STMicroelectronics has made its first silicon carbide (SiC) wafers that can be run on a 200mm line, a move that should improve costs for its automotive- and industrial-focused power semiconductor devices.
Although a number of companies are running SiC-capable lines, they have been limited to 150mm wafers up to now though an increasing number of manufacturers such as GlobalFoundries have taken an interest in production on 200mm wafers as SiC devices become more commonly used for their high-temperature and high-voltage capabilities. The foundry joined SEMI’s task force on SiC material and wafer specifications late last year; Cree and Rohm are planning 200mm SiC fabs.
The move by ST to upgrade SiC manufacturing follows the company’s 2019 acquisition of Norstel: its fab in Norrköping, Sweden developed the ingot technology for 200mm wafers. SiC’s much higher hardness compared to bulk silicon represents a major challenge in developing wafer-production and processing techniques.
ST claimed its initial 200mm SiC wafers are very high quality, with minimal yield-impacting and crystal-dislocation defects. The company said, in collaboration with technology partners covering the entire supply chain, it is developing its own 200mm SiC manufacturing equipment and processes.
ST currently makes its high-volume STPower SiC products on two 150mm wafer lines in its fabs in Catania, Italy, and Ang Mo Kio, Singapore. The transition to 200mm production will include the building of a new SiC substrate plant so it can source more than 40 per cent of its SiC substrates internally by 2024.
“The transition to 200mm SiC wafers will bring substantial advantages to our automotive and industrial customers as they accelerate the transition towards electrification of their systems and products”, said Marco Monti, president of ST’s automotive and discretes group. “It is important in driving economies of scale as product volumes ramp. Building robust know-how in our internal SiC ecosystem across the full manufacturing chain, from high-quality SiC substrates to large-scale front- and back-end production, boosts our flexibility and allows us to better control the improvement of yield and quality of the wafers.”