LONDON Intel Corp. and STMicroelectronics NV, two leading chip makers investigating chalcogenide-based phase-change memory as a likely successor to flash as a non-volatile memory have teamed up in their research work on the topic.
Both Intel and ST are researching phase-change memory under separate licensing agreements with Ovonyx Inc., a wholly-owned subsidiary of Energy Conversion Devices Inc.(Rochester Hills, Mich.). Ovonic Unified Memory attempts to exploit a reversible phase change between the amorphous and crystalline states that can be affected in chalcogenide alloys, typically an alloy of antimony telluride and germanium telluride.
However, the two companies are set to present a jointly authored paper at the upcoming VLSI Technology Symposium, which takes place in Honolulu, Hawaii, June 13 to 15.
Engineers from both companies are set to outline a 90-nanometer manufacturing node phase-change memory process based on a chalcogenide material storage element with a vertical PNP bipolar junction transistor as the selector device.
“The small cell area of 12F2, the good electrical results, and the intrinsic reliability demonstrate the viability of the PCM cell concept,” according to Intel and ST authors writing in the abstract for the full paper.
Other benefits of the process are programming currents as low as 400-microamps and good distributional data achieved on multi-megabit arrays for set and reset programming, endurance and data retention. The data set demonstrates the suitability of PCM for fabrication of a high density array at 90-nm, the authors claimed.
ST is known to have developed a 128-Mbit large array demonstrator using a 90-nm process and is considering commercial high-volume production of a multigigabit phase change memory at the 45- or 32-nm node (see May 26 story).
ST and Intel already work together commercially in the NOR flash memory domain although they have not shared manufacturing processes or products so far.
The companies said they would provide hardware- and software-compatible NOR flash memory products based on common specifications for inclusion in mobile phones in December 2005. The companies started with 512-Mbit devices manufactured at the 90-nm node and said common subsystem specifications would be extended to 65-nm focusing on single-chip 1-Gbit NOR memory.