Ellipsometer/reflectometer is optimized for ultra-thin gate oxide metrology

17-Jul-2001

Philips Analytical announces a new Laser ellipsometry/reflectometry tool - the PQ Ruby Sub'tomic - capable of measuring gate oxide layer thickness with an accuracy better than 0.025 Ångströms Offering a repeatability below 0.025 Ångströms - less than 1/100th of the thickness of a SiO2 mono-layer - Philips Analytical's Sub'tomic ellipsometer/reflectometer is tuned specifically to the measurement of Ultra Thin Gate Oxides. The performance of the PQ Ruby Sub'tomic is therefore already ahead of today's requirements of the International Technology Roadmap for semiconductors. The study and characterization of ultra-thin gate oxide layers is becoming a major challenge as the semiconductor industry continues to scale device dimensions to reduce channel length. As channel lengths are reduced to below 180 nm, gate dielectrics are also scaled concomitantly to a thickness below around 20 Ångströms. Critical here is the measurement of films with thicknesses of a few atomic dimensions, which requires sub-atomic measuring repeatability. The PQ Ruby Sub'tomic is a specialized version of Philips' standard PQ Ruby ellipsometer/reflectometer. Designed principally for in-line process control in IC production, it can determine thicknesses and optical refractive indices as well as absorption constants and reflectivity of thin films. However, whilst the standard instrument is targeted at general metrology of transparent and absorbing films, the PQ Ruby Sub'tomic has been optimized primarily for the analysis of UTGO layers. In particular, the typical 0.04 to 0.06 Ångström repeatability of the standard PQ Ruby ellipsometer/reflectometer has been improved to 0.025 Ångströms. The PQ Ruby Sub'tomic is the first of a range of dedicated application-specific metrology tools currently being developed by Philips Analytical from its standard product families. By focusing development work on existing equipment and dedicating technologies to specific applications, the company's aim is to optimize performance and eliminate as far as possible metrology-related bottlenecks in the semiconductor production process. Besides its specialized functions, the Sub'tomic is also fully capable of performing all the functions of the standard PQ Ruby, allowing it to act as backup for other metrology equipment. It offers the same user-friendly features including cassette-to-cassette capability with single or dual load port, small footprint, high throughput (greater than 120 wafers/hour) and easy-to-use SEMI E95-0200 compliant PQ Diamond software.

https://www.chemeurope.com/en/news/3912/ellipsometer-reflectometer-is-optimized-for-ultra-thin-gate-oxide-metrology.html