LONDON -- Although we do not expect to be told Thursday (November 6, 2003) what high-k insulator and metal-gate materials Intel Corp. has chosen for its 45-nanometer manufacturing process, the rest of the industry is focusing on hafnium-based layered concoctions for the insulator and nitrided titanium or nitrided tantalum for the gate.
Robert Chau, director of transitor research at Intel and an Intel Fellow, is scheduled to give an invited talk to an International Workshop on Gate Insulator being held in Tokyo Thursday. The program could be viewed here here when this story was first posted.
"Hafnium-based materials, and especially hafnium dioxide, have received most attention over the last few years," said Marc Heyns, an IMEC Fellow, and leading researcher on high-k dielectrics and metal gates, immediately prior to the recent IMEC Annual Advanced Research Meeting, held in Leuven, Belgium, in October.
According to Heyns, likely alternatives to hafnium dioxide include hafnium silicate, nitrided hafnium silicate, and hafnium aluminum oxide, together with various capping layers, but as the number of atomic layers reduces to just a few chemical notation can become moot.
A study of the workshop program reveals that other companies in Japan and Texas have recently had a propensity to study HfSiON with or without an additional silicon dioxide layer.
As for the gate metal, not strictly the topic of this workshop, an IMEC research review shows that, "titanium nitride, tantulum nitride and nickel silicide are currently the most likely candidates."
The wording of Intel's press release on the upcoming presentation indicates that it has identified metal materials in the plural to replace today's polysilicon gate material. The likelihood is that Intel has chosen one material for NMOS transistors and different material for PMOS transistors.
IMEC has itself investigated tantalum nitride and titanium nitride gates over three nanometers thickness of hafnium dioxide as well as titanium nitride over a hafnium dioxide stack.
It is notable that Intel announced at the time of the IMEC AARM that it has joined a collaborative research program to work with IMEC, Samsung, Infineon, Philips and STMicroelectronics on 45-nm and more advanced manufacturing process technologies (see October 15 story).
For many years Intel appeared to ignore calls to investigate alternatives to silicon dioxide, indicating that with its manufacturing prowess it could push silicon dioxide -- the industry's staple, stable insulator -- further than others. With its Tuesday (November 4, 2003) announcement the company appears to be taking a leading position, apparently having made its choices while others are still conducting engineering experiments.
It remains to be seen whether Intel is in the mainstream or whether Chau at some point intends to pull a materials rabbit out of his hat.