Hafnium(IV) oxide

From Wikipedia, the free encyclopedia

Hafnium(IV) oxide
IUPAC name	Hafnium(IV) oxide
Other names	hafnium dioxide, hafnia
Identifiers
CAS number	[12055-23-1]
Properties
Molecular formula	HfO2
Molar mass	210.49 g/mol
Appearance	white odorless powder
Density	9.68 g/cm3, solid
Melting point	2758°C
Boiling point	5400°C
Hazards
NFPA 704	0 1 0
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Hafnium dioxide is the inorganic compound with the formula HfO₂. Also known as hafnia, this colourless solid is one of the most common and stable compounds of hafnium. It is an electrical insulator with a band gap of approximately 6 eV. Hafnium dioxide is an intermediate in some processes that give hafnium metal.

Hafnium(IV) oxide is quite inert. It reacts with strong acids such as concentrated sulfuric acid and with strong bases. It dissolves slowly in hydrofluoric acid to give fluorohafnate anions. At elevated temperatures, it reacts with chlorine in the presence of graphite or carbon tetrachloride to give hafnium tetrachloride.

[edit] Applications

It is used in optical coatings, and as a high-k dielectric in DRAM capacitors. Hafnium based oxides are currently leading candidates to replace silicon oxide as a gate insulator in field effect transistors.

It appears to have planned use by both IBM and Intel to continue scaling down semiconductor features to continue Moore's Law, to continue to increase logic density in computer processors, increase clock speeds, or lower power consumption. See article:

• http://www.nytimes.com/2007/01/27/technology/27chip.html

[edit] External links