Materials science: A rarefied insulator

Adv. Mater. 20, doi:10.1002/adma.200702234 (2008)

A new material based on rare-earth elements such as cerium might overcome a barrier to making smaller silicon chips. Silicon dioxide is the traditional chip insulator, but is too bulky for smaller chips. Alternative compounds with suitably high dielectric constants are too rigid, and have proved not to insulate fully.

Now Dmitry Kukuruznyak at the Max Planck Institute for Metals Research in Stuttgart, Germany, and his colleagues have constructed another potential insulator: the rare-earth aluminium–silicon apatite RE₆(AlO₃)₅(SiO_3.5). Rather than forming rigid crystals, this compound self-organizes into flexible films on silicon at temperatures below 1,030 °C.