• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.4
• /
• pp.400-406
• /
• 2024

Next-generation wide-bandgap semiconductors such as SiC, GaN, and Ga2O3 are being considered as potential replacements for current silicon-based power devices due to their high mobility, larger size, and production of high-quality wafers at a moderate cost. In this study, we investigate the gradual modulation of chemical composition in multi-stacked metal oxide semiconductor thin films to enhance the performance and bias stability of thin-film transistors (TFTs). It demonstrates that adjusting the Ga ratio in the indium gallium oxide (IGO) semiconductor allows for precise control over the threshold voltage and enhances device stability. Moreover, employing multiple deposition techniques addresses the inherent limitations of solution-processed amorphous oxide semiconductor TFTs by mitigating porosity induced by solvent evaporation. It is anticipated that solution-processed indium gallium oxide (IGO) semiconductors, with a Ga ratio exceeding 50%, can be utilized in the production of oxide semiconductors with wide band gaps. These materials hold promise for power electronic applications necessitating high voltage and current capabilities.

• Electrical & Electronic Materials
• /
• v.8 no.3
• /
• pp.272-277
• /
• 1995

We report the properties of optically pumped stimulated emission at room temperature (RT) from column-III nitride semiconductors of GaN, AlGaN/GaN double heterostructure (DH) and AlGaN/GaInN DH which prepared on a sapphire substrate using an AIN buffer-layer by the nietalorganic vapor phase epitaxy (MOVPE) method. The peak wavelength of the stimulated emission at RT from AIGaN/GaN DH is 369nm and the threshold of excitation pumping power density (P$\_$th/) is about 84kW/cm$\^$2/, and they from AlGaN/GaInN DH are 402nm and 130kW/cm$\^$2/ at the pumping power density of 200kW/cm$\^$2/, respectively. The P$\_$th/ of AIGaN/GaN and AlGaN/GaInN DHs are lower than the single layers of GaN and GaInN due to optical confinement within the active layers of GaN and GaInN, respectively.

• Advances in nano research
• /
• v.5 no.4
• /
• pp.303-311
• /
• 2017

The continuum elasticity model is applied to investigate quantitatively the growth features and nucleation mechanism of quantum dots, nanopits, and joint QDs-nanopits structures in GaInAlN quasyternary systems. We have shown that for GaInAlN material system at the critical strain of ${\varepsilon}^*=0.039$ the sign of critical energy and volume is changed. We assume that at ${\varepsilon}={\varepsilon}^*$ the mechanism of the nucleation is changed from the growth of quantum dots to the nucleation of nanopits. Obviously, at small misfit (${\varepsilon}$ < ${\varepsilon}^*$), the bulk nucleation mechanism dominates. However, at ${\varepsilon}$ > ${\varepsilon}^*$, when the energy barrier becomes negative as well as a larger misfit provides a low-barrier path for the formation of dislocations, the nucleation of pits becomes energetically preferable. The free energy of mixing for $Ga_{1-x-y}In_xAl_yN$ quasiternary system was calculated and studied and its 3D sketch was plotted.

• Design & Manufacturing
• /
• v.18 no.2
• /
• pp.9-16
• /
• 2024

Recently, there has been extensive research conducted on the miniaturization of semiconductors and the improvement of their integration to achieve high-quality and high-performance electronic devices. To integrate and miniaturize multiple semiconductors, thin and precise wafers are essential. The backgrinding process, which involves high-precision processing, is necessary to achieve this. The backgrinding system is used to grind and polish the back side of the wafer to reduce its thickness to ㎛ units. This enables the high integration and miniaturization of semiconductors and a flattening process to allow for detailed circuit design, ultimately leading to the production of IC chips. As the backgrinding system performs precision processing at the ㎛ unit, it is crucial to determine the stability of the equipment's rigidity. Additionally, the flatness and surface roughness of the processed wafer must be checked to confirm the processability of the backgrinding system. IIn this paper, the goal is to verify the processability of the back grinding system by analyzing the natural frequency and resonance frequency of the equipment through computer simulation and measuring and analyzing the flatness and surface roughness of wafers processed with backgrinding system. It was confirmed whether processing damage occurred due to vibration during the backgrinding process.

• Ceramist
• /
• v.10 no.3
• /
• pp.34-47
• /
• 2007

Photoinduced phenomena in non-crystalline insulators and semiconductors, specifically oxide and chalcogenide glasses, are briefly reviewed with some comments.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2001.02a
• /
• pp.135-136
• /
• 2001

• Proceedings of the Korean Vacuum Society Conference
• /
• 1995.02a
• /
• pp.28-28
• /
• 1995

• Proceedings of the Korean Vacuum Society Conference
• /
• 1996.06a
• /
• pp.108-108
• /
• 1996

• Proceedings of the Korean Vacuum Society Conference
• /
• 1995.06a
• /
• pp.15-15
• /
• 1995

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1993.11a
• /
• pp.1-1
• /
• 1993