Differentiated Silicon Starts with Differentiated Substrates
By: Manuel Sellier
There is a consensus that “bleeding edge” technologies, i.e. the continuation of Moore’s law whatever the cost of the technology, is bringing less and less return on investment for most players in the semiconductor industry. In this context there is a critical need for more innovations beyond traditional CMOS scaling. There are many opportunities for innovation in the value chain from semiconductor materials and devices to services, but the simplest one starts with substrates.
RF SOI and FD-SOI are great examples of how the industry is pushing differentiation with substrates to develop new standards for RF communication and low power computing. GLOBALFOUNDRIES has been a successful pioneer in this strategy. First, RF SOI has become the de-facto technology for a large number of components of the Front End Module (FEM) in cellular phones. From almost nothing 10 years ago, today the total market for RF SOI is around 1.5 million wafers (8 inch equivalent). Second, FD-SOI is now the technology of choice for mmWave RF-CMOS connectivity and battery powered devices requiring a very high level of energy efficiency. We will review, in this post, how Soitec is supporting GF with outstanding RF SOI substrate solutions.
How SOITEC supports GF with differentiated RF SOI technology
5G will rapidly change the way people and objects around the world communicate; GF and Soitec are supporting this change providing innovative technologies that support the evolution towards 5G and its coexistence with other existent and future standards.
Different communicating devices (vehicles, smartphones, “things”) RF Front Ends require differentiated technologies that could offer the right cost/performance trade-off facilitating their introduction and adoption. Soitec offers two families of RF SOI substrates: HR-SOI using a high resistivity base substrate and RF Enhanced Signal Integrity TM (RFeSI) SOI which adds a trap rich layer on top of the high resistivity base helping deliver on stringent linearity requirements – both of which are compatible with standard CMOS processes and foundries.
These two families of substrates are available in 200 and 300 mm diameters and offer different advantages in terms of linearity, insertion loss, isolation, noise figure and other key specifications and therefore can be used to design and manufacture different blocks and functions in the RF Front End. The examples here below are given as reference only as integration strategy differs largely among different RF Front End solutions providers.
- Antenna tuners, which require very high linearity are typically implemented on RFeSI substrates
- Receiver/ Transmitter switches requiring good linearity, low insertion loss, high isolation and high integration level can be manufactured on HR-SOI and/or RFeSI substrates
- Low noise amplifiers (LNA) on the receive path typically implemented in technology nodes below 90nmare commonly manufactured on 300 mm HR SOI wafers and if integrated with switches and other supporting blocks in 300 mm RFeSI ones.
- Power amplifiers could be fully integrated in 300 mm RFeSi substrates with switches and LNAs for connectivity, IoT and 3G/early 4G cellular applications
Thanks to a long-term strategic partnership GF and Soitec have been timely delivering products tailored to address the needs of a very demanding RF Front End market in continuous evolution. This partnership extends in many fields including engineering and manufacturing, securing state of the art performance in high volume production.
Soitec is integrated into GF’s roadmap thanks to a shared vision of the market evolution. In the most recent example, GF’s next generation mobile and 5G RF Front End 8SW technology was designed to fully exploit the benefits offered by Soitec’s products.
In a semiconductor world where everybody is looking for differentiation, RF SOI and FD-SOI represent unique platforms delivering major advantages. RF SOI value is now fully recognized. It has been adopted by most of the players in the cellular FEM business. It will see continued growth with the increased complexity of radios at 4 and 5G. Soitec is committed to serve this industry with the right level of capacity and quality.
In our next post we will review how Soitec is supporting GF with outstanding FD-SOI substrate solutions.
Manuel Sellier is Soitec’s product marketing manager, responsible for defining the business plans, marketing strategies, and design specifications for the fully depleted silicon-on-insulator (FD-SOI), photonics-SOI, and imager-SOI product lines. Before joining Soitec, he worked for STMicroelectronics, initially as a digital designer covering advanced signoff solutions for high-performance application processors. He earned his Ph.D. degree in the modeling and circuit simulation of advanced metal–oxide–semiconductor transistors (FD-SOI and fin field-effect transistors). He holds several patents in various fields of engineering and has published a wide variety of papers in journals and at international conferences.