タングステン(VI)ヘキサフルオリド 化学特性,用途語,生産方法
説明
Tungsten(VI) fluoride, also known as tungsten hexafluoride, WF6, is a toxic, corrosive, colorless gas, with a density of
about 13 g/L (roughly 11 times heavier than air). It is one of the densest gases known under standard conditions. WF6 is
frequently used by the semiconductor industry to form tungsten films, through CVD. The WF6 molecule is octahedral with
the symmetry point group of Oh. The W-F bond distances are 183.2 pm. Between 2.3℃ and 17℃, tungsten hexafluoride
condenses into a pale-yellow liquid with a density of 3.44 g/cm3 at 15℃. At 2.3℃ it freezes into a white solid with a cubic
crystalline structure, with lattice constant of 628 pm and a calculated density of 3.99 g/cm3
. At 29℃ this structure converts to an orthorhombic solid with lattice constants of a = 960.3 pm, b = 871.3 pm, and c = 504.4 pm and a density of
4.56 g/cm3
. In this phase, the W-F distance is 181 pm, and the mean closest intermolecular contacts are 312 pm.
化学的特性
Tungsten hexafluoride is a toxic, colorless gas
or a light yellow liquid.
使用
In the electronics industry as a source of tungsten metal that connects the aluminum layers within semiconductor devices.
一般的な説明
A toxic corrosive light yellow liquid or gas. Boiling point 67°F. Melting point 37°F. Noncombustible. Used in the manufacture of other chemicals and in the manufacture of electronics.
空気と水の反応
Decomposes in water giving hydrofluoric acid, another corrosive material.
反応プロフィール
Tungsten hexafluoride emits very toxic and irritating fumes containing metallic tungsten and tungsten fluorides when heated to decomposition. Reacts violently with tetramethoxysilane [Jacob, E., Angew. Chem., 1982, 21, p. 143].
健康ハザード
TOXIC; may be fatal if inhaled, ingested or absorbed through skin. Vapors are extremely irritating and corrosive. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution.
火災危険
Some may burn but none ignite readily. Vapors from liquefied gas are initially heavier than air and spread along ground. Some of these materials may react violently with water. Cylinders exposed to fire may vent and release toxic and/or corrosive gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket.
安全性プロファイル
A poison and corrosive
liquid or gas.
職業ばく露
A strong halogenating agent. Used to
apply tungsten coatings to other surfaces by vapor deposition
process; making electronics and components; in the
manufacture of other chemicals.
輸送方法
UN2196 Tungsten hexafluoride, Hazard Class:
2.3; Labels: 2.3-Poisonous gas, 8-Corrosive material,
Inhalation Hazard Zone B. Cylinders must be transported
in a secure upright position, in a well-ventilated truck.
Protect cylinder and labels from physical damage. The
owner of the compressed gas cylinder is the only entity
allowed by federal law (49CFR) to transport and refill
them. It is a violation of transportation regulations to refill
compressed gas cylinders without the express written permission
of the owner.
不和合性
Decomposes on contact with water and
moist air, forming highly corrosive hydrofluoric acid.
Violent reaction on contact with methyl silicate.
廃棄物の処理
Return refillable compressed
gas cylinders to supplier. Nonrefillable cylinders should be
disposed of in accordance with local, state and federal regulations.
Allow remaining gas to vent slowly into atmosphere
in an unconfined area or exhaust hood. Refillabletype
cylinders should be returned to original supplier with
any valve caps and outlet plugs secured and valve protection
caps in place.
タングステン(VI)ヘキサフルオリド 上流と下流の製品情報
原材料
準備製品