Investigation of an on product high-k/metal metrology methodology using an in-line, high throughput XPS measurement technique

In this paper, we investigated a novel and unique, high throughput, inline XPS technique for thin film (<; 100 A) measurements, such as SiON and HfO₂. Inline XPS measurement capability was evaluated using four separate techniques; offline SIMS, offline XPS, inline ellipsometry and inline micro X-ray fluorescence (XRF). A Nitrogen sensitivity test determined that the detection limit was on the order of 5×13 atm/cm² in a thin SiON layer. The success of decoupling the thickness of the bi-layer HfO₂/SiON/Si film was demonstrated. Long term dynamic precision and short term repeatability for high-k film measurements are also discussed for both thickness and composition. These values were determined to be less than 1% of the nominal value (1sigma).