SINGLE WAVELENGTH ELLIPSOMETRY WITH IMPROVED SPOT SIZE CAPABILITY

• Main Authors: KVAMME DAMON, WANG FUMING, SALCIN ESEN, PETERLINZ KEVIN, HENNIGAN DANIEL R, KWAK HIDONG, GREENBERG URI
• Format: Patent
• Language: Chinese; English
• Published: 28.09.2018
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

Methods and systems for performing single wavelength ellipsometry (SWE) measurements with reduced measurement spot size are presented herein. In one aspect, a pupil stop is located at or near a pupilplane in the collection optical path to reduce sensitivity to target edge diffraction effects. In another aspect, a field stop is located at or near an image plane conjugate to the wafer plane in thecollection optical path to reduce sensitivity to undesired optical-structural interactions. In another aspect, a linear polarizer acting on the input beam of the SWE system includes a thin, nanoparticle based polarizer element. The nanoparticle based polarizer element improves illumination beam quality and reduces astigmatism on the wafer plane. The pupil and field stops filter out unwanted lightrays before reaching the detector. As a result, measurement spot size is reduced and tool-to-tool matching performance for small measurement targets is greatly enhanced. 本文中呈现用于执行具有减小的测量光斑大小的单波长椭圆偏振测量法SWE测量的方法及系统。在方面中，光瞳光阑位于集光光