X-FAB Silicon Foundries SE, a leading analog/mixed-signal and specialty foundry, has recently announced the introduction of integrated passive device (IPD) fabrication capabilities, expanding its expertise in RF technology. The company unveiled the XIPD process just before the European Microwave Week event in Berlin where attendees can interact with the technical staff at booth 438C.

Inductor test structure on XIPD wafer

The XIPD process is derived from the popular X-FAB XR013 130nm RF SOI process and incorporates an engineered substrate and a thick copper metallization layer. This technology allows customers to directly integrate passive elements such as inductors, capacitors, and resistors into their device designs, resulting in significant space and cost savings. The fabrication takes place at X-FAB's facility in Corbeil-Essonnes, France, leveraging the company's extensive experience in copper metallization.

The demand for devices with wider frequency support driven by the ongoing roll-out of 5G cellular infrastructure, development of 6G communications, and the latest generation of radar and satellite communications has increased. The XIPD platform enables the fabrication of fully integrated high-quality passive components with improved performance characteristics, meeting the requirements for more compact RF/EMI filtering, matching networks, baluns, and couplers. This eliminates the need for surface-mount or discrete passive components, which can be inconvenient due to component deviation at high frequency or increased component sourcing complexity. The XIPD technology streamlines system design, accelerates development cycles, simplifies manufacturing, and reduces engineering expenses. It covers an extensive frequency range from the sub-6GHz band to the high-end of the mmW band.

X-FAB distinguishes itself by providing a European-based foundry service for integrated passive production, regardless of volume. The company offers a comprehensive process design kit (PDK) that supports both the Cadence and Keysight ADS design environments, allowing customers to perform accurate simulations and achieve first-time-right design of the complete RF sub-system. Initial prototyping is already underway with several key customers.

Rudi De Winter, CEO of X-FAB, addresses the challenges associated with shrinking RF semiconductor devices and relatively large passive components. He highlights that the adoption of the XIPD technology not only enables significant space savings but also reduces costs. This has the potential to be a game-changer for customers, allowing the co-packaging of active and passive dies while achieving high yields.

Greg U'Ren, X-FAB's RF Technology Director, emphasizes that current acoustic-based technology solutions for filtering are not capable of operating in the mmW frequency range required by next-generation communication standards. The XIPD solution addresses this limitation by enabling customers to realize compact RF system designs and minimize losses through fully integrated hardware. The company is already working on projects requiring 70-80GHz operation, which would be unthinkable using a discrete passive arrangement.