RF on SOI at GF

Unless you have been living under a rock for the last decade, you can’t help but notice the increased importance of RF: bluetooth, WiFi, 3G, LTE, NFC, RFID and more. There is a lot of digital design associated with these standards, especially the highest bandwidth ones, but they also all contain a radio, often called a modem. Some, like LTE, have to have enough power to reach a cell-phone tower several miles away, others, like NFC, only need to work over short distances. At the FD-SOI and RF-SOI Forum in San Francisco at the end of last month, Peter Rabbeni of GlobalFoundries presented on SOI: An Enabler for RF Innovation and Wireless Market Disruption. Some RF can be done using standard CMOS but a lot requires more esoteric technologies such as SiGe (silicon-germanium), GaAs (Gallium-Arsenide). Or SOI. In fact RF on SOI is growing at a CAGR of over 20% and that is before the Internet of Things (IoT) really takes off with its almost universal requirement for wireless connectivity. Currently SOI has about 65-70% market share of RF switches. SOI brings some advantages that other approaches lack, primarily due to the isolation that comes from the high-resistance substrate, and the fact that it is basically a mainstream process that can be manufactured in a standard CMOS fab at comparatively low cost. Since standard logic can also be built on the same wafer, it is easy to integrate the control with the RF on a single die and even integrate the power amplifier on the same die. Further, due to the isolation, it is possible to stack devices to handle higher voltages. One of the challenges in radios is being able to create tunable filters. This is a pre-requisite for being able to use a single radio for multiple frequency bands. This is something enabled by SoI as is shown by some cutting-edge work done by ST and University of Twente. GlobalFoundries has various technologies suitable for RF, one of the most important being the 130nm RF SOI process which is manufactured in Singapore. This process is targeted to the RF front-end market for RF switches, integrated PA and high-voltage devices. There are a number of customers designing in the standard process today and there are also customer-specific SoI processes such as is used for the Peregrine Global1 product. In addition to GF’s own RF business, IBM has a large RF business that is manufactured in their Burlington VT fab. They are an industry leader in this business. It is complementary to the GF portfolio and the two roadmaps will be integrated once the acquisition of IBM’s semiconductor business by GlobalFoundries is completed. IBM also has a large share of the SiGe market for very high performance. GF has some SiGe business but nowhere near as extensive. Again, the two businesses will be integrated post-acquisition. The presentation should soon appear here.