Highly Reliable and Scalable Tungsten Polymetal Gate Process for Memory Devices Using Low-Temperature Plasma Selective Gate Reoxidation

We applied a very low-temperature plasma-type selective gate reoxidation process to W/poly-Si gate for suppression of abnormal oxidation of a low contact resistive WSix/WN diffusion barrier. The device with the plasma selective gate reoxidation showed superior gate oxide reliability and improved stress immunity of transistor compared to the thermally selective gate reoxidized devices