The CS920 is based on Candela’s industry proven laser based, spot scanning, multi-channel architecture. In this latest technology we have used two lasers, one in the UV regime and one in the visible (violet) regime with an innovated optics layout.
For the first time in laser based defect inspection, KLA-Tencor is enabling scatterometry on transparent substrates like SiC for enhanced sensitivity inspection to capture defects such as microscratches and particles. In addition, using the scatterometry on the UV laser, provides the sensitivity for pits and particles inspection on the epi and GaN based materials.
The UV laser also provides another significant benefit: the broadband optics collection path of the CS920 includes two PL channels, which are able to detect and classify very weak photoluminescence from SiC defects (basal plane dislocations and stacking faults).
This inspection system retains the industry standard Candela OSA (Optical Surface Analyzer) technology: reflectometry, optical profilometry, scatterometry and phase-shift interferometry from the violet laser. This architecture allows, for the first time, single tool and single wafer-load detection and classification of known key defects for SiC and GaN based materials.
Candela CS920 integrates this new and uniquely capable optical architecture into a fully automated platform that can handle the wafer sizes relevant to the industry and be used as an efficient process control solution.