In modern semiconductor logic and image sensor manufacturing, different transistors require varying gate oxide thicknesses; core devices rely on scaled thin oxides to maximize drive current and switching speed, while I/O or pixel transistors need thick oxides to withstand higher operating voltages and prevent tunneling leakage T1.The Nitride Hard Mask Etch step is explicitly designed to transfer the photolithographic Dual Gate Oxide (DGOX) boundary pattern into the silicon nitride layer A2.By se