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Soitec manufactures new eSI substrates for 4G LTE advanced smartphones
Soitec has reached high-volume manufacturing of its new Enhanced Signal Integrity™ (eSI) substrates, enabling cost-effective and high-performance RF devices. The eSI products, based on Smart Cut™ technology, are said to be the first ‘trap-rich’ type of material in full production. They are already used in manufacturing by most of the leading RF foundries and have been adopted as the preferred substrates for 4G and LTE mobile computing and communication applications.
These substrates, on which devices are manufactured, have a significant impact on the final devices’ performance. Soitec’s eSI substrates are designed by introducing an innovative material (a trap-rich layer) between the high-resistivity handle wafer and the buried oxide. This layer limits the parasitic surface conduction present in standard high-resistivity silicon-on-insulator (HR-SOI) substrates, boosting the performance of RF devices.
Because this layer is built into the substrate, it reduces the number of process steps and relaxes design rules, leading to a lower cost process and possibly a smaller die area per function. RF designers can therefore integrate diverse functions such as switches, power amplifiers and antenna tuners with excellent RF isolation, and good insertion loss, thermal conductivity and signal integrity.
“Our proprietary eSI product, developed and fine tuned during the past few years, is now qualified by several key customers and is already being used in volume production of mobile handsets on today’s market,” said Bernard Aspar, Senior Vice President and Soitec’s Communication & Power Business Unit General Manager. “As we are continuing to pioneer innovation in RF-engineered substrates, we are very pleased to deliver a technology that enables market-leading companies to be successful with a cost-effective RF device solution addressing stringent 4G and LTE requirements.”
While standard HR-SOI is capable of meeting 2G and 3G requirements, eSI substrates achieve much higher linearity and isolation, allowing designers to address some of the most advanced LTE requirements at a competitive cost.