In-line inspection on thickness of sputtered HfO/sub 2/ and Hf metal ultra-thin films by spectroscopic ellipsometry

摘要

HfO/sub 2/-based dielectrics are most promising high k materials to substitute SiO/sub 2/ for the MOS gate dielectric. To guarantee the deposition process under well control, an in-line inspection to characterize the thickness and uniformity of both HfO/sub 2/ and Hf metal ultra-thin films must be established. In this work, we proposed an in-line, non-destructive optical method to measure thickness of both films, and this method has potential to be inducted into production control. Upon spectroscopic ellipsometry (SE), reactive DC sputtered HfO/sub 2/ and Hf metal ultra-thin films with featured-thickness of 40 /spl Aring/ or larger were well analyzed, and accuracy of wafer mapping measurement fell in 3 /spl Aring/.