Candela 8520 Surface

The KLA Candela 8520 is a second-generation integrated surface and photoluminescence inspection system. The Candela 8520 is the successor to the Candela CS920. The system is an unpatterned wafer inspection solution designed for power device applications. The system handles 6-inch and 8-inch wafers, including SiC wafers.^[1][3]

The Candela 8520 employs proprietary optical technology to simultaneously measure scatter intensity at varying angles of incidence, topographic variations, surface reflectance, phase shift, and photoluminescence. The system can detect and classify both macro and micro defects. Micro defect classification is performed by comparing the optical signature from normal- and oblique-incidence illumination. Macro defect classification uses optical signatures and defect attributes. The inspection method achieves full-surface coverage in minutes, producing high-resolution images and wafer maps with automatically classified defects.^[3]

Applications include substrate quality control, substrate vendor comparison, incoming and outgoing wafer quality control, CMP and polishing process control, wafer clean process control, epitaxy process control, substrate-to-epitaxy correlation, epitaxy reactor vendor comparison, and process tool monitoring. The system also supports LED material inspection and inspection of other high-end compound semiconductor devices.^[4][5]