Search

Thin film based gas sensor is an advanced application of thin film especially Ga2O3 (GO) thin film gas sensor is useful for high temperature gas sensor. The effect of moisture or environment on thin film properties has more influence on gas sensing properties. Radio Frequency sputtered Ga2O3 thin film was synthesized and processed in ultra-high pure hot water at 95 °C for different time durations. The structural properties were verified by the Xray Diffraction technique and the observed spectra revealed the formation of hydroxyl compound of Gallium (Gallium Oxide Dueterate – GOD) on the surface of the thin film and evidenced for structural defects as an effect of moisture. Decreased crystallite size and increased dislocation density was showed the crystal defects of prepared film. From the Ultra Violet – Visible spectra, decreased optical transmittance was noticed for various processing time. The formation of needle like GOD was confirmed using Field Emission Secondary Electron Microscope (FESEM) images.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.7186

Cracked die is a serious failure mode in the Light Emitting Diode (LED) industry – affecting LED quality and long-term reliability performance. In this paper an investigation has been carried out to find the correlation between severe cracked germanium (Ge) substrate of an aluminum indium gallium phosphate (AlInGaP) LED and its electro-optical performance after the Temperature Cycle (TC) test. The LED dice were indented at several bond forces using a die bonder. The indented dice were analysed using a Scanning Electron Microscope (SEM). The result showed that severe cracks were observed at 180 gF onward. As the force of indentation increases, crack formation also becomes more severe thus resulting in the chipping of the substrate. The cracked dies were packaged and the TC test was performed. The results did not show any electro-optical failure or degradation, even after a 1000 cycle TC test. Several mechanically cross-sectioned cracked die LEDs, were analysed using SEM and found that no crack reached the active layer. This shows that severely cracked Ge substrate are able to withstand a −40°C/+100°C TC test up to 1000 cycles and LED optical performance is not affected. A small leakage current was observed in all of the cracked die LEDs in comparison to the reference unit. However, this value is smaller than the product specification and is of no concern.

ZnTe thin films were prepared by Stacking of elemental (Zn and Te) layers (SEL) followed by inert gas annealing. The optical parameters were calculated from the transmission spectra. The bandgap of the annealed samples was found between 1.95 eV and 2.06 eV. The change in film thickness after annealing was observed using cross sectional SEM image of the annealed samples. The surface morphology of the annealed Te/Zn stack was also analyzed and observed as very smooth, compact and dense surface. The prepared film was Zn rich evidenced by EDAX. The observed result encourages in pursuing the SEL method for the preparation of compound semiconductor from II-VI group materials.DOI: http://dx.doi.org/10.5755/j01.ms.18.2.1908

In response to the critical needs of high power density, advanced thermal gap fillers (TGF) are required for the long-term reliability of electronics packaging. In this study, dispensable thermal gap filler (Al87GO6) with 87 wt.% Al2O3, 6 wt.% graphene oxide and 7 wt.% polymers were fabricated as two parts (Part A and Part B). The thermal conductivity of cured Al87GO6 (3.87 W/m.K) was 1.03, 1.11 and 1.24 times higher than commercially available thermal gap fillers TGF A, TGF B and TGF C, respectively. Part A and Part B components of Al87GO6 TGF exhibit a higher plateau value of zero shear viscosity. The lightweight graphene oxide has significantly reduced Al87GO6 TGF's density by ~30–48%. The dielectric constant of Al87GO6 TGF was around ~6–17% lower than commercial TGF. Hence, the fabricated Al87GO6 TGF can be used as an alternative TGF for efficient heat dissipation. [ABSTRACT FROM AUTHOR]