially welded pipes

International audienc