Metrology and inspection equipment maker Lasertec Corp of Yokohama, Japan has launched SICA88, the latest model of its SiC wafer inspection and review systems. Featuring both surface and photoluminescence (PL) inspection capabilities, SICA88 enables users to concurrently inspect and analyze surface defects as well as crystallographic defects. Lasertec has already received orders from multiple customers including ROHM Co Ltd.
SiC power devices are already being used in applications such as air conditioners, solar cells and railway cars and they are beginning to capture additional markets, with expectations that they will be widely used in electric vehicles, says the firm. However, producing SiC power devices is technically demanding, as various problems remain unsolved, including crystallographic defects that occur in the production process. Quality control and cost reduction therefore pose major challenges. SiC wafer manufacturers find it necessary to enhance and maintain wafer quality while SiC device manufacturers are expected to maintain high yields while reducing production cost.
The SICA inspection tool is designed to help overcome these challenges. Lasertec launched SICA61 in 2009 for R&D use and SICA6X in 2011 for production use. Since then, SICA has become known for its high sensitivity and accurate defect classification capability and has been widely adopted by many users, says the firm.
SICA88 introduces a new platform that combines PL inspection capability with the confocal DIC optics used in the previous-generation SICA models for surface inspection. It now offers simultaneous detection and classification of not only scratches and epitaxial defects on the wafer surface but also crystallographic defects such as basal plane dislocations (BPD) and stacking faults (SF) inside epilayers, assisting the detection and analysis of defects that cause device malfunctions. The SICA88's throughput is 20 wafers per hour (for 6-inch wafers, in high-throughput mode), which is twice that of the SICA6X, and BPD inspection is possible without compromising throughput.
Lasertec says that one of the best ways to utilize the SICA88 is as a process monitor in wafer production, epi processing and device processing to assist root-cause analysis. It also offers a wafer-grading capability that helps to achieve process cost reductions and higher device yields.
