Soitec (Euronext Paris) announced a business agreement with Qualcomm Technologies, Inc. on the supply of piezoelectric-on-insulator (POI) engineered substrates for 4G and 5G RF filters. Soitec’s piezoelectric-on-insulator substrate brings strong value proposition to smartphones’ 5G filters for mass markets.

An agreement to secure supply for Qualcomm Technologies’ new generation of RF filters

After multiple years of collaboration with Qualcomm Technologies, Soitec has concluded an agreement to bring POI wafers production to high volume manufacturing to be used for Qualcomm Technologies’ RF filters going to smartphones RF front end modules.

“With our game-changing thin-film technology and innovation in the Qualcomm® ultraSAW RF filter products, we continue to push the boundaries of what’s possible in mobile technology”, said Christian Block, senior vice president and general manager, RFFE, Qualcomm Germany RFFE GmbH. “This agreement with Soitec is key to ensure the supply of high-performance POI substrates from Soitec, and to securely support the demand from our OEM customers for high-performance Qualcomm ultraSAW RF filter products. The combination of Soitec Smart Cut^TM based Piezoelectric-On-Insulator substrates and Qualcomm Technologies’ filter design and system expertise leads to high-yield multiplexers with multiple filter functions per die.”

Soitec’s POI substrate chosen for its unique value for RF filters

POI is an innovative substrate manufactured thanks to Soitec’s proprietary Smart Cut^TM technology in 150 mm. At its foundation lies a high resistivity silicon substrate, complemented by a buried oxide layer and a very thin and uniform layer of a mono-crystal piezo material on top. Soitec’s POI engineered substrates have been designed to build the latest generation of 4G/5G Surface Acoustic Wave (SAW) filters. They offer performance with built-in temperature compensation.

“This business agreement is the outcome of a collaboration between Soitec and Qualcomm Technologies. We are very pleased that Soitec POI substrates are now an important part of Qualcomm Technologies’ 5G offering for mobile devices”, said Dr. Bernard Aspar, Senior Executive Vice President of Soitec’s Global Business Units. “Soitec has a long experience in serving RF markets notably with large RF-SOI volumes. We are confident in our ability to handle high-volume production for POI to become a standard in materials for 5G RF filters, thanks to our robust and proven Smart Cut^TM technology”.

Microwave Journal published a technical article article about the POI process and its capabilities last October, "Piezo-On-Insulator Engineered Substrates for 4G/5G RF Front-End Filters." The POI process can produce SAW filters with lower loss, better performance over temperature, wider bandwidths and higher frequencies than traditional SAW processes making it well suited for 5G applications. It also offers significant size reductions compared to traditional SAW devices by enabling multiple filters to be incorporated into a single die. 

In talking with Soitec, they went into high volume production last Sept on 150 mm wafers with the capability to go to 200 mm wafers in the future. Qualcomm announced their ultraSAW product last Feb in an announcement here. They detailed device performance with 1 dB lower insertion loss compared to regular BAW filters. Qualcomm says the ultraSAW technology provides “power efficient” RF signal chains in multi-mode mobile phones, enabled by the following features:

• Low insertion loss.
• High frequency selectivity.
• Excellent transmit, receive and cross isolation.
• Q-factors >5000, significantly better than those of BAW.
• Temperature drift in the single-digit ppm/Kelvin range.
• Low cost.

The piezoelectric material expertise associated with Smart Cut™ technology allows Soitec to manufacture large volumes of uniform engineered substrates in their dedicated production line and is available to support the stringent filter requirements of 5G so should have a significant advantage in the market.

Qualcomm is a trademark of Qualcomm Incorporated, registered in the United States and other countries. Qualcomm ultraSAW is a product of Qualcomm Technologies, Inc. and/or its subsidiaries.