Ibrahim A. Alhomoudi

Strain-induced modulation of perpendicular magnetic anisotropy in Ta/CoFeB/MgO structures investigated by ferromagnetic resonance

We demonstrate strain-induced modulation of perpendicular magnetic anisotropy (PMA) in (001)-oriented [Pb(Mg1/3Nb2/3)O3](1−x)-[PbTiO3]x (PMN-PT) substrate/Ta/CoFeB/MgO/Ta structures using ferromagnetic resonance (FMR). An in-plane biaxial strain is produced by applying voltage between the two surfaces of the PMN-PT substrate, and is transferred to the ferromagnetic CoFeB layer, which results in tuning of the PMA of the CoFeB layer. The strain-induced change in PMA is quantitatively extracted from the experimental FMR spectra. It is shown that both first and second-order anisotropy terms are affected by the electric field, and that they have opposite voltage dependencies. A very large value of the voltage-induced perpendicular magnetic anisotropy modulation of ∼7000 fJ/V·m is obtained through this strain-mediated coupling. Using this FMR technique, the magnetostriction coefficient λ is extracted for the ultrathin 1.1 nm Co20Fe60B20 layer, and is found to be 3.7 × 10−5, which is approximately 4 times larger...

Optimization of in-plane SiC capacitive accelerometers design parameters

This paper introduces methods to find the design parameters that result in the best sensitivity for a given in-plane differential capacitive accelerometer. We show how to find the optimum electrode length for a device of a specific design area. Design and simulation results for a CMOS-compatible single-axis silicon carbide accelerometer are reported, based on the methods proposed here. The accelerometer uses two supporting beams to increase the device flexibility in the sensing direction, resulting in a 9.14 fF/g sensitivity. It has a total of 2.4% nonlinearity over a range of ±2 g, with a minimum detectable signal of 2.2 mg, when using a 20 aF resolution readout chip.

Modeling and Experimental Studies of Spalling Process in Silicon Wafers

Analyses involving both modeling and experimental measurements for the residual stresses evaluation in Ni thin films on silicon wafers have been studied with focus on determining the optimum condition that leads to spallation. Different thicknesses of stressor thin films (Ni in our case) have been electroplated on Si(100) and Si(111) wafers to predict the critical residual stress in the Ni/Si system that are required for steady-state crack depth. The Ni film thicknesses and the total critical stresses in the Ni films required for steady state spalling processes were specified for different crack depth in Si(100) and Si(111) wafers.Copyright