Investigation of different dielectric materials as gate insulator for MOSFETs

The scaling of semiconductor transistors has led to a decrease in thickness of the silicon dioxide layer used as gate dielectric. The thickness of the silicon dioxide layer is reduced to increase the gate capacitance, thus increasing the drain current. If the thickness of the gate dielectric decreases below 2nm, the leakage current due to the tunneling increases drastically. Hence it is necessary to replace the gate dielectric, silicon dioxide, with a physically thicker oxide layer of high-k materials like Hafnium oxide and Titanium oxide. High-k dielectric materials allow the capacitance to increase without a huge leakage current. Hafnium oxide and Titanium oxide films are deposited by reactive magnetron sputtering from Hafnium and Titanium targets respectively. These oxide layers are used to create metal-insulator-metal (MIM) structures using aluminum as the top and bottom electrodes. The films are deposited at various O2/Ar gas flow ratios, substrate temperatures, and process pressures. After attaining an exact recipe for these oxide layers that exhibit the desired parameters, MOS capacitors are fabricated with n-Si and p-Si substrates having aluminum electrodes at the top and bottom of each. Comparing the parameters of Hafnium oxide- and Titanium oxide- based MOS capacitors, MOSFET devices are designed with Hafnium oxide as gate dielectric

Stability Analysis of island grid with wind energy and energy storage to support large scale deployment of renewable energy in Indonesia

This study performs transi ent stability analysis for integrating wind power into an existing diesel-based remote/mini grid. A model was created of the eastern grid in Sumba Island, Indonesia, which has a network of diesel generators, three 20-kV buses, and primarily lighting load with a peak load of approximately 5.7 MW. The impact of integrating one 850-kW Type 3 wind turbine generator (WTG) is studied. During the high wind and low load scenario, the loss of the WTG or the loss of the largest conventional generator at a bus caused instability in the grid. The addition of a 500-kW storage unit, hybrid power plant controller, and the designation of an existing 550-kW diesel generator with 10-second cold-start time as the backup were used to stabilize the grid. This solution was shown to improve the reliability of the energy supply, enhance the stability of the system, and reduce greenhouse gas emissions. With the potential for minigrids/microgrids to provide power to 620 million people in Africa, the proposed solution has significant applicability