The thin gate oxide growth step serves as the critical foundation for the core low-voltage logic transistors within the 40nm dual gate oxide (DGOX) integration scheme P3.Following the complete removal of the sacrificial oxide, which ensures a pristine, damage-free silicon surface, this step thermally grows an ultra-thin dielectric layer P4.This process is fundamentally distinct from the subsequent thick gate oxide growth steps, as the thin oxide is strictly optimized to maximize gate capacitance