Rohm Introduces New SiC Schottky Barrier Diodes

ROHM has announced the development of next-generation SiC (Silicon Carbide) Schottky barrier diodes (SBD), featuring lower loss and higher voltage capability compared to silicon-based SBDs. In addition, the company states that the SCS110A series provides advantages over even other SiC SBDs currently on the market regarding forward voltage and operating resistance. This makes them well suited for a wide range of applications, including PFC (power factor correction) circuits, converters, and inverters for power conversion such as those used in EV/HEV and air conditioning units.

In the power electronics sector, conversion losses generated in conventional (Si-based) semiconductor devices have become increasingly problematic, prompting a search for a viable alternative. Silicon carbide (SiC) has emerged as the most promising candidate due to its superior material properties, in particular lower loss.

ROHM has been performing R&D on SiC for years, beginning with the successful development of an SiC MOSFET prototype in 2004, followed by power modules and SBDs. Improvements and enhancements were made to the SiC SBDs based on customer feedback in 2005. This led to the development of a uniform production system for SiC devices and the acquisition of SiCrystal AG (Germany) in order to ensure a stable supply of high-quality SiC wafers.

The SCS110A series of SiC SBDs feature a reverse recovery time (trr) of 15nsec – much less than the 35 to 50nsec of conventional Si-based FRDs. As a result, recovery loss is reduced by as much as 2/3rds, decreasing heat generation as well. In addition, the products ensure more stable operation during temperature changes than silicon FRDs, contributing to smaller heat sinks.

According to the company, compared with competitor SiC SBDs, the series improves trr and reduces chip size by 15%, along with operating resistance, temperature characteristics, and forward voltage (VF=1.5V at 10A), resulting in greater efficiency. ROHM states that it has also solved the problems associated with the mass production of SiC SBD devices, such as uniformity of the Schottky contact barrier and formation of a high-resistance guard ring layer that does not require high temperature processing, making uniform, in-house production possible.

The devices are available now in OEM quantities.