Chery revealed that phase-change memory had been selected as the non-volatile memory for 28nm fully-depleted silicon-on-insulator (FDSOI) manufacturing process during a presentation at ST's Capital Markets Day held in London, May 11 (see ST opts for phase-change memory on 28nm FDSOI). He also said that the technology was being aimed initially at automotive applications.
Chery told eeNewsEurope: "We are very advanced with a customer. The technology is ready for prototyping; production will be next year." However, Chery added that nature of automotive qualification means that full mass production of automotive 28nm PCM-on-FDSOI microcontrollers may take longer.
Phase-change memory based on germanium-antimony-tellurium GeSbTe chalcogenide materials have been under research for more than 50 years and its introduction as an IC memory has been blighted by technical problems with voltage level drift, thermal performance and thermal cross-talk in the memory array, which in turn effect data retention and cycling endurance
Micron brought stand-alone PCM memory to market in December 2008 and pulled out at the beginning of 2014. Since then Intel has introduced solid-state drives (SSDs) based on a non-volatile memory technology developed with Micron called 3D-XPoint. However, Intel has revealed very few details or performance characteristics of the memory technology. 3D-XPoint is thought to be a novel GeSbTe formulation of PCM at approximately 28nm design node.
The extended temperature requirements of automotive applications suggest that ST has itself found a superior performing phase-change material either by way of a novel ratio of Ge, Sb and Te and/or by additional doping.
Chery declined to answer detailed questions about PCM-on-FDSOI. He said: "I expect 28nm PCM to address a wide range of microcontrollers, automotive, general purpose and secure." He continued: "The most advanced technology goes to automotive."
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