SOI chips for cars: Higher performance at lower prices

June 25, 2015 // By Christoph Hammerschmidt
X-Fab Silicon Foundries has developed a 180nm SOI (silicon on insulator) process technology for automotive and industrial applications that operate in harsh environments – an industry’s first. The 40V and 60V high-voltage devices for X-Fab’s XT018 180-nanometer SOI platform is said to outperform bulk CMOS technologies – at up to 30 percent lower prices.

The XT018 technology includes broad design support, resulting in fewer design cycles and the possibility of first-time-right success; it offers cost-competitive implementation of next-generation automotive solutions and enables engineers to get their designs faster to the market. The new devices make the XT018 process ideal for advanced automotive applications such as monolithic motor controllers and physical layer transceivers including integrated or stand-alone LIN/CAN transceivers.

Hitherto, SOI technologies were regarded as rather exotic and expensive solutions, explained X-Fab product marketing director Volker Herbig. The company’s XT018 SOI technology however offsets the added SOI cost with smaller chip size (which translates into higher productivity) higher performance and easier design.

The XT018 platform is specifically designed for next-generation automotive, industrial and medical applications with up to 200V operating voltage and operating temperatures up to 175°C. It combines the benefits of SOI wafers with Deep Trench Isolation (DTI) plus those of a state-of-the-art six-metal-layer 180nm bulk CMOS process. Using SOI wafers as the starting material, in combination with trench isolation instead of the more commonly used junction isolation techniques in CMOS, simplifies the design concept. The SOI wafers eliminate the parasitic bipolar effects to substrate, reducing latch-up risk. They also enable the development of devices such as truly isolated diodes, allowing reverse supply voltage protection that is difficult to achieve with bulk CMOS or BCD technologies.

The centrepiece of the new technology platform is a low Ron 40V NMOS transistor with industry-leading on resistance of 26 mΩ-mm². It is complemented by robust 40V and 60V ESD enhanced devices as well as matching PMOS and depletion transistors.

The XT018 SOI technology allows for much more compact designs compared to the conventional junction isolation scheme. For example, it allows area-efficient lateral isolation between circuit blocks against cross-coupling for the output driver and sense inputs. The enhanced XT018 foundry platform is available immediately including full PDK support for all major EDA vendors, extensive device characterization and modelling,