In the CONTACT module, tungsten (W) deposition follows the formation of the Ti and TiN layers to complete the metal plug that connects the silicon substrate to the first metal routing layer P2.Tungsten is selected for contact plugs due to its excellent conformality when deposited via chemical vapor deposition (CVD), allowing it to fill high-aspect-ratio holes without voids P1.The preceding Ti layer acts to lower the Schottky barrier and form an Ohmic contact at the silicon interface T2.Meanwhile