In a dual-gate oxide (DGOX) integration scheme, modern CMOS image sensors require both low-voltage logic transistors and high-voltage pixel/I-O transistors T1.This step specifically grows the thicker dielectric layer required to sustain higher operating voltages without experiencing destructive dielectric breakdown T1.By executing this growth after the nitride hard mask etch and subsequent clean, the thermal oxidation selectively targets the exposed silicon regions while the remaining nitride ma