Tantalum Oxide

Description:

Tantalum pentoxide, also known as tantalum (V) oxide, is the inorganic compound with the formula Ta2O5. It is a white solid that is insoluble in all solvents but is attacked by strong bases and hydrofluoric acid. Ta2O5 is an inert material with has a high refractive index and low absorption (i.e. colorless), which makes it useful for coatings. It is also extensively used in the production of capacitors, due to its high dielectric constant.
Owing to its high band gap and dielectric constant, tantalum pentoxide has found a variety of uses in electronics, particularly in tantalum capacitors. These are used in automotive electronics, cell phones, and pagers, electronic circuitry; thin-film components; and high-speed tools. In the 1990s, interest grew in the use of tantalum oxide as a high-k dielectric for DRAM capacitor applications. It is used in on-chip metal-insulator-metal capacitors for high frequency CMOS integrated circuits.
Due to its high refractive index, Ta2O5 has been utilized in the fabrication of the glass of photographic lenses.

Evaporation Parameters:

Evaporation temperature	~2000° C
Source Container	Tantalum or graphite liner for E-beam
Rate	2-5 Å/sec.
Partial pressure of oxygen	~1 x 10-4 Torr
Substrate temperature	175° C to300° C.
Z-Ratio	0.3

Physical Properties of Solid Material:

Molecular Weight	441.89 g/mol
Melting Point	1872° C
Color	White or black
Crystal Density	8.2g/cc

Compositions:

Grade		Ta2O5-1	Ta2O5-2	Ta2O5-3
Ta2O5 (metal basis)		>99.9%	＞99.99%	＞99.999%
F.S.S.S		0.5~2um	1~3um	1~3um
Impurities	Nb	<0.005%	<10ppm	<2ppm
	Fe	<0.005%	<10ppm	<3ppm
	Si	<0.002%	<10ppm	<3ppm
	Ti	<0.002%	<3ppm	<1ppm
	Ni	<0.002%	<3ppm	<1ppm
	W	<0.003%	<5ppm	<2ppm

Application:

Tantalum oxide is intermixed with silicon in gate dielectric structures. It may be used to synthesize hexagonally packed mesoporous tantalum oxide molecular sieves. Ion-beam sputter deposition of tantalum oxide films was investigated for possible optical coating applications. It may be used in making optical glass for lenses and in electronic circuits.