Crocus seeks to overturn MRAM patent

November 05, 2013 // By Peter Clarke
Crocus Technology, a developer of magnetic memory technology founded in France in 2004, has filed a petition with the US Patent and Trademark Office to overturn a magnetoresistive RAM patent that is part of the portfolio held by Spin Transfer Technologies Inc. (Fremont Calif.).

The move would seem to be part of Crocus claiming ownership in the spin-torque transfer MRAM sector, an area where it has yet to introduce components. A number of leading semiconductor companies are showing interest in STT-MRAM as a possible replacement for SRAM in cache memories and elsewhere in advanced systems.

US patent 6,980,469 on high-speed low-power magnetic devices based on current induced spin-momentum transfer was issued in 2005 to co-inventors Professor Andrew Kent, Enriquw Gonzalez Garia and Barbaros Ozyilmaz of New York University. Spin Transfer Technologies (STT) was founded in 2007 by investment company Allied Minds and New York University to develop and commercialize Orthogonal Spin Transfer MRAM technology, OST-MRAM.

Besides startups such as STT and Avalanche Technologies, SK Hynix is working with Toshiba on STT-MRAM and in August 2011 Samsung Electronics Co. Ltd. acquired STT-MRAM vendor Grandis Inc. and folded the company into its R&D team to work on a next-generation memory. Qualcomm has also shown an interest in MRAM technology and is working with Globalfoundries to develop the technology.

The Inter Partes Review petition filed by Crocus seeks to cancel all or part of US patent 6,980,469 on the grounds that the patent describes technology that was already prior art and covered by the patent portfolio of Crocus, a portfolio that includes spin-torque transfer (STT-MRAM) technology.

Crocus claims that its patented technology makes non-volatile memory blocks more efficient and is suitable for making robust and secure embedded memory. In addition, Crocus claims it enable the creation of magnetic sensors with high sensitivity, low-noise and high-temperature tolerance.

Crocus holds 154 patents and licenses its technologies to foundries and design houses, including Tower Semiconductor Ltd. (Migdal Haemek, Israel), which is working with Crocus on the production of non-volatile memory and magnetic sensors.

"We've invested heavily over the last nine years to develop the technology, its manufacturing processes and the ecosystem. Our strong portfolio of patents covers the design and